the silkworm

Giant African snail (Achatina fulica Bowdich, 1822) - As a Molluscan Pest: First Report on Mulberry from Aurangabad, (M.S), India

gkrajeshrajesh@gmail.com — Mon, 01 Apr 2013 18:16:00 +0000

Sunil B. Avhad and Chandrashekar J. Hiware

Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S), India.

E-mail- sunil_zoology@rediffmail.com, drhiware@rediffmail.com

Sunil B. Avhad

Abstract: The Molluscan as a pest of agriculture and horticulture have already been known in many regions. The present communication deals with molluscan pest the Giant African snail; Achatina fulica (Bowdich, 1822) observed a first report on mulberry fields from Aurangabad district, Maharashtra during June.2009- May. 2011. The incidence of snails was recorded in all the tehsils, in the every months starting from August to December. According to sericulturists of the area, severe cocoon loss was not only due to infestation but also due to the stinking smell of mucus layer (both wet and dry conditions) released by the Giant African snail, Achatina fulica on mulberry plant. The silkworm showed an aversion towards feeding on such leaves and as result, considerable quantities of harvested leaves were wasted without converting in to silk cocoons.

Key-words: Giant African snail, Molluscan pest, Mulberry, Aurangabad. Maharashtra state.

Introduction:

In India, sericulture is one of the most important agro and forest based cottage industry, earning a foreign exchange of Rs. 400 corers / annum and providing gainful employment to over six million peoples. Technically sericulture is rearing of silkworms either on mulberry or non-mulberry plants for production of silk. Today India is the second largest silk producer of raw silk and also has the distinction of being the world’s largest consumer of silk. In developing countries such as India, agriculture and agro-based industries play a vital role in the improvement of rural economy. The limited availability of land, the limited cash returns and agriculture being confirmed to one or two seasons in the year, have made villages to look for supporting rural industries and one of them is sericulture. Maharashtra, a state without a tradition of silk production has a large gap between demand and supply of raw silk and more than 4,000 (Anon., 2008). This demand for raw silk could become a source of rural employment within Maharashtra. The main constraints to sericulture in Maharashtra state were: lack of mulberry tree varieties adapted to local agro-climatic conditions, lack of suitable silkworm races, and lack of knowledge and skills among the farmers.

Mulberry (Morus spp.) leaf is the only natural food for the silkworm, Bombyx mori L. It is a perennial, evergreen, luxuriant crop cultivated in all types of soils, both under rainfed and irrigated conditions. The crop is prone to depredation of diverse organisms, because of its fast growth and green foliage throughout the year, in varying proportions either for space, food or both. So far, over 300 insect and non-insect species of pests are known to infest mulberry in varying intensities during different stages of the crop and seasons (Naik, 1997). Though the frequent leaf picking and pruning of the attack of pests, many of them still final enough time and place on mulberry for feeding and breeding on it. From India, about 100 insect pests have been reported on various varieties of mulberry.

Among the non- insect pests of agricultural as well as horticultural crops, the Giant African snail, Achatina fulica Bowdich is reported as most important one in many parts of the world. The characteristic symptom of the infestation was that the snails were feeding on the bark of the stem. This brings down the nutritive value as the vascular is injured and senescence of mulberry leaves leading to defoliation. The incidence is one of the major factors that decide the productivity and profitability in sericulture is the maximization of quality mulberry leaf yield per unit area. However, the mulberry leaves from snail attacked plants are not suitable for silkworm feeding as they are found to be nutritionally inferior (Shree et al., 2006).

Materials and methods:

The molluscan pests’ collection was carried out in six sites namely Aurangabad, Sillod, Fulmbari, Khultabad, Paithan and Gangapur from June 2009 to May 2011. All the sites were visited and sampled monthly with different collection methods. All the specimens were identified with the help of available literature and Zoological Survey of India, Western office, Pune division, India.

Results and discussion:

Achatina fulica (Common name: Giant African snail, Phylum: Mollusca, Class: Gastropoda, Superfamily: Achatinoidea, Family: Achatinidae, Subfamily: Achatininae, Genus: Achatina, Species: fulica). Occurrence from the mulberry plant, Morus alba L., from Gangapur mulberry fields, Aurangabad district, Maharashtra, India throughout year but active during rainy season. Type of Damage and Symptoms is as extensive chewing of blossoms, leaves, and shoots stunts the growth of young trees and trees that have been top worked. The land snail can especially be a problem following wet winters and springs. Land snail feeding is not a problem in mature groves. Thick, dry leaf mulch suppresses snail numbers and large trees tolerate any modest chewing.

Giant African snail (Achatina fulica Bowdich)

The adult snails have a height of around 7 centimeters (2.8 in), and their length can reach 20 centimeters (7.9 in) or more. The shell has a conical shape, being about twice as high as it is broad. Either clockwise (sinistral) or counter-clockwise (dextral) directions can be observed in the coiling of the shell, although the right-handed (dextral) cone is the more common. Shell colouration is highly variable, and dependent on diet. Typically, brown is the predominant colour and the shell is banded (Skelley et al., 2011).

In the present study the occurrence of the Giant African snail, Achatina fulica is reported from Gangapur, Aurangabad (M.S), India mulberry field during rainy season but there occurrence is throughout the year, due to hibernation time these are not much active as compare to rainy season. Shree et al., (2006) also report on the occurrence of the Giant African snail, Achatina fulica in some parts of Karnataka is infest mulberry. The incidence of snails was recorded in all the villages, in the every months starting from August to December. According to sericulturists of the area, severe cocoon loss was not only due to infestation but also due to the stinking smell of mucus layer (both wet and dry conditions) released by the Giant African snail, Achatina fulica on mulberry plant. The silkworm showed an aversion towards feeding on such leaves and as result, considerable quantities of harvested leaves were wasted without converting in to silk cocoons.

Acknowledgement

The authors are thankful to the all the farmers from Aurangabad district and to the University authorities, Head, Department of Zoology, Dr. Babasaheb Ambedkar Marathwada University Aurangabad, (M.S.) India, for providing necessary laboratory and library facilities during this work.

References

Anonymous, (2008). Annual Progress Report, 2008, CRS, BAIF, Uruli Kanchan.

Naik, S. L. (1997). Bioecology of thrips infesting mulberry. M.Sc. Thesis, University of Agricultural Sciences, Bangalore 77p.

Shree, M. P; Ravi Kumar K and Nagaveni, V (2006). Infestation of Giant African Snail on Mulberry. Indian Silk, Vol.45, No.6, Pp. 14-16.

Skelley, P. E; Dixon, W. N; and Hodges, G. (2011). Giant African land snail and giant South American snails: field recognition. Florida Department of Agriculture and Consumer Services. Gainesville, Florida.

South Indian sericulture- portrait of a bygone era

gkrajeshrajesh@gmail.com — Sun, 24 Mar 2013 12:57:00 +0000

Dr. Simon Charsley

An interview with K.V. Achuthan Nair, by Dr Simon Charsley, University of Glasgow

That Bangalore hosts International Sericultural Commission, is in recognition of the importance of South Indian Sericulture to global silk industry. The story, how sericulture took roots in these parts lay buried deep in history, relics sparse. What toils, earnest and selfless efforts have gone into its making! The story unfolds through this interview; conducted by Simon Charsley with K.V. Achuthan Nair (DD Seric Rtd, Department of Sericulture, Karnataka) on Friday 11 September 1992. Achuthan Nair passed away on 8^th August 2010, at 96.

To Achuthan Nair in the morning.

From Kerala originally but no family home left there: we discussed the tharavad[1] and its advantages a little.

Now 76, having retired at 55 in 1972, so must have been born 1916/ 17[2]. When he retired he thought it would be good to relax, take up some social work or some such, but people had kept coming to consult him about sericulture. They then asked him to keep the chemicals etc he was recommending so that they could get them conveniently. So he set up R.V. Enterprises[3]: they have their own product, Polmr dust[4] for grasserie and flacherie.

In 1943 he joined the Madras Department in Kollegal together with Punja[5], Ranganatha Rao[6], Venugopalan Nair[7] – 5 or 6 of them. It was hard because they had no stipend during the training period. At the time unemployment was very bad in Kerala. He knew someone in the government secretariat who let him know about the opportunity. So it was chance that he came to sericulture.

It was the war that gave impetus to it. The British Empire had no-one else to supply silk for parachutes and they asked all states to implement projects for it. Madras put up a project for making filature silk and was given 300 basins and the filature was started. Nobody worried about the supply of cocoons, but there were only 25,000 acres - or should this have been 2,500? - under mulberry and this would be sufficient for 50 basins only. So then they got further a project for expansion of the mulberry acreage, production of eggs, research, etc.

1958 training batch of All India Sericulture Institute, Mysore
Achuthan Nair is seen sitting fourth from left

During training they were taken to Berikai just south of the Mysore border, northeast of Hosur Town in Madras, because there were a few Muslims there rearing worms on just three acres of mulberry and the Department had a small unit for purchasing cuttings from them for use in new areas. It was indigenous varieties and they were very mixed. They would just select the better bushes in the field to take cuttings from.

At Denkanikottai there was also a little rearing going on. When they went there as students during training, it was very remote, no good communications. Just one bus and because of the petrol shortage this ran on charcoal: it burnt charcoal to make gas and ran on that. No sanitary conveniences or anywhere to get food. They joked about who would be the unlucky man to get posted there. When he actually was he was asked how he felt about it. He said 'I like it, sir'. Surprised, his officer asked why: 'Because you are posting me there', he said. There was no source of food there, and he also had a problem that after he graduated he had been given charge of the family land in his own place in Kerala.

It was a sort of sacrifice they made to go to such places, but he formed a club there, the Friends Union, out of the few educated people around, in the Department and others. They used to play cards but not for gambling. They got a badminton court in the farm and in the end people started coming there on leave.

But before that A.T.Janakiram[8] was his senior officer. He had joined as a Probationer as early as 1930 and had a reputation for being very strict and difficult about allowing anyone casual leave. But he came to visit, saw him there and asked V.R. Uttaman[9] who was his immediate superior (and still living at the time), why he had not given him leave: he looked reduced and needed to go home. He replied that he could not go because he had too much to do. 'I will look after your work', said Uttaman. Of course he did not; someone else was deputed to do it, but he was very appreciative of his efforts - but he did not reward him by giving him a transfer from that place.

One particular drawback of the place was that, if there were a reduction in the cocoon rate, everyone blamed him and came and pressured him, since he was alone there. He had also to be a bit deceitful since Kollegal had to have seed cocoons every day. If left to themselves, when one man cut his mulberry others would follow, so they tended to get everyone wanting to rear at once. He would have to prevent this happening by telling them that the layings were pebrinised: if they wanted to risk it that was up to them. 'No, sir, we will wait'. The seed cocoons went by van to Kollegal at night, via Bangalore, in special cylindrical baskets. These were bamboo with gaps for ventilation and lids and they travelled on their sides, piled to allow plenty of ventilation and avoid crushing. They would get to Kollegal in the early morning.

They also started a farm in Hosur with 80 acres under mulberry, under the big Andivadi tank. Government acquired the whole irrigated area, 100 acres and it was divided into 7 units, each run independently but co-ordinated by a senior officer. It was for rearing Foreign Race (FR) seed cocoons which also went to Kollegal, and there were good selected rearers around the farm too. Hosur Cattle Farm was where the basic FR seed was prepared, i.e. it was already an embryo P system. Stock races were maintained at Coonoor, with J(apan) and C(hina) nos. There were also farms at Berikai and Denkanikote for the improvement of the indigenous race. They were therefore quite independent of Mysore, except that they would get in Mysore race from time to time as new blood, to be crossed with their own. Apart from this there was a little rearing in Hindupur which was also in Madras at the time, and there were small demonstration farms there.

Locally, 'Pure Mysore' - so termed - was being reared, very crudely. They would allow the moths to emerge from the seed cocoons, mate, and the pairs would be removed to other trays. The males would be removed; the females would lay just on the tray itself, with no disinfection. Eggs would hatch and the worms would be fed on the same tray. They would then be given to whoever required them. It was not rearing as chawki but immediate selling. Later they began using paper for laying. Another practice was to keep eggs on brass eating plates. When the worms emerged they would feed them on the plates and cover the plate with tray. This was to keep them cool, and in the coolest part of the house. After second moult they would transfer them to ordinary trays.

The price of cocoons was very low, Annas 3-4 per lb., and why sericulture continued was questioned. The answer given was that Karnataka was airconditioned, i.e. very good for worms naturally, whatever rearers did to them. There were landlords with plenty of land, 30-40 acres under mulberry. They would go out and bring the leaf home, giving it to family members, the women, to rear. They might be taking 1000 layings for 30-40 acres, getting only 15-20 lbs per 100. The money was pocket money for the ladies, and the waste went for cattle food. The cuttings of mulberry would be stacked up like a haystack and would provide the fuel for months.

[Were tenants the rearers?] The basic idea was that it was the landlords themselves, but a portion of mulberry might be given to the poorest families on share basis. This was certainly happening then too. There was not much irrigation; most land was just rain-fed and by September the dry crops had been harvested and there was no work for the labourers. Sericulture could provide work for the idle labourers since the mulberry would still sprout up to Jan/Feb. Rearing, it seemed, was essentially by the family. SCs[10] could not enter houses of caste Hindus so could not work in rearing there. During menstruation ladies could not touch the worms. They said they were Lakshmi and there was puja to them, especially at moulting. This was felt to be a bad time for the worms when they had to be looked after well, hence the puja. An attachment to the worms was certainly felt. [This may actually refer more to Kollegal, since he went on to say that the Hosur rearers were almost all Muslims.]

So he joined the Department after training in 1944, and was posted as Seed Campaign Officer at Hosur for the indigenous seed. His job was to expand the mulberry planted and get people rearing. In the initial stages people were very resistant, fearing some calamity in the house if they took it up. When he approached they would also ask him, what was the charitable thing in rearing? If you grow sugarcane, the thief may come and take it and we may also offer it to visitors. So there was dharma in growing it. Where was the dharma in mulberry? Of course we may get money, but we do not want to do it. So he would contact an important man and go and visit him. They would enquire about the welfare of the country, and what his sons were doing, and would go away. He would repeat such visits. Eventually he would ask him to do one thing for his sake: plant 2 acres of mulberry. He would say 'Sir, for your sake I will plant it'. So he would guide him and rear the worms as if they were his own in that man's house.

For Muslim rearers, sericulture was convenient because their ladies were not allowed to go out, but inspection was a problem. They would have to inform them in advance that they were coming, so that they could bring the worms out. But then he used to tell them that if they insisted on this he could not make them seed rearers, so they then allowed the Department people in. In fact it was identified with Muslims and they had a joking term, 'Pashadega' or some such - about which he was worried in case it implied derogatory attitudes to another community – because it seemed to be all Pashas who did it.

He was also preparing the layings and issuing them, limiting it to 100-150 per shed. He had to prepare the layings himself; he could not entrust it to anyone else because if someone missed disease, it would be he himself who would be blamed by the Department and by the sericulturists.

Kollegal was a small area and the Department there could do everything very well. In Mysore they always had big areas and a large number of rearers to contend with, and this was more difficult. He was very preoccupied about not criticising the Mysoreans: they had been good to him, so he should not do so.

He also at times had some difficulty about being a Keralan[11] and running things in Karnataka, but clearly he does have the feeling that things do not quite work properly there. The Madras officers were well trained and they had experience of everything. Everywhere the rearing was in patches of several or single villages. Even distant villages might take it up because of some marriage connection, but even neighbouring villages might not. It was a matter of personal inconvenience and convictions. He stressed that village heads were very strong in those days. If a leader did not want it done, it would not be done. He accepted also the other way round: if a head wanted to introduce it, others would follow.

A good idea to regard the rearing area as made up of villages rather than individual rearers, with clusters and isolates, e.g. the three acres at Berikai where rearing somehow managed to persist. There the rearers, who were Muslims, would reel their own cocoons on charkas. After the seed area was established, such reeling was not allowed but in practice the reject cocoons which did not go for seed continued to be reeled locally. The main centres for sericulture in Kollegal were Kuntur, Kamagere and Hanur, a little at Palya, [i.e. not a very different pattern to subsequent.]

Kuntur: there is a story that Tipu passed that side and saw it. He had heard about Kollegal silk and announced 'This is Kollegal'. [The significance of the story is not quite clear, but it seems to be that Kollegal was claimed to have been identified with silk in Tipu’s time.] There is a pond in Kuntur which was said to have absolutely neutral water which was the source of the very good colour of the silk there. It was one of the early reeling places, also Doddinduvadi and Surapura.

Cocoons were purchased by reelers who would go to the rearers’ houses, see the worms and advance money for the cocoons. The rearers were then bound to sell to them. The reeler would take a handful and put it aside 'for God', before weighing the rest and paying for them. They also charged interest on the advance. It was to avoid this kind of thing that cocoon markets were set up. The reelers were Muslims mainly. ... [Discussion of prominent individual reelers].... Achuthan Nair did not know much about the silk trade. The Filature got cocoons from Mysore in the end. He thought there were small purchasers of silk in Kollegal but the big people like Rachegowda would go to B'lore. There were lots of cocoon brokers who took the cocoons to Mysore. The markets the Department set up were at Kollegal, by the filature, Kamagere and Hanur, but the cocoons from them were being bought for the filatures since there were no reelers coming to them.

Later in his career he was in charge of the silkworm gut manufacturing section at Coonoor. Ripe worms were soaked in acid and the gut was removed and stretched. Then the sericin was removed by boiling with soap. It was for external use only and was replaced with nylon, but that has disadvantages: people may be allergic to it and it snaps, neither of which happens with silkworm gut. Previously it had been produced in Spain by ladies incubating the cocoons under their breasts and exported to Johnson & Johnson in London: a complex and extraordinary tale in fact here. He also tried to develop gut for fishing as it is undetectable in water, and even to make brushes out of the waste, but the operation had to be closed.

Farewell to KV. Achuthan Nair, from All India Sericulture Institute,
on 31.03.1960 Mr. Nair is flanked by MN. Narasimhanna
on his right and NK. Guruprasad (Principal) on his left

1948-53 he was at the Hope Silk Farm in Hosur for FR production, and in 1956 when Kollegal joined Mysore he was Sericultural Superintendent in charge of the Central Grainage there.

Their separate organisation continued for some time. He then went to CSB as Sericultural Expert in the All-India Sericultural Training Institute here in Mysore. At the time research was still at Channapatna under the State government, but he was starting it at the Institute. All the sericultural processes had to be organised there and he trained two batches. They came from all over India and are now in good position everywhere.

He would have been happy to continue there but he had not had experience of serving in Karnataka. Had been in Madras [Hosur and Kollegal] with its different atmosphere: competitive and with the opportunity to have experience of all stages of sericulture. Uttaman became Director at this time. He called him and told him that there were vacancies at Chamarajanagar, Kolar and? Channapatna: which did he want? He said he wanted to go where he could best show good work. So Uttaman told him to take Chamarajanagar. There had previously been no organisation there and he had to establish everything. It also had the hill station at BR Hills and Uttaman thought his experience at Coonoor would be useful. So he organized the division. This was in 1960. He had to give technical advice to the villagers and there were farms to be opened. He wanted to purchase the land there where the Farm/and grainage are now, but the 21 or 25 Uppaligashetty landowners were not willing to part with it at the rate of compensation offered. ... [Account of obtaining land there, told off the record, apparently because it implied criticism of what went on in Karnataka.] ... . He was in charge of 3 taluks and had also to start chawki rearing there. The rearing at the time was by very crude methods and the object of the centres was to demonstrate better. For each there was a demonstrator and a labourer, supposed to be supervised by a committee of sericulturists. The committee was expected to lease mulberry land for the use of the centre but sometimes this was not possible. Then the farmers would have to bring in the leaves to feed their own worms. Maybe ten people would bring leaves from ten different gardens: that was not good as they tended to get mixed up in the feeding. If the committees had worked well, Chawki Rearing Centres (CRCs) – would not have turned out badly.

Sericulture was always a side industry. The poor man can't afford to produce a successful crop because of all the drawbacks he labours under in the form of shortage of resources. And for the rich man, he has other diversions, so is less interested. They used to consider sericulture as a poor man's industry, but just recently it has turned into a richman's.

Markets: along with the CRCs they were opening cocoon markets in Chamarajnagar. The first idea was that should be one within 5 miles of every rearer, so that he would be able to get there easily. They would have 4/5 reelers present for auctions and they would be forced to attend. But then the reelers would not come: suppose the rate was lower in some other market, they would want to go there. And rearers similarly. It was not possible to control it by legislation. A rearer went to court arguing that he had produced the cocoons and should be able to sell where he pleased. So they retained the markets where transactions were good, but in the end could not force people to use any particular one. Finally few survived but the big ones, and more people go to Ramanagaram. [So what about small markets like Harave and Hanur that still existed?] They were big markets earlier and still have some people wanting to sell only there. Harave was at a centee of rearing. Nearby is Maliyur with MLA[12] M.C. Basappa whose brother M.C. Swamy was a very good rearer from the beginning. He was an Agriculture graduate and used to take 400-500 layings and rear continuously. He is one of his customers for chemicals.

After the War there was a setback. Imports began and a tariff of 150% was imposed to maintain the home industry. It was sericulturists’ capacity to make use of idle labour which interested government, safeguarding the interests of labour. Indian silk was costly, hence the need for protection.

Killing silkworms: In Berikai there was a Tamil family, Gowdas, Mariswamy & Co. They were vegetable seed preparers and suppliers. They were good agriculturists and friends of his, and they used to attend his functions. He requested them to plant mulberry, but for all of 32 years’ friendship they resisted. They asked him not to press them. And it was the connection with killing worms which worried them. So there were some people who did think like that. A story of an orthodox Brahmin lady in Madras: when she saw a boy in charge of reeling she asked him what community he belonged to. He said he was an Iyengar Brahmin. She: ‘Why, being born as a Brahmin, should he do such a cruel action? Is it not sinful?’ Then seeing some silk fabric, she immediately wanted it. So the boy wanted to know, was that not sinful too? She: that it was different’.

The purity of silk: Pithambara = 'yellow silk' and it is mentioned in the Puranas as being used by the Gods. [Why?] Because silk is a non-conductor of heat and electricity. So even now Brahmins used to wear silk only. For worshipping, they didn't allow the pupa to be killed. Ripe worms are put on a plate and allowed to roam around producing silk. Maybe 5-6 and they move about the plate forming a sheet of silk, and this sheet is used to keep the idol on in old Brahmin homes. He himself clearly feels that it is a somewhat illegitimate betrayal of the silkworm to steal its cocoon and destroy it in the process, a creature dependent on man. But nowadays nobody has any such sentiments anymore.

Sericulture before Tipu. There were no sources for this. [This led him to stress how] in the 1940s there was no book to refer to for sericulture. Even when he was the sericulture man in the Institute he had to note down everything for himself. All aspects of science come together and interact in sericulture. He would discuss points that occurred to him with the specialists in Botany etc. [In fact there was already some good Indian literature, e.g. N.G.Mukerji’s Handbook of Sericulture of 1910/11, N. Rama Rao and M. Yonemura’s on silkworm rearing of 1925, Maxwell-Lefroy’s Report of 1916/17, On the Silk Industry of India, and others; but none have been easy to find.]

Any new people wanting to take up sericulture come to contact him. They come with grand notions of starting with 20-50 acres: he tells them to plant 2 acres for a start. Can then continue rearing from that and know all the pinpricks of sericulture. Then they can expand. If you fail after plunging in, you will fail really badly. His contribution he sees as increasing yield by 1 kg. He did have a scheme after retirement to set up a grainage and farm, get in other retired people to establish a consultancy service, but there were problems in getting a grainage licence etc, so he settled down with just himself and consultancy. The only thing is that he cannot go and visit the farms. If he went to one, he would have to go to all and that is impractical. But he does see private consultancy as the way the industry has to go.

He is also keen on people setting up local sericulture organisations, with their own grainages etc, on the Japanese model. [I commented that in the 1920s there had been so much talk of conferences and associations and that kind of thing, but it had gone away. Why were things different now?] He thought it was because there were so many more educated sericulturists now that it is increasingly possible to organise. Such a scheme with which he is associated - confidential - was now under application.

[Individual contacts: ... .]

He was also in the Seed Area for 5 years as Assistant Director in charge of the whole thing: in these days there are so many Deputy Directors and a Joint Director and still it does not run properly. He noted that it was cyclical, every 5 years. In 1965 there was talk of pebrine but with the co-operation of his staff they could easily control it. Responsibility is the thing. [I put it to him that in the early stages of the industry Brahmins had played a big part, subsequently Lingayats had been very important.] He agreed and also that this had something to do with the idea of service they had. Subsequently people just in it as jobs and not really interested. [The way things were running down was an inevitable theme, but there was also a very positive side to his account.]

[Mr Nair was, as seen above, a very interesting informant, a charming man as well. It was a pleasure to spend time with him, his delightful smile animating an otherwise aging face.]

Editors Notes

[1] Tharavad: name of the joint family of Hindus in Kerala. The Nair tharavad used to be a complex house hold with unique joint family lifestyle, now almost nonexistent.

[2] Achuthan Nairs’s son, Krishnan Unni confirms that Mr. Nair was born in February 1917 in a village called Cheramangalam in Palakkad district, Kerala State, South India. Having lost his parents at an early age, he grew up under protection of relatives and graduated from Annamalai University in Science (a rare achievement those days).

[3] RV Enterprises: Achuthan Nair set up his company together with Mallaraja Urs, Assistant Director Sericulture. R in the name came from Ratna Urs (Mrs Urs) and V from Valsala (Mrs Nair) - Reported by Sivakumar, Mr. Nair’s son.

[4] Krishnan Unni reports that the name ‘Polmr’(pronounced as ‘polmer’) was coined by Mr. Ravi Varma, a friend of Achuthan Nair, and then Area Manager of Kerala Soaps & Oils Limited (now Kerala Soaps), a state owned soap manufacturing company. Mr. Ravi Varma’s daughter Samyukta Varma is a well known Malayalam film actress. Both sons think that the rather strange name was created by combining the first letters of various chemical constituents of the powder. However they aren’t sure what these chemicals were.

[5] Former Deputy Director, Department of Sericulture, Karnataka

[6] Former Project Coordinator, National Silkworm seed Project, of CSB

[7] Former Director, Department of Sericulture, Karnataka

[8] Former member Secretary of CSB. He was instrumental in the foundation of Department of Sericulture, Uttar Pradesh.

[9] Former Director, Department of Sericulture, Karnataka

[10] Scheduled Caste: The Indian constitution recognizes list of scheduled castes and scheduled tribes eligible for various reservations on account of their socially deprived status.

[11] One hails from the southern state of Kerala, and speaks Malayalam; commonly called Malaylee.

[12] Member of (state) Legislative Assembly.

READ A PREVIOUS STORY BY Prof. CHARSLEY

Contact Prof Charsley: simoncharsley@yahoo.co.uk
Acknowledgements: We thank Mr. Krishnan Unni, CSR&TI, Mysore, to whose collections the two photographs belong and Mr. J. Justin Kumar, CSR&TI, Mysore who made available the scanned images. We are indebted to Mr. M.N.S.Iyengar, Joint Director, CSB (Retd) who (over telephone) shared some interesting information regarding individuals whose names appear in the text. This info is used in editor's note

Science in India- Raman's vision

gkrajeshrajesh@gmail.com — Wed, 27 Feb 2013 10:29:00 +0000

G.K. Rajesh

CEO and Member Secretary, Council for Nature Conservation and Environmental Protection, India

February 28, the day on which the discovery of Raman Effect was was officially announced by Sir. CV. Raman, is celebrated as 'National Science Day' in India. In the eve of National Science day, 2013, we remember Sir. CV. Raman, and his vision on scientific progress in India

Sir CV. Raman

The 2010 report of the Science Advisory Council to Prime Minister of India is titled “India as a Global Leader in Science”. It is interesting to see that the initial skepticism this title evokes in the minds of readers (about the validity of the claim) is shared by the authors. In the foreword to this vision-document, Dr Manmohan Singh, the Prime Minister asserts that it makes a realistic assessment of the opportunities that lie ahead and the challenges that the country face, in developing strong capabilities and acquiring global leadership in the area of science. The report in its very first page critically examines the validity of the growing perception around the world that India is one of the potential global leaders in science. Quoting a statement from the 2005 report of US National Academy of Science (NAS), that ‘the emergence of India and China as global leaders in science would pose challenges to the position held by US in the world of science’, it cautions the readers against getting carried away and categorically asserts that India is yet to become a major force in global science. The report goes on to illustrate that India has not produced any perceptible peak in the global distribution of number of scientific papers produced.

