Crop Watch West/SW autumn/winter 2005

22 November 2005

Bryce Rham – Procrop

Five inches of rain since my last report pretty much brought drilling and spraying to a standstill, but the ground is now drying well and spraying has resumed. The first frost of the year arrived on 14 November.

The primary issue is to wait for leaves to dry prior to spraying and stop early enough to allow spray residues to dry on leaf surface before frost sets in.

I have never seen as much crop scorch as this year due to very warm conditions and lush growth; the succession of night frosts will harden the crops off to any applications made now.

Aphids continue to be a worry, although rainfall during last month has slowed down activity. If frost continues for 5-7days and can reach a consistent –5oC, this will remove the need to apply insecticide to previously sprayed early drilled crops.

Winter barley

The majority of forward crops are at 2-3 tillers, with mildew and net blotch visible on most varieties. No fungicide applications will be made until spring – frost will soon kill any mildew.

Herbicide applications should be complete by the end of this week if the weather warms up enough and stays dry.

Winter oilseed rape

Phoma has steadily been increasing to levels that I have not seen in recent years. Later drilled backward crops have received a fungicide treatment but forward crops are still only showing some 5% infection and are so dense that I do not see a need to apply any fungicide yet.

Also, I can see no way of getting Kerb (propyzamide)/ Crawler (carbetamide) down to the soil surface due to the dense canopy of forward crops.

Crops are starting to open out due to frost and will check during the next week to see if applications can start. High water volumes and pressure will be the order of the day.

Winter Wheat

The majority of crops are in good condition. Most early sown crops are showing signs of mildew and forward crops are at Growth Stage 23.

If conditions are suitable, autumn spraying will hopefully be complete by the end of this week, with crops sown after beet and potatoes now being left until early spring.

Some crops on heavier land are showing yellow patches due to water logging.


15 November 2005

Neil Donkin

Over the past six weeks the Vale of Severn has had 230mm of rain and high winds, which has brought work to a standstill, except on free-draining soils. We now have the first frosts of the year.

Oilseed rape
Where fungicides have not been applied phoma is now severe. Even Es Astrid, with its high level of resistance, has reached threshold. Apply fungicides as soon as possible.

If you treated earlier and phoma is again spreading, spray again four weeks after the first dose. Spraying conditions are unlikely to be ideal so it is worth adding a sticker/extender adjuvant.

Monitor crops for pigeons. There are very few acorns or beech mast this year and pigeons are already on rape crops in large numbers.

Weeds have grown rapidly in the mild weather and particularly where blackgrass or ryegrass is a problem they need treating urgently or, in many cases, need a follow-up to the first spray.

Note that Atlantis (iodosulfuron + mesosulfuron) needs warm, growing conditions leading up to spraying and that, if we go into a series of hard frosts, grass growth will be curtailed. Atlantis, in those circumstances, would be better held over until the spring.

In barley, where herbicide choice is more limited, Corniche (diclofop-methyl + fenoxaprop-P-ethyl) can be used even in very cold conditions.

Mildew is showing on many crops, but it is rarely worth treating in autumn – except on light land or with a very backward crop. Frost will kill it anyway.


8 November 2005

Tim Horton – Cleanacres

The mild, wet weather has promoted growth of crops and weeds.

Grassweeds in particular, are emerging in most crops and although the pre-emergent treatments are working well, follow up herbicides should be considered depending upon individual field pressures.

In winter barley, where the options are limited, it is particularly important to target small weeds. The best blackgrass control strategies are based on considering control in the whole rotation.

Aphids are still migrating into crops in the mild conditions increasing the risk of Barley Yellow Dwarf Virus infections. With few spraying days available it is important to prioritise applications for the most efficient use of the opportunities.

Slugs continue to graze cereal and oilseed rape, but most crops are now growing away from any initial problems. Later drilled fields will need monitoring particularly if the seedbed is loose, cloddy or stony.

Oilseed rape has shown significant growth making the targeting of grass weeds with contact herbicides particularly difficult.

