Crop Watch – West autumn/ winter 2006

21 November 2006

Neil Donkin – Countrywide, Gloucestershire
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Some 35mm of rain in the past seven days has stopped any remaining field work and with day temperatures down to single figures, it may be that autumn has arrived at last.

Cereals
The majority of spraying has been completed but there are still late-drilled crops waiting for weed control. Limited crop damage has been caused where crops were sprayed just prior to the frosts in early November but they now seem to be recovering.

If you can get on the land, conditions are good for Atlantis (iodosulfuron + mesosulfuron) application and blackgrass is actively growing.

Many barley crops have high levels of net blotch, but, except where the barley is backward, it is unlikely to be worth treating.

Blackgrass or ryegrass in barley, which have survived early post-emergence sprays, should be treated with Axial (pinoxaden) while still small, rather than trying to control large over-wintered weeds in the spring

Oilseed rape
Phoma is still active in some varieties and will need a second treatment before Christmas; this is particularly important in less well-developed crops where fungal spores can wash down the stem over winter.

Fungicides can be mixed with propyzamide where appropriate; the herbicide works best with lower soil temperatures and adequate soil moisture.

Winter beans
Best weed control is obtained by levelling the soil surface after ploughing-in the seed and applying a herbicide immediately. Usual choices are mixtures of Stomp (pendimethalin) and simazine or Centium (clomazone) and simazine where cleavers are expected to cause problems.

Note that you need to have Specific Off-label Approval before using Stomp on beans.

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14 November 2006

Dan Dines – Association of Independent Crop Consultants, Wiltshire/Dorset
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With drilling completed, the shooting invites can now be accepted!

Conditions for the last drillings were ideal, but some fields planted in October have patchy emergence on the headlands where conditions were a bit wet at the time of planting. Drilling headlands after the fieldwork would have eased this problem.

The first frosts coincided with the first good spraying opportunity for some time. Despite the combination of frosts and some very lush crops, incidence of scorch has been minimal due to careful products/mix selection and not spraying too late in the day when a frost has been forecast.

In cereals where pre-em herbicide applications for grassweed control were timely, they have worked very well. In some situations it is hoped an early post-em follow-up based on isoproturon has done enough.

Some Atlantis (iodosulfuron + mesosulfuron) treatments have been applied, but where recommendations are outstanding, do not compromise activity by applying in suboptimal conditions.

Any outstanding aphicide treatments urgently need applying, but at last aphid migration into crops is on the decline.

The earliest phoma fungicides were applied about a month ago and these crops are now being assessed for further infection. Phoma levels, varietal resistance and size of crop all need to be taken into account when assessing the need for a second fungicide.

Cabbage stem flea beetle larvae have been found in some crops, but currently at levels well below the threshold of two larvae per plant.

Propzyamide or carbetamide applications are being planned for late November/ early December, but a bit more frost before application will help open up the crop and improve spray penetration onto the soil.

This autumn’s intense rain storms have resulted in a number of incidents of soil erosion, and in some cases in fields considered to be lower risk. Lessons need to be learnt in order to minimise erosion problems and avoid Cross Compliance breaches in future years.

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7 November 2006

Bryce Rham – Association of Independent Crop Consultants, Shropshire
(Click to contact)

October has been a difficult month with continuous heavy rain showers throughout. Drilling has been sporadic but seedbeds have still been generally good. First frosts arrived this week with a low of -7.2 degrees Celsius recorded.

Winter Barley
Most forward crops are at growth stage 23-24 and growing very quickly. Net blotch and mildew can be found at low levels in most early-sown crops, but not to a point that needs controlling.

The majority of crops have been sprayed and post emergence herbicides are working well. Frosts this week stopped growers applying sprays, as crops are very tender – will start as soon as frosts stop or not below -1 degrees.

Winter oilseed rape
Phoma is evident in most crops, with Lioness showing the highest levels and Astrid the lowest. Fluzilazole has been the product of choice and has been applied to approximately 75% of crops to date.

Conditions have not been cold enough to allow applications of Kerb (propyzamide)/ Carbetamex (carbetamide) as yet (a run of three consecutive frosts at the end of last week will not be enough to reduce soil temps below 5 degrees). Also, forward crops are too dense to allow penetration of actives as yet. Backward crops finally got going and are now giving reasonable ground cover.

Winter wheat
Most forward crops at growth stage 25 and giving complete ground cover. Mildew is evident in Alchemy.