India’s strife towards building its own science began in the last decades of 19th century. This so called renaissance gave birth to a few world-class scientists in the country and one among them went on to bring home its first Nobel prize in science. Sir CV. Raman was a torch bearer of the Indian renaissance who strived till his last breath to cultivate true science in this country. This article takes a re-look at his vision and tries to assess the country’s progress in the lines envisioned by Raman.

The Nobel Prize won by C.V. Raman in 1930 for Physics was also India’s last one in science. It took 38 years for yet another scientist of Indian origin, to qualify this distinction. Har Gobind Khurana (1968), S. Chandrasekhar (1983) and Venkitaraman Ramakrishnan (2009) followed Raman’s foot prints but built their research career in foreign lands affiliated to foreign universities; hence their medals can’t be counted as India’s. In this context, it may be noted that independent India is devoid of any Nobel medal in science. Table 1 compares the number of Nobel medals in science, per capita GDP and Human Development Index of BRICS countries. India ranks lowest in HDI and Per capita GDP. While acknowledging the country of origin of the medallist, the Nobel foundation also mentions to which country and institution the person has been affiliated at the time of the award. In this count, India and Russia are the only BRICS nations with any Nobel laureate by affiliation. Russia has two medals and India has one. But for Raman, India wouldn’t have been in that list.

Table-1. Nobel medals of BRICS Countries (Source: World Bank Data)

Russia has a total of 17 medals: 12 before 1991 and 5 since then. However Russia, prior to 1991 can’t be counted among BRICS nations as until then it was a part of the super power, USSR. Out of the five Nobel medals received by Russia since 1991, two are its own by way of affiliation. Nevertheless these medals can’t be compared to the one brought home by Raman. While the post-Soviet Russia had inherited a great legacy of scientific advancement materialised by the erstwhile USSR, India had nothing of that sort. Raman’s research was largely homemade. A closer look at the medal count in table 1 reveals a fundamental issue prevailing in BRICS countries. These countries lack the ‘circumstances’ required for nurturing and leading young scientists to international recognitions like Nobel. The message they give out to the aspiring young scientist is very clear: ‘get out, if you want a medal’. Raman had clearly understood this and had the firm conviction that the only way to India’s scientific progress is to build her own science here. He spoke at the Mysore Chamber of Commerce on 18th April 1937

“If I am given a budget of ten lakhs a year for ten years and a free hand, I will solve all the problems connected with India’s scientific and industrial development, and place India in a position to produce everything from a battleship to a pin” (Uma Parameswaran, 2011)

Being a contemporary of Gandhi, Raman’s idea of self reliance in scientific research would have been influenced by the nationalist movement. How far-sighted Raman’s vision on self reliance in science was, is evident from the facts presented in table 2.

Table-2. Performance of BRICS countries in Scientific Research (Ranks within brackets) (Source: World Bank Data)

Table 2 compares the number of patent applications filed, export of high-tech scientific products and number of scientific publications from BRICS nations. China tops the list in all categories. India is in second or third position except in case of exports of high-tech products. However a comparison of the number of patent applications filed from India and that by Indians residing abroad reveals the true state of India’s scientific environment. The number of patents filed by Indian scientists from outside India is four times that those filed from India. While Brazil and South Africa share similar conditions, the case of China and Russia is different. 75% of China’s and 67% of Russia’s patent applications are filed from within those countries. This is a clear indicator, not only of the high levels of self-sufficiency these countries have attained in scientific research, but also of the fact that the number of scientists leaving these countries for research is much lesser when compared to India, Brazil and S. Africa. Raman had realised this danger in 1930s itself and had his own plans for preventing this intellectual leakage. He mentored two generations of scientists in this country.

During his tenure at Indian Association for Cultivation of Sciences, Calcutta University, IISc Bangalore, Central College and RRI, Bangalore Raman nurtured a large number of young researchers. S. Bhagavantam, Sathish Dhavan, A.S. Ganesan, G.N. Ramachandran, KS. Krishnan, Nagendranath, KR. Ramanathan, S. Chandrasekhar, A. jayaraman, PR. Pisharoty, HJ. Bhabha, Vikram sarabhai, S. Ramaseshan are to name a few, who went on to building science in this country. PR. Pisharoty speaks about the magnetic influence Raman had on his students.

“He inculcated in them (students) a capacity for long hours of work and a self- confidence that they can and should pit their brains against the best brains of the world. Under his magnetic personality, these qualities lasted at least as long as the students were with him; but alas, many of them lost these qualities soon after they moved away from his proximity. However, whenever any of them went to him, he re-generated those qualities in them through a few minutes of conversation.” (Pisharoty, 1971)

Let’s get back to the data presented in table 2. During 2010 the export of high-tech products from China was 28% of all exports of the country. In case of India it is just 7%. While China published 74,000 scientific papers India published only a quarter of it. A survey conducted by Nature in 2004 revealed that India occupies only 22nd position among countries that made impact-making scientific publications. China, South Korea and Poland are far ahead of India in this respect. India’s relative position in the world of science has declined in the last twenty years. We produce more science than before, but several more ambitious countries like China and S. Korea have outpaced us (DST, 2010). The 2010 report of Science Advisory Committee to Prime Minister of India points out that in order to contribute significantly to world science and to make an impact on it, India’s contribution to global scientific literature would have to rise to something like 10% (from the present 2% or so). Raman was a great champion of scientific writing. He is reported to have instructed his colleagues, the day before his death:

“Do not allow the journals of the Academy to die, as such journals are the only indicators as to whether science is taking root in our country or not” (Lynall, 2008)

Mary-Ellen Lynall, a researcher from Cambridge writes:

“Raman’s personal contribution to the development of scientific journals in India is astounding. When Raman entered science, there was no scientific journal of international repute in India . . . Holding positions of power does not in itself indicate strong support for Indian journals; as demonstrated by the many Indian scientists today who are associated with the editorial boards of Indian journals, yet publish abroad. Raman, however, was not in this category, writing 133 articles, 15 major book reviews and hundreds of short notices for ‘Current Science’ alone. . . Raman was truly the father of scientific publishing in India and Indian scientific publishing was undoubtedly most successful in the years when ‘Current Science’ and the ‘Proceedings’ were under his direction”

Today young scientists prefer to publish in high-impact international journals, which would fetch them international recognition and better citations. Some argue that there is nothing called Indian science and science is international. This may be true. But there is the question of identity of a scientific community. If scientists publish in a home journal, it gives identity to a scientific community. Experts say that a scientific community needs its own peer-review system to maintain its health (Lynall, 2008). Journals facilitate this.

Table. 3. Some Science and Technology indicators for select countries (Source: DST, 2010)

Table 3 compares the improvement made by India, China and S. Korea during the period from 1997 to 2006 in total number of scientific publications and percentage of high impact publications. This comparison clearly shows at what stupendous pace China’s scientific publications grew in a decade. S. Korea has also done extremely well, more so qualitatively. India has done well but not very well. The prescriptions made by Raman seventy years ago for building true science in India appear to be still relevant but not yet fully implemented. However the effect that he had left behind is still luminous, impelling and inspiring new generations of young minds. Let us hope that it would keep catalysing scientific progress in India for many more years to come.

READ A MALAYALAM VERSION IN DESHABHIMANI DAILY

References

Department of Science and Technology (2010) India as a Global Leader in Science; report of Science Advisory Council ti the Prime Minister

Lynall Mary-Ellen (2008) C.V. Raman’s work on scientific journals: legacy and lessons for Indian science. Current Science .Vol.94, No.03. p.305

Pisharoty.P.R (1971) Sir. CV. Raman as a teacher at Bangalore. Current Science No.9, p222

Uma Parameswaran (2011) C.V. Raman, A Biography. Pub. Penguin Books

J. Nagaraju: a Mémoire

gkrajeshrajesh@gmail.com — Wed, 09 Jan 2013 09:03:00 +0000

Dr. Pierre Couble

Dr. Pierre Couble

Dr. Couble, renowned molecular biologist and silkworm biologist was a close associate and friend of the late Dr. J. Nagaraju. Dr. Couble, in spite of his busy scientific engagements, has found time to write a reminiscence on his departed friend. We at 'THE SILKWORM' are honoured in publishing this reminiscence.

Dr. Pierre Couble is currently The CNRS Research Director, CNRS-Université Lyon, France. Contact him at: Pierre.Couble@univ-lyon1.fr

Dr J. Nagaraju passed away on the 31st of December 2012. All those who knew him are devastated by his sudden death. Dr Nagaraju was a passionate, inspired and imaginative scientist and a beloved friend. He brought a vast contribution to silkworm biology, in many distinct areas. His curiosity was endless, with a permanent attention that scientific progress be useful to society.

Dr J. Nagaraju started his career at the Central Sericultural Research and Training Institute in Mysore (Karnataka), as a Central Silk Board (CSB) employee. In 1989, he came to Lyon (France) for a two-year stay at the CNRS to work on the cellular and molecular genetics of the silkworm. This is when we started to work in collaboration. Back to India, he was invested by the CSB with the mission of running Seribiotech, a brand new research laboratory in Bangalore in the fast emerging field of biotechnology, aiming at blending fundamental and applied research. After the Seribiotech experience, Dr Nagaraju moved to Hyderabad in 1998 and joined the Center for Cellular and Molecular Biology (CCMB) and the Centre for DNA Footprinting and Diagnostics (CDFD) where he settled down finally. In 1997, he stayed for one year at Harvard University in the laboratory of Daniel Hartl.

Dr. Pierre Couble and Dr. Nagaraju In Durban, summer 2008

Dr Nagaraju first developed fingerprinting of the Bombyx genome by various approaches to assess the genetic diversity of the silkworm in multiple ecotypes and inbred lines. With his little team at Seribiotech, he characterized the first B. mori microsatellites, their type, abundance and polymorphism, and their potential for traceability of genetic resources. He maintained interest in repetitive DNA throughout his career and more recently developed SilkSatDB, a silkworm microsatellite data base and then InSatDb, an interactive interface to query information regarding microsatellite characteristics of fully sequenced insect genomes.

As a major silk-producing country, India is home to the mulberry silkworm but also to three other varieties of natural silks: tasar, eri and muga, unique silkworm species that feeds on specific host plants. In this field, Nagaraju pioneered the study of the diversity and of the population structure of these rare silkmoths, of dwindling culture.

His experience in the study of genome polymorphism and plasticity led him to investigate the genetic diversity of Basmati rice, a high added value product of India agriculture. By using SSR markers, he could develop rapid multiplex microsatellite marker assays for the authentication of traditional Basmati varieties, which awarded him the gratefulness of the Indian government.

In CCMC and CDFD, he also took interest in many fundamental questions. One concerned determination of sex, a fascinating paradigm owing to the myriad of sex determining primary signals among insect species, which he approached with Giuseppe Saccone (Italy). He worked at deciphering the collection of the genes carried by the Z chromosomes (in silkworm males are ZZ and females ZW) and initiated a study of the female specific chromosome W that is strongly female determining and was long thought to harbor feminizing genes. Dr Nagaraju identified such a W-chromosome linked gene, a remarkable finding since that gene may be a master contributor of the female sex. He conducted such critical work in collaboration with Kasuei Mita, Toshiki Tamura and colleagues from Japan. Unfortunately, this masterpiece will be published after his death.

Recently, Dr Nagaraju’s group and we in Lyon constructed silkworm transgenic lines which added a genetic trait that confers refractoriness to infection by baculovirus, a major pathogen in Indian sericulture facilities. The beneficial trait was introgressed into a commercial race, allowing to combine high silk productivity and immunity to the virus. This first industrial application of transgenesis illustrates the will of Dr Nagaraju to exploit genetic concepts practically. Several important traits have not yet been handled successfully in traditional breeding schemes. Dr Nagaraju always pleaded for the incorporation of modern genetic analysis in selection, which coupled with conventional breeding, allows the dissection of complex, multi-gene controlled traits. In this respect, Dr Nagaraju was a restless go-between, linking the community of the basic scientists and that of the sericulture industry.

The sad passing away of Dr Nagaraju poses the question of his successor as a guide of Indian silkworm research programmes and as a recognized international spokesperson who always worked to connect science and society.

Dr. J. Nagaraju passes away

gkrajeshrajesh@gmail.com — Tue, 01 Jan 2013 17:59:00 +0000

Dr. J. Nagaraju, noted molecular biologist and Khorana Chair at Centre for DNA Fingerprinting and Diagnostics (CDFD) passed away in Hyderabad on 31.12.2012. He was also heading the Laboratory of Molecular Genetics, Consultant Scientist of Agricultural and Processed Food Products Export Development Authority (APEDA) - CDFD Centre for Basmati DNA Analaysis and Co-Ordinator, Laboratory of DNA Fingerprinting Services. Dr. J. nagaraju had an illustrious scientific career. After obtaining Ph.D. from University of Mysore he became a Research Associate in Prof. Pierre Couble's Laboratory (Molecular Genetics), University of Lyon, France and held Visiting Scientistship in Daniel Hartl's Laboratory, Harvard University, USA. He was instrumental in setting up the Seribiotech Laboratory (Central Silk Board, Ministry of Textiles, Govt. of India) in 1992 and served as its Head till he moved to CDFD in 1998. Dr. Nagaraju has immensely contributed to silkworm genomics and genetics. His demise has caused a severe blow to the scientific world, particularly to silkworm molecular biology.

The sericulture fraternity of India should be thankful to him for laying strong foundations for seri-biotech here. At the laboratories founded by him at Kodathi, Bangalore and at CDFD Hyderabad, he had not only worked day and night, grinding tissues, running PCRs and fine tuning protocols, but also trained an impressive number of young hands at practical biotechnology. From very humble beginnings he rose to an international stature, bringing up with him India’s silkworm molecular biology, brushing shoulders with giants in the field. With his demise India’s silkworm sciences has become much poor. Sadly, the discipline will have to wait a long time to see yet another scientist of his stature to take his place.

Scenario of mulberry disease of Eastern and North Eastern India

gkrajeshrajesh@gmail.com — Sat, 30 Jun 2012 11:34:00 +0000

Dr. S.K. Dutta

S. K. DUTTA, M.K.GHOSH and B.B.BINDROO
Central Sericultural Research and Training Institute,Central Silk Board, Berhampore-742101, West Bengal

Dr. Sandip Kumar Dutta is a senior scientist with Central Sericultural Research and Training Institute, Central silk Board, Berhampur, India. A PhD in Mycology and Plant Pathology, Dr. Dutta has a long innings in plant pathology related research under Central Silk Board, India. Dr. Dutta can be contacted by email : dutta_sandipkumar@yahoo.in and by telephone: +91 9735601099

Mulberry (Morus alba, L.) is the sole food of the mulberry silkworm, Bombyx Mori L. This plant, belonging to family Moraceae is a deciduous plant. Incidence of a wide variety of diseases is one of the major hindrances for sericulture activity in Eastern and North Eastern India.

Mulberry can be grown under various climatic conditions from temperate to tropical. Among the commercially exploited mulberry varieties of Eastern and North Eastern India incidence of Powdery mildew (Phyllactinia corylea), Bacterial leaf spot (Xanthomonas campestris p.v.mori), Pseudeocercospora leaf spot (Pseudocercopsora mori), Myrothecium leaf spot (Myrothecium roridum) and leaf rust (Peridiopsora mori) are predominant.
Beside reduction in leaf yield, these diseases reduce the quality of foliage considerably. Meteorological factors viz, Temparature, relative humidity, Rainfall etc. play a vital role in providing congenial circumstances for pathogenic multiplication and disease severity in different agro climatic zones. Intensity of disease may be positively or negatively correlated with meteorological variables. Generally disease spread through germination of spores, depending on leaf wetness. Leaf wetness depends on humidity, rainfall and dew. Wind is related with spore dispersal. In general scanty rainfall, low agricultural inputs and out break of pests and diseases are contributing factors for economic loss to farmer

A study was conducted in 10 states in the north eastern parts of India to assess Severity (PDI) of different diseases were in different climates round the year, to arrive at a set of disease calendars. Seven calendars are presented here as an outcome of the study. We believe that the calendars will be useful to farmers by enabling them to anticipate disease outbreak and take up necessary prophylactic measures against them. The diseases under study are Bacterial Leaf Spot (BLS), Pseudocercospora leaf spot (PLS), Leaf rust (LR), Myrothecium leaf spot (MLS) and Powdery mildew (PMLD).

The states and locations where the study was conducted are furnished in table 1. Table 2 , gives the disese calendar for the five diseases in various states in north eastern India. Tables 3 to 7 give the disease calendar for each disease in locations where the incidence is significant.

Table-1: The States and locations where the study was conducted

Table 2: Disease calendar for Eastern and North Eastern India

Table 3: Disease calendar for Bacterial Leaf Spot

Table 4: Disease calendar for Eastern and Myrothecium Leaf spot

Table 5: Disease calendar for Eastern and North Eastern India

Table 6: Disease calendar for Pseudocercospora leaf spot

Table 7: Disease calendar for Leaf Rust

APPLICATIONS OF INSECT GROWTH REGULATORS IN SERICULTURE AND AS FOOD SUPPLEMENTS

gkrajeshrajesh@gmail.com — Tue, 19 Jun 2012 11:50:00 +0000

A. Banerji

School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam Dist. 690525

Dr. Asoke Banerji

Dr. Asoke Banerji is Distinguished Professor at Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kerala. The main thrust of research activities of Professor Banerji’s group has been directed towards emerging areas of natural product chemistry and Biotechnology. He gave a new direction to the natural product research by purpose-oriented investigation of the plant extracts following reverse pharmacological approach. During the course of research work, an array of natural products belonging to different groups (medicinal as well as other activities) were isolated and characterized. Professor Banerji has several patents to his credit. In addition to medicinal compounds, he has contributed to other areas also such as natural dyes, biopesticides, bioremediation, biotransformation, high-value agrochemicals. As a result of screening of indigenous flora, several insect growth regulators (IGR), both phytoecdysoids and juvenoids, were isolated and characterized. Processes for their preparation in commercial scale have been developed. Some of the isolated phytoecdysoids are being used in the commercial formulations for use in sericulture isolated. A list of selected publications of Dr. Banerji, provided at the end of this article will give the readers an idea about the span of his work in phytochemistry.

SUMMARY

Indigenous plant sources of insect growth regulators (both phytoecdysterones and juvenoids) have been identified. Viable methods for their commercial preparations have been established. Optimum doses and timing of application of IGRs for sericulture determined. In addition to sericulture, phytoecdysterones are also useful as food supplement (nutraceuticals) or for fortifying existing health foods/supplements and important biochemical tool for genetic engineering.

INTRODUCTION

Insect growth regulators (IGRs) such as juvenile and moulting hormones or their analogs (juvenoids and ecdysoids) when used judiciously, have been found to be useful in sericulture industry. In addition, ecdysoids also show a variety of other uses such as insecticidal, as biochemical tool in gene expression studies, as wound healing and anabolic agents ( body building agents with enhancing protein synthesis), as nutraceuticals and cosmetics (hair growth) IGRs occur in insects in very small amounts and are not practical source for these phytochemicals. However, with the discovery of their occurrence in significant quantities in some plants, IGRs and their analogs became easily available in substantial amounts. As a result, many new bioactivities of ecdysoids and juvenoids were discovered. Besides use in sericulture, they have found applications in apiculture and aquaculture (prawns). Ecdysoids show remarkable anabolic activities in human and are very much in demand as nutraceuticals (food supplements) including body building agent. Realizing the economic potential of IGRs, bioprospection for these compounds from indigenous plant sources was undertaken. Our survey indicated that a large number plants belonging to different taxa contain IGRs. Our focus was on plants showing insecticidal activities and two main IGRs, viz. ecdysteroids (ecdysterone analogs) and juvenoids (juvenile hormone analogs). Suitable bioassays for each of the activities were established and about 500 plants were screened for IGRs. This resulted in the discovery of several sources of IGRs from different geographical locations.

IGRs IN SERICULTURE

India is one of the largest silk producing countries. Mulberry silk accounts for most of the silk produced in India. Three other species namely, Eri, Tasar and Muga are mainly grown in the north-eastern India. India is also one of the major consumers of silk. Sericulture, the agro-industry of cocoon and silk production is the source of income of several marginal farmers of India. However there is a shortfall of 7000 metric tonnes of silk fibre within the country. The silk production in India needs improvement in quantity as well as quality compared to other silk producing countries. Central Sericulture Research and Training Institute (CSRTI), Mysore has been involved in the improvement of the mulberry seri-technology in a holistic way. However there is considerable scope of improving the varieties of silk produced in north eastern India.

Sericulture is a labour intensive agro-based industry which provides additional income to marginal farmers. Substantial part of labour in sericulture management goes in the picking up of the mature larvae for mounting. The duration of mounting period is quite variable. Duration of the moulting from beginning to end may vary between 48-72 hours. This implies that labour must be available continuously all through the period (day and night) of moulting. Application of exogenous ecdysoids helps in the synchronization and reducing the time for spinning. Its application hastens the maturation without affecting the quality and yield of silk. Application of ecdysoids synchronizes and shortens the period of moulting to 18-24 hours. This helps considerably in the management of sericulture and reduces the cost of labour. Hastening the moulting period also contributes in the reduction in the consumption in the feeding of mulberry leaves without affecting the yield of silk fibre. Use of juvenoids on the other hand, tend to keep the fifth instar silkworm young by extending the larval period and increasing the silk secretion. It postpones the spinning stage by few hours. Thus when applied judiciously, IGRs can contribute significantly in increasing the silk production.

PHYTOECDYSOIDS IN SERICULTURE

Sampoorna-A commercial phytoecdysoid

Ecdysoids and their analogs (called phytoecdysones) occur in significant quantities in many indigenous plant sources. A simple bioassay based on sclerotization of house fly last-instar larvae was developed. Several hundred extracts from plants were screened following this bioassay. Initiation of the sclerotization within 24 hr of treatment was indicative of presence of phytoecdysoids (PEC). PECs were isolated following activity- guided fractionation of plant extracts and active principles were isolated . More recently, non-biological methods based on chromatographic, spectroscopic and LC/MS methods have been developed in our laboratory for quick identification and quantification of PECs and their analogs. A convenient method for their isolation has been developed (patent pending). Results of our screening of plant extracts show that PECs have wide occurrence in plant kingdom. In collaboration with CSRTI, Mysore, optimum time and dose of application of PEC have been established. Commercially viable sources of PECs have been discovered for possible application in sericulture industry and other applications such as food supplement (nutraceuticals). Commercially viable process for preparation of PEC in large scale has been developed. Application of PEC in the farmers fields have established that there is considerable savings in labour cost . In countries like China, Japan, France, IGRs are in regular use in sericulture.

PHYTOECDYSOIDS AS NUTRACEUTICAL

Amrutha- a commercial phytoecdysoid

Formulations with PECs as active constituents have found use as health promoting products. PECs do not have adverse effects on human health even at gram levels. They show anabolic activities and are useful constituents in many commercial food preparations. They are useful adjunct for fortifying many of the currently used beverages and food supplements. They are popular in many countries as natural body building agents. In addition they show a variety of biological applications such as molecular switches, and have potential use in researches on gene expression and related studies.

JUVENOIDS (JH)

The juvenile hormone (JH) activity of plant extracts/isolated compounds were determined using 5^Th instar nymph of red cotton bugs (Dysdercus koenigii). Juvenoids are analogs of insect juvenile hormones. Several compounds, showing JH activities have been found in many common plants. Application of JH’s to silk worm prolongs the larval period. Synthetic JH analogs are in use in sericulture industries in countries such as Japan, China. There is no commercial Indian source for juvenoids.

Samrudhi- a commercial juvenoid

Imported synthetic JH analogs are expensive. Hence there is a need for identification of cost effective JH formulation for improving silk productivity. Several sources JH analogs from plants have been identified in our laboratory and isolation and characterization of the active principles have been carried out. Eco-friendly economic process for their preparation has also been developed by our laboratory. Based on existing information, it can be predicted that use of IGRs will give a boost to sericulture industry.

PROSPECTS OF USE OF IGRs IN INDIA

IGRs are in use in many countries in sericulture, aquaculture and apiculture. They are in great demand for body building formulations and cosmeceutical preparations. Indian farmers have realised the beneficial effects of IGRs and some preparations have appeared in the market. As a result of our studies several plant –based sources for PECs and JHA have been discovered. Protocols for their application have been developed. Detailed information on the sources, quality control and applications of indigenous IGRs is available for commercial exploitation. Entrepreneurs interested in the commercial exploitation of these products for sericulture, food supplement or as biochemical tool are welcome to contact me at Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham. banerjiasoke@gmail.com or mobile +91 9895527851.

Select list of publications of Dr. A. Banerji

1. A. Banerji, G. J. Chintalwar and M. S. Chadha, Isolation of Ecdysterone from Indian Plants, Phytochemistry, 10, 2225 (1971)

2. A. Banerji and G. J. Chintalwar, Phytoecdysones and Flavonol Glycoside from Sesuvium portulacastrum, Indian J. Chem.,9, 1029 (1971).

3. A. T. Sipahimalni, A. Banerji and M. S. Chadha, Biosynthesis and Interconversion of Phytoecdysones in Sesuvium portulacastrum L. J. Chem. Soc. Chem. Commun., 692 (1972).

4. A. Banerji and G. J. Chintalwar, Biosynthesis of Bakuchiol, A Meroterpene from Psoralea corylifolia Phytochemistry, 22, 1945 (1983).

5. A. Banerji and G. J. Chintalwar, Biosynthesis of Bakuchiol from Cinnamic and p-Coumaric acids. Phytochemistry, 23, 1605 (1984).

6. N. K. Joshi, K. M. Lathika, A. Banerji and M. S. Chadha, Effects of Plumbagin on Prothoracic glands of Dysdercus cingulatus in "Endocrinological Frontiers in Physiological Insect Ecology" (Eds. F. Sehnal, A. Zabra and D.L. Denglinger) Technical University Press, Wroclaw (Poland) pp. 69 (1988).

7. N. K. Joshi, K. M. Lathika, A. Banerji and , M. S. Chadha, Effect of plumbagin on Growth and Development of Red Cotton Bug, Dydercus Koenigii, Proc. Indian Natn. Sci. Acad., B54, 43 (1988).

8. V. Ramakrishnan, G. J. Chintalwar and A. Banerji, Environmental Persistance of Diallyl Disulphide, an Insecticidal Principle of Garlic and its Metabolism in Mosquito, Culex pipens Quinquifaciatus Chemosphere, 18, 1525 (1989).

9. A. Banerji and G. J. Chintalwar, Fate of Leucine in the Biosynthesis of Bakuchiol, a Meroterpene from Psoralea corylifolia. Indian J. Biochem. Biphys., 26 394 (1989).

10. D. L. Luthria, V. Ramakrishnan, G. S. Verma, B. R. Prabhu and A. Banerji, Insect Antifeedants for Atalantia racemosa. J. Agric. and Food Chem. 37, 1435 (1989).

11. 57. N. K. Joshi, K. M. Lathika, V. Ramakrishnan, A. Banerji and M. S. Chadha, Plumbagin-Induced Inhibition of Ovary Development in Dysdercus cingulatus. in "Regulation of Insect Reproduction IV', Eds. M. Tonner, T. Soldan, B. Bennettova, Academia Publishing House of the Czechoslovak Academy of Sciences Praha, pp. 287 (1989).