Phoma leaf spot has continued to spread such that most crops have now passed the threshold for treatment and a fungicide should be applied at the earliest opportunity starting with the most backward and susceptible fields and finishing with the most forward.


31 October 2005

Joss Wood – AICC

With such perfect autumn drilling conditions, subsequent rainfall and mild weather, wheat emergence/establishment has been very good.

Such conditions, however, have led to high levels of slug activity and have necessitated liberal application of molluscicides, in some cases several times.

Oilseed rape crops are extremely ‘proud’, but until this past week, levels of phoma have been very low. A fungicide with growth regulatory properties, Caramba (metconazole) is being applied at this time.

Pre-emergence residual weed control appears to have been very effective, and where Kerb (propyzamide) is planned I will wait for cooler conditions before applying.

With such mild conditions, the risk of BYDV from aphid activity is very high in cereals, so a pyrethroid insecticide will be added to the post-em herbicides in most cases.

Where root development is poor, phosphite liquid will be added to the mix. Where soil analyses dictate (which is in most cases) potash will be applied in early spring in mixture with ammonium and magnesium sulphate.

Early control of resistant ryegrass from pre or early post emergence use of Crystal (flufenacet + pendimethalin) or Liberator (diflufenican + flufenacet) has been excellent. Hopefully, the need for a follow up in the spring will be limited.


25 October 2005

Bryce Rham – Procrop

Weather during the last month has been generally dry with occasional heavy downpours, but this week it has turned decidedly wet with 1-2in of rain having fallen already. Drilling is pretty much up to date with the exception of wheats waiting to be drilled after sugar beet and maize yet to be harvested. Seedbeds have in the main been excellent with a high proportion rolled providing good conditions for pre- and post-emergence autumn herbicides.

Winter Oats

With better contracts available there is a slightly higher area this year. The main varieties are Gerald and SW Dalguise. Aphids are visible in crop so unless treated with Secur (imidacloprid) seed treatments will need treating with an aphicide + manganese within the next 10 days. Add Quantum (tribenuron-methyl) if groundsel is a problem.

Oilseed Rape

The most forward crops are up to the top of my boots! My greatest concern is going to be the efficacy of propyzamide and carbetamide due to the size of the crop canopy. Conditions are still too warm to be applying these products yet, so I suspect we will have to use high water volumes and high pressure.

Later sown crops are at 4-6true leaves. There is very little evidence yet of phoma, and unless infection becomes severe it will be unlikely forward crops will receive a fungicide. Later sown Lioness may need a fungicide applied with graminicide. Lioness has a lower rating than Castile for phoma and has been the only variety where phoma has been seen as yet.

Winter Wheat

Most forward crops at growth stage 21-22.Claire has visible mildew symptoms. Conditions have been ideal and 60-70% of the crop has received autumn treatment with either pre-em, peri-em, or true post-em at three true leaves. Pre-ems have worked very well due to moisture and seed beds, and these crops have had a follow up treatment of aphicide +/- herbicide dependent upon pre-em rate.

Unless conditions cool down dramatically early sown/sprayed crops will need a follow up aphicide, as winged aphids are visible in emerging crops. Slugs becoming more of an issue due I think to continued warm weather and wetter conditions, thus continued hatches of juveniles. Keep an eye on wheat after rape where you thought all was ok.


18 October 2005

Neil Donkin

Some 52mm of rain in the past week, coupled with relatively high temperatures, will ensure rapid crop and weed growth.

Oilseed rape
Crops which had a low dose graminicide early-on to remove the first flush of volunteers are ready for a second, heavier, treatment to remove blackgrass. If using a contact acting material such as cycloxydim, be sure that all weeds have emerged.

Phoma forecasts have so far been low risk, but I am starting to see occasional lesions in crops. The wet weather will encourage the disease and crops need to be monitored regularly.

Similarly, wet conditions favour slugs; check especially in backward crops.

