Crop Watch – East autumn/winter 2005

22 November 2005

Jon Yeoman – Frontier Agriculture

Take advantage of the colder, drier air to cool grain in stores to below 5oC, preventing mites from breeding and killing insects. Continue to monitor stores for temperature and moisture and blow where required.

Pigeon numbers are increasing earlier than last year, and are starting to take advantage of thinner, barer patches in oilseed rape. Monitor these areas and deploy scaring devices where required.

Oilseed rape will now be hardened off by the current frosts, so where crop growth is large enough, control of charlock can be considered. Those crops not already treated for phoma should be as soon as conditions allow where lesions are visible.

Most cereal crops have had some form of autumn herbicide treatment now. Monitor the success of these programmes, noting areas in which weeds are still present for possible follow up treatments.

There has been a lot of powdery mildew on cereal crops this autumn following the very mild conditions. This colder period of weather should now put pay to that infection, with older leaves dying naturally through the winter period.

For those late-drilled wheat crops after roots, keep a watch for the Wheat Bulb Fly forecasts that will start to be released soon. With such a mild autumn numbers could be high this winter.


15 November 2005

Andrew Blazey – TAG Consulting

Winter Cereals

Mild temperatures mean aphids are still migrating, so check crops that have not received an aphicide since the middle of October and treat again if aphids can be found. Pay attention to early lush crops in sheltered fields.

Several farms have begun Atlantis (iodosulfuron + mesosulfuron) applications – keep going as the weather stays mild and growing conditions remain good.

Generally autumn residuals are working well. Begin to assess their effect and the need for follow up treatments. There may be the possibility of following up with autumn Atlantis if mild conditions persist.

Remember to observe gaps between isoproturon and Atlantis and only apply to an actively growing plant.

Slugs have still not slowed down. Be vigilant, especially in thinner crops.

Where drilling is still to be done after late lifted roots don’t forget cross compliance requirements for margins by hedges and ditches.

Winter oilseed rape

Most crops are past the threshold of 10% incidence of Phoma. Urgency of treatment will depend on the size of the crop – smaller plants are at high risk (for a change that rules out most crops in East Anglia!)

Patience is still required for propyzamide applications, although soils are approaching a temperature conducive to effective application, actually hitting the target remains a problem, fingers crossed for some frosts!

Sugar beet

Lifting continues apace, plan for long term clamping, check for rots as the beet come in and avoid clamping these.  Make sure you have clamp sheets available for when harder weather arrives.

Grain storage

A lot of stored grain is still too warm, use cooler nights to cool grain below 14oC. This will significantly reduce insect activity.


8 November 2005

Mark Hemmant – Agrovista UK

Unusually warm soil temperatures for the time of year mean that beans are emerging much more quickly than usual. Every effort should be made to apply pre-emergence herbicides very soon after drilling, as post-emergence herbicide options are very limited.

Phoma levels in oilseed rape have been steadily increasing, yet many crops remain unsprayed with fungicide. Priority should be given to crops with small plants. Fungicides can be tank-mixed with a treatment for cabbage stem flea beetle larvae if required.

Grassweed control in oilseed rape may need to be delayed. Soil temperatures are still too warm to get the best out of propyzamide or carbetamide and in many cases we need some cold weather to open up the canopies to allow sprays to hit their target. Many crops now have more than nine leaves – the ‘cut-off’ for Aramo (tepraloxydim).

In winter wheat, many early drilled crops of Claire are carrying high levels of mildew and traces of brown rust. Mildew is also easily found on Pearl, along with moderate levels of net blotch. Autumn fungicides may be worthwhile on light soils.

Herbicides (where applied) have performed well. Blackgrass in forward crops is tillering and requires urgent treatment. A robust herbicide will be required to give good control and preserve yield.

Check crops for aphids and continue to monitor later sown crops for slugs.

If planning to sow spring cereals this autumn consider ordering Evict (tefluthrin) seed treatment – wheat bulb fly egg counts are reported to be high.


31 October 2005

Bridget Carroll – Independent Agronomist

Most oilseed rape has established well and even late drillings are looking good. However, there is some variability in Autocast crops and decisions are having to be made now about whether they should be left. About 70% have been successful.

Most herbicides are either on or going on, but we’ll be waiting for a temperature change before using Kerb (propyzamide) or Carbetamex (carbetamide).

However there is a reasonable risk of phoma out there because the conditions have been favourable.

