CropWatch

West: Tough fungicide choices coming up

2012-02-06T12:45:21Z

February again and is spring just around the corner? It certainly seemed like it 10 days ago with fields looking as green and advanced as a normal March. The cold snap has steadied things up and at least the Charlock looks a bit sicker now. Once again frost had the greatest effect where SOLA bifenox was applied previously.

A striking effect of the mild winter was seen last week in South Wales in a BYDV trial. Untreated plots and the guard area around the trial were heavily infected; plants in these areas had roughly half the biomass of those in the treated areas.

Most cereals have high shoot numbers and will require careful nitrogen and PGR management. Even with high levels of mildew winter barley still carries lots of tillers. Wheat is very similar with early drilled Grafton carrying 10 or more tillers. Don't forget that HGCA lodging rating is not an absolute figure and can vary by several points depending on sowing date and shoot number. Root lodging is likely to be most severe in early sown, over thick crops so take every step to keep these crops in check.

Grass weed control has been generally good in cereals with virtually all the bad blackgrass fields receiving their full programme of treatments before Christmas. We even managed to treat a few fields with post emergence materials in January - they have worked very well. A few later ones will need a tidy up as soon as this cold snap passes and soil temperatures rise.

Oilseed rape continues to produce leaf and large canopies are the norm. We have been monitoring carefully for light leaf spot but so far have failed to find infection. All crops had a prothioconazole treatment in late autumn for Phoma. We will ensure that our stem extension PGR fungicide has good light leaf spot activity.

Looking ahead, my inbox and desk top are creaking under the weight of SDHI promotional material. I think fungicide selection this year will be like picking an England rugby team! Will it be a complete clear out of the old stagers or will there still be few places for the old heads? None of the older fungicides have retired yet but perhaps a few are showing their age! The triazoles certainly need more help to do the same as 10 years ago.

North: More winter required

2012-02-06T12:22:20Z

At last, a nice bit of winter though there's no promise of it lasting, but let's hope. Up until last week, we'd only had seven frosts with only one before Christmas - on 7th November. Therefore, we have to expect significant aphid numbers and a serious threat of BYDV - unless this bit of winter lasts and particularly if we get serious cold without snow cover. It's not been cold enough yet and snow is coming.

Oilseed Rape crops have thick, strong deep roots and a nice rosette from which to develop new growth. Thankfully, all our efforts to control Cabbage Root Fly appear to have worked as all crops inspected since New Year are free from this damaging pest. However, I am still expecting to see crops which were not treated in autumn taken out in spring - as happened last year. Phoma & light leaf spot levels are very low so, despite all the commercial hype, they don't require any treatment.

Rape crops are obviously short of nitrogen, as all recent new growth has been robbing older leaves for the nitrogen to do it. Therefore, even well established crops will be having fertiliser this month - but not much in terms of rate and preferably as a high-ammonium product to minimise leaching risk.

Wheats are still full of mildew, but it's not active so is not a problem. Rust levels, however, are a high risk but there is no panic. Just make sure that T0 fungicides are ordered up for March.

Before that, we may have to start taking out truly massive wild oats which will make control tricky in early March, as we normally use the potent grass herbicides in April when it's warm enough. Quite a number of crops will require two-stage treatment, with the extra cost - ouch!

South: Pigeons arriving in numbers

2012-02-06T11:58:07Z

The cold weather has finally brought the GAI of oilseed rape crops back to somewhere close to where we would expect them to be at this time of year. Over the last month they have lost 0.75-1.0 GAI, which means that the forward crops are now allowing carbetamide applications to hit the ground where it's needed.

Two nights dropping to -10C have helped Fox (bifenox) to work on charlock. I was worried about how some crops going to look where there was more charlock than rape.

With the cold weather the pigeons are just starting to arrive but numbers are still far lower than we would normally expect. While the cold weather lasts I'm expecting numbers to increase. As long as they are not eating the crown of the plant they won't be doing any major damage, however be ready to control numbers before they do damage.