12. A. Banerji, Radiosynthesis of 35S-Labelled Bioactive Compounds and their Metabolics, Proceedings of national symposium on nuclear techniques in the study of pesticides in food agriculture and environment, The University of Acultural Science, Hebbal, Bangalore Feb. 8-10, 1989.

13. A. Banerji, Insect control by biotechnical procedures - Lessons from plant kingdom, in “Insect Chemical Ecology” (Ed. I. Hrdy), Academia Praha, pp. 235.

14. A. Banerji, Biotechnical Potential of Natural Products, Bioelectrochemistry and Bioenergetics, 27, 105 (1992).

15. A. Banerji, Insect Plant Interactions: Natural Insect Control Agents, Recent Advances in Insect Physiology and Toxicology, 41, Ed. G.T. Gujar, Agricole Publishing Academy, Delhi, (1993).

16. A. Banerji in Role of Allelochemicals in the Ecodynamics of Insects and Plants. "Biochemical Perspectives in Chemical Ecology of Insects", ed. T. N. Ananthakrishnan, Oxford & IBH Publishing Co., New Delhi, 000 (1995).

17. G. R. Shivakumar, K. V. Anantha Raman, K. Venkata Rami Reddy, S. B. Magadum, R. K. Datta, S. S. Hussain. A. Banerji and S. K. Chowdhury, Effect of Photoecdysteroids on Larval Maturation and Economic Parameters of the Silkworm, Bombyx mori., Indian J. Seric., 34, 46, (1995).

18. G. R. Shivkumar, K.V.A. Raman, S.B. Magadum, R.K. Datta, S.S. Hussain, A. Banerji and S.K. Chowdhary, Effect of Phytoecdysteroids on the Spinning, Cocoon and Reeling Parameters of the Silkworm, Bombyx mori L., Allelopathy Journal, 3, 71, (1996).

Note: To read another related article on phytojuvenoid published earlier in this journal, CLICK HERE

A New Highly Productive Silkworm Sex-Limited Pure Genetic Line

gkrajeshrajesh@gmail.com — Wed, 15 Feb 2012 05:34:00 +0000

H.S. Homidy, D. Gahakwa, A.N. Papaskiri and A. Rutayisire

Professor H.S. Homidy

Professor Homidy Khomid Soky (HS. Homidy) is International Expert on program development of sericulture, of the Ministry of Agriculture and Animal Resources, Rwanda (IFAD/PDCRE/RHODA/RAB). His research interest in sericulture are wide and varied such as: breeding of silkworm, biochemistry, physiology, technologies of silkworm hybrid (F1) egg productions, silkworm rearing, productions of cocoons and post-harvest, disease control, maintenance of mulberry plantations, mulberry crop protection etc. During his 23 years of research career he has held important positions as deputy director on research National Research Institute of Sericulture, Uzbekistan, Vice-minister Ministry of Silk Industry republic of Uzbekistan, Director of National Research Institute of Sericulture, Uzbekistan, Manager of scientific technological centre of Uzbek Scientific Research Institute of Sericulture etc. He has to his credits two books, 61 research papers 20 PhD theses and three patented inventions. Professor Homidy is the Vice president of the Black, Caspian Seas and Central Asia Silk Association (BACSA).
He may be contacted at: Email: khomid_khomidy@mail.ru , Republic of Rwanda Kigali , Tel: +250783280724

Abstract

Generation of highly productive sex – limited pure genetic silkworm lines remains interesting both in theoretical and in practical aspects using the practice of sericulture to allow simplified production of highly heterocyst silkworm egg hybrids.

During process of selection on preservation of characteristics and adaptation to new environment conditions of silkworm breeds, with the breed named Progress (Uzbek selection - Japanese type), the sixth generation silkworm larvae with different skin color were generated. The new silkworm larvae genetic pure line revealed sex-limited characteristics. Their distinctive feature consist of: silkworm larvae having marking on the first and fourth segment are female and having marking in first to fifth segments (type multi-lunar) are male larvae. ‘Trialson’ the new genetic pure line up to the fifth generation has shown stability of their phenotypic signs and essential differences between females and males. Thus the balance of sex at larvae stage of 1 ♀♀: 1 ♂♂ was achieved. The new genetic pure line is superior in viability of pupation (92,64%), weight of a cocoon (2,48 g) and cocoon shell (0,567 g). Fresh cocoons yield average attained 44,46 kg/box and accordingly with excellent raw silk yield (7,515 kg/box).

Keywords: Sex – limited silkworm pure genetic line, heterosis, hybrids, sexual chromosomes, morphological signs.

Introduction

Mulberry silkworm (Bombyx mori L.) became the first object on which to practically solve the problem of artificial sex regulation. The main reason for using sex – limited silkworm lines is to make easier and more effective, the process of silkworm egg production especially in terms of sex discrimination. The first attempts to create sex-limited silkworm breeds were made by Tichomirov (1891), followed successfully by other researchers like Tazima (1944), Hasimoto (1948), Astaurov (1972), and Lee at al. (1988). The first silkworm strain, having marked female larvae and plain male was created by Tazima (1944) by treatment of newly laid silkworm eggs with X-rays and translocation of the P+ allele and its connection with the sex chromosome W. Later, using the same method Hasimoto (1948) managed to create a new sex-limited breed having zebra female and plain male larvae. By this method, the initial material used was sex limited races that were crossed with other races having plain larvae or yellow eggs. After that the hybrid population was maintained by batch rearing for four generations and with inside batch mating (inbreeding). Strunnikov (1969) expanded the studies, directed toward the creation of marked differentiation by sex at the egg stage but also with sufficiently good viability. The main distinctive special feature of these lines is that females are developed from the dark eggs while males arise from the bright eggs. On the basis of translocation lines, two breeds, one which is characterized by the oblong form of cocoon, and another with cocoons that are rounded, were created. Concerning the sex-limited character of cocoon color, it is established, that the female cocoon is yellow and the male white. It permits an easy sex-discrimination and the male cocoon can separately be reeled to produce high-grade silk (Chen, 2002).

After discussion of such impressive results on silkworm sex regulation at different stages using X-ray, it was possible to think, that the problem is completely resolved, but however in the literature there is no information on any research or discovery of natural mutation in sex marking of silkworms. In these circumstances, our research was to adapt silkworm breeds delivered from different geographical zones to sub - equatorial climate of Rwanda, to study phenotypical changes including possibilities of occurrence natural mutation in these breeds.

Materials and methods

Study area

This study was conducted at the sericulture unit at the Rubona Research Station, previously under the Rwanda Agricultural Research Institute. Rubona station 2.26 (2° 15' 49 S; 29.81 (29° 48' 27 E) is located in the mid-altitude agro-ecological zone in southern Rwanda, 125 km from Kigali, the capital city. The station has a subequatorial climate and is located at high altitude (1700 m over sea level), with an annual average temperatures around 18-21 °С and rainfall between 1300 -1800 mm. The dry season start from June up to August – September.

Study design

We used a completely randomized design where all the silkworm breeds available were subjected for research of adaptability reaction to new sub - equatorial climate of Rwanda. The study focused on any possible effect of transformation of the silkworm breeds, particularly on revealing mutant genetic lines.

Process that transformed the silkworm

During selection on adaptation of silkworm breeds delivered from different geographical zones to new environment conditions, with breed named Progress (Uzbek selection) Japanese type, in the sixth generation of selection, some silkworm larvae with different skin color were revealed. For improvement and preservation of cleanliness of the silkworm sex-limited breeds, the moderate and remote related breeding – i.e. inbreeding V-VI degree was applied. Selection was carried out based on phenotypical signs of sex-limited silkworms. More than 150 individual families were prepared, but after their detailed analysis, only 105 families were saved. After results on hatchibility of layings, 50 best families were taken for rearing by using Homidy et al., (2001) silkworm rearing procedure.

Data analysis method

Data collected from our work was analysed using common-method of statistical analysis of qualitative and quantitative data (Tabachnick, B.G. & Fidell, L.S. 2007).

Results and discussion

The idea of Serebrovsky (1935) consisted to use an artificial method, particularly, use of X-ray radiation, to get the silkworms sex-limited. The target was to get male and female silkworms with morphological differences distinguishable at an early stage of development. This phenomenon is due to the genes translocation. The genes responsible for morphological signs are located on sex chromosomes.

New pure silkworm sex-limited pure line GH-02

During our research work on sex-limited silkworm, mainly using the selection technique, we produced a new genetic pure line that has code named GH-02. This new genetic pure line

revealed sex-limited traits in the larvae stage as well. The distinctive feature of this line consist of the silkworm larvae having carpet type markings on segments, typical characteristics of females; and silkworms having usual type marking on their segments, characterizing male larvae . Breeding and selection studies on the new genetic pure line GH-02 up to the fifth generation showed stability on the phenotypic signs, which are essential differences between females and males. Thus, the balance of sex at larvae has now been stabilized at the ratio of 1 ♀♀: 1 ♂♂ (Table 1).

Cocoons of New pure silkworm sex-limited breed (GH-02)

The analysis of the obtained indicators on phenotypical signs of new genetic pure line GH-02, shows that viability of pupation rate of 90,24±0,3 - 95,04±0,2 %, weight of a cocoon-2,80±0,02-2,16±0,01g, cocoon shell -0,582±0,1-0,553±0,2 g and percent cocoon shell-21,0±0,01 - 25,6±0,02%. Fresh cocoons yield by 1 box silkworm eggs an average makes 44,46 kg, thus cocoons yield at females reaches 49,49±3,2 kg/box. The essential difference was not observed in color of female and male cocoons, thus essential differences were revealed in their technological parameters, like filament length-1242±6,7 - 1287±5,3 m, good cocoons reelability (average) 87,5 % and excellent raw silk yield 7,32±1,2 - 7,71±1,5 kg/box.

Table 1. Testing new silkworm six-limited pure line GH-02

Conclusion

It is important to understand that sericulture is focusing on deducing new highly productive breeds with improved raw silk yield and disease resistance. During the process of research on adaptability response of silkworm breeds delivered from different geographical origins to local condition, for the first time in Rwanda, at larval stage it was discovered a new sex limited genetic line of silkworm. This new genetic pure line (code named GH – 02) had showed to be disease resistant and highly yielding in terms of raw silk with good technological parameters of filament. The difference was significantly observed in body coloration during 4th and 5th instars larval stage, in female carpet coloration appeared while in male usual coloration appeared and thus it was easy to make separation according to sex, they can be used for production of 100% silkworm hybrid eggs. The reason of occurrence of this sexual segregation could be natural mutation, attributable to the geographical location of our scientific laboratory (1700m over sea level).

References
Tazima Y. (1944) Studies on chromosome aberrations in the silkworm. II Translocation involving second and W-chromosomes //Ibid. N12. Р.109-181.

Hasimoto H. (1948) Sex-limited zebra in X-ray mutation in the silkworm. //J.Sericulture Japan. 1948, Р.16.

Astaurov B.L. (1972) Prospect of animal sex regulation //J. Nature.№2. P.48-57.

Lee S., Kim S., Kim K., Lee S., Lee H., Lee Y. (1988) Induction of sex-limited cocoon color character by translocation of yellow blood gene Y(TT -25.6) on to W chromosome by gamma irradiation in silkworm. Bombyx mori. //Korean J. of Breeding, 21(3), P.219-223.

Strunnikov V. (1969) Greeting of man's posterity at silkworm (Bombix mori L). //Academic scientific Reports. V.189. №5. P. 1155-1158.

Chen Y. (2002) Conservation status of silkworm genetic resources in China. Expert consultation on promotion of global exchange of sericulture germplasm resources", Satellite session of XIXth ISC Congress, 21st -25th, September 2002, Bangkok, Thailand.

Homidy H., Ahmadaliev A. and Papaskiri A. (2001) Technology of silkworm rearing. Patent № 055075 Uz.

Serebrovsky A. (1935) Hybridization at animals. M.: Biomedgis. P.290.

Tabachnick, B.G. & Fidell, L.S. (2007). Using Multivariate Statistics, Fifth Edition. Boston: Pearson Education, Inc. / Allyn and Bacon, ISBN 978-0205459384

Bio-pesticides and Bio-fertilizers for sustainable sericulture

gkrajeshrajesh@gmail.com — Sun, 28 Aug 2011 15:04:00 +0000

Dr. Dayakar Yadav

Dr. Dayakar Yadav is senior scientist with Central Silk Board (CSB), India. After obtaining PhD in Mycology and Plant Pathology in 1980, he had a long and fruitful research career with reputed organizations in India such as Karnataka State Forest Department, University of Agricultural Sciences, Bangalore, Karnataka State Sericulture Research and Development Institute, Central Sericulture Germplasm Research Institute (CSB), Central Sericultural Research & Training Institute, Central Silk Board. He has published more than 60 research papers in reputed journals and attended overseas training programs in Japan and China.

Introduction

The 20^th century has witnessed a slow but steady emergence of bio-pesticides and bio-fertilizers as potential supplementary and environment friendly inputs to their chemical counterparts. With the documentation of nearly 2500 bioactive plant species, over 1000 protozoa pathogenic to insects, 700 species of invertebrates and an array of other micro and macro-bioagents; their role in future crop protection cannot be ignored. Likewise; bio-inoculants or bio-fertilizers, primarily the nitrogen fixers and the phosphate solubilizers, hold vast potential in meeting plant nutrient requirements while minimizing the use of chemical fertilizers. Furthermore, successful exploitation of genetic engineering technology (metagenomics) to incorporate non-native pesticide producing genes into crop plants has added another dimension to the potential use of these inputs in agriculture. Currently, Asia-Pacific countries are the leading advocates of bio-pesticides and bio-fertilizers for sustainable agriculture.

Agriculture practices and its impact on the earth

In the beginning of 21^st century, agriculture accounts for the major share of human use of land. Pasture and crops alone taking up 37 percent of the earth's land area and over two-thirds of human water use is for agriculture (in case of Asia it is four-fifths). Crop and livestock production have a profound effect on the wider environment. They are the main source of water pollution by nitrates, phosphates and pesticides, also the major source of the greenhouse gases methane and nitrous oxide and contribute on a massive scale to other types of air and water pollution. The overall external costs of all three sectors can be considerable. However, the long-term consequences of these processes are difficult to quantify. If more sustainable production methods are used, the negative impacts of agriculture on the environment can be attenuated. Indeed, in some cases agriculture can play an important role in reversing them, for example by storing carbon in soils (i.e., organic carbon) enhancing the infiltration of water through bio-fertilizers and bio-pesticides.

Role of Fertilizers and pesticides in sustainable environment

Concern has also grown in recent years that the use of fertilizers, particularly inorganic fertilizers, can lead to serious environmental consequences. Environmental contamination of this type, however, is largely a problem in the developed world and a few regions of the developing world. As fertilizers make up a small share of the total production costs in many developed countries, farmers often apply fertilizers in excess of recommended levels in order to ensure high yields. Over application of inorganic and organic fertilizers is estimated to have boosted nutrient capacity in the soil by about 2000 kg of nitrogen, 700 kg of phosphorus, and 1000 kg of potassium per ha of arable land in Europe and North America during the past 30 years. Such oversupply of nutrients can lead to environmental contamination, which often has negative consequences for humans and animals.

Pollution of groundwater by agricultural chemicals and wastes is a major issue in almost all developed countries, its use efficiency has to be improved or use alternate source of manures. Though the current use in many developing countries is very inefficient, China which is the world's largest consumer of nitrogen fertilizer, up to half the nitrogen applied is lost by volatilization and another 5 to 10 percent by leaching. Nitrogen synthetic fertilizers are considered the most detrimental to the environment, causing leaching and runoff that freshwater habitats and wells. Nitrogen synthetic fertilizers are a major contributor to increased N2O emissions, which are 300 times more potent than CO2 as greenhouse gas, which is ominous for global warming as synthetic fertilizer use is forecasted to increase roughly 2.5 times by mid-century.

Insecticides, herbicides and fungicides are also applied heavily in many developed and developing countries, thus polluting the fresh water resources with toxic and other poisons that affect humans and many forms of wildlife. Pesticides also reduce biodiversity by destroying weeds and insects and hence the food species of birds and other animals.

Over the past 3 to 4 decades, usage of insecticides show signs of decline, both in developed countries especially France, Germany and the United Kingdom and in a few developing countries, such as India. In contrast, herbicide use continued to rise in most countries. As concern about pollution and the loss of biodiversity grows, future use of pesticides may grow more slowly than in the past. The future is likely to see increase use of "bio- pesticides and ecological methods of disease and pest control.

A pesticide of biological origin like viruses, bacteria, pheromones, plant or animal compounds is known as bio-pesticide. They are highly specific affecting only the targeted pest or closely related pests and do not harm humans or beneficial organisms while chemical pesticides are broad spectrum known to affect non-target organisms including predators and parasites as well as humans. The striking feature of bio-pesticides is environment friendliness and easy biodegradability, thereby resulting in lower pesticide residues and largely avoiding pollution problems associated with chemical pesticides. Further, use of bio-pesticides as a component of Integrated Pest Management (IPM) program can greatly decrease the use of conventional (chemical) pesticides, while achieving almost the same level of crop yield. However, effective use of bio-pesticides demands understanding of a great deal about managing pests especially by the end users.

In terms of production and commercialization also bio-pesticides have an edge over chemical pesticides like low research expenditure, faster rate of product development as well as flexible registration process. The global weighed average consumption level of bio-pesticides is approximately 1 kg/ha. With the global organic farming area comprising about 24 million hectares, global bio-pesticide consumption is thus estimated at about 24 million kg. The bio-pesticide market is growing very rapidly, in 2005 it accounted for about 2.5% of the total pesticide market, which was merely 0.2% during 2000. This share is expected to a level of about 4.2% by 2010 while the market value is estimated to reach more than US$ 1 billion (Source: BCC research). However, the overall growth rate of bio-pesticides is estimated to be about 10% per annum for the next 5 years.

Research experiences towards sustainable Sericulture development

The Sericulture-based Integrated Farming System Management (IFSM), Integrated Nutrient Management (INM) and Integrated Pest Management (IPM) programmes are farmer-centered and farmer-participatory aimed at promotion of eco-friendly approaches for sustaining productivity and also optimization of resources utilization. These two projects were implemented in Andhra Pradesh, Tamilnadu and Karnataka states during 2002 to 2007. Under these projects, a number of technologies were evolved towards sustainable sericulture which can be translated to other crops. The technologies developed were of integrated nature and cost effective serving the purpose of eco-friendliness, sustainable development and reduction in cost of production in silk.

More poor people depend upon sericulture for their livelihood. Poverty alleviation necessarily demands increased sericulture productivity, which is a largely a function of 'technology'. Absence of technological intervention would lead to increased depletion of natural resource base. Poverty subverts efforts to introduce sustained sericulture in ways detrimental to the environment. This would lead to a decline in sericulture production potential, and sustaining capacity of sericulture would also decrease. With the ever-increasing population poverty gets perpetuated widely and deeply, furthering environmental degradation.

'Silk and Milk'

Karnataka, amply termed as silk bowl of India, from three southern states around 1.4 lakh ha. of mulberry, wherein approximately 42 lakh MT of annual production is estimated. The wastage (bed refusal) of silkworm rearing activity is used as cattle feed; silkworm litter or faucal matter as organic manure; pupae for extraction of oil / feed for poultry etc. One hectare of mulberry garden can produce about 25- 28 tones of mulberry leaf year from which 1200- 1500 kg of cocoons are produced. During this activity, about 20% (750-10000 kg/ha/crop) of leaf and/or twigs which is considered as bed refusal is fit to use as fodder for cattle. Bed refusal (uneaten leaves and tender stump) produced during rearing is effectively used by the farmers to rear cattle. It constitutes about 50% of the fodder requirement of cattle. Further, the bed refusal and tender stumps produced out of one hectare of mulberry is almost sufficient for 7 -8 cows. Apart from this, around 5% of the mulberry, which will either be soiled or unfit due to over maturity, can be used as fodder to the cattle. Rearing of eight cattle along with silkworm rearing will in turn meets the FYM requirement of one hectare of mulberry plantation. Valuable FYM will also be produced at the farm itself. Mulberry leaf stalk/stump forms the low cost/no cost alternative fodder for the cattle. By and large it is important that dairy animals have good appetite and mulberry leaf is palatable and the animal eats it very well.

Soil Health

Proper soil management without impairing soil health is the prerequisite for achieving higher productivity in sericulture. The situation has created a renewed interest in the biological transformation of sericultural farm wastes including all organic wastes into valuable manures which can be profitably used in the mulberry fields for the cost-effective production of mulberry leaves. This nutrient-rich compost is a better supplement for farmyard manure, the cost of which is escalating day by day due to shortage of cattle dung.

Integrated Plant Nutrient Supply

Azotobacter

Heavy use of nitrogen started up showing in increased nitrate concentration in underground waters in states like Maharashtra and Punjab. Due to these alarming signals, Integrated Plant Nutrient Supply (IPNS) has become a sustainability concept. IPNS involves meeting a part of the nutrient need of crops by organic manures, crop residue, green manures, dual-purpose legumes and bio-fertilizers. The need for IPNS was suggested by long-term fertilizer experiments on wheat. Application of N alone reduced the yield of wheat to zero after 13 years. Application of P along with N extended it to 22 years but in NPK plot some yield was obtained even after 22 years.

However, plots receiving a part or all nutrients through FYM not only maintained but also recorded a gradual increase in crop yield over years. Combined application of FYM and inorganic fertilizer was the best.

Bio-fertilizers: In recent years, use of bio-fertilizers holds much promise to improve the yield of crops. Bio-fertilizers sustain soil fertility resulting in increased crop yield without causing any environmental, water, or soil hazards. Out of many microorganisms, which are identified as biofertilizers, Azotobacter chroococcum, Azospirillum brasilense, A. lipoferum, Phosphorus Solubilizing Bacteria (PSB) and Vesicular Arbuscular Mycorrhizae (VAM) have proved to be beneficial in mulberry nutrition.

VAM

VAM

VAM in root cell

VAM fungi in association with higher plants play an important role in phosphorus nutrition and increase plant growth and yield. Application of phosphorus @ 30 kg/ha/year as Mussorie Rock Phosphate (MRP) with Glomus mossae inoculation significantly increased the cocoon yield. Moreover, cocoon quality due to application of phosphorus @ 30 kg/ha/year in the form of MRP with G. mossae and G fasciculatum inoculation was statistically at par with plant receiving full dose of phosphorus (@ 120kg/ha/year) without VAM inoculation. Thus curtailing 75% of phosphorus application in mulberry cultivation and reduce of cost of cultivation. Combined inoculation of VAM with diazotropic Azospirillum brasileAdd captionnse yields more mulberry leaf biomass with high nutrient level than inoculation of individual organisms.

Phosphobacterium

Phospho bacterium

Similarly to VAM and PSM the Phosphobacterium when applied to the soil, it solubilizes the insoluble phosphorus in the soil to make it available to the plants for absorption. This helps in efficient use of Phosphorus and save application of Phosphorus. Many of the cultivated soils contain high amount of total phosphorus but availability is limited due to insoluble forms. Only water-soluble phosphorus is useful for the crop plants. Many bacteria are capable of solubilising insoluble soil phosphorus, of which the role played by Phosphorus Solubilizing Bacteria - Bacilus megatherium var phosphaticum is significant.

Organic Manures

With a view to minimize the use of chemical fertilizers, farmers are able to produce different organic manures and apply as part of IPN system. Recycling of Sericultural Farm Wastes as Compost: It was established that various composts prepared out of sericulture farm wastes on mulberry revealed that application of compost prepared out of silkworm rearing wastes @ 20 MT per hectare per year or application of recommended dose of farm yard manure (20 MT per hectare per year) and chemical fertilizers also produced same quantity of leaf as against the conventional farm yard manure and chemical fertilizers. Two years crop data showed significant increase in leaf yield (61.5 tonne/ha) with application of compost @ 4.5 tonne/ha/year in conjunction with full dose of chemical fertilizers. Compost application @ 4.5 MT/ha/year (Prepared from silkworm rearing waste mixed with biogas spent slurry) + 300: 120: 120 NPK kg/ha/year produced a leaf yield was 57.8 tonne /ha/year. The study indicates that the compost and vermi-compost produced out of sericulture wastes are qualitatively superior over FYM.

Fortification of Vermi-compost

Fortifications carried out by blending the sericultural wastes with microbial inoculum - Azotobacter, phosphate solubilizing microorganisms (PSM) and add rock phosphate and single super phosphate. The process of vermi-composting of sericultural wastes (200 kg/trench) was carried out by introducing a mixed culture of juvenile earthworms Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus @ 500 grams per trench. The chemical analysis of vermi-compost had organic carbon content ranged from 9.15 to 10.65%. NPK contents (2.45%; 1.75% and 1.17% respectively) was maximum in Semi decomposed sericultural farm wastes fortified with both S.S.P. and R.P. @ 12.5 kg each/MT of wastes and by inoculating with Azotobacter and P.S.M. Each cycle of vermi-composting was completed in 60 days compared to all other treatments.

Green Manure Compost

A large number of leguminous crops are used for green manuring in South India. Daincha (Sesbania aculeata), sunnhemp (Crotalaria juncea), wild indigo (Tephrosia purpurea), indigo (Indigofera tinctoria) and Pillipesara (Phaseolus trilobus) are the most popular crops with farmers. A number of other leguminous crops like cowpea, lablab, red gram; Crotalaria striata, etc., are also to able to fix atmospheric nitrogen and do not necessarily depend on the nitrogen in the soil. The phosphorus present in green manure is in organic combination and becomes available for use by mulberry in the succeeding harvests. Green manure decomposes easily without leaving much of the residue in the soil. The amount of humus added to the stock already in the soil is negligible. In this respect it is different from farm yard manure. If, however, the green manure crop is allowed to mature and is ploughed in, it decomposes slowly and some humus is added to the soil.

Pesticides of Plant Origin

One of the viable alternatives to chemical pesticides is the development and use of better botanical pesticides, which are environmentally safe, effective against pests, easy, and economic. As plants and insects have co-evolved over millions of years, they have accumulated specific secondary plant chemicals (SPCs) to counteract the insect damage. These bioactive chemicals include insecticides, anti-feedants, Insect Growth Regulators (IGRs), juvenile hormones, ecdysones, repellents, attractants, arrest ants, etc. Hence, plants are thought to be an important alternative source for chemical pesticides. Over the years more than 6000 species of plants have been screened and nearly 2400 plants belonging to 235 families were found to possess significant biological activity against insect pests.

Towards sustainable environment, health and development certain innovative technologies have been developed recently to control root rot diseases caused by Rhizoctonia bataticola (anamorph of Macrophomina phaseolina) on crops like mulberry, carrot, banana etc., it is well known that the soil borne pathogens cause severe damage to crops especially in tropical belt where the environment is suitable for the pathogen to survive and damage the host plants and complete their life cycle. A novel method was developed using plant bio-formulations, which are anti-fungistatic, and inhibitor of root rot fungal pathogen in soil. Some of the plant species, which are known to inhibit growth of fungus, like Guizotia abyssinica (L. f.) Cass. (ramtilla), Azadirachta indica A. Juss. (neem), Brassica juncea (L.) Czern. (India mustard) are inhibitors of fungal growth in soil up to 93%. A new formulation was developed ‘Navinya’ an eco-friendly plant based formulation, which was tested for its efficiency on host plants at hot spot areas where root rot is a major cause of damage to mulberry plantation. The formulation was effective in inhibiting the fungal pathogen in its spread and inhibits the growth and makes the plant recover, to support the host plant small quantity (8%) growth promoting substances like succinic acid, boric acid is added along with inorganic chemicals (12%) in the formulation. Among the 15 villages participated in the trials all found satisfied with the control of the disease in mulberry plantations.