Cereals have gone in really well, and despite the worst slug year ever I’m a bit concerned over the thickness of some of the early drillings. I’ll be watching for mildew, especially in Claire, and septoria, though I probably won’t treat until the spring unless it’s really severe.

Pre-em herbicides have performed really well and some top ups are going on now. In general blackgrass levels are slightly lower than last season, which probably reflects two good years of control with Atlantis (iodosulfuron + mesosulfuron) lowering seed return to the soil.

Aphid levels don’t seem that high at the moment, though I’m not sure why. It’s a bit odd because some untreated crops have been exposed to them for quite a while.


24 October 2005

Jon Yeoman – Frontier Agriculture

Later drilled cereals are emerging very quickly in warm moist seedbeds.

Most second wheats are drilled, and wheats after root crops are following quickly behind liftings.

Slugs are now only a problem in poorer seedbeds, and possibly as small patchy areas after min-till cultivations. Control of aphids in crops beyond the second leaf should now be programmed in, along with autumn herbicides.

Care should be taken with isoproturon mixes, and those containing oils, as crops are generally very lush, and largely have not ‘hardened’ in autumn frosts. Watch the weather forecasts, and avoid spraying ahead of the first sharp frosts of the autumn.

Oilseed rape continues to put growth on. Those crops that were struggling in chopped straw seedbeds are now much better established.

Phoma lesions are just becoming visible in crops, so fungicide programmes should be considered from now onwards dependent upon variety.

Sow thistles where present, are now clearly visible in oilseed crops, and should be controlled before they harden off for the winter. Winter beans are being ploughed in now, and autumn residuals should be applied while the soil conditions allow following levelling of the ploughing.


18 October 2005

Andrew Blazey – TAG Consulting

Slugs continue to be a menace on open seedbeds after oilseed rape, beans and set-aside, even where crops have been treated. Continue to monitor damage and retreat if necessary.

Recent mild weather means conditions have been too lush to begin high rates of isoproturon (IPU) based programmes.

Where crops were established early and no insecticidal seed treatment was used, BYDV (Barley Yellow Dwarf Virus) treatment is urgent. Consider using lower dose of IPU with a pyrethroid to avoid scorch.

Some gout fly has been noted but levels are generally low.

Many early sown wheats are carrying mildew on older leaves, treatment at this stage will not be economic.

Where using a grassweed strategy based on a sulfonylurea, such as Lexus (flupyrsulfuron-methyl) or Atlantis (mesosulfuron-methyl + iodosulfuron-methyl-sodium), remember to wash out thoroughly before going into other crops.

Oilseed rape
Continue to monitor backward and smaller crops for slug damage and treat as required.

Phoma levels are slowly increasing; the threshold for control is 10% of plants infected.

Crop canopies are closing over on forward crops – where grassweed control is required this may prevent the target being hit.

As conditions are currently too warm for Kerb (propyzamide)/ Carbetamix (carbetamide) consider using a fop/dim based graminicde now while the target can still be hit.

If resistance means that control with a fop/dim is likely to be poor, delay application of Kerb/Carbetamex until later in the winter when the canopy opens up, hopefully!

Winter beans
Crops should be sown from now onwards. Aim to establish 18 plants/m2. Losses are likely to be higher where ploughed in rather than drilled.

Spray off any stubble or seedbeds prior to drilling with glyphosate. Make sure seed is drilled deep enough for any planned pre emergence weed control.


11 October 2005

Mark Hemmant – Agrovista UK

Phoma risk is moderate to high in the region and a few crops of early sown winter oilseed rape are now at threshold (10-20% plants affected) for treatment. Other crops will need regular monitoring.

There is a lot of interest in the use of an autumn plant-growth regulator treatment on forward crops, combined with a phoma treatment.

Blackgrass is present in many crops and may need treating now with Aramo (tepraloxydim). Soils are currently too warm and dry for the effective use of propyzamide or carbetamide.

Check compatibilities of fungicide / growth regulators with graminicides and any trace elements.

Backward crops will still be at risk from slugs which remain very active.

On winter cereals pre-emergence herbicides are achieving good grassweed control so plan to apply an effective treatment straight after drilling/rolling.

Where pre-em treatments have been ‘missed’ there may still be an opportunity to apply peri-emergence, but check the label (Uranus /Arizona (linuron+trifluralin), for example, is strictly pre-emergence of the crop only).