The majority of crops have been sprayed. With only wheat after potatoes and sugar beet left to drill, most growers are looking forward to this being the last year that they will have to toil away in November, December and January, drilling wheat after beet that in general has substantially reduced yields when compared to end-September/ mid-October sowings.

First applications of Atlantis (mesosulfuron-methyl + iodosulfuron-methyl-sodium) will be made to blackgrass and italian ryegrass fields in the next 10-14 days.

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30 October 2006

Neil Potts – Matford Arable Systems, Devon
(Click to contact)

Most crops have now been drilled and the establishment has been very good with little or no slug activity seen in any crops.

This combined with buoyant grain prices and there is at long last a little optimism about the future, which makes a tremendous difference to the working environment.

Aphids remain a constant worry as the weather remains unseasonably mild. The wet weather of late has also made it very difficult to apply aphicides and/ or autumn post-emergence herbicides.

The mild, damp weather is also adding pressure, as weed grasses in particular are growing very quickly, thereby shortening the window of opportunity to get them sprayed at an optimum growth stage.

Some early-drilled barley crops have active mildew developing in them. If the mild weather continues for a prolonged period we may have to reluctantly consider an autumn treatment to check the disease, but hopefully a spell of colder weather will arrive and slow the disease up.

Late emerging oilseed rape, due to dry seedbeds, has now had some nitrogen and is beginning to make up for lost time in the current good growing conditions. A fungicide for phoma is imminent (if not already applied), along with graminicides where necessary and minor nutrients.

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23 October 2006

Neil Donkin – Countrywide Farmers, Gloucestershire
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Mild and showery weather has given rapid crop growth and created ideal conditions for pest and disease development.

More rain is forecast for the coming week, which will limit spray opportunities and may cause spray programmes to be modified.

Phoma is present in most oilseed rape crops, but not always at threshold levels. Astrid and Castille continue to live up to their high resistance ratings. Where necessary, fungicides should be applied as soon as possible, with a possible second treatment three to four weeks later. If only one treatment is planned, use a suitably high dose.

Tall and leggy crops may benefit from the use of a growth regulating fungicide, either alone or in mixture with flusilazole. Check oilseed rape for cabbage stem flea beetle larvae by splitting the leaf stalks and main stem; the new economic threshold is two per plant.

Aphids are easy to find in many cereal crops. Where pre-emergence herbicides have been applied and a follow-up treatment is planned later in November, there is a temptation to wait and add the aphicide then. This will leave the crop unprotected during a critical period, so treat them as soon as possible.

Mildew is showing in susceptible wheat varieties and net blotch on barley. Neither is likely to be worth treating at low levels but if infestation increases on backward crops, there may be a case for spraying.

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16 October 2006

Dan Dines – Wessex Agronomy Services, Wiltshire/Dorset
(Click to contact)

Drilling this month has been a rain interrupted affair, but many farms have now just about finished planting wheat.

Wet/ showery weather, strong winds and the desire to progress with drilling (at all cost!) has resulted in spraying being behind schedule in some cases.

The mild temperatures and moist seedbeds mean cereal crops have emerged quickly and are growing strongly. Where cereals did not receive an insecticidal seed dressing a pyrethroid spray has been applied due to high levels of aphid migration into crops.

Significant slug grazing has meant pellets have been necessary in some crops, with high risk factors including, crops after oilseed rape and cloddy/ trashy seedbeds.

Pre-emergence herbicides for grass weed control appear to be working well. Where pre-ems have been delayed and grass weeds are emerging with the crop, the addition of IPU (isoproturon) or CTU (chlorotoluron) may be appropriate.

The lush and soft crops mean care is required with herbicide applications in cereals to make sure mixes are not too hot, and avoid spraying when the first frost is due.

In respect to grass weed control, a planned approach is required as intervals between products may be necessary, for example if you apply IPU you then need to allow a minimum of four weeks before applying Atlantis (mesosulfuron-methyl + iodosulfuron-methyl-sodium).

The larvae of this season’s new oilseed rape pest – turnip sawfly – has required treatment with an insecticide in a number of crops.

Phoma is above the threshold of 10% plants, with spotting in most crops and fungicides are being applied. On some strong, very forward crops fungicides with growth regulatory effects have been recommended.

Winter bean planting will start towards the end of the month. Pre-emergence herbicides will be based around combinations of simazine, pendimethalin and clomazone according to predicted weed problems.

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10 October 2006

Bryce Rham – Procrop Consultancy (Shropshire)
(Click to contact)

General

Conditions have been ideal for establishing crops, with only the last week becoming too wet at times to allow drilling to continue.