‘ILAMATHI’- A Phytojuvenoid formulation for Silkworm

gkrajeshrajesh@gmail.com — Sun, 21 Aug 2011 05:03:00 +0000

Dr. N. Chandramohan, Professor (Retd), Dr. C. A. Mahalingam, Professor and Dr.S. Subramanian, Principal Scientist (at IARI, New Delhi)

The phyto juvenoid- Ilamathi developed by TNAU

Sericulture is a remunerative agro enterprise providing livelihood to millions of people in India. In order to meet our growing demand, the production and productivity of silk has to be improved.

Among various technologies to improve the cocoon productivity, application of juvenile hormone (JH) on silkworm is practiced in several silk producing countries. They tend to keep the Fifth instar silkworm young for a specified period by extending the larval period and increase the silk secretion. It postpones the spinning stage by few hours.

Altosid, R394, Manta and ZR512 are some of the commercial synthetic JH analogues used in countries like Japan and China. Synthetic JH analogues are hitherto not available for use by sericulturists in India. Moreover, the import of the chemical is cost prohibitive. Hence there is a need for identification of cost effective JH formulation for improving silk productivity.

Department of Sericulture, Tamil Nadu Agricultural University, Coimbatore has screened several plant products and short listed fewer plants possessing JH activity, (Phytojuvenoid) against silkworms. Extraction procedures were standardized and a novel botanical formulation was developed. Comparing the growth of silkworm to different phases of moon, the new formulation has been named ‘ILAMATHI’ (young moon) as it keeps the larvae young.

The botanical formulation was found to increase the larval duration, cocoon weight and there by yield of 25.16 percent followed by a collective analysis of research station and OFT showed an increase in cocoon and over control in OFT research station 9.15% cocoon yield was realized by farmers in On Farm Trials.

For treating 100 dfls (40,000 larvae) an additional cost of Rs. 165 was required. An additional yield of 9.48 kg of cocoon was harvested with a monetary return of Rs. 848 for every 100 dfls by was of phytojuvenoid treatment. The net gain is Rs. 684 with a increment cost benefit ratio (ICB) of 1:5:14.

Application Method
Product	TNAU Botanical formulation Ilamathi
Containers size	10ml vial
Time of application	2^nd day of fifth instar larvae
Dose	1ml / litre of water
Concentration	1000 ppm

1. It is applied on mulberry leaves after dissolving 5ml of Illamathi in five liters of water, and feed to 2 day old 5 instar worms.

2. Spray fluid is applied uniformly over the shoots/leaves (in tray rearing) with help of an atomizer (or) garden sprayer and allowed to dry for 30 minutes.

3. Treated leaves are given as two first feeding for the two days old fifth instar.

Caution

1. Don’t postpone the Illamathi application beyond second day of fifth instar.

Merits of ‘ILAMATHI’

1. Application of Illamathi gives an additional cocoon yield of 8kg/100 dfls.

2. It also reduces grasserie disease in silkworm.

3. The application of ‘ILAMATHI’ is safer to silkworm and it will not hinder the growth and development of the larvae. Besides, the formulation also confers resistance to BMNPV infection. Hence application of ‘ILAMATHI’ is a novel technology to boost the silk yield and silk productivity to the farmers of Tamil Nadu.

TNAU starts BSc Sericulture course

gkrajeshrajesh@gmail.com — Sun, 07 Aug 2011 17:14:00 +0000

Prof. (Dr.) CA. Mahalingam

Universities, apart from their pedagogical role, as centers for fundamental academic research are vital to agricultural research and development. The sericulture sub sector of Indian agriculture has been a beneficiary to this. Indian sericulture has received kind attention of her agricultural universities, located at those places known for sericulture. University of Agricultural Sciences (UAS) Bangalore and Tamil Nadu Agriculture University (TNAU) are prime examples. Both these institutes have been training manpower for research and extension for long. UAS, Bangalore has been conducting an under graduate program - BSc Sericulture for past few decades. This four year’s graduate degree program has produced a prodigious volume of alumni who decorate coveted positions in the industry. An academic program need not necessarily ensure job placements to its takers. However the quality of the curriculum and its administration are very important in throwing open employment opportunities for students who opt it. Agricultural Universities are hot spots for admission seekers not just because agriculture is a very important discipline. The multiplicity of job opportunities available in public and private sector is an important reason. Recently TNAU has started a BSc sericulture program. We interviewed Prof. (Dr) CA. Mahalingam of Sericulture Department, Tamil Nadu Agricultural University regarding their new initiative.

In the given scenario of declining sericulture and falling prices for sericultural produce, what is the scope of sericulture in Tamil Nadu?

Yes sericulture is declining area-wise. Statistical data show that area has decreased many folds but the production and productivity has increased many folds too. Thanks to the many latest technologies right from Mulberry Nursery to User friendly mountages to Automatic reeling machines to Computer aided weaving designs. In Tamil Nadu after a decline in area due to Papaya mealy-bug during past two years, at present the increase in area is being witnessed. In Karnataka the area is declining but there are lots of reasons for this, one important reason is their mind block in adopting newer technologies.

Prices have not dropped very low during the past five years. There was one low during 2006. But now that due to wrong policy of government (to decrease the import duty of silk) has created some melee. But even after that the prices have stabilized now and it is around Rs. 180 for MV and Rs.240 for BV which is little above Rs. 100 profit for every kg of cocoon. The prices will remain like this atleast for another 4-5 years, keeping in view the growing demand.

The TNAU campus at Coimbatore

Is there a declining trend in employment opportunities for those who are qualified in sericulture? How is the curriculum for the new course designed to meet this challenge?

I take this argument in another form. The opportunities for any graduate, for that matter are not promising. Though all the undergraduates in TNAU passed out during past few years got employed, I can say that they are not employed in either government sector or directly with farming sector. Of course, I agree that efforts have to be made to get sericulture graduates given preference and opportunities in Central Silk Board, State Departments of Sericulture and other sericulture oriented industries.

The syllabus for BSc sericulture is formulated in such a way that 50 % courses are common to agriculture graduates and sericulture graduates, and both of them learn the same basic courses. Only from third year onwards sericulture graduates learn specialized subjects on sericulture. This will empower them to compete along with agriculture graduates in every aspect either for higher education or for job.

Why should a student choose BSc sericulture? - to be a trained farmer? Extension officer? Researcher? Do your program stress on biotechnology?

For the basic degree program, there is no much stress on biotech and molecular biology except for few introductory courses to expose them to the technology. In answering thesecond question, I suggest you to read the following article by Himanshu Pal: Government Jobs after B Sc Sericulture . As I have already said there is no direct employment for any graduate. Any graduate is armed with quality education either to become an entrepreneur (farmer?), a government officer (state or central government or private companies – extension worker?) or scientist (in SAU or CSB or private firms – researcher?).

The Syllubus and Curriculum of the BSc Sericulture course offered by TNAU can be downloaded HERE

Effect of supplementing mulberry leaves with Phyllanthus emblica L. fruit extract on the silkworm Bombyx mori L

gkrajeshrajesh@gmail.com — Wed, 01 Jun 2011 16:21:00 +0000

GK. Rajesh

Scientific Advisor, Council for Nature Conservation and Environmental Protection, CONCEPT, India

Introduction

It is well established fact that ascorbic acid plays an important role in the nutrition of silkworm. It acts as both phago stimulant and nutrient o silkworm (Ito, 1960). Karaksy (1985) showed that ascorbic acid increases silk yield of the mulberry silkworm. Mulberry leaf itself is a rich source of ascorbic acid and contains about 1.8 mg. per gram of leaf (Legay, 1958). However Karaksy (1990) showed that silkworms fed on mulberry leaves enriched with ascorbic acid showed better growth and produced heavier cocoons. Similar observations were made by Madhu Babu (1992)

Goose berry (Phyllanthus emblica L.) is one of the richest sources of ascorbic acid. Barthakur and Arnold (1991) estimated that the berry contain 5889 ppm. Ascorbic acid. Apart from this the berry contain sugars, various minerals, amino acids and vitamins etc all of which play important role in the nutrition of silkworm and silk production (Shyamala and Bhat, 1965; Subbu Rathinam and Sulochana Chetty, 1990; Ito, 1960; and Ito, 1966). In the current experiment mulberry leaves were supplemented with goose berry extract to study its effect on growth and silk production of silkworm.

Material and methods

Mature fruits of Phyllanthus emblica were procured from the department of Horticulture, University of Agricultural Sciences, Bangalore. The fruits were crushed in a stone mortar and the juice extracted through a cheese cloth was collected in amber coloured bottles and corked air tight. From the extract 20%, 40%, 60% and 100% concentrations were prepared using distilled water as diluents. The pH of the various concentrations prepared were 4.2, 2.75, 2.73 and 2.68 respectively. Each concentration served as a treatment. A distilled water control and another control without water were also maintained. Each treatment was replicated thrice. The concentrations were prepared every day fresh and were kept under room temperature. Mulberry leaves were dipped in these solutions shade dried and fed to the larvae twice a day, other feeds being un treated.

The experiment was conducted on 360 fifth instar larvae of C-Nichi race of Bombyx mori reared as recommented by Dandin et al. (2000). Each replication carried twenty larvae. The larvae were fed on mulberry variety M5.

The observations made were: weight of five mature larvae, 5 pupae, shell weight of 5 cocoons and gain in larval weight. The data was statistically analysed.

Results and discussion

The mature larval weight did not differ significantly among the treatments. Gain in larval weight was significantly higher in control (without water), other treatments on par with each other. Pupal weight was significantly higher in the 20% solution treatment, other treatments being on par with each other. Cocoon shell weight did not differ significantly among treatments.

It was observed that the larvae did not relish the leaves treated with higher concentrations. This may be due to the low pH. It is also observed that the larvae fed on higher concentrations had longer larval duration, took more time for pupation and showed pupal deformities and high post cocoon mortality. Some larvae remained inside the cocoon without undergoing pupation. Lower concentrations did not affect pupation.

These observations call for further investigations in the same line using lower concentrations of the emblica fruit extract as a food additive to silkworms, to prolong laraval duration and to mprove silk yield.

References

Barthakur,N.N;1991, Chemcal analysis f the emblica (Phyllanthus emblica L.) and its potential as a food source, Scientia Horticlture. 47: 99-105

Dandin, S.B; Jayant Jayaswal and K. Giridhar ;2000, Handbook of Sericulture Technologies, Central silk Board, p. 195-218

Ito, T; 1960, Effect of sugars on feeding of larva of the silkworm Bombyx mori. L. J. Insect. Physiol. 5: 95-107

Ito, T; 1961, Effect of dietary ascorbic acid on the silkworm Bombyx mori. L; Nature, 192: 951

Ito,T. 1978. Silkworm nutrition: In the Silkworm an Important Laboratory Tool. Tazima,Y.(Ed.) Kodansha Ltd, Tokyo. 121-157.

Karaksy, I.A and Idris, M; 1990, Ascorbic acid enhances the silk yield of the mulberry silkworm. Bombyx mori. L. J. Appl. Ent. 109: 81-86

Karaksy, I.A; 1985, The effect of ascorbic acid on silkworm Bombyx mori. L, Alexandria J. Agric. Res. 30(2):1023-30

Legay, J.M.1958. Recent advances in silkworm nutrition. Ann.Rev.Ent.,3:75-86.

Madhu Babu. Et. Al; 1992, Effect of Ascorbic acid enriched mulberry leaves on rearing of Bombyx mori. L. Indian J. Seric. 31:111-114

Ranganna, S; 1977, Manual of Analysis of Fruits and Vegetable Products. Tata Mc. Graw Hill pub. Co. Ltd. New delhi. Pp.257

Sbburathinam, K.M and Sulochana Chetty, J; 1991, Effect of fortification of mulberry leaves with minerals to silkworm Bombyx mori. L. Indian j. Seric. 30:121-23

Shyamala, M.B and Bhat, J.V; 1965, Mneral assimilation in the silkworm Bombyx mori. L. Indian. J. Exp. Biol. 4:31-34

Interview 5

gkrajeshrajesh@gmail.com — Wed, 01 Jun 2011 09:25:00 +0000

Interview 4

gkrajeshrajesh@gmail.com — Wed, 01 Jun 2011 09:25:00 +0000

Interview 3

gkrajeshrajesh@gmail.com — Wed, 01 Jun 2011 09:24:00 +0000

being uploaded

Prospect of endophyte mediated disease management in mulberry

gkrajeshrajesh@gmail.com — Sun, 29 May 2011 17:33:00 +0000

J. Justin Kumar

Mr. J. Justin Kumar works with Central Sericultural Research and Training Institute, Mysore, India. His research interests include silkworm pathology and application of bio-molecules in silkworm disease management. Mr. Justin Kumar can be contacted at justinkumarj@gmail.com

Introduction

Endophytes are fungi or bacteria occurring inside plant tissues without showing any apparent symptoms by the host (Wilson, 1995). Together with mycorrhizal fungi, endophytes form an integral part of the extended phenotype or symbiotic community of a plant (Whitham, et al., 2003). They are ubiquitous and the association of endophytic organisms with their host plants is intricate (Tadych and White, 2009). A single leaf or root of a plant can harbor different species of endophytes. Thousands of endophytes are reported to be useful to mankind (Tan and Zou, 2001; Strobel, 2002; Strobel and Daisy, 2003). Many compounds of endophytic microbes have been used in agriculture, medicine, and industry. Endophytes also play important roles in the ecology of plant communities, resistance to insects and diseases, increase plants’ capacity to absorb water and minerals, and augment their ability to withstand dry periods.

Sericulture could immensely benefit from the endophytes. Providing quality feed, standard rearing conditions, protection from diseases and pests to the host plant as well as to the insect are the basic conditions for successful silkworm rearing. In this regard, the endophytes can play a vital role in the quality leaf production from mulberry (Morus alba L.), the sole food plant of the silkworm (Bombyx mori L). Probably the first report of endophyte isolated from mulberry is by Sato, et al., (2000), and the bacterial strain they reported Xanthomonas compestris was non pathogenic one. Improved plant growth, higher nutrient content, resistance to insect pests and herbivores, resistance or tolerance to diseases, increased competitiveness, enhanced tolerance to stressful factors such as heavy metals, low pH, high salinity, etc., are the benefits from the endophytic interaction.

Mulberry diseases and its management

Foliar and soil borne diseases are a major constraint in the production of quality mulberry leaf. Major diseases in mulberry are the following

Cultural, mechanical, agrochemical and biological approaches employed to control the mulberry diseases individually or in combination as integrated approach. Though agrochemicals are effective for the disease control, the residual toxicity to the silkworm and environmental constraints have made it imperative to search for biological remedial measures. In this direction a lot of antagonistic microbes were studied for the control of diseases. But these microbes are affected by biotic and abiotic factors and its effectiveness has been inconsistent. Under these circumstances, the endophytes have received much attention for its use as biocontrol agents. The advantage is that, once inside the host, they are better protected against environmental stress and microbial competition. Further, some of the endophytes produce endospores, which can be formulated and stored (Ji, et al., 2008). Studies have been conducted on the application of endophytic Bacillus strains for the control of soilborne pathogens in many agricultural crops.

It is interesting to note that in many other crops/plants, the endophytes are being isolated and tested and found effective against pathogenic microbes, which is indicated in the table.

Prospects in mulberry disease management

Ji, et al., (2008) have made an attempt to control Ralstonia solanacearum (Smith) the soil borne bacteria, causing wilt disease in mulberry. They showed that the Bacillus subtilis strain Lu144 effectively reduced the bacterial wilt of mulberry when it was applied to sterile or non sterile soil before the infection by the pathogens. Mu, et al., (2008) have succeeded in colonizing an antagonistic bacteria Burkholderia cepacia strain Lu10-1, isolated from healthy mulberry by acupuncturing, seed soaking, root soaking and leaf daubing. They suggested that this strain can play an important role in the biological control of mulberry diseases. Ji, et al., (2010) have reported that the B. cepacia strain Lu10-1 can multiply and spread in mulberry seedlings rapidly and efficiently. They found that the strain is antagonistic to Colletotrichium dematium, the anthracnose causing pathogen. It is an indication that there is a lot of scope for further studies for effective utilization of endophytes of mulberry or other plants in the mulberry disease management. The possible challenges may be

Identification and isolation of suitable endophytes
Colonization of such endophytes to mulberry
Safeguard against loss of palatability to silkworm during such colonization

Though the endophytic studies have gained momentum in the recent past, it holds a lot of promises for resolving many problems confronted in the agriculture and medical fields. Though a large number of endophytes are host specific and unique, there are a number of endophytes which can be found in many species of plants, and hence holds a promise that such candidates are accessible for experimenting in the sericulture field, whether for host plant improvement of silk insects or on the silk insects itself! Search for novel endophytes existing in the host plants, enumerating and striking its potential holds the key to success.

References

Aly AH, Edrada ER, Wray V, Muller Werner EG, Kozytska S, Hentschel U, Proksch P, Ebel R (2008). Bioactive metabolites from the endophytic fungus Ampelomyces sp. isolated from the medicinal plant Urospermum picroides. Phytochemistry, 69: 1716-1725.

Araujo WL, Marcon J, Maccheroni W Jr, Van Elsas JD, Van Vuurde JWL and Azevedo JL (2002). Diversity of endophytic bacterial populations and their interaction with Xylella fastidiosa in citrus plants. Appl. Environ. Microbiol. 68:4906-4914.

Atmosukarto I, Castillo U, Hess WM, Sears J, Strobel G (2005). Isolation and characterization of Muscodor albus I-41.3s, a volatile antibiotic producing fungus. Plant Sci., 169: 854-861.

Berg G, Krechel A, Ditz M, Sikora RA, Ulrich A and Hallmann J (2005). Endophytic and ectophytic potato-associated bacterial communities differ in structure and antagonistic function against plant pathogenic fungi. FEMS (Fed. Eur. Microbiol. Soc.) Microbiol. Ecol. 51:215-229.

Ji X, Lu G, Gai Y, Gao H, Lu B, Kong L and Mu Z (2010). Colonisation of Morus alba L. by the plant-growth-promoting and antagonistic bacterium Burkholderia cepacia strain Lu10-1. BMC Microbiology, 2010, 10:243. doi: http://www.biomed central.com/1471-2180/10/243.

Ji X, Lu G, Gai Y, Zheng C and Mu Z (2008). Biological control against bacterial wilt and colonization of mulberry by an endophytic Bacillus strain. FEMS Microbiol. Ecol. 65: 565-573.

Kim S, Shin DS, Lee T, Oh KB (2004). Periconicins, two new fusicoccane diterpenes produced by an endophytic fungus Periconia sp. with antibacterial activity. J. Nat. Prod. 67: 448-450.

Mu Z, Lu G, Ji X, Gai Y, Wang Y, Gao H and Cha C (2008). Identification and colonization of an antagonistic endophyte Burkholderia cepacia Lu10-1 isolated from mulberry. Acta Microbiologica Sinica, 48: 623-630. [Chinese]

Newman LA, Reynolds CM (2005). Bacteria and phytoremediation: new uses for endophytic bacteria in plants. Trends Biotechnol. 23: 6-8.

Sato M, Wei W, Kawakita H and Yamanouchi H (2000). Isolation and characterization of bacteria from colonies exuded from “germ-free” mulberry shoots cultured in vitro. J. Seric. Sci. Jpn. 69(2): 147-152.

Silva GH, Teles HL, Zanardi LM, Marx Young MC, Eberlin MN, Hadad R, Pfenning LH, Costa-Neto CM, Castro-Gamboa I, Bolzani YS, Araújo AR (2006). Cadinane sesquiterpenoids of Phomopsis cassiae, an endophytic fungus associated with Cassia spectabilis (Leguminosae). Phytochemistry, 67: 1964-1969.

Strobel G and Daisy B (2003). Biopropsecting for Microbial Endophytes and Their Natural Products. Microbiol. Molecular Biol. Rev. 67(4): 491-502.

Strobel GA (2002). Microbial gifts from rain forests. Can. J. Plant. Pathol. 24: 14-20.

Tadych M, and White JF (2009). Endophytic Microbes. Encyclopedia of Microbiology (Third Edition). p. 431-442.

Tan RX and Zou WX (2001). Endophytes: a rich source of functional metabolites. Nat Prod Rep. 18(4):448-59.

Whitham, T.G., Martinsen, G.D., Young, W., Gehring, C.A., Schweitzer, J.A., Wimp, G.M., Bailey, J.K., Fischer, D.G.., Lindroth, R. and P. Keim. (2003). Community and ecosystem genetics: A consequence of the extended phenotype. Ecology, 84: 559-573.

Wicklow DT, Roth S, Deyrup ST, Gloer JB (2005). A protective endophyte of maize: Acremonium zeae antibiotics inhibitory to Aspergillus flavus and Fusarium verticillioides. Mycol. Res., 109(5): 610-618.

Wilson, D. (1995). Endophyte: the evolution of a term, and clariﬁcation of its use and deﬁnition. Oikos 73, 274–276.

You F, Han T, Wu JZ, Huang BK, Qin LP (2009). Antifungal secondary metabolites from endophytic Verticillium sp. Biochem. Syst. Ecol., 37: 162-165

Indian Sericulture- Past glory and future challenges

gkrajeshrajesh@gmail.com — Sat, 28 May 2011 16:00:00 +0000

GK. Rajesh

Scientific Advisor, Council for Nature Conservation and Environmental Protection, CONCEPT India

This paper attempts to take a comprehensive look at the Indian silk industry and to identify the key issues of the sector. The impact of silk imports on domestic silk industry and sericulture are analyzed based on available data up to the year 2005. While the paper doesn’t offer any solutions for the problems, a few issues are thrown up which call for immediate research attention. The available (very few) studies on the economic issues of Indian silk industry are reviewed. The analysis has been restricted up to the year 2005 considering the fact that no much change has taken place in the industry since then.

Silk has a miniscule percentage of the global textile fibre market- less than 0.2%. But this figure can be a gross under-estimation, since the actual trading value of silk and silk products is much more. The unit price for raw silk is roughly twenty times that of raw cotton. The annual turnover of the China National Silk Import and Export Corporation alone is US$ 2–2.5 billion (ITC Silk review, 2001).

Sericulture has important socio-cultural implications. Studies have established large scale employment generation potential and high income generation potential of sericulture (Hanumappa, 1986). Jayaram et.al (1998) showed that every acre of sericulture practiced under irrigated conditions had a potential to employ 247 men and 193 women round the year. They have also shown that the small scale mulberry farms provided ample scope for employment of owned family labour and suggested its potential to solve the problem of seasonal unemployment. Lakshmanan et.al; (1999) found that female labour is quite dominant in all sericultural activities, to an extent of nearly 50%. Saraswathi and Sumangala (2001) observed that in the indoor activity of silkworm rearing women participation was as high as 94.67 % and that except for the peak period the entire sericultural activity is conducted using family labour. Most of the activities in silk production are in the informal sector and menial in nature. Thus about 90% of the employment goes either to the landless or to the marginal farming families that hire out these labour, or to the sericulture families (Sinha, 1989). While considering the price spread in the whole industry, it can be seen that 48% of it goes to farming sector, as illustrated below.

Sericulture and silk production are labour-intensive at the village level, employing both men and women at all stages of production (note-1). In China, it occupies some 20 million farmers, as well as 5 lakh people in the silk processing industry (ITC silk review 2001). In India, sericulture is a cottage industry in 59,000 villages, providing full and part-time employment to some six million people from the farm sector, and silk processing industry (ITC silk review 2001).

Sericulture in India – it’s past and present.

The silk trade flourished in India during the medieval period. Under the Moughals, silks from Kashmir and Bengal were exported mainly by the Moors, who during the 14^th and 15^th centuries transmitted it to Europe (Nanavaty, 1990). The British had identified the qualitative shortcoming with Indian silk and tried to improve it by bringing experts to modernize the rearing and reeling techniques. In 1771, the ‘China worm’ was introduced with the idea of improving cocoon quality. The government promoted the extension of land under sericulture. Rent was slashed by half for those lands, and that too was exempt for the first two years of cultivation. The government also promoted a higher wage structure for processing raw silk (Ray Indrajit, 2005). Technology was substantially improved in conformity with the European know-how and practices so that British weavers accepted raw silk of Bengal. In fact, the overseas market responded very favorably to the first consignment of the new technology in 1772 (Ray Indrajit, 2005). The government was also successful in diffusing Chinese worms in sericulture. Another breakthrough was achieved in the sphere of the production system. The government successfully organized sericulture as a cottage industry. The industry’s technology and organization were thus thoroughly reformed by the close of the eighteenth century in tandem with the requirements of the European market. Consequent to the abolition of British East India Company’s monopoly on private trade the company wound up its silk trade in 1833, leaving it to private entrepreneurs. During the last quarter of 19^th century Bengal silk began to decline due to lack of proper organization, husbanding authority and the absence of technical know how (Ray Indrajit, 2005).

Hanumappa and Erappa (1988) cites sericulture development in the princely state of Mysore as an example of the crucial role the state can play in augmenting the sources of rural income. Sericulture flourished in Mysore during the 18^th century under Tipu Sultan. The technology was transferred from Bengal. Japanese and Italian silkworm strains were imported and experts hired from these countries (Nanavaty, 1990). Spread of diseases during 1866 and the world depression in 1929 along with competition from imported silk and rayon lead to downfall of Indian silk industry on the eve of World War II. A tariff protection commenced from 1934 to save the industry from cheap imports of silk (National Commission of Agriculture, 1976). Durng the World War II, the Indian silk industry again surged, mainly due to demand from the Allies for silk for manufacture of parachutes (note- 2).

The first authentic inquiry into the conditions of Indian silk industry was undertaken in 1914-15 by H. Maxwell Lefroy and E. C. Ansorge (Lefroy and Ansorge, 1915). In a report they observed that the industry was scattered and unorganized producers were subjected to exploitation. They suggested formation of a central organization to address the needs of the industry (Lefroy and Ansorge, 1915). Subsequent recommendations by a Silk Panel in 1946 lead to the formation of the Central Silk Board in 1949.

Central Silk Board (CSB) is a statutory body, under the administrative control of the Ministry of Textiles, Government of India. One of the earliest commodity boards to be constituted by the Government of India, the Board coordinates the development of sericulture and advises the Government on policies governing export and import. It has the responsibility for pre-shipment inspection of silk goods exported from the country. The Board is also responsible for organizing sericultural research, training, basic seed (egg) production and collection of statistics pertaining to sericulture and silk industry (National Commission of Agriculture, 1976 and Gopalachar, 1978).

The Central Silk Board (CSB) established a number of sericulture research institutions in 1960s. With systematic efforts, it became possible in 1970s to develop a technology suitable for tropics. New mulberry varieties coupled with agronomical practices were made available to the farmers. Packages of practice were developed for silkworm rearing, besides realising new bivoltine races. Popularisation of the bivoltine hybrids was given priority. Since seed preparers started using bivoltine as a male parent for the preparation of cross breeds, the traditional poor yield crosses have been replaced to the extent of 85%. Consequent to this, mulberry sericulture was spread to non- traditional states like Kerala, Maharashtra, Rajasthan and Gujarat in the 1980s. While other crops (grains) perish due to very little precipitation, mulberry survives such acute situation where ground water is also not available for raising the crops, thus providing subsistence to a large number of farmers (National Commission of Agriculture, 1976).

Currently in India mulberry silk is chiefly produced in 5 states viz. Karnataka, Andhra Pradesh , Tamilnadu , West Bengal and Jammu & Kashmir, contributing to about 99% of the total mulberry silk produced. Interestingly, the states of A.P and T.N with almost no silk production during 1960 (Vasumathi, 2000), currently occupy the second and fourth position respectively. West Bengal at present contributes about 11.8% of the total cocoon / silk production, while Karnataka contributes the lion's share (43.95%) with Andhra Pradesh and Tamilnadu contributing 38 % and 4 % respectively. Production statistics up to 2005 is furnished in table 1.