Autumn residuals are now being applied to forward crops, combined with a pyrethroid if required – there have been isolated reports of gout fly eggs being found on emerging crops in the last week. Crops will be quite soft so be careful with tank-mixes and avoid overlaps.


4 October 2005

Bridget Carroll – Independent Agronomist

The fight against slugs continues – though fine, firm seedbeds doubtless help they are not the full story.

The increase in oilseed rape will only exacerbate this. Pre-pelleting does help, as does rolling, whatever method of establishment has been chosen.

Expensive pellets are not necessary, as the half life of metaldehyde is only about seven days, so even if the pellet is present it will not be active much over 7-10 days. Establishment of OSR using a subsoiler with seeder attached looks good and no slugs!

Blackgrass does appear to be emerging early as predicted. Use of pre-ems is being reduced and this will help with reduced crop damage too.

From AICC trials this year it does appear to be able to get very cost effective blackgrass control on some pretty resistant blackgrass without breaking the bank. Dose rate and sequence information has been particularly useful.

Low cost triazole-based fungicide programmes appear to be coming out of trials best for spring 2005 with little or no use of strobilurins.


27 September 2005

Jon Yeoman – Frontier Agriculture

Cereal drilling is well under and even second wheats are now being drilled.

Seedbed conditions are generally good, but slugs have been a major problem this autumn especially in winter oilseed rape, where some crops have been re-drilled.

With seedbed temperatures being warm and moist, cereals are germinating and emerging quickly. But caution should still be taken to monitor for slugs, especially if wet weather returns.

Cereals treated with the Secur seed dressing will have a degree of hollowing protection, but leaf stripping could still be a problem. Roll seedbeds wherever possible as a first line of defence against slugs, treating where evidence is seen of activity.

Watch drilling depth where pre emergence products are to be used. Ice (flufenacet + pendimethalin) requires 32mm of settled soil for pre emergence treatments.

Volunteer grasses should be treated with a graminicide now in oilseed rape where not already done so. Removing crop competition is important now that day length is shortening, ensuring that plant numbers and yield are maximised.

Downy mildew has been a problem recently in oilseed rape, especially in trashy seedbeds, but cooler weather now should reduce this disease naturally.


20 September 2005

Andrew Blazey – TAG Consulting

Many farms in East Anglia have started drilling first wheat. Slug populations are high on heavy land following oilseed rape. Be vigilant, aim for fine consolidated seed beds, test bait and treat if necessary.

There are large variations in thousand seed weights this season so remember to check each batch and adjust rates accordingly. For the last 10 days of September you should aim to establish approximately 150-200 plants m2 for wheat and 200-250 for barley.

Damp weather has encouraged stale seedbeds. If you can be patient and let them green up and desiccate prior to drilling, glyphosate is significantly cheaper than post drilling options.

Where planning pre emergence grass weed control a fine and firm seed bed is required to get the best out of the products. Check product labels for correct drilling depths for safe treatment.

Grassweeds and volunteers are also requiring attention in many crops. Where broad leaf weed/flea beetle control is still outstanding there may be an opportunity to mix in a graminicde if compatible.

Remember to choose a graminicide appropriate to the grass you are targeting and use a nozzle to give you optimum coverage of small grassweeds to maximise control.


13 September 2005

Mark Hemmant – Agrovista UK

Before planting cereals or oilseed rape it will be important to assess slug damage risk, particularly where there has been a historical problem and for crops following rape or beans.

See HGCA Topic Sheet No.88 on slug pellet timing and placement in winter wheat and oilseed rape. Trapping can no longer be done with slug pellets (use bran or chicken layer mash).

Rain at the weekend (Sep 10/11), will have been welcomed by those with oilseed rape crops struggling with establishment, but it will have increased phoma risk.

There have been occasional reports of phoma infection on newly emerged crops. Rape stubbles need to be disposed of as soon as possible and the new crop needs monitoring for infection and treating if threshold levels are reached.

Yield losses caused by Phoma infection are a lot higher when on small crops and consequently the treatment threshold is lower (10% infection). Many rape crops have high numbers of volunteer cereals, which can be controlled with a low rate of graminicide.

Ahead of drilling, make best use of stale seedbed opportunities, particularly if you have resistant grassweeds. Use all methods available to minimise glyphosate drift.

For cereals where blackgrass, ryegrass or sterile brome occur, an effective pre-emergence herbicide will be essential.