With dry surface soil up to now, pre-emergence herbicides have been slow to work. As a result, blackgrass has reached the three leaf stage apparently unscathed.

Where blackgrass is resistant/difficult, there is an awkward decision to be made now; either use a holding operation with an isoproturon mixture (with Hawk (clodinafop-propargyl + trifluralin) or pendimethalin), assuming that Atlantis (mesosulfuron-methyl + iodosulfuron-methyl-sodium) will be used in spring.

Or wait until we think all blackgrass has emerged and treat with an Atlantis mix in the late autumn.

The danger with the latter approach is that more blackgrass may emerge in the spring and then what do we do? The other option is potentially more expensive and IPU mixtures may not achieve a lot.

Aphids are easy to find in many crops and need to be treated soon. Where cereals were drilled after grass, the frit fly forecasts are low.

Monitor crops for leatherjacket damage; there were huge numbers of cranefly laying eggs in grass fields during September. Most damage is not seen until the spring.


11 October 2005

Tim Horton – Cleanacres

Early to mid September-drilled cereal crops are establishing well, in fine, firm seedbeds.

Pre-emergent herbicide applications are generally holding the blackgrass adequately, but forward crops should be considered for follow up applications depending upon grass weed species and populations.

Recently drilled fields have had significant flushes of blackgrass in the stale seedbed which, having been removed before drilling, will help reduce the weed pressure and improve overall control in the crop.

Forage maize is being harvested which will allow the last of the cereal crops to be drilled.

A few cloddy areas on the heavy soils are suffering slug grazing, some of which have needed treatment. Any areas where the seedbed is less than ideal can be at risk but wheat crops after oilseed rape have been an area of particular concern this year.

The first signs of phoma lesions on older leaves can be found in forward oilseed rape crops. The dry weather last week (w/e 9 October) would have limited the infection but rain will encourage the spread of spores from old oilseed rape stubble to new crops. These lesions suggest that an earlier phoma treatment would be justified this autumn.


4 October 2005

Joss Wood – AICC

On the whole, oilseed rape establishment has been satisfactory, but as usual the effect of seedbed conditions, prolonged dry weather and slugs have compromised emergence and plant establishment.

In some cases, where seed was placed into very dry, “strawy” seedbeds, emergence has been virtually non-existent, and awaits a good rain, which could be too late for reliable plant stand going into winter.

Early post-emergent weedkillers, together with graminicides seem to be working well, although rain is badly needed to promote residual activity.

Drilling of first wheats, barley and oats has continued apace, with farmers making the most of ideal sowing conditions. Most has been planted in Dorset, apart from some second wheats and crops following maize silage, which was cut last week (w/e 2 October).

With rain and high soil temperatures, emergence will be rapid. Secur seed dressing will give early control from aphid /Barley Yellow Dwarf Virus, otherwise an application of cypermethrin will be necessary at the 2-3 leaf stage.

With resistant ryegrass becoming more of a problem (blackgrass not largely a problem in Dorset), stale seedbeds followed by glyphosate have become an essential “tool” in its’ control.

This will be followed with a pre-emergent application of Crystal (flufenacet + pendimethalin), removing any possibility of early competition, not only from ryegrass, but also from blackgrass.

The need for follow up spraying will be assessed as the season progresses.


27 September 2005

Bryce Rham – Procrop

Conditions have been generally dry since the beginning of the month, with localised downpours across the county.

Drilling has concentrated everyone’s mind on cross compliance margins against watercourses and hedges, with a range of options being carried out:

  • Ploughing/cultivating to edge and providing a seedbed for natural regeneration
  • Ploughing/cultivating to 2m from centre of hedge/watercourse. Always leave 1m from top of bank
  • Ploughing/cultivating to edge of field and establishing a cocksfoot/timothy margin

Oilseed rape

Oilseed rape is growing well except on heavy soils where lack of moisture has slowed growth. Most forward crops are at six true leaf and late drilled crops at cotyledon stage. Downy mildew is present on some cotyledons but it has not yet spread to true leaves.