Inability to exploit export potential

Table 2 gives India’s export, import and demand supply gap. The annual production of raw silk in India was 17305 tons, of which mulberry raw silk alone accounts for 15445 tons in 2005. The demand for raw silk was much higher than the production at 10180 tons. Hence, India imported 10538 tons of raw silk in 2005. The imports have steadily increased from 6015 tons in 2000 to 10538 tons in 2005 representing a compound annual growth rate of 9.8%, against a mere 0.25% compound growth rate in production. Over the five year period the demand supply gap has increased by 73%. The imports as a percentage of production have increased from 39% to 68%. This analysis indicate that India has neither been able to meet the increasing demand for silk in the domestic market by increasing domestic silk production, nor to exploit the huge export potential; instead resorted to rawsilk imports to fill the domestic demand supply gap.

Table 3 gives India’s export earnings from silk (all commodities) over the period 2000 to 2005. It is seen that though the silk exports showed a compound growth rate of 7.95% over the years, its percentage share in total textile exports from the country has been stagnant over the years.

Table 4 gives the value of silk and other textiles imported by India over the years. The percentage share of silk in the total textiles import has increased over the 6 years by 5.7%, whereas the net foreign exchange earning from export and imports has remained stagnant.

From the above analysis it is clear that even after being the second largest producer of silk, India contributes only 16% of global silk production and it is the largest importer of rawsilk. India has been unable to meet the increasing demand for rawsilk by the domestic industry through increasing domestic supply. This is because of two reasons namely low productivity and low quality.

Impact of cheap imports on domestic industry

Apart from India’s inability to exploit the export potentials and dependency on imported raw material, another grave issue is pertaining to cheap imports of raw materials ruining the domestic sericulture industry. It is reported that Chinese raw silk and silk fabrics are reportedly being imported into the country at very low prices (Tikku, 1999).

The data furnished in table 4 reveal that the rawsilk imports to India increased from 7896 tons in 2001, to 10506 tons in 2002, which is a 33% increase in one year. During the subsequent year the domestic silk production fell by 5.6% (from 17351 tons of 2002 to 16369 tons of 2003).The domestic silk production further fell by 10% (from 16369 tons of 2003 to 14620 tons of 2004).

Table 5 compares the annual growth rate in rawsilk imports for five years from 2000 against the performance of Indian sericulture industry and reeling sector to generate an idea about the comparative dynamics (Note:3).

It is seen that the growth rate of silk imports were very high from 1999 to 2003 except for 2000-01. The growth rate in the value of imported silk (in Indian Rupee terms) has been lower than that of quantity of imports. The prices of domestic rawsilk and cocoon are observed to be worst affected during the years 2001-02 and 2002-03, the periods in which imports grew very high and prices of imported silk kept falling. Thomas et. al (2005a) showed that the cocoon price get influenced by the yarn prices with a lag of six to ten days. From the table 5, it is clear that during 2001-02 and 2002-03 when domestic rawsilk prices fell by 4.9% and 24.1 % respectively, the cocoon price also fell by 4.8% and 10.8%. This has impacted on cocoon production, lowering it by 8.2% and 8.4% during 2002-03 and 2003-04 respectively. The data shows that the effect of imports influenced the mulberry plantation also. During 2002-03 in Karnataka alone 23% of the existing mulberry plantations were uprooted and in the subsequent year another 10% uprooting occurred. 6780 charka reeling units have closed down over the six years where as the number of cottage basin reeling units have increased by 846 only. The number of multi-end reeling units has also fallen by 59. This means considerable labour displacement from the charka sector during the six years which is not likely due to up gradation of the charka units into cottage basins.

The fall in: prices, quantity of cocoon production and mulberry area and labour displacement from the reeling sector cannot be completely attributed to the rawsilk import. Many other socio economic factors could be at play. However it is seen that subsequent to a protectionist intervention of the government during 2003, the quantity of imports fell by 2.3%, domestic rawsilk prices increased from Rs. 805.00 to Rs. 984.00 per kg (22.2% growth) and cocoon prices increased by 17.8% (note-4). During the subsequent year the quantity of cocoon production showed slight improvement (2.2% growth) and the mulberry uprooting rate came down from 10.26% to 2.23%. This indicates that the silk imports have had a deleterious effect on the domestic sericulture.

It is generally held that the imported rawsilk is consumed by the powerlooms since power looms require qualitatively superior and strong yarn for the warp and the relatively poor quality local yarn is fit for the weft only (Thomas e.al, 2005b and Vasumathi, 2000).

Table 6 gives the growth rate of rawsilk imports over 6 years from 1999-00 against number of handlooms and power looms in the country. It is seen that the number of power looms have stagnated at 29340 over the years and the number of handlooms have increased by 30299 during 2001-02. The rawsilk imports have been in the increase. Thomas et.al. (2005b) found that only 50-53% of the yarn requirement of the power loom sector is met from Chinese imports. Thus it may be inferred that a considerable portion of the imported yarn is being absorbed by the handloom sector also, which is traditionally known as the sole consumer of charka silk (Vasumathi, 2000).

A study conducted by Thomas et.al. (2005b) revealed the pattern of rawsilk usage as given in table 7

Thomas et.al. (2005b) also have shown that the imported Chinese silk is superior to the locally available silk with respect to denier, cleanness, cohesion, gumming losses and uniformity. Table .8 presents a comparison of imported silk with local silk based on these attributes.

Naik .G & Babu (1993) have estimated that the total high quality silk production in India could meet at the most 60 percent of the estimated demand and have cautioned about the negative implications of the Chinese raw silk on the development of Indian silk industry. They also noted that diversion of imported silk into domestic sector benefit only the consumer. By avoiding this diversion, the demand for domestically produced high quality silk would have increased the good health of the industry. Some of their recommendations for amelioration of the current situation include - improvement in research and extension facility, adequate supply of inputs and proper marketing facilities and modifications in the production system.

Summary and conclusion

In spite of its small volume in global textile production, silk has importance in developing economies primarily because of its favorable socio economic consequences. The development of sericulture had been the states priority in every country. The case of Indian sericulture is no exception to this. A number of regulations were made in favor of the farm sector. Many ambitious projects were launched and a large number of technologies made available. In spite of all this, poor productivity, poor quality, high cost of production and labour intensity continue to be the hall marks of Indian silk industry. In order to cater to the needs of sophisticated power-looms and in response to the relaxation in exim policies, large quantities of high quality silk has been imported at prices lower to local silk. This has disrupted the domestic silk reeling industry and sericulture farm sector, leading to considerable labour displacement. Protectionist government interventions have temporarily eased the problem. But how long tariff protections could help the domestic industry is a question. Data shows that imported silk is finding place even on the traditional handlooms, clearly demonstrating its comparative advantage. The recent data shows that the price of imported silk is in the increase while the government has announced a slash in customs duty of raw silk imports from 30% to 5%. While the farmers and reelers staged an agitation the weaving sector welcome the gesture. Thus the industry is divided in its opinion on cheap imports, indicating the necessity for the government to take appropriate policy decisions. Where does our comparative advantage lie? Is it in the sericulture farm sector or in the silk weaving industry? If the farm sector has to survive, is it sufficiently equipped to take up the challenge of ensuring high quality raw material supply? If this is ensured, is the silk reeling sector capable of absorbing the high quality cocoons? These are the questions that the Indian silk industry has to answer before proceeding any further.

Notes

While considering patterns of location of sericulture, Federico (1997) observed, “……. . the ideal environment for silkworm raising was densely populated area, with dispersed dwellings and few opportunities for non-agricultural work. It is not surprising that sericulture did not develop at all where the population was scarce and labour, expensive (as in the United States) or where people lived in large villages far from the fields (as in the interior of Sicily or Spain)……..Silkworm raising does not need strength but does require much care and caution in handling the worms, which are exteremely delicate animals, very sensitive to any form of ill-treatment and /or sudden change of temperature. Therefore sericulture was traditionally women’s work, while men cultivated the mulberry trees and sometimes helped to transport the leaves.”
The industry in Mysore doubled its pre-war size. Mulberry acrage rose from 26500 to 80000. Number of filature basins in Mysore and Madras rose from 300 (in 1939) to over 2000 (in 1945). Filature silk production rose from 2300 kg(1937) to 137000 kg (1945) (Nanavaty, 1990)
The majority of silk produced in India is through charka, the traditional reeling device and less sophisticated cottage basin reeling units. Semi and fully automatic reeling machines are used to produce high quality silk in Japan, Korea and China. Multi-end reeling machines have been developed and popularized in India to produce high quality silk which need good quality cocoons of uniform size and shape as raw material
Antidumping investigations were undertaken by Directorate General of Anti-Dumping and allied Duties (DGAD&AD) on a petition by the reelers affected by the falling domestic prices. The designated authority imposed antidumping duty on landed goods so as to raise import prices to US$ 27.97 per kg.on all imports of mulberry raw silk of 2A grade and below originating in or exported from Peoples Republic of China. The duty came into force wef. 3^rd July 2003. (Ministry of Textiles, Government of India, 2007)

REFERENCES

Gopalachar, A.R.S. (1978) 3 Decades of Sericultural Progress (Sericulture Industry in

India

Potential and Prospects) pub. Central silk Board, India.

Hanumappa, H.G. and Erappa, S. (1988) Sericulture in Princely Mysore (1914-1945) a Survey. Paper presented at Seminar on South Indian Economy,C. 1914-C. 1945. CDS, Trivandrum, April, 25-28, 1988.

Hanumappa,H.G., and Erappa, S. (1986) Economic issues in sericulture: Study of Karnataka. ”Economic and Political Weekly” 20(31)1322-1324.

ITC Silk Review (2001) http://www.intracen.org/

Jayaram, H., Mallikarjuna, V., Lakshmanan, S., Ganapathi, Rao, R. and Geetha, Devi, R. G. (1998) Labour Employment Under Different Mulberry Farm Holdings-a Comparative Study. Indian Journal of Sericulture, 37(01), p52-56.

Lakshman, S; B. Mallikarjuna., R. Ganapathi Rao; H. Jayaram and R.G. Geetha Devi (1999) An empirical investigation on labour productivity in mulberry sericulture. “Indian journal of Sericulture” 38(1) 48-52

Lefroy, MaxWell, H. and E.C. Ansorge (1915) Report on an Inquiry into the Silk Industry in

India

(1915), Vol. I, Calcutta,

Mattigatti, R; Srinivasa, G; Iyengar, M.N.S; Datta, R.K. and Geetha Devi, R.G (2000) Price spread in silk industry- an economic analysis. “Indian Journal of Sericulture” 39(2) 163-64

Naik Gopal and Babu KH, (1993), Demand and Supply Prospects for High Quality Silk,Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi.

Nanavathy, M. (1990) Silk, Production, Procesing and Marketting, Pub: Wilely Eastern Ltd.

National Commission of Agriculture (1976) Report of the National Commission on Agriculture, sericulture and apiculture; Government of India, Ministry of Agriculture and Irrigation, New Delhi. P.447-480

Ray, Indrajit (2005) The Silk Industry In Bengal During Colonial Rule: The De-Industrialisation. Thesis Revisited. Indian Economic Social History Review; 42; 339

Saraswathi, J.M. and Sumangala, P.R. (2001) Participation of Farm Women In Sericulture Enterprise. “Indian Journal of Sericulture” 40(1) 86-91

Sinha, Sanjay (1989) Development Impact Of Silk Production, A Wealth Of Opportunities. “Economic and Political Weekly,” January 21, 157-163.

Thomas Jacob, Arun Kumar, K.S, Reddy and Lalith. A (2005a) Quantification of Relationship Between Silk Cocoon and Silk Yarn Prices- an Application of ARIMA Model. In Reading in Sericulture Economics Marketing and Management. Eds. K.S. Arun Kumar, R.K. Datta and G. srinivas. Pub: Santhosh Creations, Bangalore.

Thomas, Jacob., Arun Kumar, K.S, Lalith. A and Reddy.S (2005b) Requirement of Quality Silk Yarn of The Power Loom Sector-A Quantitative Analysis. In Reading In Sericulture Economics Marketing And Management. Eds. K.S. Arun Kumar, R.K. Datta and G. Srinivas. Pub: Santhosh Creations, Bangalore.

Tikku, M.K. (1999) Tangled Threads Silk Growers and Imports. Economic and Political Weekly, March 6-13, p. 578

United Nations (1994) “Silks In Asia,” Economic and Social Commission for Asia and the Pacific.

Vasumathi ( 2000) An Analytical Study Of The Silk Reeling Operations In Karnataka.

INTERCROPPING IN MULBERRY WITH CEREALS, PULSES AND OIL SEEDS UNDER RAINFED CONDITIONS OF CHAMARAJANAGAR DISTRICT

gkrajeshrajesh@gmail.com — Sat, 02 Apr 2011 07:55:00 +0000

P.K.Das, R.Gururaj, S.B.Magadum, C. Doreswamy , Shivashankar Murthy

The first & third authors have retired as Scientist-D in November & September 2010 respectively from Regional Sericultural Research Station, Chamarajanagar (Karnataka) of Central Silk Board, Ministry of Textiles, Govt. Of India.

The third and fourth authors are with Krishi Vigyan Kendra, Hardanahalli, Chamarajanagar
Please read a previous article by Dr. PK Das

What is intercropping?

Intercropping can be defined as agricultural practice of cultivating or growing of two or more crops simultaneously on the same area of land for increasing the returns from unit area of land. The crops are not necessarily sown at exactly the same time and their harvest times may be quite different, but they are usually “simultaneous” for a significant part of their growing periods. It is a practice often associated with sustainable agriculture and organic farming. Intercropping is one form of polyculture, using companion planting principles. Intercropping may benefit crop yield or the control of some kind of pest, or may have other agronomic benefits. In intercropping, there is often one main crop and one or more added crops, with the main crop being the one of primary importance because of economic or food production reasons. The two or more crops used in an intercrop may be from different species and different plant families, or they may simply be different varieties or cultivars of the same crop species. Intercropping offers farmers the opportunity to engage nature's principle of diversity on their farms. Spatial arrangements of plants planting rates and maturity dates must be considered when planning intercrops. Intercrops can be more productive than growing pure stands.

Objective of intercropping:

The most common objective of intercropping is to produce a greater yield on a given piece of land by making use of resources that would otherwise not be utilized by a single crop and thereby to augment the income. Careful planning is required, taking into account the soil, climate, crops, and varieties. It is particularly important not to have crops competing with each other for physical space, nutrients, water, or sunlight. Intercropping of compatible plants also encourages biodiversity, by providing a habitat for a variety of insects and soil organisms that would not be present in a single crop environment. This biodiversity can in turn help to limit outbreaks of crop pests by increasing the diversity or abundance of natural enemies, such as spiders or parasitic wasps. Increasing the complexity of the crop environment through intercropping also limits the places where pests can find optimal foraging or reproductive conditions.

Watch the story as a movie

Informations available on intercropping in mulberry

Intercropping has been tried in paired row system of mulberry under irrigated condition in Kharif with French bean (Phaseolus vulgaris) and Radish (Raphanus sativus) and with Sabssige (Anethum graveolens) , Methe (Trigonella foenum graecum) and Palak (Spinacea oleracea) in Rabi at CSRTI, Mysore. Intercropping was also done with Bengal gram, Gladiolus, Marigold, Amaranthus and Cluster bean to improve the net returns (Ravindran et.al , 2003, CSR&TI, Mysore). Intercropping in rainfed mulberry with different cereals, pulses, millets, oil seeds and vegetables was studied in ICAR adhoc research project on “Development of appropriate inter cropping system for rainfed mulberry garden” (Shankar and Devaiah, 2002 , UAS , Bangalore). The report revealed that there was no adverse effect in mulberry or on silkworm growth and production. Besides, it also increased the net income per unit area of mulberry garden.

Different types of intercropping:

1. Row intercropping: This involves growing two or more crops simultaneously where one or more crops are planted in rows.

2. Mixed intercropping: Here two or more crops are simultaneously grown intermingled in the same plot with no distinct row arrangement.

3. Strip intercropping: It involves growing two or more crops simultaneously in different strips wide enough to permit independent cultivation but narrow enough for the crop to interact agronomically.

4. Parallel multiple cropping: In contrast to multiple cropping in series, one could visualize the situation of parallel multiple cropping where two crops of dissimilar growth habit are made to grow simultaneously in such a way that they do not affect the performance of each other adversely.

5. Relay intercropping: Growing component crops in relay so that growth cycles overlap.

6. Multi tier intercropping: It is a system of growing together crops of different heights at the same time in the same piece of land and thus using land, water and space most efficiently and economically.

7. Alley cropping: Alley cropping is essentially an agro forestry system in which food crops are grown in alleys formed by hedge rows of trees or shrubs.

Feasibilities of intercropping in mulberry under rainfed condition at Chamarajanagara

Chamarajanagara district is a traditional sericultural belt in Karnataka. Presently, mulberry is cultivated in a area of approximately 8,313 hectares. Out of this, 6,957 hectares (83.7%) are existing under rainfed and 1,356 hectares (16.3%) under irrigated conditions. To improve the economic production per unit area of mulberry garden specially under rainfed condition, it is important to grow other short duration agricultural crops adopted to grow under local agronomical conditions along with mulberry within available space. Under rainfed condition of Chamrajanagar it is recommended to grow S-13 / S-34 mulberry varieties in red / black soil respectively in a spacing of 90 cm x 90 cm as bush plantation in plain lands. While growing of the same varieties in a spacing of 180 cm x 180 cm ( i.e 6’ x 6’) is also recommended as tree plantation in undulating as well as sloppy lands or hilly areas. Thus the available space between mulberry rows under bush or tree plantations provides a good opportunity for intercropping. It has been observed that in Chamarajanagara district ragi, ground nut and cowpea are generally grown by the agricultural farmers during Kharif (June- September) with the available soil moisture due to rain as subsidiary crops and as major source of income while horse gram is grown during Rabi season (October – January). However, their use in rainfed mulberry garden is hardly seen due to limitation of knowledge of intercropping among the sericultural farmers. This is further constrained by the non availability of proper technology package of intercropping in rainfed condition. Though It has been observed that during last seven years (2000-2007) Chamarajanagar received an average rainfall of 729.8 mm / year ( Table-1), in true sense most of the year received below average rainfall accept the years 2000-2001 & 2005-2006 and most of which were restricted from the month of June to October. Thus it is highly important to grow short duration intercrops which can be grown in mulberry taking advantage of this scanty rainfall to augment the income of farmers and make sericulture more remunerative. However, it is very important to develop meticulous plan to grow intercrops with this low rainfall. With these in mind intercropping in mulberry was studied at Regional Sericultural Research Station, Chamarajanagar from June 2007 for three years to see the feasibility of intercropping in mulberry for augmenting income of the sericultural farmers of this area. The project was undertaken in collaboration with KVK, Chamarajanagar. Intercropping was taken up only during rainy season by growing four intercrops (ragi, cowpea, groundnut and Horse gram) under 90 cm x 90 cm spacing with S-13, paired row plantation (90cm + 180 cm) x 60 cm with V-1 and mulberry tree under 180 cm x 180 cm and 240 cm x 240 cm spacing with S-13. Four experiments were conducted simultaneously in four different gardens considering 4 treatments (4 intercrops) with 3 replications each

Achievement

The data clearly revealed that among all the intercrops, groundnut has influenced maximum on the leaf yield of both the S-13 and V-1 mulberry varieties. Among all the planting geometry, tree plantation under 180 cm x 180 cm spacing showed the promising result. A maximum percentage of improvement in the leaf yield (45.7 %) was observed in the first year from S-13 mulberry variety as tree plantation under 180 cm x 180 cm spacing with groundnut intercropping (Table-2). The second year data also clearly revealed that among all the intercrops, groundnut has influenced maximum (35.8%) on the leaf yield of S13 mulberry variety as tree plantation under 180 cm x 180 cm spacing (Table-3). A silkworm rearing was conducted in 2^nd year which did not show any significant variation in the larval growth, survivability and cocoon yield due to intercropping as compared to control (sole mulberry) suggesting no adverse effect of intercropping on mulberry leaf quality ( Table-4). A substantial yield of intercrops specially groundnut and cowpea was also recorded under both the S-13 and V-1 mulberry varieties indicating a positive role of intercropping in augmenting income (Table -5). However, the intercropping in 3^rd year failed due to poor rainfall. The cost benefit ratio was worked out for intercropping under mulberry. The intercropping with cowpea and groundnut was found to be quite profitable while horse gram and ragi intercropping was found not profitable under rainfed mulberry.

Recommendation:

v Hence, intercropping once in a year in S-13 mulberry during rainy season with cow pea and specially with groundnut under 3 ‘ x 3’ row system of plantation, V-1 mulberry with paired row system as well as S-13 mulberry under tree plantation with 6’ x 6’ or 8’x 8’ is recommended.

v This will augment the farm income besides proper utilization of farm land.

v While intercropping with cowpea the seed rate should be @ 20 kg / ha and groundnut @ 100 kg / ha following line / row sowing method keeping a distance of 1 feet from line to line / row to row.

v Chemical fertilizers should be applied for the intercrops at the rate of 30:50:30 NPK kg / ha / year besides application of the recommended dose of fertilizers for mulberry during rainy season. FYM can be applied as per the recommendation of mulberry cultivation under rainfed condition.

Future Plan of Action:

The intercropping in rainfed mulberry is under popularization among the sericulturists of Chamarajanagar. For which the DOS has been also involved for assisting in the farmers field. An Action plan has also been submitted to DOS.

Microsporidia - A Taxonomic Nomad

gkrajeshrajesh@gmail.com — Mon, 21 Feb 2011 09:45:00 +0000

Dr. K. Chandrasekharan

Dr. K. Chandrasekharan is a Senior scientist with Central Silk Board, India. He obtained his BSc and MSc degrees in Zoology from the University of Calicut, Kerala. His Ph.D was from the University of Mysore on white muscardine disease of silkworm caused by Beauveria bassina. Before joining CSB he had worked on the biological control aspects of pests of coconut, with special reference to the parasitoid hyperparasitoid interaction of the coconut pest Opisina arenosella in the field, as a UGC/CSIR fellow. In CSB his initial work was in Tasar sericulture sector. After moving to the Regional Sericulture Research Station , Kodathi, Bangalore he worked for a short spell on transfer of technoloies to the field. There after till now his work is at the Silkworm Pathology Laboratory at the Central Sericultural Research and Training Institute at Mysore. Presently he is engaged in developing suitable strategies for the management of silkworm diseases. The team he is working with has developed and commercialised a number of products for managing silkworm diseases, which are commercialised in the trade names 'Asthra, Ankush, Amruth, and Vijetha supplement'. He has published nearly 120 papers and supervised 6 students for their MSc dissertations.
Dr. K. Chandrasekharan can be contacted at E-mail: kchandrasekharan@rediffmail.com

Microsporidia are a group of obligate eukaryotic intracellular parasites first recognized more than 150 years ago with the description of Nosema bombycis the parasite causing pebrine disease in silkworms. Microsporidia infect almost all animal phyla and among the more than 144 described genera, several have been demonstrated in human disease. Pebrine caused by the microsporidian, N. bombycis is one of the most dangerous and devastating disease in silkworm. This disease devastated sericulture industry in several countries and even it wiped out the industry from some of the European countries. This disease was first reported during 1845 in France and later spread to several other European countries. In 1870, Louis Pasteur developed a practical method to control the disease which saved the industry during that time and this method of mother moth examination is still followed to prepare and supply pebrine free layings.

Spores of N. bombycis

Several microsporidia other than N. bombycis (Vairimorpha sp., Pleistophora sp., Thelohania sp. etc.) are also reported as causative agents of this disease. They mainly transmit by ingestion of spores (horizontal transmission) and in addition, many species of microsporidia are transmitted vertically or trans-ovarially (generation to generation) from an infected adult female to her offspring, either through the egg surface or within the egg.Microsporidia are primitive eukaryotes with well defined nuclei and plasma membrane but lack some typical organelles found in the typical eukaryotes like mitochondria, stacked Golgi and peroxisomes. Microsporidian spores have a characteristic coiled polar tube, tubule or filament, layered polaroplast, a posterior vacuole and protective exospores made up of proteins and chitin which is responsible for the spores’ high environmental resistance. Microsporidia infiltrate into the host cells through the polar tube or polar filament found in the spore. They are widely distributed in nature with over 1200 characterized species. Recently microsporidia have also been documented as parasitic to human beings. Although the largest number of microsporidian species infect arthropods (especially insects), most animal phyla contain at least a few species that are infected by microsporidia.

Taken from: http://www.palaeos.com/Eukarya/Units/Microsporidia/Microsporidia.000.html

The microsporidia have occupied the attention of taxonomists for a long time and have been subject to several reclassifications at all levels of organisation, from the species level up to that of their phylum’s affinity with other eukaryotes. The classification of Microsporidia has evolved through time with growing scientific research and the specifics are still thoroughly debated. Recent studies indicate phylum Microspora under the Fungal kingdom or at least as a sister kingdom to Fungi. The class, order and family within the Microspora phylum are also frequently revised and debated. Since from its inception, microsporidia was changed to distinct and varied taxonomic groups and hence microsporidian group can be considered as a taxonomic nomad.The name "Protozoa" was coined by Goldfuss (1817) and Siebold (1845) defined it and made phylum Protozoa. Order Microsporidia was erected by Balbiani in 1882 and initially this order was placed under the phylum Protozoa (kingdom Protista), and class Sporozoa along with the well known pathogens like Plasmodium and Leishmania. Later Doflein (1901) created a subclass Cnidosporidia, and order Microsporidia came under this sub class until a separate class Microsporidea under the sub phylum Cnidospora was erected by Honigberg et al. (1964)

Classification of microsporidia as a class in the phylum Protozoa (Honigberg et al. ,1)964)

Microsporidia was later elevated into a separate phylum called Microspora under sub kingdom Protozoa which was erected in 1969 to accommodate this unique group of organisms (Sprague (1969, 1977), Levine et al. (1980)).

Classification of Microspora as a separate phylum of the animal subkingdom Protozoa (Levine et al. 1980, Sprague 1969, 1977)

Sprague et al. (1992) introduce a different classification system, based on whether the species is diplokaryotic at some point in the life cycle (Dihaplophasea) or uninucleate throughout its life cycle (Haplophasea). The Dihaplophasea are further separated into those in which the diplokaryon is formed through meiosis (Meiodihaplophasida) and those in which the diplokaryon is formed through nuclear dissociation (Dissociodihaplophasida).

Taxonomic position of Nosema sp. in the Phylum Microsporidia (Sprague et al.1992)

Many mycologists and invertebrate pathologists now consider that the Microsporidia have been proven beyond any reasonable doubt to be comparatively recent and highly derived endobiotic fungi. They are neither extremely ancient eukaryote nor affiliated with protozoans as most textbooks indicate. None of this realignment to the fungi is being disputed by either microsporidiologists or phylogenetic mycologists. The rationale for this realignment is well presented by James et al. (2006). These fascinating organisms connect to the fungal tree of life at the base of the nonflagellate fungi (among or near the fungi traditionally treated as the Zygomycota) but their exact affinities and nearest remain uncertain. Recent scientific studies using genetic tools have proved that microsporidians are more fungal than protozoal in nature. Now pebrine can be better classified as a mycosis rather than microsporidiosis.

James et al (2006) developed the phylogenetic hypotheses for Fungi using data from six gene regions and nearly 200 species. The results indicate that there may have been at least four independent losses of the flagellum in the kingdom Fungi. These losses of swimming spores coincided with the evolution of new mechanisms of spore dispersal, such as aerial dispersal in mycelial groups and polar tube eversion in the microsporidia (unicellular forms that lack mitochondria). The enigmatic microsporidia seem to be derived from an endoparasitic chytrid ancestor similar to Rozella allomycis, on the earliest diverging branch of the fungal phylogenetic tree. The recent results using RPB1, a- and b-tubulin, and other genes, have suggested a fungal origin of the microsporidia (Hirt et al.,1999; Katinka et al., 2001 and Keeling 2003), a placement consistent with their having the shared traits of closed mitosis and spores that contain chitin and trehalose (Cavalier-Smith, 2001). Only one study has placed the microsporidia with a specific fungal lineage, in which a relationship was demonstrated between members of the Zygomycota and microsporidia by using tubulin proteins (Keeling, 2003). However, tubulin proteins seem to have evolved at different rates in flagellated and non-flagellated fungi (Keeling, 2003; Corradi et al., 2004).