Cereals that had high levels of mildew, and in places rust a month ago now look a lot cleaner, again due to the cold weather. I have found crown rust in forward oat crops last week. The downside is that in wheat, the levels of septoria are now clearly visible - I think a lot of it was there before but was being 'hidden' by the mildew.

Disease risk is still high for this year, so unless the cold weather lasts for most of this month then T0 sprays will need to be robust and very well timed. The longer the cold weather lasts, does mean that timings for the start of disease control programmes will become more normal. At the moment things may well start considerably earlier than we expect.

More manganese deficiency is visible than I would normally see, especially on heavier land and on barley crops. These will want treating as soon as possible, maybe before we do anything else. Correcting trace element problems will also help to reduce stress on crops which in turn can reduce disease levels especially mildew.

East: Cold spell will help clean up brassica weeds in OSR

2012-02-05T16:39:13Z

As this is being written, three inches of snow cover the ground and there have been at least three decent frosts. All this, is to my mind, is a very good thing. Many crops are just too lush and forward especially since the Christmas period, with them greening up and appearing to be taking up mineralising nitrogen. It's just not right for this time of year.

Disease levels in wheat which had calmed down during late November were being reported as increasing again, particularly yellow rust with some brown rust as well. Many people had resisted the urge to apply fungicide up to this point on the advice of most experts, but if the mild weather had continued, rethinks were on the cards.

However, this spell will certainly put a brake on things and may bring things back to where they should be disease wise anyway, time will tell.

Management of these forward crops is, however, going to be a perplexing issue, particularly in fertilising and plant growth regulation. This also applies to oilseed rape.

Cereal herbicide effectiveness has been very varied due to the dry conditions in the autumn with some follow-up sprays also not working to their best. This is going to be very problematical, especially in relation to blackgrass. Quite a few wild oats are also showing up though these will be easier to deal with.

The one thing that must not happen where blackgrass is to be treated is a reduction in the rate of the iodosulfuron/mesosulfuron products from the recommended one. At the moment there is nothing on the horizon to control blackgrass even remotely effectively post-emergence so the loss of these materials to continued resistance must be avoided. Short term gains will lead to long-term pain!

One other benefit of this cold period is the obvious discomfort of the large amounts of brassica weeds that have dogged many rape crops. Many crops have been treated to a greater or lesser effect, but the combination is now working on these bigger weeds.

The few crops of herbicide tolerant oilseed rape are, however, clean from these brassica weeds showing the effectiveness of this technique.

West: Absence of pigeons a blessing for late emerged crops.

2012-01-31T10:00:29Z

The mild autumn has meant that crops have continued to grow, which has been a huge relief where crops were starved of moisture until rain arrived around the 3rd week October and did not emerge until that point. It has also allowed the very backward rape crops to get to the advanced stage of 4 true leaves and pretty much all germinate!

Ground conditions are very good as, in fairness, it has to date been relatively dry since the first rainfall of October. We have had somewhere in the region of 5" of rainfall since that point.

We had our first taste of winter three weeks ago, with a four day run of temperatures down as low as -5C. Frosts are forecast for most of this week as well. The good field conditions has meant clients have started to apply P&K where required. With the warm winter some wild oats are already 8-10" tall and I have been finding spring germinating wild oats for the last 2-3 weeks.

Winter barley crops are very forward and some were treated with a mildewicide late November/early December, along with manganese, due to the extreme levels of mildew. Frost has now quietened the mildew down on untreated crops and if we have a cold February then I suspect we may well hold off until T1. I will monitor dependent upon weather conditions. Crops treated with manganese in the late autumn have as yet not required a follow up treatment and untreated crops are OK to date.

Open oilseed rape crops that were big enough were treated with carbetamide pre-Christmas. Remaining crops that are more forward have opened up since the frosts which has allowed more to be done and I am sure that another cold week will allow us to finish off the remaining crops.

I have yet to see any major issues with pigeons, which again has been a real blessing where crops emerged late and are small. I am convinced that the pigeons would have been the final straw for some crops.

