Crop Report: 01 June 2007
Report compiled by Farming Online from reports
received from members of the Association of Independent Crop Consultants
Disease Alert - Brown rust still widespread and moving up the canopy.
Active in the South, East and West on Alchemy in particular. Also at lower levels in Claire, Consort, Robigus and Solstice.
Late applications of T2 fungicides have left some crops at risk allowing the disease to infect the top of the canopy. Control only lasting about three weeks.
Disease Alert - Yellow rust.
Reports from East and West Midlands of occasional crops of Robigus heavily infected where spray misses or delayed T2. The current run of cool wet days have favoured this disease.
Pest Alert - Wheat Orange Blossom Midge. Risk diminishing as cool wet weather continues but be vigilant as pressure builds at the weekend.
NOTE. Once crops reach flowering stage their natural resistance to WOBM increases and treatment is no longer necessary.
Crop development - Crops stay on course for an early harvest.
Although the lower temperatures over the last week have curtailed growth, crops are still ahead of last year. They are now at the growth stage
when temperature is the main determinate of when they will be fit to harvest. Optimum temperatures for flowering and polllination are given as
between 18 and 24°C., slowing rapidly when temperatures drop to the low teens. The low temperatures over the last week will have curtailed flowering
and will not have been perfect for pollination either, but it is too early to tell whether it will have effected grain set. The rate of increase in
grain dry weight increases with temperature; there seems to be positive linear relationship between temperature and mean grain growth rate up to
temperatures of 16°C., but a negative relationship at temperatures higher than 16°C.
Highlights
Winter rape
Sclerotinia in South West.
Winter Wheat
Many crops at ear emerged.
Anthesis in early sown crops.
Brown rust still widespread on Alchemy, Claire, Solstice and Zebedee.
Midge threat diminishing.
T3 targeted against rust and ear diseases.
Lodging after heavy rain and winds.
Fusarium control timing critical.
Winter Barley
Crops setting seed.
Disease levels low.
Spring Beans
Crops flowering.
First signs of downy mildew.
First signs of chocolate spot.
Soil Temperatures
Winter Oilseed Rape
South East: all crops have now finished flowering and await desiccation/combining.
South West: seeds now green rather than translucent. Crop still standing well and prospects look good with adequate moisture supply during seed fill.
Sclerotinia : high level of Sclerotinia in a spray miss. Plants were almost completely dead with 2 feet of stem grey and
mouldy with Sclerotia formed in the stem. From a distance this part of the field appeared completely brown. The disease was so advanced that infection must have
taken place extremely early when conventional wisdom suggested that it was too dry. Driving around the countryside it is easy to spot rape crops which have had
no treatment.
Information on fungicide activity on sclerotinia.
East: the next operation for most crops will be desiccation or harvest. Some lodging now occuring.
East Midlands: many crops look well with a lot of pods with good sized seeds. Generally crops that have had metconazole are holding up well in the wind and rain and are very even across fields.
West Midlands: crops now finishing flowering.
North East: apart from late sown crops or areas of flood or pigeon damage, crops have now finished flowering.
Winter Wheat
Ambrosia flowering 22 May 07 Photo Farming Online.
South East
Crop development: All September and early October sown crops now commonly range between GS55-61 and in many cases anthers are visible - this is
still around 2 weeks ahead of normal (harvest in last week of July?). Crops have generally improved dramatically in appearance; however yield prospects on lighter/shallower soils
have been slashed by around 25-50% in some cases.
Brown rust : widespread on lower leaves of all September sown crops of Alchemy, Claire, Solstice and Zebedee in particular. Active pustules
now increasingly evident on upper leaves of crops where last fungicides applied around 2-3 weeks ago, with odd pustules now appearing on leaf 3 and 2 of thicker crops.
Mildew : still very hard to find any active pustules.
Septoria : very little evidence of Septoria in many crops from leaf 4 and above.
Eyespot : a few very early drilled Solstice (18-22 September) crops have such severe penetrating eyespot on main shoots, that in some cases these are already lodging.
Yellow rust : controled by fungicides.
Aphids : low levels of Grain aphids now being found in many wheat crops, but in general only isolated colonies can be found.
Wheat blossom midge : none seen yet. Most crops now flowering, so should no longer be at risk.