Winter oilseed rape

Early sown crops have established well and are now at six to eight true leaf stage. Pre-emergence herbicides have all worked well despite lack of moisture early on. Crops sown later have in some cases struggled to establish due to lack of moisture and some are still at cotyledon to 1 true leaf.

There has also been evidence of flea beetle feeding even when treated with Chinook (beta-cyfluthrin + imidacloprid) that has required additional insecticide. Backward crops have also been treated with 60kg/ha product of nitrogen.

I’ve seen the first signs of phoma picked up this week on Lioness albeit at low levels, so will look to apply fusilazole/mbc from end of this coming week.

Winter wheat

Good conditions have allowed a large area of the crop to be established with crops emerging within a week of drilling. The last ten days have seen some slowing down of emergence to more normal expectations. The most forward crops are at four leaf stage. Due to well consolidated seed beds and rapid growth, slug damage has been minimal with just the normal patching up on certain areas.

Aphids can be found in most crops. Deter (clothianidin) dressed crops will be treated at a later point depending on weather conditions, sowing date and seed rate.

Aphid pressure is driving herbicide applications which until now have been based primarily upon flufenacet + IPU/DFF to keep annual meadow grass under control. Next week I will switch to chlorotoluron + DFF for ryegrass control and DFF/pendimethalin/IPU for more general weed control. I’m using small amounts of picolinafen/pendimethalin+ipu where cranesbill is becoming an issue.

There are also very low levels of mildew on early drilled Alchemy.

Winter barley/winter oats

Crops are either emerging or two-leaf stage on the most forward crops. Spraying will commence this week on crops drilled in the third week of September.

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3 October 2006

Neil Potts – Matford Arable Systems, Devon
(Click to contact)

Since my last report, the area has been very dry with some localities having had no appreciable rain since mid-August.

In these areas the winter oilseed rape has been in the ground for up to five weeks but has only just germinated with recent rain.

As a consequence these crops will probably require a small top dressing of nitrogen to try to generate some biomass prior to going into the winter. If these crops remain small, great care will have to be taken over Phoma control as the smaller crops are more vulnerable to the disease.

Drilling is well under way with many having already completed all that can be drilled. Many of the oat and wheat crops are emerged and with the fine and mild weather aphids represent a real threat to the performance of the new crop – increasing the risk of BYDV.

With the rapid growth of these crops, even Deter (clothianidin) treated crops will require a BYDV treatment in mid-October and if the weather stays mild, a further follow-up treatment in November.

Those who have planted early without an insecticidal seed treatment should apply a BYDV treatment urgently.

Wheat varieties planted this year reflect the regions propensity to get bad Septoria and include Alchemy, Robigus, Deben, Gatsby and Einstein which always stays cleaner than its five-rating for Septoria indicates.

Maize crops have been harvested 10-14 days earlier than usual with surprisingly high dry matters. Many of the maize stubbles have already been turned around into wheat crops, which bodes well for wholecrop wheat performance for the 2007 crop.

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25 September 2006

Neil Donkin – Countrywide Farmers, Gloucestershire
(Click to contact)

Oilseed rape
Warm, moist soils are encouraging rapid growth of oilseed rape crops. Slugs are a problem in some crops, so it is important to keep monitoring for them and pelleting if necessary.

Volunteer cereals are growing quickly and where dense, need to be treated by the three leaf stage, otherwise they can have a smothering effect.

Preferably treat with a low dose of graminicide with the option to follow-up later when any remaining volunteers and other grass weeds have emerged. Treat blackgrass once it has three leaves; larger weeds are harder to control.

Look out for phoma over the next week or two, as conditions are ideal for its development. Apply a fungicide if 10% of plants are affected, giving priority to crops where the rape plants are small.

Cereals
Blackgrass dormancy is low this year and in cereals it is emerging along with the crop. Moist soils should allow pre-emergence sprays to work well, but if you are unable to treat pre-emergence, apply an early post-emergence, residual herbicide once the blackgrass has one leaf. Do not delay!

Slugs will be a problem in cereals, especially after oilseed rape and beans. Check crops regularly until well established.

The other two major pests to watch for are aphids and gout fly. Aphids are already on crops at the one leaf stage and will need early treatment. Look out for the tiny white eggs of gout fly on leaves and treat with a suitable pyrethroid if found.

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19 September 2006

Dan Dines, Wessex Agronomy Services (Wiltshire/ Dorset)
(Click to contact)

The recent rains have come just in time to help establishing oilseed rape crops, which range from just emerging through to the six leaf stage.