There are no major issues with light leaf spot as yet, although odd lesions are starting to be found. Charlock has taken a bit of a hit with the first frosts BUT need more to continue the good work. I have more fields with shepherds purse and hedge mustard than ever before, which as far as shepherds purse is concerned, means more clomazone pre-em on crops going in this autumn. Where controlling cranesbill with Fox (bifenox) I am led to believe that there will be some activity on these weeds as well as charlock, particularly once the charlock has been opened up by the frost. Remember that Fox needs specific off label approval documentation and is at growers' own risk.

Late germinating winter wheat crops are at the 1 tiller stage (sown 1st week September). Late sown crops after beet are at the 3-4 leaf stage. Where crops had moisture early on, they are very forward with up to seven tillers on them.

Mildew levels are similar to the barley. Being pretty rampant pre-new year, particularly Solstice and Oakley, but are now looking significantly cleaner albeit with quite a lot of dead leaves in the bottom of the crop. As yet I have not found any yellow rust in either of these two varieties and I have had a GOOD look, not 'just over the hedge'!

If conditions are suitable in early March I will be tempted to apply Atlantis (iodosulfuron+mesosulfuron)/Broadway Star (florasulam+pyroxsulam) at this point due to much earlier germination of target weeds.

My biggest concern at the moment is whether I am going to need to apply an aphicide to my deter dressed crops based upon the unusually mild conditions to date. I have had to apply manganese to quite a few light land crops in early January which is not the norm and may well have to treat in February, dependent on growing conditions.

East: Get ready for spring action.

2012-01-30T07:59:13Z

There is an air of optimism as crops have come through the winter in good condition, promising good yield potential. The mild winter weather has had a huge impact on our agronomic starting point this spring; it has encouraged well tillered, forward crops, weed growth and disease development, whilst having little impact on aphid survival. The recent cold snap during the transition of January to February is unlikely to change the magnitude of these factors but may influence the pace of fieldwork in early spring.

Following the mild winter it is worth checking that all cereal crops were protected against BYDV infection (by seed treatment and or foliar sprays) into early November, at least. Any crops unprotected until this time could host aphids from an extended autumn flight bought about by mild conditions. As a precaution it could be worth controlling any overwintered populations in these crops before colonies expand and spread the virus in early spring.

Lush crops will need robust early season PGR strategies and disease susceptible crops will require early attention. Some of the first spring pesticide applications will include spring weed control in OSR for thistles, mayweed and cleavers with a clopyralid based spray e.g. Galera (clopyralid + picloram). In forward rapeseed crops the windows for this application is likely to be tight, catching crops as temperatures and day length increase but before buds are raised above the canopy.

Remaining post emergence grassweed applications e.g. Atlantis (mesosulfuron + iodosulfuron) should be applied once spring growth starts in earnest, targeting overwintered grasses whilst they are relatively small.

The T0 fungicide is typically applied at early stem extension (usually mid-March). This season yellow and brown rust pressure is already apparent (pustules in crops are easier to find than this time last season!). Most yellow rust susceptible varieties will receive a triazole holding spray during February to prevent disease build up prior to T0. In some instances it may be practical to mix an early triazole for rust control with the Atlantis (check the Atlantis spring tank mix guide).

Wheat bulb fly (WBF) risk is somewhat lower this season compared with spring 2011 as egg populations are approximately half and crops are well tillered. However, egg hatch has begun and "at risk" crops should be monitored carefully for WBF damage. If required egg hatch sprays, rolling, early nitrogen and later dead heart sprays can be deployed to reduce the impact of this pest.

N planning and N Max calculations should be completed in accordance with NVZ guidelines before any field applications are made. Fungicide prices are beginning to firm and growers should plan strategies based product performance and likely return on investment.

North: Improving weather lifts growers spirits.

2012-01-29T22:40:11Z

Much improved weather in the past few weeks has given growers an opportunity to attempt to catch up with winter ploughing. However, in late lifted potato fields where soil structure was more or less destroyed, gentle handling will be required to get them back into order to plant spring barley.