Slugs have caused very few problems due to excellent seedbeds and dry conditions and only a few crops require specific treatment.

Volunteers have been sprayed off over the last week, using propaquizafop at rates of 0.15-0.3l/ha.

Winter wheat
Most advanced crops now at 3 true leaf. The majority sown to date is Claire with rates ranging from 75-90kg /ha depending on seedbed and Thousand Grain Weight. Robigus rates are as low as 75kg/ha and up to 90kg/ha due to its capacity to tiller well and potential lodging risk from sowing this early.

Second wheats are now being drilled and popular varieties are Einstein and Napier. Einstein rates are as high as 140kg/ha due to big seed and poor tillering capacity.

Where crops are at three true leaf, about 10-15% of plants have gout fly eggs, but no specific action is being taken because early sown crops were treated with Secur. No gout fly eggs have been found in crops at one true leaf.

Winter oats and winter barley drilling commencing this week also barley varieties primarily Camion, Carat + Siberia and some Pearl


20 September 2005

Neil Donkin

Gloucestershire has had rain at last but with huge variation across the county, from 100mm in one day to light showers only.

Oilseed rape
The long dry period has led to uneven germination of crops and associated cereal volunteers. In these circumstances it is advisable to control the first flush of volunteers at the three leaf stage, using a very low dose of a graminicide.

Be prepared to re-treat later, possibly with a higher dose, when you feel all grasses have emerged. Butisan (metazachlor) and Katamaran (metazachlor + quinmerac) can be applied post-emergence for broad-leaved weeds but check that the crop has reached the expanded cotyledon stage across the whole field.

Slugs are attacking some crops; inspect very frequently as a young crop can disappear almost overnight.

Once crops are drilled, deciding on grass weed control strategy is the next main item.

The arguments for and against different approaches for blackgrass and ryegrass control have been well reported in the press. The most important message is that, if you have difficult/resistant grass weeds, you should use a sequence of products and not rely on one hit in the spring when the weeds will be large. This will only encourage further herbicide resistance.

Meadow grass should not be ignored; it removes a lot of nitrogen and can cause harvesting problems. Isoproturon (IPU) does not seem to be controlling it as well as it used to, so consider a mixture such as IPU/pendimethalin instead.


13 September 2005

Tim Horton – Cleanacres

Watch out for slugs in cloddy or poorly consolidated areas in oilseed rape. Heavy dews are allowing significant slug activity where the seedbed allows easy movement with many of these patches requiring treatment with slug pellets.

Where seedbeds are good and well consolidated then crops are emerging quickly producing a good even establishment. Early removal of volunteers and grass weeds will be beneficial, conserving moisture for the crop, and reducing early competition.

Wheat drilling has started in a few places but with grass weeds emerging in stale seedbeds then take advantage of this weed chit and remove them before drilling.

Flushes of brome and blackgrass are common and removal before drilling will reduce the pressure on the in-crop herbicides and is the cheapest control of these weeds.

The majority of farms on the Downs are looking to start drilling next week (w/c Sep 19). Seedbeds are good with moisture in most places, but with blackgrass likely to continue to emerge rapidly, then it is important to have a planned approach to control.

Early slug activity in emerging rape crops and in stubbles suggest a potential problem if seedbeds are not fine and firm.


6 September 2005

Joss Wood – AICC

Harvest yields have, on the whole, been very satisfactory – which is just as well, given current prices. Fortunately drying costs have been kept to a minimum, thanks to good weather during harvest.

Once again the use of pre harvest glyphosate has enabled timelier harvesting, as well as reducing the need for drying.

First wheats largely achieved 8.9-10.5t/ha (3.6-4.25t/acre) and might have yielded more were it not for a scorching weekend at the end of June, which “flash dried” many crops, causing some shrivelling of grain and consequently lower Specific Weights. Perhaps this also accounts for higher protein levels.