Presently work has focused on the determination of the nucleotide sequences for ribosomal RNA (rRNA) genes, which have been used as diagnostic tools for species identification as well as for the development of a molecular phylogeny of these organisms. Microsporidia have historically been considered to be “primitive” protozoa, however, molecular phylogenetic analysis has led to the recognition that these organisms are not “primitive” but degenerate and that they are related to the fungi and not to other protozoa. Molecular phylogeny has also led to the recognition that the traditional phylogeny of these organisms based on structural observations may not reflect the “true” relationships among the various microsporidia species and genera.

Studies using DNA techniques indicate phylum Microspora should be classified under the Fungal kingdom or at least as a sister kingdom to Fungi. The class, order and family within the Microspora phylum are also frequently revised and debated. Traditionally, species were identified by observing the physical characteristics of the spore, life cycle and relationship with the host cell. However, studies using genetic tools (namely ribosomal RNA sequencing) have challenged this approach and suggest genetic markers a more correct method for scientific classification. More research is still needed to better understand the origins of microspora and of individual species.

Liu et al., (2006) concluded in their studies that Microsporidia are the sister group of the rest of the Fungi and should not be classified as true Fungi, but that topology does not conflict with the delimitation of the monophyletic Fungi as proposed here. The analysis of James et al. (2006) suggested that Rozella, which was not sampled by Liu et al. (2006), is the sister group of the Microsporidia. Based on the genetic analyses of Keeling et al. (2000), Gill & Fast (2006), James et al. (2006) and Liu et al. (2006) phylum microspora has been included under the fungal kingdom in the recent phylogenetic classification of fungi by Hibbett et al. (2007). No subdivision of the Microsporidia is proposed, in the classification by Hibbet et al (2007) owing to a lack of well-sampled multilocus analyses of this group.

Phylogeny and classification of Fungi (Hibbet et al., 2007)

The study of microsporidia has reached the breaking point where the classical cytology, which has been the base of microsporidian studies since the very beginning, has lost its importance and it has actually been replaced by the molecular biology. Vossbrinck and Vossbrinck (2005) have adopted the new view, and the result is a new phylogeny and a new classification for a selection of microsporidian species. Five major clades with three taxonomic (class) designations in the phylum Microsporidia were identified in the phylograms. In the Class Aquasporidia, primarily parasites of freshwater organisms are included. The majority of the marine Microsporidia are designated as the Class Marinosporidia, which represents the parasites of marine hosts. Microsporidia isolated from terrestrial hosts are designated into the Class Terresporidia, and are mainly parasites of insects with economic importance.

Taxonomic position of Nosema sp. in the Division Microsporidia of Fungal kingdom (Vossbrinck & Debrunner-Vossbrinck , 2005)

The new classification necessitates a paradigm shift in our understanding about the pebrine disease in silkworm. More over the new understanding may revolutionise our strategies to mange pebrine disease of silkworm.

Refernces

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Cavalier-Smith, T. (2001) In: The Mycota (Eds McLaughlin, D. J., McLaughlin, E. G. & Lemke, P. A.) 3–-37 (Springer, New York)

Corradi, N. et al. (2004) Arbuscular mycorrhizal fungi (Glomeromycota) harbour ancient fungal tubulin genes that resemble those of the chytrids (Chytridiomycota). Fungal Genet. Biol. 41, 1037–-1045.

Doflein F. (1901) Die Protozoen als Parasiten und Krankheitserreger nach biologischen Gesichtspunkten dargestellt. Jena.

Gill E. E. and Fast N. M. (2006) Assessing the microsporidia–fungi relationship: combined phylogenetic analysis of eight genes. Gene. 375: 103–109.

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Hibbett et al. (2007) A higher-level phylogenetic classification of the Fungi. Mycological Research. 111: 509-547.

Hirt, R. P. et al. (1999) Microsporidia are related to fungi: evidence from the largest subunit of RNA polymerase II and other proteins. Proc. Natl Acad. Sci. USA 96, 580–-585

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Katinka, M. D. et al. (2001) Genome sequence and gene compaction of the eukaryote parasite Encephalitozoon cuniculi. Nature. 414, 450-453

Keeling P. J. (2003) Congruent evidence for alpha-tubulin and betatubulin gene phylogenies for a zygomycete origin of Microsporidia. Fungal Genetics and Biology.38: 298–309.

Keeling P.J. et al. (2000) Evidence from beta-tubulin phylogeny that Microsporidia evolved from within the fungi. Molecular Biology and Evolution. 17: 23–31.

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Liu Y. J. et al. (2006) Loss of the flagellum happened only once in the fungal lineage: phylogenetic structure of kingdom Fungi inferred from RNA polymerase II subunit genes. BMC Evolutionary Biology 6: 74.

Siebold C. T. E. (1845) Lehrbuch der Vergleichenden Anatomie der Wirbellossen Thiere. In: Lehrbuch der vergleichenden Anatomie 1 (Eds. von Siebold C.T.E. and Stannius H.). Berlin.

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Sprague, V. (1977) Classification and phylogeny of the microsporidia. In: Bulla, L. A., and T. C. Cheng, (Eds.) Comparative pathobiology, Vol. 2. Systematics of the microsporidia. Plenum Press, New York.

Sprague, V. et al. (1992) Taxonomy of phylum Microspora. Crit. Rev. Microbiol. 18: 285–395.

Vossbrinck C. R. and Debrunner-Vossbrinck B. A. (2005) Molecular phylogeny of the Microsporidia: ecological, ultrastructural and taxonomic considerations. Folia Parasitologica. 52: 131–142.

Sericulture in the Cévennes: from a first visit, autumn 2010

gkrajeshrajesh@gmail.com — Fri, 19 Nov 2010 18:39:00 +0000

Simon Charsley

Simon Charsley

Prof.Simon Charsley’s name evokes mixed feelings of respect, admiration and affection in our minds. Of course, he belongs to the older generation, the classical phase of Indian sericulture and in every sense is a classicist. Marked by its characteristic all pervading ‘enthusiasm’ (to borrow Charsley’s own word), the classical phase has left a large legacy, of which the succeeding ‘techno-savvy’ age was little solicitous. Charsley was born in 1939 in England while the Second World War was looming large. He studied Philosophy and Social Anthropology at Cambridge. After obtaining PhD from the University of Manchester in 1968, Charsley started teaching Social Anthropology at the University of Glasgow, where he still continues to teach at the age of seventy one. He has held positions at Makerere College, Uganda (1965-6), University of Manchester (1967-8), Department of Sociology, University of Glasgow (1968-85) etc. Prof. Charsley had a key role in the preparation of ‘Beneficiary Assessment’ (BA) for the World Bank’s National Sericulture Project and was the Principal Adviser for BA to the CSB. Professor Charsley calls himself an expert on South Indian Sericulture and is proud of donning that label.

Professor Charsley spent his prime years in India, and took up study on a topic which would have appeared rather unfashionable to the contemporary intelligentsia. His introduction to Indian Sericulture was quite accidental. In his own words”... I first came to India on a Younger Scientist exchange programme and found sericulture in Mysore. The enthusiasm that I met led me to a research project on the silk industry and how it worked in practice, and also to many good friends....” That was in the mid seventies- an era marked by rapid modernisation of Indian sericulture sector. The result of his intensive study of the rural livelihood was the classic “Culture and Sericulture (1982)” which still remains one of the most authentic documentations on Indian sericulture and probably the only one comparable to the work of Lefroy and Ansorge (1915), though different in perspective and purpose. Subsequently he wrote a number of papers practically covering every aspect of the industry viz.regulated markets, middlemen, technology, silk reeling etc. which still remain most valuble reference material for students of respective disciplines.

Indian sericulture is indebted to Prof. Charsley, primarily for bringing it into the contemporary developmental rhetoric. He was the first and (unfortunately) the last to address sericulture as a livestock industry. Probably its scope of being so designated is largely under-estimated by the academics and policy makers. Prof. Charsley argued that sericulture shares much with and historically has led the way for other livestock industries and advocated its importance in the developmental context. His view of sericulture- as a ‘study material’ in social and anthropological assessment of development in a society where people are separated not only by status, culture and life circumstances but also by religion caste and politics is still highly relevant.
It is high time that the International Sericultural Commission considered prof. Charsley for its prestigios Louis Pasteur award. In this article Professor Charsley writes on the remnants of sericulture and silk industry in Cévennes, in southern France. The article shows how well the sericultural past is preserved in the French psyche, that they use it as a tourist bait. Shouldn’t we take a cue from this?

The Cévennes, in southern France, is an attractive area for summer tourists who want something other than sea and beaches. It is part of the Massif Central, the mountainous centre at France’s heart, with a high and wild National Park and, to its east and south, an area of wiggling wooded river valleys with precipitous rocky sides. These enclose small towns and villages with handsome old limestone houses often clinging to the steep slopes. It is a country of striking views and opportunities for enjoying ‘the great outdoors’. It is also one in which economic decline left, set in the marvellous landscapes, a supply of old houses in need of renovation. Over the last 30 years or so it has attracted numerous British and other northern Europeans to buy such houses, renovate them, construct swimming pools and settle in for at least a major part of the year. It is also a region with a distinctive history, much of it of peasantfarming, poverty, conflict and disasters. The disasters have arisen over the centuries from depopulating disease, political and religious warfare, extremes of torrential flooding, destructive frosts and, for these and other reasons, repeated collapse of livelihoods. However, its history has also included the memory of a golden age of prosperity, based in sericulture. There is evidence for its beginning here as early as the twelfth century but its conspicuous flourishing is considered to date only from the early eighteenth century. Though serious retreats as well as advances followed, it climaxed in 1853 after advancing during the first half of the nineteenth century. Then, struck by epidemics of silkworm disease, particularly pebrine before any effective means of controlling it was known, and by imports of cheap silk from Italy and the Far East, it ran down to virtual extinction over the following hundred years. After the Second World War, before it had entirely disappeared, efforts to give it a kiss of life were made with government support but no success.

A promotional poster: Saint-Hippolyte museum

The most recent effort at revival began to be seriously considered in the 1970s. In 1972 a school teacher in the village of Monoblet, by name Michel Costa, set about reviving knowledge of silkworm rearing as an instructive and engaging activity for his primary school pupils (Laurens 2004: 145). Perhaps he had been stimulated himself by a special edition of a school newspaper, Le Petit Cévenol, from 1930. It had been written, illustrated and printed by six girl pupils aged 9 to 12 years and was centred on their participation at home in the silkworm rearing which was still going on in their villages at the time (Cévennes 1997: 3-19). In 1977 a new Mayor of Monoblet came in with a project for ‘soil to silk garment’ production, and Michel Costa, his deputy as mayor, founded an Association for the Development of Sericulture in the Cévennes (ADS) to encourage and support rearing. By 1981 there had been sufficient progress for a co-operative of rearers and weavers to be formed with government support. It set up business in a former filature. About the same time, factories were started, also by ADS at Monoblet and by another organisation at Le Vigan, a larger town 30 kms to the west. They were to reel, prepare raw silk for weaving and to weave it. A further enterprise of ADS was a Silk Museum first at Monoblet and then moved to another former silk centre, Saint-Hippolyte, where a silk-garment workshop and a boutique for selling silk products were also established. As a later observer notes (Laurens 2004: 145), a mutually supporting network of linked enterprises of rearing and manufacturing and marketing and displaying was filling out.

Mountages displayed at the Saint-Hippolyte museum

About this time a British entomologist and biologist, Dr John Feltwell, who settled and restored an old magnanerie or rearing house, also became involved. In 1983 he reported on ‘The revival of the silk industry in Basse-Cévennes’ in the Proceedings of the British Entomological and Natural History Society. The revival, he said, was ‘not necessarily run by Cevenol people in the heart of the Cévennes’: they remembered ‘all too well the great labour and energy expended in the magnanerie and are not likely to return to it lightly’ (1983: 24). But there was also sericultural progress to excite potential rearers and enthusiasts. A new mulberry significantly more productive and less demanding in land and in labour for leaf picking appeared. This was a legacy of government attempts from the 1950s to revive the industry then. New varieties from Japan had been sent in 1956 to an agricultural research centre near Alès, the old hub of the Cévennes silk industry. There a cultivar named Kokuso 21 had been identified as particularly promising for Cévennes conditions. It was still growing there 25 years later and in 1982 cuttings were made available for sale at the Monoblet museum (Feltwell 1983: 25).

From the beginning of this attempted revival there had also been a separate strand to thinking about it, or perhaps two such strands. Heritage or patrimoine as the French usually call it more pointedly, increasingly recognised as fulfilling a need for identity for the Cévennes and its people was one. In 1987 the Council of Europe [1] started sponsoring such heritage projects with its ‘Cultural Routes’ programme. Silk and Textile Routes were amongst the first projects to be selected for development, and funds for ‘Chemins de la Soie – European Silk Itineraries’ were provided (Clavairolle 1994). UNESCO also had a similar initiative at the global level [2], distinguished in France as ‘Routes de la Soie’, and Cévennes was a prime site for it. Heritage and identity were becoming an international industry in themselves.

A French filature: from St. Jeans Museum

The other and more directly material strand of thinking was an interest in securing a profitable place on the international tourist map. Remains of the sericultural past there were aplenty on the ground, but they did not have any such obvious appeal as sun, sea and the beach for northern European visitors. Things of potential interest needed to be given value, developed and pointed out if they were not to be missed by uninformed visitors. It was a more obvious asset to have sericulture being practised, though its seasonality in a temperate climate was a limitation: it would not be as readily available as tropical sericulture, but could at least be made to coincide with the main summer holiday season for visitors [3]. As well as live rearing providing additional points of attraction, they could be linked with sights to be discovered in countryside well worth exploring for its own sake, and with static displays in museums and elsewhere. The experience offered could thus be enriched and the potential returns increased. Promotion to the tourist industry through paper publications as well as television and then the internet took off. In recent times therefore, silk and its history have been promoted as a major focus around which other attractions in the Cévennes could be built up. It is visible as houses often standing high above terraces that were originally built on the steep and rocky hillsides with hard manual labour for the creation of mulberry plantations. An almost fanatical attention came to be aimed at charting the distinctive styles of silk-rearing architecture to be seen in the streets of villages and small towns, as well as large isolated houses set in what were once mulberry plantations. From the nineteenth century altogether different and even larger filature buildings also survive, built for capitalist ventures beside the rivers that provided their essential water supply. The last of these closed at Saint-Jean du Gard in 1965. One grand old filature was reopened in the early 1990s but by 1999 the project had been abandoned. Today the buildings are either converted to other purposes or remain derelict, but their working days, together with other picturesque aspects of sericulture, are pictured in the museums alongside collections of the silks, equipment, machinery and the propaganda media of the industry. There and in the shops catering for the visitors, originals and reprints of the postcards which played an important part in publicising and glamorising sericulture, at the beginning of the twentieth century particularly, continue in the same exercise today [4].

A renovated rearing house with a mulberry twig on the fore ground

Just what happened over the last two decades is not yet documented, but the revival of sericulture as industry and livelihood is over. Today, three museum displays remain and one restored magnanerie, somewhat out of the way in its location, opens in the two main tourist months of the year. The only rearing being carried on is on an occasional and minute scale in connection with the displays at these. Nevertheless there is a presence and the memory is alive.
From Alès however, once Alais, capital of the Cévennes and centre of the industry, the only remaining sign of the silk industry is a fine statue of Louis Pasteur, great pioneer of microbiology who, starting in 1865 carried out his research on pebrine, the most dangerous of silkworm diseases there [5].

Statue of Louis Pasteur at Alès with a
mulberry tree in the background

He unravelled the complex nature of the disease and the means that were soon to be known across the sericultural world, of controlling it by practices of cellular rearing and microscopic examination of the mother moths. In the twentieth century, the Alès State Sericultural Research Station was taken onto a world stage. Its director, André Schenk, in 1948 organised there the 7th International Sericultural Congress which was to re-launch the worldwide trading industry after the set-backs of the War period. Then in 1955 it held the first International Technical Sericultural Conference from which emerged the International Sericultural Commission of which Schenk was the first Secretary-General. Its history in silk was coming towards its end however. In 1978 the Alès Research Station itself closed, its activities and staff moving mainly to France’s great city of the silk trade, Lyons on the River Rhône in the east of the country. Pasteur, his statue identifying him as ‘saviour of sericulture’, still looks out on the town from his prominent position in front of Fort Vauban, the seventeenth century castle in the centre of the town now again flourishing, but in other ways. Its distinguished presence in sericultural history is over.

Prof Charsley can be contacted at Email: s.r.charsley@socsci.gla.ac.uk

For more details and his work go to: http://www.gla.ac.uk/departments/sociology/staff/simoncharsley/

To read Prof. Charsleys blog go to: http://www.simoncharsley.blogspot.com/

REFERENCES

Cévennes 53/4. 1997. Architectures et Paysages de la Soie: le Fil de la Mémoire. Florac: Parc National des Cévennes

Clavairolle, Françoise 1994. ‘L’éducation des vers à soie: savoirs, représentations, techniques’, L’Homme, 129, 34: 121-45

Feltwell, John 1983. ‘The revival of the silk industry in the Basses-Cévennes’, Proceedings of the British Entomological and Natural History Society, 16: 24-29

Laurens, Lucette 2004. De l‘arbre d’or à la sériciculture: filière et gestion culturelle du territoire dans les Cévennes’, in Charlery de la Masselière, Bernard (ed) Fruits des terroirs, fruits défendus: identités, mémoires et territoires, Toulouse: Presse universitaire de Mirail

FOOT NOTES

1. The Council of Europe was established by the Treaty of London in 1949 with its seat in Strasbourg, France. It now has 47 member countries, compared with the 27 of the European Union, and many activities and organisations, including a Parliamentary Assembly and the European Council on Human Rights. See http://www.coe.int/ ; http://en.wikipedia.org/wiki/Council_of_Europe .

2. UNESCO: United Nations Educational, Scientific and Cultural Organization. ‘The Silk Road’, routes across the landmass west of China along which silk and other good traded from ancient times, was a paradigm for its Cultural Routes programme in 1994.

3. The rest of silk processing and manufacture, with the exception of weaving, are in practice likely to be more difficult to display accessibly and interestingly.

4. Cards and one of their main creators, the multi-talented Gabriel Lafont, are valuably displayed and discussed by Daniel Travier in Cévennes 53/4, 1997: 20-21.

5. Also for a time in 1869 at St Hippolyte du Fort.

OUT BREAK OF A NEW INVASIVE PEST, PAPAYA MEALYBUG "PARACOCCUS MARGINATUS" IN SOUTH INDIA - A SERIOUS THREAT TO SERICULTURE INDUSTRY

gkrajeshrajesh@gmail.com — Wed, 13 Oct 2010 08:40:00 +0000

JB. Narendrakumar

J.B.Narendra Kumar and M.A.Shekhar

Mr. J.B. Narendra Kumar, Scientist-C working with Central Sericulture Research and Training Institute, Mysore, India. An agriculture post-graduate, interested in the agriculture entomology. Mr Narendrakumar can be contacted at jbnarendra@gmail.com

Dr. M.A. Shekhar, Scientist-D is the Sectional Chief of Pest Management Laboratory, Central Sericulture Research and Training Institute, Mysore. Has developed many IPM packages for the control of mulberry and silkworm pests

INTRODUCTION

The papaya mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae) is native of Mexico and Central America and it was first noticed in the year 1992 (Williams and Granara de Willink, 1992). During the year 2006, this pest was first reported in Coimbatore area of Tamil Nadu on Papaya. Now it has become a major pest of mulberry spreading fast in sericulture districts of Tamil Nadu causing heavy loss to sericulture industry and has made an entry into bordering districts of Karnataka also, ie., Chamarajanagar and Mysore. As per a recent survey report, an area of about 2,500 acres of mulberry plantation in three districts of Tamil Nadu is severely infested with this invasive pest. Many mulberry gardens have been dried up due to severe infestation and considerable acreage of mulberry has been uprooted.

HOW TO DIFFERENTIATE PAPAYA MEALYBUG FROM TUKRA MEALYBUG?

When mealybugs are pressed in between two pieces of white paper, papaya mealy mealybug gives greenish yellow stain, whereas tukra mealybug gives a pinkish stain. Also, when papaya mealybugs are transferred into alcohol, the body colour turns to black within half an hour. Adult females of papaya mealybugs are yellowish with short waxy filaments around the margin and measure about 3 mm with short caudal filaments, body fluid is yellow in colour, and specimens in alcohol turn bluish black. The detailed biology of the pest is yet to be studied.

LIFE CYCLE

Each adult female mealybug lays about 400-500 eggs with an incubation period of 3 to 4 days depending up on the prevailing temperature. In females, there are 3 stages (ie., egg, nymph & adult) and in case of males, there are 5 stages of development (ie., egg, nymph, pre-pupa, pupa & adult). The first instar nymphs (crawlers) are very active, very small and occupy tender shoot portion or tender leaves and feed by sucking the sap. Later they settle at one place, and continuously suck the sap. Adult females live for 30 to 60 days whereas males do not feed and live for very short duration. They possess a pair of transparent wings. The females do reproduce parthenogentically. Adult females are yellow in colour covered by white waxy secretion and short waxy filaments around the body and short caudal filaments.

The pest feeds on the sap of the plants by inserting its stylets into the epidermis of the leaf and stem. In doing so, it injects a toxic substance into the plant system thus resulting in chlorosis, stunted growth of plants, deformation of leaves, early leaf drop, a heavy build up of honey dew secretion and finally death of plants. Normally insecticides are not much effective against mealybugs due to waxy covering over their body. Since the adult mealybugs are sedentary in nature, biological suppression of this pest by natural enemies is an ideal alternative and has less risk to non target organisms.

HOST RANGE

It has got a wide host range of over 60 species of plants including economically important ones such as Annona squamosa (Custard apple), Carica papaya (Papaya), Psidium guajava (Guava), Hibiscus rosa-sinensis (Shoe flower), Cajanus cajan (red gram), Ipomoea spp. (sweet potato), Manihot esculenta (Tapioca), Gossypium hirsutum (cotton), Jatropha curcus (Jatropha), Vigna ungiculata (Cow pea), Tectona grandis (Teak), Solanum melongena (brinjal), Lycopersicon esculentum (Tomato) and weed plants like Parthenium hysterophorus (parthenium) & Abutilon indicum (country mallow). Annona squamosa, Carica papaya, Manihot esculenta and Melongena (Meyerdirk and Kauffman, 2001). It is infesting many weeds like Parthenium, hedge plants belonging to Euphorbiaceae family. In Tamil Nadu it has even devastated Jatropa plants which were grown for bio diesel purpose.

DAMAGE SYMPTOMS IN MULBERRY

Heavy infestation of the Papaya mealy bug is noticed on the under surface of leaves and usually along the veins and midribs in older leaves and on all areas on the tender leaves. Severely affected older leaves turn yellow and dry up. Tender leaves become crinkled. Terminal shoots become bunched and distorted. Heavy mealybug populations produce a large volume of honeydew, which facilitate the development of black sooty mould, which covers the infectedportion. The mealybug injects a toxin as it feeds on leaves, which results in chlorosis (yellowing) stunting, deformation, early leaf fall. Development of sooty mould makes the mulberry leaves unfit for silkworm rearing. The Papaya mealy bug infests all parts of the mulberry plant unlike the pink mealy bug, Maconellicoccus hirsutus, which infests only the apical portion.

MANAGEMENT OF PAPAYA MEALYBUG

For the management papaya mealy bug infesting mulberry no studies have been carried out. To meet the immediate requirements of the industry a modified IPM was formulated on the line of IPM of pink mealy bug infesting mulberry. The same modified IPM was tested with in the severely infested mulberry gardens in Tamil Nadu (Erode and Coimbatore districts) where, nearly 1500 to 2000 acres of mulberry gardens were infested. The farmers are following the modified IPM package formulated and recommended together by CSR&TI, Mysore and Tamil Nadu Agriculture University, Coimbatore and are able to reduce the infestation to a considerable extent. Modified IPM package has given 70 - 80 percent reduction in pest infestation. The silkworm rearing brushing capacity which had come down drastically by 80 to 90% has increased and the leaf yield has also considerably improved.

To prevent the outbreak of the pest, authorities of the region should draw a comprehensive plan on war footing measures. The young crawlers of the pest are very minute and appear like fine powder to naked eye and they can be easily drifted to different places through wind. It is not possible to combat this pest only through chemical measures. Simultaneously, we should also employ physical and biological methods to reduce the incidence of this dreaded pest.

In North America this pest has been controlled to an extent of 90% through classical bio-control approach. CSRTI, Mysore in collaboration with NBAII (Formerly PDBC), Bangalore and Tamil Nadu Agricultural University, Coimbatore has initiated a research project to develop control measures on the lines developed in North America. NBAII has already made all proposals to import the exotic bio-control agents to test them in India to control this pest.

IPM PACKAGE FOR PAPAYA MEALY BUG, PARACOCCUS MARGINATUS

Prune the entire mulberry garden and make in to one batch. (If 2 batches are maintained, the pest will migrate from one garden to adjoining garden. To avoid this prune the entire garden at one time).
Collect the pruned shoots along with infested portions in polythene bags. Place these cut infested portions on burning fire.
Immediately after pruning, spray 0.2 % DDVP (25ml in 10 lts water) over the pruned stumps and surrounding soil.
Burn all dry branches, shoots present in and around mulberry field by taking it out of the plot.
2nd spray of 0.1% Roger 10 – 15 days after pruning (30ml in 10lts)
3rd spray of 0.2% DDVP 10 days after 2nd spray.
5 days after 3rd spray, release predatory lady bird beetles (Cryptolaemus montrouzieri or Scymnus coccivora) @ 250/500 beetles for 1 acre.

All the farmers have to practice the above control measures simultaneously.

In addition, the same treatment of chemical insecticide spray should be given to near by Agriculture and Horticulture crops also.

Efforts should be made to enmass spray of insecticides to all near by crops and adjoining fallow land, as the pest is polyphagous and it may shift to adjoining weeds also.

NOTE: As a prophylactic measure, all the farmers should compulsorily spray 0.2% D.D.V.P. to mulberry gardens of age 15 to 20 days after pruning in each crop. This will help in controlling other insect pests of mulberry too.

In Sri Lanka & Hawaii islands, release of parasitoids alone has given control of papaya mealybug to the tune of 90-95%. These parasitoids have been already imported. Once they are released in the infested mulberry gardens, spraying of insecticides may be discontinued.