Later drilled crops require careful monitoring for slugs, especially where seedbeds are trashy/ cloddy and crop vigour is being reduced by downy mildew.

Blackgrass in some crops is now at the two to three leaf stage, but there may be more to emerge.

As well as achieving good levels of control, blackgrass herbicide strategies need to consider resistance management, e.g. reducing reliance on fops and dims and including propyzamide or carbetamide in the program.

Winter cereal drilling is starting in earnest. Fields need to be checked a few days before planting, whether ploughed or min-tilled, for annual grass and broadleaved weeds.

Glyphosate should be applied if weeds are present in order to make a clean start for the coming season’s crop. Once drilled, monitor crops for slugs, initially targeting your efforts to high risk fields, e.g. cloddy seedbeds after oilseed rape, and using slug traps as a useful tool for assessing populations.

Early-drilled wheats will by now be at the one leaf stage. If such crops have not received an insecticidal seed dressing they will require careful monitoring for aphids. Also, monitor crops for gout fly eggs, as very high levels may justify timely treatment.

Germination of winter beans appears variable this year, so where farm saved seed is planned, samples should be sent off for testing ASAP. Should the sample fail, purchased seed can be sourced.

DEFRA and the Environment Agency are out in force at the moment carrying out Cross Compliance and Nitrate Vulnerable Zone inspections, so a few hours in the office checking records are up to date will be time well spent.

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12 September 2006

Bryce Rham – Procrop Consultancy (Shropshire)
(Click to contact)

Wheat harvest has finally been completed. After a good start, the August weather was very unhelpful with continuous intermittent showers hampering efforts to complete the job. Spring bean combining will be completed this week.

Winter oilseed rape drilling is virtually complete with, in the main, very good seedbeds. Crops drilled over the last week have gone into very dry seedbeds and germination could be an issue.

Predominant variety is Castille with Lioness a close second, sowing rates based upon 70-80seeds per sq meter.

Pre-emergence herbicides applied have been based on Butisan (metazachlor) + Treflan (trifluralin), Noval and Katamaran (metazachlor + quinmerac) dependant upon levels of broad leaved weeds and poppy, cleaver and blackgrass.

Pre-ems will work best on earliest drilled crops when there was more moisture. Dry weather this last week will reduce effectiveness, although the mornings have been bringing heavy dews which will help.

Slugs have not been a major problem, although crops need monitoring closely until at least the four true leaf stage.

Some crops will be sprayed for volunteers this week using Falcon (propaquizafop); Laser (cycloxydim) will be used for rye grass and Aramo (tepraloxydim) for blackgrass.

Winter wheat drilling has started with a significant switch to Alchemy, which has yielded better than Claire when sown early. Seed rates are 80-90 kg/ha, which will increase to 100kg/ha next week.

Other primary varieties are Gladiator, Einstein and Ambrosia – these will be sown from the third week of September as either first or second wheats. Second wheats will be dressed with Latitude (silthiofam) + SPD or Jockey (fluquinconazole + prochloraz).

Primary milling wheat will be Solstice which will be drilled from the end of this week. No pre-ems but will apply Crystal (flufenacet + pendimethalin) + diflufenican at varying rates dependant on grass weed problem at peri emergence of crop, this worked very well last year.

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5 September 2006

Neil Potts – Matford Arable Systems (Devon)
(Click to contact)

At the time of writing harvest is nearly complete with only crops of beans left to cut. The harvest has been a solid one but not a record breaker.

Winter barleys were generally good, pushing 7.5-8 tonnes per hectare in many places and better than this where grown after a break crop in place of a first wheat.

The oat harvest has been a bit more variable with the heavier, more moisture retentive soils fairing better than the light and dry sites. The same can be said of the wheat harvest, although many are saying that the drought did not impact yield as much as they thought it might have done.

The other factor that affected yield this year was the wet second fortnight in May that delayed many T2 applications to the wheat crop. On farms that got some T2’s applied before the wet spell and some after, the yield difference has been about 0.5 tonnes per acre.

Winter oilseed rape crops are either planted or in the process of being planted and seedbed preparation for cereals is underway. There appears to have been a good chit of grass weeds and the recent rain will help further.

The maize crop has made good progress this year with the marginal sites showing less marginality, due to the much warmer than usual June and July. I expect to see the first of the maize crops harvested in the next week to 10 days.

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View last season’s Crop Watch reports:
Autumn/ winter 2006
Spring/ summer 2006
Autumn/ winter 2005
Spring/ summer 2005