Despite early harvest rains, Hagbergs are higher than expected and Solstice in particular has produced good quality as well as yield. Second wheats (mainly Einstein) have yielded a respectable 8t/ha (3.25+ t/acre).

Winter oilseed rape has produced an acceptable average of 3.7t/ha (1.5t/acre), with good oil levels. Yields are ok, but still below the 4.9t/ha (2t/acre) we are aiming to achieve. Best yield came from a seed crop of Lioness, producing over 2t/acre.

Peas were disappointing, never reaching their full potential. Yields averaged 3.7t/ha (1.5t/acre), well below the 2t/acre potential they were showing earlier in the season – due to extreme heat in late June, followed by an intense wet period. Quality was also affected by bleaching.

Spring barleys have yielded very well, achieving an acceptable 6.4t/ha (2.6t/acre) average, although screenings and Nitrogen levels were higher than normal. Most have achieved malting specification.

Most oilseed rape crops have now been planted into good seedbeds and where applicable pre-emergence herbicides have been applied. The early completion of harvest should enable timely planting of the remaining autumn crops. Let’s hope so.


30 August 2005

Bryce Rham – PROCROP

Winter wheat harvest is nearly completed with yields generally good but not exceptional.

Winter oilseed rape drilling commenced seven days ago with some people already drilled up. Variety of choice seems to be Castile, which in this area has yielded well, and although Lioness has had a few poor yields there will be a certain amount drilled.

Seedbeds are good to very good and now with some moisture, growth should be rapid and pre-em’s should work well. Base pre-em choice on poppy/cleaver/broad leaf weed populations.

Winter wheat drilling will commence at the end of this week (w/e Sep 4) with Claire being variety of choice due to its growth habit (seed rate approx 80Kg/ha dependent on Thousand Grain Weight).

We will also be trying some Alchemy to see if it will replace Claire for this early slot. Seed will be dressed with Redigo (prothioconazole) secure and will also be trying some Redigo Deter (prothioconazole + clothianidin). Will use low rate of Crystal (flufenacet + pendimethalin) for meadow grass control, and to start programme for IRG control.

Mid-September sowings will consist of Solstice for quality market and Einstein for its yield potential. Robigus will be sown towards the last week of September/first week of October.

Sowing rates will be kept as low as possible due to potential lodging problems and its capacity to tiller extensively.

Second wheats will start end of September and will be dressed with a take-all dressing. Varieties of choice for this slot will be Gladiator/Napier with Consort still taking a small area due to its consistent performance.

We will drop take-all dressing on second wheats destined for the second half of October and beyond.


23 August 2005

Neil Donkin – Countrywide

Most cereal crops have been cut and the next tasks on the agenda are planting oilseed rape and preparing the way for the next cereal crop.

It is very important to get oilseed rape off to a good start. Get it wrong and you will have a thin, patchy crop; get it right and there will be a decent crop to work with for the rest of the year.

Oilseed rape seed is small. To ensure adequate germination and hence good establishment it needs a fine, moist seedbed, consolidated but not compacted. The aim should be to maintain moisture, to ensure good soil to seed contact and to remove any compaction to allow the tap roots to develop fully.

Minimal cultivation is probably the best option, provided that ploughing is not required to remove compaction. It saves on time, conserves moisture and soil structure and uses less fuel.

A fine, firm seedbed will also reduce slug damage and give the optimum conditions for pre-emergence herbicides.
Remember cross-compliance when drilling and leave two metres from the middle of the hedge.

Once drilled, keep monitoring for slugs and flea beetles. Chinook seed dressing will control the latter only up to the expanded cotyledon/first two leaves stage, after which further treatments may be needed.

Preparation for other crops, at this stage, should centre around encouraging germination of grass weeds. It is the ideal opportunity to reduce the weed burden, using a very cheap herbicide to which there is no resistance.

Shallow cultivation followed by pressing or rolling is the best option. Leave as long as possible to allow weeds to germinate, then spray off with glyphosate before further cultivation.

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