On the whole autumn sown crops have improved since the turn of the year due to the generally clement growing conditions. Winter barley crops that had shown typical yellow patches in the autumn due to waterlogged soils have greened up well. Mildew can be found at low levels which will require treatment, along with a net blotch/rhyncosporium spray plus a top up of manganese when ground conditions allow.

Winter wheat crops are generally more dense than I care to see. A robust growth regulator programme will be the order of the day probably commencing with the T0 fungicide treatment.

Oilseed rape crops are more variable with the majority looking well. Light leaf spot is present in some crops especially those which missed out on an autumn application due to the challenging spraying conditions. An early application of flusilasole and/or prothioconazole should be included in the spray schedule.

There should be no great rush to apply early nitrogen to most crops once the NVZ shutters are open in a fortnight's time. Crop nitrogen levels are more than adequate for the time being. The effect of the extreme conditions during last year's cereal harvest and potato lifting will no doubt come back to haunt us. Thus checking the soil nutrient status of potential problem fields is vital.

South: All change for a completely different season.

2012-01-27T08:09:08Z

It's hard to believe February's already arriving. The few frosts we've had so far have done little more than steady our winter crops, leaving them thicker and lusher than we've seen for many years. What a contrast to this time last season.

Our key priority for both wheat and rape this year is clearly holding them back. A far more encouraging position than we've had of late, but one which poses its own unique set of challenges.

Perhaps the biggest of these is spring nitrogen. In the past, dare I say it, things were simple. We just altered our Nitram timings. But these days we have a serious dilemma. Mainly because we're using nitrogen:sulphur compounds which come in fixed ratios and are already on-farm, ready and waiting.

We have to get a decent amount of sulphur onto our crops early. And, recent experience has taught us the drought insurance value of early nitrogen, but about the last thing most of our crops need if they're to stay standing is early N.

At the moment I can't see us putting any fertiliser on our wheat or oilseed rape until the end of February at the earliest. At the same time, we'll probably be splitting the first dose so we get enough S on early without going over the top on the N. With the lack of individual nutrient flexibility we have these days, this is our only real option.

Plant growth regulation will also give us far more of a challenge this season. Bearing in mind that most of the varieties we're growing have yet to experience major lodging pressures in commercial practice, we're planning particularly robust PGR programmes.

Even though I've walked a good 5000 acres in the past couple of weeks, I haven't been able to find any disease worth speaking of in our OSR. Combined with very long leaves on most of our crops, this means we're facing little real stem canker risk. Subsequently, we won't have to compromise maximum plant growth regulation for sufficient disease eradication in our pre-stem extension fungicide choice.

Where we will need good early disease eradicant action, though, is in our wheats. They've hardly lost any lower leaves since November and, while mildew levels have subsided nicely, they're carrying a huge reservoir of Septoria. Susceptible varieties are also coming through the winter with worrying amounts of yellow rust. We simply can't afford to be chasing disease. Which means we'll be starting off with a robust, well-timed, decent rate T0 including a major triazole component.

Black-grass is another particular concern. We made the most of a good Atlantis spraying window to compensate for this season's generally poor pre-em control. Even so large amounts of tillering black-grass seem to be coming through the winter. Thankfully, our good thick crops should compete very well - pointing-up the importance of growing the most competitive wheat varieties in the future.

Disease Problems Come To The Fore

2011-12-01T18:38:15Z

CropWatch South - Iain Richards, Masstock - 2/12/2011

Disease Problems Come for the Fore

We're currently doing something I've never previously done in 20 years as an agronomist - spraying winter barley in December for mildew. Two weeks back and we were content to leave it to the onset of colder, wetter weather to limit the spread of early infections. But the persistent mildness and lack of rain has certainly put paid to this, with mildew levels in crops on thinner and more manganese deficiency-prone soils, in particular, suddenly romping away to affect 60% or more of the leaf area in some cases.