Recent Achievements in Selection and Breeding of the Silkworm Bombyx mori L in Bulgaria

gkrajeshrajesh@gmail.com — Mon, 13 Sep 2010 16:22:00 +0000

P. Tzenov

Dr. PANOMIR IVANOV TZENOV was born in Vratza, Bulgaria in 1961. He took his MSc from The University of Zootechnics and Veterinary Medicine – Stara Zagora in Animal breeding engineering – sericulture. He obtained his PhD. in sericulture in 1996. Dr. Tzenov started his career as a technologist in silkworm egg production at the “Silkworm breeding and egg production enterprise”, Vratza, under the Sericulture Experiment Station (SES) Vratza. He became the head of the station in 1987. From 1994 to 2003 he served as The Director of SES, Vratza and as National Director of the project “Rehabilitation of sericulture”, financed by FAO during 2000 – 2002. Presently he holds the position of Executive director of Bulgarian National Center of Agricultural Sciences (NCAS), Sofia. He is member of various reputed national and international forums such as International Working Group on Sericulture Germplasm” under FAO, International Working group on the global silk handcraft cottage industries and silk enterprises development” under FAO, The Publishing council at the National Center of Agricultural Sciences, Bulgaria etc. He is the founder president of Black, Caspian Seas and Central Asia Silk Association (BACSA). He has contributed immensely to general sericulture, silkworm breeding, egg production, rearing technology and cocoon and silk processing. He has 164 published papers to his credit and holds author’s certificates for two commercial silkworm hybrids. Dr. Tzenov is the chairman of the advisory committee of CONCEPT: Council for Nature Conservation and Environmental Protection, India.
Dr. Tzenov can be contacted at: panomir@yahoo.com

ABSTRACT

A method for selection of silkworm breeds and hybrids, tolerant to adverse rearing conditions, based on a previous testing of silkworm breeds/hybrids and choose of the most tolerant was developed. Two new four-way hybrids, manifested the highest tolerance to adverse rearing conditions along with a satisfactory high productivity under optimal rearing were created. By using a polyvoltine strain in the breeding process two new silkworm breeds were created as parents of a F1 silkworm hybrid which is characterized with comparatively good productivity and simultaneously a higher tolerance to adverse rearing conditions. All the 3 new tolerant to adverse rearing conditions silkworm hybrids have been examined in the system of State agency for variety testing and recognized as original. Two new silkworm hybrids for higher silk yield were created. They manifested average fresh cocoon weight 2.674 g, silk shell weight 0.632 g, shell percentage 23.64 %, filament length 1347 m, raw silk percentage 42.00 %, fresh cocoon and raw silk yield by one box of eggs 43.88 kg and 7.57 kg respectively - a productivity, comparable with the best world standard. A method for selection of sex limited for larval markings silkworm breeds, characterized with higher tolerance to adverse rearing conditions was developed. By breeding of 4 new sex – limited for larval markings strains a higher egg production efficiency by means of higher cocoon yield and fecundity at the P1 egg category level was obtained and a F1 four – way hybrid, having high productivity, combined with a higher tolerance to adverse larval rearing conditions was created and approved by the government as original. A method for selection of sex limited for cocoon colour highly productive silkworm breeds was developed. Four new sex – limited for cocoon color silkworm F1 commercial hybrids which manifest a pupation rate and productivity, comparable with those of the control have been created.

Keywords: silkworm, Bombyx mori L., selection, breeding, Bulgaria

INTRODUCTION

The beginning of a purposive silkworm selection and breeding in Bulgaria was dated 114 years ago with the establishment in 1896 of the Sericulture Еxperiment Station (SAES) in Vratza. In the 30th - 40th years of the last century two main strains were maintained and reared at the field level in Bulgaria, namely Yellow local, with yellow cocoons and cream color of raw silk and White Baghdad, having white cocoons. The White Baghdad race is considered as the oldest at the Balkan peninsula and had been selected by the ordinary farmers for many years.
One of the main targets of Sericulture Experiment Station (SES) in Vratza since its establishment and during its more than one century old activity has been the improvement of silkworm races and hybrids in order to increase the cocoon and raw silk yield and their quality.

Up to the beginning of 30’s of 20th century the station had not maintained its own silkworm genetic resources, but tested periodically the strains imported from different countries (mainly France and Italy) before their introduction at the private egg producing companies.

In the 40’s the station introduced several yellow cocoon races like Askoli, Var, Abrucio and Almeria from France and Italy and using this material some local yellow cocoon lines were evolved.

During the period 1944 – 1952 hybrids between the Yellow local and Golden Chinese race had been tested in Bulgaria and introduced to the field. In order to improve the lines of the Yellow local race, European yellow cocoon breeds Askoli, Var and Alpen were imported during the period 1949-1950. In the end of this period white cocoon silkworm breeds and hybrids became more popular in the world due mainly to their better silk dyeing quality. From 1965 to 1970 many new silkworm lines have been selected in Bulgaria by segregation from Italian and Japanese white cocoon F1 hybrids.

In 1969 the government approved the first white cocoon Bulgarian F1 commercial hybrids.

After 1970 the silkworm breeding work in Bulgaria was expanded and many new breeds and hybrids had been created and introduced until nowadays.

Taking into account the very big importance of the genetic resources for a successful breeding work the number of breeds, maintained at SAES - Vratza and the Agricultural universities was increased from 20-25 at the beginning of 70’s to over 300 in 2010.

The research work in the field of silkworm genetics and breeding was directed to studies on the interactions between the genotype and environment, heterosis expression in F1, positive transgressions expression in F2, combining ability, heritability, correlations, regressions, inheritance of the main qualitative and quantitative characters, implementation of the intensive inbred-lines breeding, methods for creation of initial populations for silkworm breeding, breeding of sex-limited breeds, use of partheno and androgenesis in the silkworm breeding, breeding of silkworm lines and hybrids for summer-autumn rearing, and having higher tolerance to adverse rearing conditions etc..

In the recent years the silkworm breeding in Bulgaria was directed to three main aims: viz. Breeding strains and hybrids tolerant to adverse rearing conditions; Breeding strains and hybrids for higher silk yield and Breeding sex-limited for larval markings and cocoon color strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions and hybrids, with high cocoon and silk productivity.

Breeding strains and hybrids tolerant to adverse rearing conditions.

In this work we used two methods. They were 1. Method of breeding tolerant to adverse rearing conditions silkworm breeds and hybrids by a pre-testing some accessions from the genetic resources and 2. Method of breeding tolerant to adverse rearing conditions silkworm breeds by using polyvoltine strain.

Method of breeding tolerant to adverse rearing conditions silkworm breeds and hybrids by a pre-testing some accessions from the genetic resources.

For the purpose 15 silkworm breeds of the Japanese type, 13 breeds of the Chinese type and 16 F1 hybrids between some of the breeds were used. All the breeds/hybrids were with white cocoon color and uni and bivoltine. The breeds were chosen from the silkworm germplasm, maintained at SAES-Vratza for having comparatively high values of the main quantitative characters (Tzenov and Grekov, 2007). Then the breeds were tested for three times regarding their tolerance to adverse rearing conditions during the 4th and 5th instars (t 28-31 oC, RH 75-80%, feeding amount and rearing space – reduced by 50 %, very reduced ventilation). The breeds who manifested the highest pupation rate under adverse larval rearing conditions were crossed between some of them using the scheme Japanese type x Chinese type and the opposite and the F1 hybrids were further tested also under both standard and adverse rearing regime. Then the hybrids performed the best under the adverse rearing conditions and manifested comparable to the control productivity under standard rearing conditions were chosen and further tested. As a result two new four-way hybrids, namely (KK x Hesa 1) x (Vesletz 2 x Gergana 2), (KK x AS) x (Vesletz 2 x Gergana 2) and the reciprocal crosses, manifested the highest tolerance to adverse rearing conditions along with a satisfactory high productivity under optimal rearing were created (Tzenov and Grekov, 2008, 2009). Both the hybrids have been examined under the system of State variety testing commission and recognized as original.

Simultaneously, each silkworm breed selected by the adverse rearing test was mass reared for 6 generations under adverse conditions and only the individuals survived and having the highest cocoon weight, shell weight and shell percentage were selected for further reproduction. After the 6th generation the breeds have been maintained by batch rearing, following the standard methodology for pure lines.

Method of breeding tolerant to adverse rearing conditions silkworm breeds by using polyvoltine strain.

In this breeding process two uni-bivoltine white cocoon pure lines Super 1 and Hesa 2 and the polyvoltine strain Bonde 517, characterized with yellow-green cocoon color were used.

he breeds Super 1 and Hesa 2 are highly productive with fresh cocoon weight of 2.100 – 2.400 g, shell weight 0.460 – 0.520 g and shell percentage 21 – 22 %. Bonde 517 strain is a typical polivoltine, the cocoons are spindle shaped and flossy, the fresh cocoon weight is 1.000 – 1.100 g, shell weight 0.115 – 0.130 g and the shell percentage is 11 – 12 %. On the other hand this strain has a very high tolerance to adverse rearing conditions, especially high temperature and humidity and it is also comparatively resistant to NPV.

The first step of the breeding process was making F1 and F2 crosses of Super 1 x Bonde 517 and Hesa 2 x Bonde 517. In F2 there was segregation in colored and white cocoons with different shape and texture (Tzenov at al., 1997, 1998, 1999, 2000). Seven male cocoons out of 32 kg cocoons obtained per each cross, having white color, elongated (oval) shape, and similar to those of the uni-bivoltine line texture were selected and mated with selected females of the lines Super 1 and Hesa 2 respectively. Then the two populations were bred by inbreeding for 6 generations, batch rearing, selection for cocoon color, shape, texture and the main quantitative characters. After that the selection process continued with outbreeding for 8 generations, batch rearing, selection for cocoon color, shape, texture and the main quantitative characters. Finally the new silkworm breeds SB 1 and HB 2 were created. The breed SB 1 is of the typical Japanese type, namely larvae with markings, white and elongated with constriction cocoons. The breed HB 2 is of the Chinese type with plain larvae, white and oval cocoons. The main characteristics of the newly evolved breeds are presented in Table 1to3.

Then we tested the F1 hybrids between the two new breeds under optimal larval rearing conditions (Table 4 and 5.). The results manifested that the two hybrids had significantly lower cocoon and silk shell weight than the control, the hybrid Super 1 x Hesa 2. However we also tried the newly evolved breeds as components of a four – way hybrid SB1xSuper 1 x HB2xHesa 2 and the reciprocal. The four – way hybrids manifested a productivity, comparable to the control (Table 4 and 5.). Both the single and four – way hybrids were also tested under adverse rearing conditions during the last two instars (Table 6) and showed remarkably higher pupation rate than the control. As a result the new silkworm hybrid SB1xSuper 1 x HB2xHesa 2 and the reciprocal cross which is characterized with comparatively good productivity and simultaneously a higher tolerance to adverse rearing conditions was created, tested in the system of State agency for variety testing and recognized as original.

Breeding strains and hybrids for higher silk yield.

For the aims of breeding two new silkworm strains, named B1 and Svila 2 have been created for a period of 7 years selection work. The breed B1 is of the Japanese type, having larvae with markings and elongated cocoons with constriction. The breed Svila 2 is of the Chinese type, with plain larvae and oval cocoons. Both the strains are characterized with cocoon weight 2.100 – 2.300 g, shell weight 0.500 – 0.600 g and shell percentage 24 – 26 %. Then from the silkworm germplasm, maintained at SAES – Vratza four other silkworm breeds have been chosen (Hesa 1 and Vratza 35 of Japanese type and Hesa 2 and Merefa 2 of Chinese type) which performed comparatively the highest silk productivity. Using the 6 strains, 10 new F1 silkworm hybrids were created and tested while the Bulgarian hybrid Super 1 x Hesa 2 and the Japanese hybrid Shunrei x Shogetsu had been used as controls (Table 7 and 8).

The results obtained manifested that some of the new hybrids perform higher values than the Bulgarian control and weree close to the Japanese control as regards the fresh cocoon weight, silk shell weight, shell percentage, fresh cocoon and raw silk yield by one box of eggs and filament weight characters values.

It may be concluded that the best hybrids for higher cocoon and raw silk yield are Hesa 1 x Svila 2 and the reciprocal, B1 x Merefa 2, Vratza 35 x Svila 2, B1 x Svila 2 and the reciprocal cross. Among them the best one are Hesa 1 x Svila 2 and B1 x Svila 2 and their reciprocal crosses having average fresh cocoon weight 2.674 g, silk shell weight 0.632 g, shell percentage 23.64 %, filament length 1347 m, raw silk percentage 42.00 %, fresh cocoon and raw silk yield by one box of eggs 43.88 kg and 7.57 kg respectively.

It may be concluded that the two new Bulgarian hybrids have a productivity, comparable with those of the Japanese hybrid Shunrei x Shogetsu, recognized as the best world standard.

Breeding sex-limited for larval markings and cocoon color strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions and hybrids, with high cocoon and silk productivity.

Breeding sex-limited for larval markings strains as parents of commercial F1 hybrids, tolerant to adverse rearing conditions.

The aims of the breeding process were three fold, viz. To create 4 new silkworm breeds, sex – limited for larval markings as analogues of ordinary breeds, characterized with higher tolerance to adverse rearing conditions; To use the newly bred strains as parents of four – way hybrid in order to obtain higher cocoon yield and fecundity at the P1 egg category level and The parents of the F1 hybrid (P1) to be sex – limited for zebra larval markings in order to make easier the sex discrimination.

The method of creation the 4 new sex – limited for larval markings breeds was as follows (Tzenov & Guzman, 2004, Tzenov, 2005):

1. Initial population: cross between females of sex limited for larval markings strain, received from Japan and males of strain, tolerant to adverse rearing conditions;

2. Backcrosses for 9 generations, using as male parent the tolerant to adverse rearing conditions strain, mass rearing;

3. Backcrosses for 3 generations, batch rearing;

4. New sex – limited breed.

The newly created sex – limited breeds have the following morphological characteristics:

SN1: the females are zebra, the males are with normal markings. The cocoons are white, elongated with constriction.

Iva 1: the females are with normal markings, the males are plain. The cocoons are white, dumbbell with high constriction.

Magi 2: the females are zebra, the males are plain. The cocoons are white in color, oval.

Nova 2: the females are with normal markings, the males are plain. The cocoons are white in color, oval.

In order always in the P1 generation to have females with zebra markings we performed only the crosses SN1 x Iva 1 and Magi 2 x Nova 2 (Tzenov, 2005, 2008). The average number of normal eggs in a laying in the 4 pure breeds was 618, while in the P1 crosses it’s 664. The performance of the pure breeds, their P1 crosses and the F1 commercial hybrid are given in tables 9 and 10

It is evident that both P1 and F1 hybrids manifest a comparatively high productivity. The F1 hybrid SN1 x Iva 1 x Magi 2 x Nova 2 was also tested under adverse rearing conditions (table 6) and showed a comparatively high pupation rate, compared with the control. The hybrid has been tested in the system of the State variety testing commission and approved as original.

It may be concluded that by breeding of 4 new sex – limited for larval markings strains a higher egg production efficiency by means of higher cocoon yield and fecundity at the P1 egg category level was obtained and a F1 four – way hybrid, having a high productivity, combined with a higher tolerance to adverse larval rearing conditions was created.

Breeding sex-limited for cocoon color strains as parents of commercial F1 hybrids, with high cocoon and silk productivity.

Three silkworm breeds were used, namely the Japanese breed D 50 and the Bulgarian breeds Super 1 and Hesa 2. The Japanese breed D 50 was received from the Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Fukuoka, Japan. The breed D 50 is genetically sex limited for cocoon color – the female cocoons are yellow and the male cocoons are white. The breed has larvae with ordinary markings and elongated cocoons with constriction. On the other hand the breed performs a very low productivity and the population contains the so called gene „translucent skin larva”. It’s known that this character is controlled by over 23 alleles, located at different chromosome loci. The „translucent skin larva” gene is also lethal or it determines sterility in the female moth. In the case of the breed D 50 the females with translucent skin lay eggs which embryo dies later on. In the D 50 breed population about 50 % of the larvae are with translucent skin and the rest have normal skin.

The breed Super 1 is of the Japanese type, having larvae with markings and spinning white cocoons with elongated shape. The breed Hesa 2 is of the Chinese type, having plain larvae and spinning white cocoons with oval shape. Both the breeds are highly productive and used as parental lines of several Bulgarian F1 commercial silkworm hybrids.

The breeding target was to create two new breeds having the same morphological characters and similar productivity as the original Bulgarian breeds Super 1 and Hesa 2, but sex limited for the cocoon color. For the purpose female individuals of D 50 strain were crossed with male individuals of Super 1 and Hesa 2. The breeding scheme is given in Fig. 1. The first generation (G1) was mass reared as mixture of 60 laying (one laying are the eggs laid by one mother moth) separated in 10 replications. In G1 all the female individuals spun only yellow cocoons and all the males – white cocoons which proved the stable inheritance of the linked with the W chromosome „y” allele, responsible for yellow haemolymph and yellow cocoon color. From the cocoons obtained, females with golden yellow cocoon color were selected and then measured individually to detect their fresh cocoon and silk shell weights and the shell ratio. The individuals having the highest parameters were selected and then mated with selected male individuals from the breeds Super 1 and Hesa 2. A random cocoon sample had been taken in order to check the silk reeling parameters of the population. The second generation (G2) obtained was reared and maintained by the same method and then crossed again with selected males of Super 1 and Hesa 2. During the fifth instar the larvae of the population D 50 x Hesa 2 G2 were separated into plain and with markings while only females from the plain larvae group were used for further breeding. Then in the 3rd generation (G3) a separate batch rearing was performed where the eggs of each silkworm moth were grown separately. Each population was reared in a volume of 32 laying each one having 200 larvae counted after the 2nd molt and then a selection of the 10 best laying regarding the pupation rate, cocoon, silk shell weights and shell ratio was implemented. The cocoons of the chosen 10 laying were measured individually and then only 20 female and 20 male cocoons from each laying, having the highest parameters were selected.

The selected cocoons from each laying were sib - mated in order to obtain the 4th generation (G4) which was inbreed. The purposes of this inbreeding were first to check the population uniformity reached at this stage through detecting the segregation after the inbreeding and secondly to reject the laying which manifest the „translucent skin larva” character. The fourth generation was reared in a volume of 32 separate batches, each 4 originated from one laying of G3 after inbreeding. After rejection of several 4 – laying batches manifesting the „translucent skin larva” character the rest laying/individuals were object of the same selection procedure like in G3. The selected female individuals of G4 were again crossed with males of the breeds Super 1 and Hesa 2 respectively in order to obtain the 5th generation (G5). Then the 5th generation was further reared and all the morphological and economically important parameters were detected.

During the larval rearing of each selection generation, separate batches of the breeds Super 1 and Hesa 2 have been also reared in parallel in order to make comparison between the productivity of the newly selected populations and the original breeds. The data obtained were processed statistically using the well recognized methods. Then in G 6 generation we repeated the inbreeding in order to obtain G 7, which generation was again crossed with males of Super 1 and Hesa 2 respectively. The 8th generation we already considered as a new breed and gave names of the newly bred strains as L 1 (D 50 x Super 1) and L 2 (D 50 x Hesa 2).

Hybrids between the new breeds L 1 and L2 as well as four – way hybrids L1 x Iva 1 x L2 x Nova 2 and the reciprocal crosses have also been produced and tested.

It is evident from the data shown in Table 11 that the breeds L 1 and L 2 still manifest lower values of the basic productive characters than those in the strains Super 1 and Hesa 2. May be an other reason is the depression which causes the translocation of the Y allele on the W chromosome (Kimura at al., 1971; Yamamoto, 1989; Datta at al., 2001). On the other hand the productivity of the newly selected breeds is much higher if compared with the Japanese sex limited strain D 50. This picture is however different in the new hybrids, compared with the control.

The data presented in Table 12 show that all the four sex limited for cocoon color silkworm F1 hybrids display a higher pupation rate than the control. The hybrid L1 x L2 and the reciprocal has fresh cocoon weight, silk shell weight and shell ratio very close to the control. Both new four way hybrids manifest lower than the control values of the three characters studied, which we explain by the participation in them as mail parents of the sex limited for larval markings breeds Iva 1 and Nova 2, having a higher tolerance to adverse rearing conditions, but a little lower productivity.

It may be concluded that we created 4 new sex – limited for cocoon color silkworm F1 commercial hybrids which manifest a pupation rate and productivity, comparable with those of the control, the hybrid Super 1 x Hesa 2.

REFERENCES

Datta, R. K., Basavaraja, H.K., Mal Reddy, N., Kalpana, G.V., Joge, P.G., Palit, A.K., Jayaswal, K.P. (2001)„CSR8” Sex limited bivoltine breed. A boon for graineurs. Indian silk 39 (11): 5-7.

Kimura, K., Harada, C., Akai, H. (1971) Studies on „W” chromosome translocated in yellow blood gene in silkworm, Jap. J. Breed. 21: 199 – 203.

Tzenov, P., Y.Natcheva, N.Petkov (1997) Study of on the cocoon coulor and cocoon shape characters inheritance in F1 crosses between in bivoltine and multivoltine races of the silkworm Bombyx mori L., Bulg. J. of Agric. Sci., 2, 181-185.

Tzenov, P., Y. Natcheva, N. Petkov (1998) Inheritance of the larval marking character in hybrids between multivoltine and unibivoltine silkworm, Bombyx mori L., races, Bulg. J. of Agric. Sci., 4, 3, 373-378.

Tzenov, P., Y.Natcheva, N.Petkov (1998) Cocoon shape inheritance in hybrids between multivoltine and uni-bivoltine silkworm, Bombyx mori L. races. Bull. Ind. Acad. Sericultural, vol. 2(2), 8-15, India.

Tzenov, P., N.Petkov, Y.Natceva (1999) Study on the inheritance of food ingestion and digestion in hybrids between univoline and multivoltine silkworm, Bombyx mori L., races, Sericologia, 39 (2), France.

Tzenov, P., Y.Natcheva, N.Petkov (1999) Study of the cocoon color segregation manifested in crosses between uni-bivoltine and multivoltine silkworm, Bombyx mori L. rаces, Sericologia, 39 (3), France.

Tzenov, P., Y.Natcheva, N.Petkov (2000) Study on the cocoon color segregation manifested in hybrids between uni-bivоltine and multivoltine silkworm, Bombyx mori L. races, Sericologia, 40 (1), 67-73 (France).

Tzenov P. & Z.I. De Guzman (2004) Breeding the new Bulgarian sex-limited for larval markings silkworm Bombyx mori L. commercial hybrid Ze/4 and study on its performance in the Philippines and Bulgaria, Sericologia 44(3), 297-312. (France)

Tzenov P. (2005) Study on the larval markings inheritance in some four-way hybrids between sex-limited for larval markings silkworm, Bombyx mori L. breeds. In: “International Workshop on Revival and Promotion of Sericultural Industries and Small Silk Enterprise Development in the Black & Caspian Seas Region”, Tashkent, Uzbekistan; 415-419.

Tzenov P. (2005) Breeding of new silkworm, Bombyx mori L. sex-limited for larval markings analogues of parental pure lines by the method of back crosses. In: “International Workshop on Revival and Promotion of Sericultural Industries and Small Silk Enterprise Development in the Black & Caspian Seas Region”, Tashkent, Uzbekistan; 419-424.

Tzenov P., D. Grekov (2007) Breeding of New Tolerant to Adverse Rearing Conditions Silkworm, Bombyx mori L. Four-way Uni-bivoltine Commercial Hybrids, Scientific conference on mountain agriculture, Troyan, May 2007.

Tzenov P. D. Grekov (2008) Development of methods for breeding new silkworm, Bombyx mori L. commercial hybrids tolerant to adversе rearing conditions. Annals of agrarian science, vol. 6, № 2, 71 – 76.Georgia.

Tzenov P., D. Grekov (2009) Breeding of new tolerant to adverse rearing conditions silkworm, Bombyx mori L. four – way uni – bivoltine commercial hybrids. In: Application of Biotechnology in Sericulture, 243 – 252. Bangalore, India

Tzenov P. (2008) Heterosis Expression in Some Main Quantitative Breeding Characters in Four – Way Sex-Limited for Larval Markings Silkworm, Bomby mori L. F1 Hybrids, 21st Congress of the International Sericultural Commission, 3 – 6 November 2008, Athens, Greece.

Yamamoto, T. 1989. Breeding of sex limited yellow cocoon races of silkworms by chromosome manipulation. Farming Japan 23 (5): 42 – 48.

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DIVERSITY OF INSECTS IN THE MULBERRY ECOSYSTEM

gkrajeshrajesh@gmail.com — Sun, 25 Jul 2010 17:56:00 +0000

A.Mahima Santhi and S. Prasanna Kumar

In this issue we present a very interesting paper by two entomologists of South India. The paper deserves special attention primarily because of its ecological approach to sericulture and entomological perspective to pest insects. Even though the primary responsibility of an agricultural entomologist is to device means to eliminate insects designated crop pests and to protect those designated economically important; the ecological balance between the pest, other (neutral) insects and the crop environment deserve his/ her attention in a long term perspective. This paper is notable at a time when such studies (at least in Moriculture) are becoming increasingly rare.

Dr. A. Mahima Santhi is a scientist with Central Silk Board, India. A post graduate in Agriculture from Tamil Nadu Agricultural University (TNAU), she earned her PhD in Agricultural Entomology from Manonmaniyum Sundaranar University, Thirunelveli, India. She holds more than eighteen years of research experience in sericulture and entomology under CSB. Currently she is heading the technical wing of Kerala State Sericulture Cooperative Federation (SERIFED) as its Deputy Director.

Dr. S. Prasanna Kumar is Professor & Head, Department of Zoology and Dean of Sciences, Scott Christian College, Nagercoil, India. A PhD in Zoology, he has more than thirty years of research and teaching experience in Entomology.

INTRODUCTION

The perennial nature of mulberry combined with monocultural practices, harbours several pests throughout the year with seasonal variations (Rangaswamy et al., 1976). The production of appreciable quantity of quality mulberry leaf is often hampered by insect pests belonging to large number of insect orders. Apart from insect pests, predators, parasitoids, naturals and detrivores also survive on mulberry plant. Studies on diversity are the preliminary for any management work. . Narendran (2001) explained that taxonomy is the foundation of biodiversity. Hence a survey was conducted in mulberry ecosystem to survey the diversity of the insects. The taxonomic diversity of the insect communities was worked out in the mulberry ecosystem.

MATERIALS AND METHODS

Survey on the insect diversity was conducted at Nagercoil, South India for continuous two years. The details of materials and methods are described here.

Insect assessment

The mulberry garden was divided into five sub plots, four at corner, and one at the centre. From each sub plots ten plants were selected at random for the observations. Thus 50 plants were observed every fortnight for two years. The number of mealy bugs, grasshoppers, scales, whiteflies, thrips, leafhoppers, bugs etc., feeding on the plants were counted. The total number of predators and parasitoids present on each selected plant were counted. Ants attending mealy bug populations were also recorded. Other insects such as butterflies, cockroaches present on the plant at the time of observation were also recorded. The soil insects such as carabids, termites were counted around the selected plants using Berlese funnel method. The average of the counted insects per ten plants was treated as one sample. The insects were collected, observed and unknown insects were preserved for identification according to Schauff (2002). The insects of various orders of class Insecta were distinguished.

RESULTS

The insects collected were identified and grouped in different orders of class Insecta according to Ambrose (2004). An average of 3388 insects was recorded per sample. Insects belonging to ten orders were recorded. The order Hemiptera recorded 60.86 per cent of total insects and order Hymenoptera recorded 22.05 per cent of insects. The order Coleoptera recorded 8.65 per cent. Other orders such as Isoptera, Lepidoptera, Dictyoptera, Odonata, Orthoptera and Thysanoptera accounted the rest. The distribution is detailed in chart.1

The details of insects recorded were given below as orderwise

Order: Hemiptera

It was the largest hemimetabolous orders with piercing and sucking mouthparts, with two sub orders, Homoptera and Heteroptera. Insects from both suborders were observed in the field.

Suborder: Homoptera

Insects which do not possess scutellum and has uniform leathery forewings are homopterans. Insects observed from this orders were herbivores. Important ones are detailed below.

Family: Pseudococcidae

Pseudococcids, generally called mealy bugs were the dominant insects. Their body was covered by mealy coating. Eggs were laid in loose cottony sac. Young ones were gregarious. Female were wingless and males winged. These mealy bugs secreted honey dew hence attended by ants. These ants protected mealy bugs from natural enemies. In the present study three species of mealy bugs were observed in the field. The mealy bugs recorded were.

a. Maconellicoccus hirsutus

These mealy bugs were present throughout the year except rainy months followed by winter season. The population was low during rainy season. The mealy bugs prefered tender leaves and twigs. Continuous feeding by mealybugs caused severe tukra symptoms.

b. Ferrisia virgata

The tailed mealy bug, which is a polyphagous pest, also infested young mulberry leaves. Their occurrence was very meagre to show any visible symptom, in few cases young shoots tips dried due to continuous feeding.

c. Planococcus citri

This was a serious pest found almost in all the months in the second year and summer months in the first year. Young ones fed on tender leaves and caused curling of leaves but not clustered like tukra. The grown up ones were seen feeding on the nodes and uniformly distributed throughout the stem. On continuous feeding the leaves become yellow and withered off. When there was severe feeding the terminal bud was killed which caused the sprouting of ancillary bud. Severe damage made the stem to dry. The mealy bugs were attended by black ant, Camponotus compressus.

d. Paracoccus marginatus

Recently papaya mealy bug incidence was noticed on mulberry crop in western parts of Tamil Nadu and Palghat district of Kerala. The papaya mealy bug is found on leaves, stem and twigs. Adult females are yellowish with short waxy filaments around the margin. The dispersal stage is the first instar crawler. The mealy bug injects a toxin as it feeds on leaves, which results in chlorosis (yellowing), stunting, deformation, early leaf drop, and buildup of honeydew. Sooty mould growing on honeydew excreted by the mealy bugs interferes with photosynthesis. Heavy mealy bug infestation kills the plants.