Grassweeds that emerge with the crop are much more competitive than plants that emerge later. This means that the pre-emergence herbicide is important for improved grassweed control and resistance management and for yield.

To optimise herbicide performance aim to achieve a well-consolidated seedbed with few clods. 32mm of settled soil coverage of seed is required for the use of the most effective pre-emergence herbicides.

Aim to apply pre-emergence herbicides straight after drilling and rolling (particularly if seedbeds are moist) and ensure that the application achieves good/even coverage of the soil.

Tank-mixing pre-emergence herbicides with the adjuvant Grounded, further improves herbicide performance.


6 September 2005

Bridget Carroll – Independent Agronomist

Harvesting is now drawing to a close, with results on the whole very good.

Second wheat is averaging over 10t/ha for some and first wheat average yields can top 12t/ha – though as usual this is not across the board – a welcome relief after some recent years which have been considerably poorer.

Thicker crops and less use of damaging blackgrass control strategies may have helped, but large amounts of sunlight in late June and July are more likely to hold the answer.

Early sown oilseed rape using in-crop and Autocast systems has largely gone well and will soon require nitrogen and volunteer control.

Conventional establishment is proving a challenge, as the continuing extended showers are leaving land very wet. It will be important to do the minimum to get crops in without damaging structures further.

Sub soilers with seeders fitted are proving a popular method this autumn. The benefit of these systems doubtless also lies in the added ability to sow wheat in better conditions – but they are not the answer for everyone.

Slugs can be easily found and will require careful control.

Blackgrass strategies are as usual causing much discussion – but the falling cost of pre-ems may encourage some growers not to rely totally on Atlantis (mesosulfuron-methyl + iodosulfuron-methyl-sodium) for control.


30 August 2005

Jon Yeoman – Frontier Agriculture

The weather is once again proving difficult to complete harvest. Some have finished, but there are areas where heavy rain has made progress difficult.

With the increased cost of drying this year, growers are understandably reluctant to cut wet crops unless absolutely necessary.

Generally wheat yields are good, and quality is not a problem in those crops cut before the rains. Ironically winter barley yields are very good, even to the point of some of the best seen by some growers.

The expected dormancy in blackgrass this autumn is expected to be lower that last, and similar to 2001 and 2003, due to temperatures being 2-3 degrees above the norm during the seed maturation period.

With recent rain, stale seedbeds and good quality drilling conditions should be achieved easily next month (September).

This should lead to good conditions for pre emergence herbicides where required for resistant grass weeds. Ensure that seed is drilled deep enough, and into good seedbeds before using pre emergence treatments.

Winter oilseed rape is slowly being drilled, but slug activity is high, and caution needs to taken in monitoring seedbeds to ensure they establish quickly before slugs clear emerging plants.


23 August 2005

TAG consulting

Oilseed Rape

Recent moisture enables an opportunity to drill rape from now on, with the aim of completing drilling by the middle of September.

If you are direct drilling or using a subsoiler drill, spray off any blackgrass before drilling and consolidate immediately after to conserve moisture.

Monitor for slug activity. Apply half rate mini-pellets at or ASAP after drilling if you know you’re going to have a problem.

Apply pre-emergence herbicides ASAP after drilling preferably within 48 hours especially if conditions are warm and moist. To apply Novall, Katamaran (metazachlor + quinmerac) or Butisan S (metazachlor) pre-emergence 15mm of soil is required over the seed. As such do not apply these herbicides pre-emergence to Autocast, broadcast or subsoiler drilled crops. These products can be used post emergence once the crop is at the fully expanded cotyledon stage.

Consider the use of Centium (clomazone)pre emergence with expected hedge mustard and cleaver populations. Please note that Treflan (trifluralin) and Centium must not be used post emergence.

Seed bed nitrogen should be applied at 30kg/ha where rape is being sown into cereal straw or after malting barley where nitrogen residues will be low.


As the end of the blight programme approaches, be aware of the maximum number of applications allowed for each product; e.g. Shirlan (fluazinam) 10, Electis (mancozeb + zoxamide) 10, and Ranman (cyazofamid) 6.
Continue to apply blight sprays until the haulm is completely dead and include with desiccation material where appropriate.

Spray off ex-oilseed rape fields before volunteers get too big if no further cultivations are planned before drilling, repeated applications may be required.

With the recent wet weather there may be good chances of flushes in stale seedbeds for controlling volunteer cereals, blackgrass etc with glyphosate.

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