To protect critical and seriously threatened barley tillers we've been getting in with straight or co-formulated fenpropimorph or fenpropidin, adding foliar manganese to help the crops recover and more effectively fight-off the challenge.

While mildew levels have also built-up in more susceptible wheat varieties, their far greater ability to compensate for early leaf losses means they don't warrant treatment yet, although we may need to treat these too if conditions allow infections to threaten winter survival.

Of far more concern with the wheat are the levels of early yellow and brown rust we've also been recording. If we don't get a decent prolonged period of cold weather, we'll be starting the spring with very worrying levels of infection in many crops. With this in mind - not to mention memories of 2007 - we're gearing up to nip any problems in the bud with a robust early T0, prioritising crops that haven't had the benefit of a foliar-disease active fluquinconazole seed treatment for an eradicant as well as protectant spray.

On the plus side, the past few weeks have enabled us to take full advantage of one of the best early post-em blackgrass control opportunities of recent years, optimising water volumes, nozzle choice and spray quality as well as application timeliness. Just as well given the autumn's particular pre-planting and pre-em control challenges.

The open early winter has also proved a boon for our primary spring cropping cultivations. We've been able to get good glyphosate weed control and set up compaction and clod-free ground nice and early for the frost. All we need now is some cold weather.

Which is also what we're badly needing for our OSR. This time last year, average soil temperatures in Hampshire were 6^oC. But we're only just seeing them fall to the 10^oC needed for the best propizamide and carbetamide activity and persistency.

Although we've started spraying our less well developed crops, we're continuing to hold-off on the more forward ones in the hope of some decent cold weather to shrink their canopies back enough for even soil application. For the best activity too, we'd really like to see lower soil moisture deficits than we have in most cases.

It's a difficult balancing act and test of nerves. With the sort of dryness we have in most of our
subsoils, though, we look like being able to have a good spraying window yet.

North: Pigeons needs a map for large oilseed rape crops

2011-11-28T13:30:00Z

November has passed like a scene in the Bill Murray film Groundhog Day with every day being a repeat of the last one, dull, dry and still. This makes your friendly agronomist look a fool as every week he declares "that's it for the year, put the sprayer away we won't get any more spray days!" This is followed the following week by "let's spray that late drilled wheat".

With such a mild and prolonged autumn, crops look really well and a flock of a few thousand sheep could fatten over winter in North Yorkshire and not make an impact. Yellow rust can now be found in the Oakley crops and is fighting a battle for leaf space with mildew. No spraying is planned for theses crops this autumn, but T0 will have to be timed well in the spring. Atlantis (mesosulfuron + iodosulfuron) sprays are working well, but nerves start jangling when there are still a few blackgrass plants looking healthy.

Winter barley has developed very rapidly and has disturbing levels of mildew particularly on the varieties Cassia and Cassata. Despite my best efforts to ignore this some crops have been sprayed.

My reluctance to spray is based on dim and distant memories of my ADAS days when autumn disease treatments often gave a negative response. This coupled with the belief that frosts will arrive soon. However, when mildew is on the newly emerging leaf I feel treatment is justified.

The best crops of oilseed rape are the late drilled ones which look perfect to go into winter. The early drilled crops are currently reaching for the sky and any self respecting pigeon would not dare enter them without a compass and a map!

Spring canopy management of these is going to be a challenge if the winter stays open. Some crops are stem extending, however, most of these tend to contain numerous spring rape volunteers. Rapid winter growth has already flushed out some pale patches in crops showing distinct magnesium deficiency symptoms well worth a look over.

East: Decisions still to be made on blackgrass herbicides

2011-11-27T17:53:29Z

Rain in early November and some perfect spraying conditions subsequently have resulted in rapid blackgrass emergence in wheats and a considerable amount of Atlantis/Horus (iodosulfuron + mesosulfuron) being applied. Soil moisture has also activated the residuals to the extent that the later sown wheats contain some sick looking blackgrass.