Highly polyphagous in nature.

Family: Margarodidae

The insect Icerya aegyptiaca was seen feeding from undersurface of the leaves. These insects were seen in groups or single. These bugs were bigger in size and orange coloured with black legs. The body was covered with white mealy waxy strands. Eventhough the pest was seen in majority of the months, the damage symptom was not serious. The population was higher during summer months.

Family: Aleyrodidae

Aleurodicus dispersus, the white fly were minute active whitish insects resembling tiny moths. The body and wings were covered with white powdery coating. The eggs were laid in irregular spirals. The white nymphs and adults were seen on lower surface of leaves. The desapping of leaves depleted the nutritive value of leaves. The incidence was noted from late January to early April.

Family: Membracidae

The cow bugs Oxyrachis tarandus were seen feeding on tender shoots. The nymphs were attended by ants. Their occurrence was very meagre. Small specks were seen at the feeding site.

Family: Coccidae

The black scales, Saissetia nigra were seen on stem and on lower side of the leaves. The occurrence was noted from January month to May. No severe damage noticed.

Family: Cicadellidae

The leaf hopper, Empoasca flavescens, adults, and nymphs fed on tender leaves and caused “hopper burn” symptoms. They were very active and jump, can move sideways. The incidence was noted during July to October months. The insect population was very low to cause economic injury.

Suborder Heteroptera

Family: Pentatomidae

The shield bug, Scutellera nobilis was seen very rarely on mulberry and did not cause much damage.

Family: Reduviidae

The assassin bug, Eirantha armipes were seen during rainy months June-July. This was an effective predator.

Order: Hymenoptera

Family: Formicidae

Beneficial interaction existed between the mealy bug and ants. The dominant M. hirsutus population was heavily influenced by ant population. The predator population in the ant attended colonies was significantly lower. Ants were seen attending mealy bug colonies.

Family: Sphecidae

The mud dauber wasp, Ammophila procera were seen very rarely on mulberry leaves. The females hunt for arthropod prey which serves as food for their offspring.

Family: Encyrtidae

The small parasitoid, Leptomastix dactylopii was rarely seen in the garden. But the parasitized mummies of mealy bug were seen during non-rainy months.

Order: Coleoptera

Coleopterans are the insects with biting and chewing mouth parts with hard exoskeleton. Forewings were hardy and hind wing membranous.

Family: Cerambycidae

The stem girdler, Sthenias gristator was seen during February month of the first year. The adult beetle girdled the young green branches of the mulberry plant and caused drying of the twig. The bark and wood up to the centre were cut by powerful mandibles and in few plants entire twig was cut into two bits.

Family: Curculionidae

Ash weevil, Myllocerus discolor and M. viridanus were seen on mulberry leaves. The presence of this beetle was recorded throughout the year. Their occurrence was slightly higher during summer months. Damage symptoms were not severe.

Family: Scarabaeidae

The dung beetles or dung rollers, Scarabaeus sp were seen on the soil during summer months. They produced dung balls for egg laying. They are grouped under scavengers.

Family: Carabidae

The ground beetle Carabus nemoralis were found throughout the year in the soil. The beetles were mainly predators.

Family: Coccinellidae

Two predatory beetles were recorded. Nephus regularis (Sic.) was the common predominant predator seen feeding on mealy bugs. They were seen inside the tukra curls. The grubs were black coloured with white mealy coating seen inside the tukra curls feeding on mealy bugs. Adults were very small oval shaped brown coloured beetles. The population of this beetle increased with increase in mealy bug population. The activity of beetles was not seen on tukra affected branches with ants.

Another yellow lady bird beetle recorded was Illeis cincta. The yellow coloured grubs and adults were seen on plants feeding on powdery mildew growth on leaves. Their occurrence was higher during winter months.

Order: Thysanoptera

Small insect with rasping and sucking mouth parts.

Family: Thripidae

The thrips, Pseudodentrothrips mori injured the epidermal tissues of leaves and desapped Leaves showed streaks in the early stages and blotches in the later stages. Leaves became brittle and were unsuitable for feeding silkworms. In severe case of attack leaves whither and dried. The attack was seen during May and June of the first year. The second attack was during December to February. Then the attack was repeated during May and June in the second year.

Order: Orthoptera

Medium sized insects with mandibulate mouthparts, the hindlegs are enlarged facilitating jumping.

Family: Acrididae

The short horned grasshopper Neoorthacris nilgriensis or wingless grasshopper was present throughout the year. The population showed slight increase during summer months when other plants dried without irrigation. The insect had shorter antennae and ovipositor. The wings were not present.

Other insects of this order, long horned grasshopper, Tettigonia viridisima of Tettigonidae and field cricket, Gryllus sp. of Gryllidae were also present in the garden.

Order: Isoptera

Soft bodied, social and polymorphic winged species living in large colonies, with biting mouth parts.

Family: Termitidae

The termites Odontotermes sp. feed upon roots and barks of young and old plants. Severe attack leads to death of plant. These termites build colony structure and live socially with workers, soldiers and queen. The presence of termite was higher during summer months.

Order: Lepidoptera

Lepidopterans are holometabolous insects, adults brightly coloured, winged insect with long tubular suctorial mouthparts. The larvae are soft bodied caterpillars with biting mouth parts. The pupae are generally enclosed in a cocoon.

Family: Pyraustidae

Diaphania pulverulentalis, the leaf roller of mulberry, incidence were recorded during September and October months. The larvae damaged by folding the leaves and by webbing the tender shoots. Early instars fed from inside the web and skeletonize the leaves. Later instars fed the tender leaves voraciously. Larval feeding caused qualitative and quantitative loss of leaves.

Other insects of Lepidoptera present were Eurema hecabe of Pieridae, Catochrysops cnejus of Lycaenidae and Danaus plexippus of Danaidae. They were neither harmful nor useful to mulberry.

Order: Odonata

The dragonfly, Libellula quadrimaculata of Libellulidae and Damselfly, Protoneura sp of family Protoneuridae were commonly seen in the mulberry leaves. These insects were general predators.

Order: Dictyoptera

Suborder: Mantodea

The preying mantis, Mantis religiosa of family Mantidae was recorded. They were effective general predators.

Suborder: Blattaria

The field cockroach Blattella sp of family Blattellidae were seen scavenging on mulberry plants. The insects occupied the tukra curls for shelter.

DISCUSSION

The order Hemiptera was the prominent order. Around 60 to 62 per cent of insects belonged to order Hemiptera. Under Hemiptera order, six homopterans and two heteropterans were recorded. The family Pseudococcidae with four species of mealy bug was the largest family recorded. Next homopteran recorded in the garden was whitefly. Hymenoptera was the second dominant order in the garden. Ants were found in association with the homopterans. There was a beneficial interaction between homopterans and ants. The parasitoid of mealy bug Leptomastix dactylopii was also recorded under this order. These insects were used in bio control programmes often in mealy bugs. (Noyes and Hayat, 1988).
The order Coleoptera was the third largest order in the garden. The coccinelids were dominant and seen throughout the year. They were effective predators of soft bodied insects and also feed on fungal growth such as powdery mildew. This was also reported by Joshi et al., (2003). The carabids were found next to coccinellids in the field. Allen (1979) reported carabids as beneficial insects.

Insects of Isoptera, Lepidoptera, Dictyoptera, Odonata, Orthoptera and Thysanoptera were found in mulberry ecosystem. Among these insect orders, Odontotermes obesus of Isoptera, Diaphania pulverulentalis of Lepidoptera and Pseudodentrothrips mori of Thysanoptera were serious pests of mulberry ( Sathya prasad et al., 2000 and Dandin et al., 2001).

The trophic interaction between plants, herbivores, natural enemies and others were studied in the mulberry field and detailed in chart.2. In the present study 68 per cent of phytophagous, 4 per cent of predators, 25 per cent of ants, 1.5 per cent of scavengers, and 1.5 per cent of neutrals were recorded. These studies should be done in all mulberry ecosystems. The natural enemies should be preserved in the garden. The balance between phytophagous insects, natural enemies, detrivores, and neutrals should be maintained for a successful mulberry crop.

REFERENCES

Allen, R.T. 1979. The occurrence and importance of ground beetles in agricultural and surrounding habitats. In T.L. Erwin, G. E. Ball and D.R white head (eds) Carabid beetles their evolution, natural history, and classification. W.junt, The Hague, The Netherlands. 485-505pp
Ambrose, D.P. 2004. The insects, structure, function, and Biodiversity. Kalyani publishers, Chennai. 821 p.
Dandin, S.B., Jayaswal, J. and Giridhar, K. 2001. Hand book of Sericulture technologies. Central silk board, Bangalore, 287p.
Joshi, S., Mohanraj, P., Rabindra, R.J. and Rao, N.S. 2003. Production and use of coccinellid predators. Project Directorate of Biological control, Bangalore, India Bull. 32, 26 p.
Narendran, T.C. 2001. Taxonomic Entomology, Research and Education in India. Curr. Sci., 81 (5): 445-447.
Noyes, J.S and Hayat, M. 1998. Oriental mealy bug parasitoids of the Anagyrini (Hymenoptera: Encyrtidae). CAB International, 551p.
Rangaswamy, G., Narasimhanna, M.N., Kasiviswanathan, K., Sastry, C.R. and Jolly, M.S. 1976. Sericultural Manual, Mulberry cultivation, FAO., Rome,150p.
Sathyaprasad, K., Manjunath, D., Mala V. Rajan and Sarkar, A. 2000. Screening of mulberry germplasm for tolerance to sucking pests. Abs. Ntnl. con. Str. for Seri. Res. dev. CSR&TI, Mysore, M 1 :7
Schauff, (2000). Collecting and preserving insects and mites, techniques & Tools, Systematic Entomology laboratory, USDA, Washington. 66p.

Is Perfect Research Possible?

gkrajeshrajesh@gmail.com — Mon, 19 Jul 2010 05:36:00 +0000

GK. Rajesh
Recently I was asked to write an essay, expressing my views on the statement "There Is No Hope of Doing Perfect Research" by the selection panel of a content writing employer. I gave them the following answer, which I wish to share with my readers.

The given question on research can be put to any ‘human activity’ and still be found equally difficult to answer. Is it possible to do anything perfect? The quickest possible response is ‘no’. A little reflection will show that this answer in the negative has nothing to do with the activity under question. It is the perceived notion of the word ‘perfect’ that drives the respondent towards the negative answer because anything perfect is understood to be ‘nearly impossible’ let alone research. Usually ‘perfect’ as an adjective is used for harmless, jocular exaggeration of the quality under question. For example the expressions ‘a perfect fool’ or ‘perfect nonsense’ do not mean the qualities under question to be absolute. They are rather cursory and superficial remarks than conclusions of any serious investigation. One rarely encounters such expressions in scientific literature. Similarly the expression “perfect research” is not found in any standard literature. Instead, terms such as reliability, validity, credibility transferability and trustworthiness are used to indicate various desirable qualities of research work (Golafshani 600). Hence, in this essay the term ‘perfect’ will be used to collectively represent these terms.

The term ‘research’ is defined as follows: “Scientific or scholarly investigations especially study or experiment aimed at the discovery, interpretation or application of facts, theories, or laws” (Allen1188), “Careful study or investigation, especially in order to discover new facts or information” (Hornby 996), “Diligent, protracted investigation” (“Webster’s” 1071). Thus research constitutes investigation and discovery/ interpretation/application of knowledge. A research may be safely regarded as fruitful if it results in the discovery of an object or a procedure which it is intended for. To call it perfect demands more assessment with regard to the quality of the discovery (whether it has all the qualities, excellences or elements that are requisite to its nature or kind), the procedure adopted (whether without fault or defect) and the way in which it was executed (whether economic and without negative externalities). For example the discovery of penicillin, in spite of its great utility may not be called perfect research since it was rather an accidental finding than result of systematic investigation originally intending to its discovery. Alexander Fleming wrote “… I certainly didn’t plan to revolutionize all medicine by discovering the world’s first antibiotic, or bacteria killer, but I suppose that was exactly what I did …” (qtd. In Wikipedia.org). The discovery of molecular structure of DNA traced from its origins in 1868 by Friedrich Miescher to the celebrated work of Watson, Crick and Wilkins in 1962 could be considered as a continuum of perfect research. While quantitative research1 is more amenable to such assessment, qualitative research2 is not.

Two case studies on my own research cited here are examples of quantitative research with mixed results. The first was my Master’s Degree dissertation work on temperature induced protein synthesis in silkworms (Rajesh GK, “Induction of Heat Shock”). Heat shock proteins are specialized proteins which are synthesized in living cells under stress of any kind. They are known to perform protective actions within the cell under trauma. My intention was to study the threshold temperature which triggers heat shock response in silkworms. The theoretical premise in which the experiment was set was excellent and the research question meaningful. But the work lacked in focus. In my slightly over enthusiastic mindset I set a very ambitious objective, not only to track down heat shock proteins but also to assess their differential expression in two breeds of silkworms. The experiment proved to be too big to fit in the time span permitted for an MSc dissertation. Though I could complete the experimental part as per my original design and with a high level of accuracy3 I could not subject the huge data generated into fruitful analysis and interpretation. Nevertheless the fraction of data that I could use was systematically put together into a neat report which received good remarks. I realized my mistake only at the end of the work. I had ben simply over ambitious and neglected the importance of focusing on the specific problem and conceptualizing the research work in a practical manner. I am sure, given more time to understand my mistake, the work could have been more systematically organized and made perfect. After all the empirical investigation was done perfectly, evidenced by the concordance of observations in replications.

The second example is of my MPhil (Economics) dissertation on factors determining adoption of a (new and improved) technology by sericulture farmers in India (Rajesh GK, “Diffusion”). I investigated the reasons why a superior silkworm hybrid had not diffused well in the country in spite of great efforts from the government for more than a decade. Being better informed and having grown wiser out of the previous experience, I was more vigilant and pragmatic this time. After an exhaustive literature survey and expert consultation a very specific and real world problem was spotted down. The proposal was presented before a distinguished panel and finalized after incorporating suggested modifications. The theoretical background was strong and the study was conceived with clarity. The empirical investigation was planned to the minutest detail and the survey questionnaire perfected after a mock survey. The data was subjected to rigorous statistical analysis and the findings were written down systematically into a comprehensive yet concise report. The dissertation was awarded with an A-plus and I received an almost flattering comment from the external jury (which I consider I am not entitled to). But I do not deem the work perfect. Once the survey was completed I realized that in spite of all my preparatory work the sample selected by me was not quite representative of the country and the sample size too small given the diversity of technology adoption strategies employed by the target population. Since it was a time bound assignment I could not extend my survey to capture the diversity. I am sure that it would make a perfect piece of research if repeated with a bigger and different set of samples.

My own imperfect researches are not convincing proof to conclude that there is no hope for perfect research. I do not agree to the statement ‘there is no hope for perfect research’; it could be so only if the term ‘perfect’ is taken on its ‘utopian sense’ of ‘ideal’. Then it is as good (or bad) as saying- anything human is imperfect. The European Commission’s Expert Group on Assessment of University Based Research commented

“There is no single set of indicators capable of capturing the complexity of research and research assessment. There is no such thing as a perfect indicator; all indicators have their own specific strengths and weakness, and assessment exercises have to take this into consideration from the outset … (“European Commission” 12).”

If there is no perfect indicator for research assessment there is no point in looking for perfect research. Research is the life blood of human development; it is relentless quest for truth. When truth itself is subject to change, there is no meaning in idealizing research, which is one of the means for attaining it. According to Schwarts, “… research is immersion in the unknown. We just don’t know what we are doing. We can’t be sure whether we are asking the right question or doing the right experiment until we get the answer or the result …” (1771). He calls this “productive stupidity” and concludes that “The more comfortable we become with being stupid, the deeper we will wade into the unknown and the more likely we are to make big discoveries”. Why waste time, thinking whether stupidity is perfect!

NOTES

1. Patton defines quantitative research as “use of standardized measures so that the varying perspectives and experience of people can be fit into a limited number of pre-determined response categories to which numbers are assigned” (qtd. In Golafshani 598)
2. Strauss and Corbin define qualitative research as “any kind of research that produces findings not arrived at by means of statistical procedures or other means of quantification” (qtd. In Golafshani 600)
3. Accuracy with respect to raising the biological specimens, adhering to the scientific standards and in quantifyication and electrophoretic separation of proteins.
Bibliography
Allen, Robert. The New Penguin English Dictionary. India: Penguin Books; 2000. Print
European Commission. Assessing Europe’s University-Based Research. Brussels: Directorate-General for Research Communication Unit; 2010. Web.
Golafshani, Nahid. Understanding Reliability and Validity in Qualitative Research. The Qualitative Report Volume 8 Number 4. Web. December. 2003
Hornby, AS. Oxford Advanced Learner’s Dictionary of Current English. London: Oxford U.P; 1997. Print
Rajesh, GK. Diffusion of the bivoltine hybrid silkworm in India. M Phil. Dissertation submitted to the Jawaharlal Nehru University, India; 2008. Print
Rajesh, GK. Induction of Heat Shock Proteins Under Temperature Stress in Silkworm Bombyx mori L. Races Analysed by SDS PAGE. MSc. Dissertation submitted to the Mysore University, India; 2005. Print
Schwartz, Martin A. The importance of stupidity in scientific research. The Journal of Cell science. 121, 1771; Web. April. 2008
Webster’s Comprehensive Dictionary of The English Language. Chicago: Ferguson Pub; 1995. Print

PACKAGE OF PRACTICES FOR MULBERRY CULTIVATION AS TREE PLANTATION FOR RAINFED SERICULTURE

gkrajeshrajesh@gmail.com — Sat, 19 Jun 2010 14:35:00 +0000

PK. Das, SB. Magadum and DS. Chandrasekhar
Dr.P.K.Das is Scientist-D at Regional Sericultural Research Station (RSRS), Central Sericultural Research & Training Institute, Central Silk Board (CSB), Government of India Chamarajanagar, Karnataka, India. He has put up a service in Central Silk Board, for more than 28 years. He worked for more than 20 years at Central Sericultural Research & Training Institute (CSR&TI) Mysore in Agronomy laboratory and developed a number of technologies for cost effective mulberry cultivation. Among his interests are recycling technologies of sericultural wastes, compost and vermicompost, Azotobacter and VA-mycorrhiza as biofertilizers and developing Integrated Nutrient Management for mulberry cultivation. He was selected as the best scientist of moriculture of CSR&TI, Mysore in the year 2005. At RSRS Chamarajanagar he is developing technologies for rainfed mulberry. He has more than 100 research publications in national and international journals and guided four Ph.D students in Applied Botany under the university of Mysore. He has also visited Japan under Japan International Co-operation Agency (JICA) project of Central Silk Board during the year 2000. Dr. Das can be contacted at pkd3@rediffmail.com

Dr. S.B. Magadum is Scientist-D with CSR&TI, Mysore, India. He has more than 35 year’s research experience. A veteran silkworm physiologist, he has published more than 140 research publications in national and international journals. Dr. Magadum can be contacted at sbmagadum@rediffmail.com

Dr. D.S.Chandrashekar is Scientist –D and in charge of RSRS, Chamrajanagar. He is an expert of mulberry pathology. He has more than 33 year’s research experience. He is currently supervising 6 Ph.D students and have more than 100 research publications in national and international journals. Dr. Chandrasekhar can be contacted at rsrschnagar@rediffmail.com

What is tree mulberry?

The mulberry plants which are allowed to grow tall with a crown height of 5 - 6 feet from the ground level having stem girth of 4 -5 inches or more is called tree mulberry. They are specially raised with the help of well grown saplings of 8 - 10 months old with any of the varieties recommended for rain fed areas like S-13 (for red loamy soil) or S-34 (black cotton soil) which are tolerant to draught or soil moisture stress conditions. Usually the plantation is raised as block plantation with a spacing of 6 feet x 6 feet or 8 feet x 8 feet as plant to plant and row to row distance. The plants are usually pruned once in a year during monsoon (July - August) at a height of 5 - 6 feet from the ground level and allowed to grow with maximum of 8 - 10 shoots at crown. The leaf is harvested 3-4 times in a year by leaf picking method under rain fed or semi-arid conditions depending upon the monsoon.

Fig-1: Two years old mulberry tree plantation

Concept of tree plantation:

Combining trees and field crops in arable lands is called as "agro-forestry". The objective of agro-forestry is to improve the productivity and sustainability of land management system through introduction of woody perennials in herbaceous crop husbandry. Selection of tree species to be used in agro forestry must be based on cultural and economic as well as environmental and biological factors. Thus growing mulberry as tree in highly eroded flat to gentle sloppy land unfit for growing arable crops, arable lands with soil fertility problems, degraded sloppy land can serve as one of the best means of agro-forestry.

Who can grow tree mulberry?

Mulberry is a perennial plant with reasonably drought tolerance capacity. It can be cultivated as a trained tree by maintaining specific spacing between trees and crown height. This type of mulberry plantation is highly suitable for farmers of semi-arid / rain fed areas in plain land, hilly regions or in denuded lands unsuitable for agriculture. This form of cultivation is already been practiced in temperate and hilly regions. Of late, the concept of tree cultivation has also spread into the plains as a sustainable crop under severe water stress condition in waste and denuded lands. With the recommended packages, it is now possible to get about 6 - 8 MT of mulberry leaf yield per hectare per year through 3 - 4 harvests. It is also possible to take up appropriate inter crops in the tree mulberry plantation to reap higher economic benefits. Considering the above, mulberry can be cultivated under rain fed conditions with different systems of cultivation. These include;

(a) Bush system of mulberry cultivation: under protective irrigation.

(b) Low-height tree type mulberry cultivation: Suitable in hilly regions.

Package of practices for mulberry tree plantation:

Development of mulberry tree saplings:

The mulberry saplings are developed in the nursery. A flat land nearer to water source is preferred as nursery site. Well drained land with loamy soil is ideal for nursery. The land must be ploughed or dug 30‑40 cm deep and allowed for weathering in sun for 2 - 3 weeks. Land is again ploughed two or three times to bring the soil to fine tilth. Root stocks, pebbles and weeds are removed at the time of ploughing and the land is leveled. The land is divided into a number of small beds to prepare the nursery. The size of each bed is decided keeping working convenience in to mind. A bed size of 3.0 m (L) x 1.2 m (B) accommodates 100 cuttings (row to row 30 cm and cutting to cutting in a row 10 cm distance) to raise 8-10 months old saplings. Each bed on all sides is separated by a bund of 25 to 30 cm width and height and provided with irrigation channel of 25 to 30 cm width and 15 to 20 cm depth. Each bed should be manured and mixed thoroughly with 5 pans of FYM / sericulture compost / vermicompost. In the case of clayey or black cotton soil, additional 5 pans of sand per bed should be mixed with soil uniformly. In the case of red loamy or sandy loam soils, there is a possibility of termite infestation. As a preventive measure, 0.1 % Chloropyriphos (5 ml per litre of water) can be sprayed to drench the soil of nursery beds (2-3 litres per bed). Regular care and irrigation should be provided for good growth.

Fig-2: Mulberry nursery under preparation

Transplantation of saplings from the nursery

For tree plantation, the saplings are transplanted from the nursery after 8-10 months of maturation. The matured saplings are removed from the nursery by deep digging and without damaging the roots. It is advisable to irrigate the nursery beds thoroughly at least 2-3 days before uprooting to facilitate easy and complete removal of saplings with roots intact. The uprooted saplings are immediately planted in the main field after removal of leaf, top clipping and dipping the roots of the plants in 0.2 % solution of Diethane -M 45 to avoid fungal root disease.

Fig-3: Appropriate mulberry cuttings for nursery to grow as saplings

Plantation of saplings in the main field & establishment care:

A flat / sloppy land with red loamy / black cotton soil or denuded land not suitable for other agricultural crops can be selected for raising tree mulberry as block plantation. Plantation can be taken only during rainy season preferably in July - September or depending upon the onset of monsoon. The land should be thoroughly ploughed by tractor / bullock plough depending upon the soil condition after receiving one or two pre monsoon shower and weeds should be removed.

Fig- 4: One year old mulberry saplings ready for transplantation as tree plantation.

Once the land is made ready, farmyard manure / sericulture compost can be applied @ 10 MT/ ha and mixed with the soil. It is highly necessary to follow soil moisture conservation practice by raising wide bunds all along the four boundaries of the plantation to avoid runoff and allow rain water percolation in the planted area during monsoon. Before plantation, pits of the size of 35 cm (L) x 35 cm (B) x 35 cm (D) are dug at 8 feet apart from each other considering plant to plant and row to row distance as 8 feet x 8 feet. Each pit is then planted with one transplanted matured sapling exactly in the centre of the pit. To determine the centre of the pits and to keep the rows straight to avoid zigzag plantation, two ropes are used length and breadth wise and the intersecting point of the two ropes is considered as the centre of each pit. The pits are then filled with soil and pressed properly for better anchorage with the ground. Once the plantation is over, all the planted saplings are pruned uniformly at 5 feet height (crown height) from the ground level within 2-3 weeks and allowed to grow for 8-10 months as establishment period or even a year without harvesting leaf / disturbing the plants. However, weeding should be done as and when required during the establishment period to facilitate better growth. After 4 -5 months of plantation, the first weeding is done manually or by using power tiller to avoid damage and chemical nitrogen fertilizer only @ 50 kg per hectare is applied to boost the growth of plants. The required fertilizer in the form of urea / ammonium sulphate is applied near each plant by making basin and irrigation is followed. If required gap filling can be made with properly grown sapling. Plants should be given life saving irrigation as and when required in non rainy period for better establishment. Further, the whole planted area can be divided in to small blocks of 15 - 20 plants in each having wide bunds all along the four sides to allow in-situ soil moisture conservation during rainy season. During the establishment period, the plants may attain a height of 10 -15 feet from the ground level with three to four branches if properly maintained.

Fig-5: Mulberry tree plantation under progress in main field.

Pruning and package to be followed from the second year:

Once the plantation is established properly, the plants are pruned uniformly at the same crown height (5 feet) where the plants were pruned earlier during the time of plantation. This should invariably be followed only during rainy season (July - September) to facilitate the vigorous growth of shoots from the second year onwards. Farmyard manure @ 10 MT per hectare per year is applied within a week of pruning and the weeding is followed with the help of tractor / power tiller / country plough to mix the manure with soil and to save the manual lobour days. Immediately after this basins around the plants are cleaned to apply fertilizers and allowing rain water percolation near the plants. Depending upon rainfall, chemical fertilizer NPK is applied @ 150:60:60 kg per hectare per year in two equal splits in the form of ammonium sulphate for alkaline soils or urea for acidic soils in early and later part of rainy season. Green manuring with sunhemp or dhaincha for the improvement of soil fertility and water holding capacity or intercropping with short duration crops (Groundnut, Cowpea, Horsegram , Ragi etc) for augmenting income can also be done from the second year onwards. If the plantation is inoculated with VA-mycorrhiza followed by green manuring, reduced dose of FYM & NPK fertilizer can be applied @ 10 MT and 50:25:25 kg per hectare per year respectively. Leaf can be harvested by individual leaf picking after every three months depending upon the rainfall and soil moisture condition. Thus it is possible to harvest 3 - 4 crops annually ranging from 7 - 8 MT of leaf per hectare per year.

Fig-6: Pruned mulberry saplings after one year of plantation.