There is still some follow up Atlantis/Horus to be applied and while conditions remain suitable, with soil temperatures still around 10C, it will be sprayed if conditions allow. In some cases larger and more difficult blackgrass warrants the addition of a contact + residual partner.

Wheat crops are a mixed bag with some very lush crops plastered in mildew and some of the earlier drilled crops still struggling to emerge. Barley tends to respond to an autumn fungicide in such circumstances more than wheat, but there has been some mildewicide applied to struggling wheats especially on lighter and chalkier soils.

Colder weather would help not only the mildew situation, but also create better conditions for oilseed rape herbicides. Most crops are up to date with fungicide and insecticide and we are now waiting for suitable conditions to apply bifenox where needed.

Although applications of propyzamide/carbetamide have been going onto some oilseed rape crops, we are only just approaching ideal conditions for them to work well. In most cases there will not be a contact element in the tank so that we can spray onto wet leaves and run product off the leaf of some very large canopies and onto the soil.

In some cases we will wait for frosty weather to open up these canopies before spraying. Many of the earlier drilled rape crops particularly are looking very short of nutrients. Tissue analysis confirms that most nutrients are deficient including nitrogen. This is presumably due to efficient scavenging of the available nutrients by large crops which are still trying to grow in comparatively mild conditions and have now run out of food. Foliar applied nutrient mixtures help to improve the look of these rape crops and will make them healthier in readiness for colder winter weather.

South: Soil temperatures finally dropping

2011-11-27T15:24:34Z

A quick glance at the calendar tells me it is December this week, hard to believe after the mild weather we have had recently.

Rape crops continue to race away and some are carrying huge canopies going into the winter. Soil temperatures have now declined enough to start applying Kerb (propyzamide) or Crawler (carbetamide) but given the size of some crops getting a residual herbicide down to the soil surface will be a problem. In large canopied crops we may have to wait until frosts open the crop up.

Phoma levels are low at the moment and opinion is split on the merit of adding a second fungicide whilst traveling through the crop. Aphid numbers are still high in crops and I am adding an insecticide to control these: cabbage stem flea beetle and rape winter stem weevil.

More advanced wheat and barley crops are carrying high levels of disease especially mildew. I have treated a few barley crops on light land, but I dont think the disease is worth treating on wheat crops at the moment, hopefully once we finally get some frosts this will sort the problem out.

Recently applied Atlantis (iodosulfuron + mesosulfuron) treatments are a mixed bag, some seem to be working well after only 10 days while others applied up to three weeks ago seem to be doing very little. Unfortunately I suspect this is largely due to resistance and that for many farms Atlantis has now been rendered virtually useless.

Looking forward this is going to make control of blackgrass on these farms interesting to say the least.

Winter bean crops drilled around the end of October are now well up and look rather too healthy and large for this time of year, thankfully most of my crops have been drilled at modest seed rates and at least don't look over thick.

West: Mild weather helps late drilled crops

2011-11-27T07:28:42Z

The unusually mild weather throughout November has been a great help to all the late drilled crops in the area. With a late maize harvest there has been a significant acreage of wheat planted later than usual this year.

The vast majority of these crops have taken as little as 12 to 14 days to emerge after planting. The mild spell has also allowed later drilled crops of oilseed rape and winter linseed to put on growth and establish better before the onset of winter. Some of the August drilled oilseed rape now has such a large canopy that it now has the potential to become a management headache rather than being straightforward.

Pre-emergence herbicides have either worked really well or grass weeds are slow to emerge this autumn. I have several known brome sites where there is very little sign of Brome emergence and certainly not enough to go with an Atalantis (iodosulfuron + mesosulfuron) or Broadway Star (florasulam and pyroxsulam) application.

This is unfortunate as the mild weather would have made for ideal timing for either of these products, which are temperature dependant for efficacy. Volunteer beans have now been controlled in many crops, particularly those established using non-inversion cultivations.

It has been many years since I have seen so much mildew present in autumn sown cereals this early in the season. It is generating quite a debate on how best to deal with the situation. With availability of mildew specific fungicides a bit of an issue, I believe trying to control mildew with a second choice product at this time of year to be a bit of a folly. The exception to this will be winter barley crops where the disease is so severe that tillers are being lost.

I have yet to see a crop that has been this badly afflicted and as a consequence am not at present recommending any action be taken against the disease. I hope we get some frost soon which will significantly slow the progress of the disease.

As this is my last blog before spring, I would like to urge growers to keep a close eye on their later drilled crops over the winter months. Late-drilled cereals could fall prey to slugs and the smaller crops of oilseed rape will be vulnerable to pigeon attacks. The mild weather has again helped here by delaying the arrival of winter migrant pigeons from the continent, but this situation is now likely to change as temperatures are dropping in northern and eastern Europe.

North: Some crops need disease control

2011-11-21T14:24:14Z

All crops generally look very well as the long run of mild weather continues. With very little rain in the past month most autumn spray programmes have now been completed.

A lot of Atlantis has been applied to small blackgrass in ideal conditions so hopefully control will be maximised. The main issue affecting cereals at present is the high levels of disease, particularly mildew.

Most barley crops are carrying some mildew but varieties such as Cassia, Cassata and Saffron are suffering particularly badly. With such mild weather the mildew has had a free run with no frosts to check disease development. Although exceptional, some crops of barley will warrant a mildewicide so that the barley plants can maintain shoot numbers, biomass and ultimately yield.

The mild weather has also been favourable to both yellow and brown rust in wheat, although some frosts would soon slow disease development. Varieties such as Oakley, Viscount and Robigus have yellow rust pustules which will need monitoring, especially if there is no sign of a cold snap.

Manganese will need to be applied to crops on deficient sites whilst ground conditions are still good. With aphid numbers still well above average for the time of year late drilled crops may need treating with a pyrethroid insecticide.

A lot of oilseed rape crops have large canopies with phoma lesions now very obvious. Fungicides have been applied to control this phoma but also to protect against light leaf spot. Frosts would also be welcome to provide some natural control of charlock and runch as well as open up some thick rape canopies so that residuals of propyzamide or carbetamide can be applied.

Winter beans are emerging very well. A pre-Christmas graminicide may be required to control volunteer cereals or grass weeds such as blackgrass on the earlier sown crops.

East: Temperatures encourage blackgrass

2011-11-21T14:21:26Z

What happened to the promised October snow!

Since my last article we have still not had any significant rainfall (or snow!), just days of mist, and unseasonably warm temperatures.

The temperatures have encouraged rapid blackgrass growth, if the blackgrass has 2 or more leaves I am still encouraging autumn Atlantis use. At the same time we have to be mindful that this product needs to go onto a dry leaf, and dry on. Needless to say the spray window each day is not that long. Atlantis should be applied with a residual partner, my early results with prosulfocarb as a tank mix partner are looking favourable.

All cereals have now had at least one aphicide and where required a trace element application of the appropriate micronutrient. Though not traditionally a large user of phosphites, last years encouraging results on second, or struggling wheats have led me to treat a larger area this autumn.

Propyzamide and carbetamide applications are well under way, at least the mist and fog has enabled the chemical to roll off the large OSR canopies to make soil contact. Although the soil temperature is above average for the time of year, the grass weeds are still relativity small and there is enough moisture near the soil surface to activate these products. I feel if we delay applications until the soil temperature is ideal, the grass weeds will be too deep rooted to kill, or the land drains will be running, either would cause lack of efficacy or environmental concerns.

As we head towards the office for the winter we must turn our attentions to the necessary administration. The coming weeks will be a good time to check the soil protection review is up to date, the crop protection management plan is up to date, and the nitrogen plan completed.

When it comes to Nitrogen planning the soil N min tests will be invaluable this year. After such a dry season it will be very interesting to see what levels of nitrogen are likely to be available to all crops from the soil. Some OSR rape crops already have a GAI of 3+ so no pre April nitrogen may be appropriate. There may be room for some cost savings, food for thought?