South West
Crop development: Main tillers now at or beyond anthesis. Side tillers range from booting to fully emerged with
anthesis just commencing. The recent rains should ensure the viability of these tillers, which have extra importance this year as so many tillers
were lost during the April drought. 50mm plus rain on Sunday and more early this week has wetted up soils considerably. On lighter, weaker structured
soils there is slight (around 5 to 10 degrees) leaning where heavy rain has softened soil around the roots and weakened root anchorage. This phenomenon
seems most marked in Einstein. All these crops were drilled at sensible seed rates with normal PGR strategies and if anything looked a little thin following
the dry April. Good crop management cannot control extreme events!
Brown rust : fungicide programmes have contained the disease but it has been a battle. With hindsight T1 spend
should have been at T0 on the most susceptible varieties. The epidemic does seem to have been innoculum driven with the earliest sown crops seemingly
the worst affected. It has been a perfect year for Brown Rust with a mild winter to ensure innoculum survival and then a change in the calendar to bring
July forward to April. A high proportion of the wheat area sown to susceptible hosts completes the winning combination for the disease. Will try hard
not to overreact following an atypical year. May consider Baytan treatment for Alchemy when drilled early. Seems to be a clear shift in rust levels
between September and October drillings.
Mildew : levels still not giving cause for concern. Generally only on the stem.
Septoria : lowest levels of Septoria for many years.
Yellow rust : no reinfection has occurred as fungicide programmes kick in.
Eyespot : starting to build again especially in drill overlaps.
Wheat blossom midge : levels are low and evenings conducive to flight have been rare. Nothing treated.
Aphids : small colonies of bird cherry aphids building on leaves one and two.
Weeds : rain and warm soils have caused an alarming flush of broad leafed weeds in the base of some crops.
Now too late for in crop herbicides so pre harvest treatments will need to be considered.
East Midlands
Crop development: Crop growth stages variable, from GS 41 up to almost GS 59. 60 mm rain - and heavy, squally showers.
Very little recent spray opportunity, and land now very soft. 90% T2's applied. Earliest soon ready for T3. Slight lodging.
Mildew : virtually absent.
Septoria : it is reasserting itself now after heavy rain, especially where spray timings 'all to pot' because of difficult weather.
Brown rust : not a major problem.
Yellow rust : now present on some Robigus where spray timings inadequate. Some horrible YR seen today (31 May) on Robigus. One small missed area 60%+ leaf kill. Spasmodic pustules on other parts of crops.
Spray timings not ideal because of rain. Will certainly need a T3.
Eyespot : no progress of disease.
Aphids : numbers so far low with no threshold levels reached.
Wheat blossom midge : earlier crops now nearly out of risk period. Weather is preventing problem right now - cool, windy and wet.
West Midlands
Crop development: Most crops now beginning to flower, although late sown crops only just at ear emergence. Prolonged spells of rain and cool conditions have raised the risk of fusarium ear blight,
especially as we have now had a rather protracted flowering stage. Some concern that low temperatures may effect pollination. Soils are now wet again.
Brown rust : brown/yellow rust has and is dominating the decisions taken at both T2 and T3. Brown rust can be found in most crops of Alchemy but at very low levels. One crop of Alchemy has brown rust up
to and including leaf 2, this is partly due to the crop being stressed and T2 delayed to four and a half weeks due to inclement weather.
Septoria : all varieties are clean in terms of septoria with Einstein, Gladiator and Ambrosia showing leaf 1-4 clean, in the main a lot of these crops ended up with a 'top and tail' T2 due to the rain that has occurred during the T2 timing. A further T3 fungicide is planned.
Eyespot : still visible on stem bases, particularly Einstein.
Yellow rust : crops of Robigus with unsprayed areas are dead through Yellow rust. One field appears to be going off across
the whole field, even where the crop has been sprayed twice with robust fungicides the yellow rust control is not 100% with visible lesions on leaf 2. However, there are also crops of Robigus with no signs of yellow rust.
Aphids : odd crop with some on the ear.
Wheat blossom midge : none seen in the week and risk diminishing.
Some root lodging has occurred with very heavy rainfall and waterlogged soils, mainly restricted to nitrogen overlaps.
East
Crop development: Crops range from GS 51 to GS 61 (start of flowering). Typically GS 57-59 (Late ear emergence). Flag fungicides finished off 22nd -24th May(10 days late).
Ear wash will start next week (weather permitting). 50 mm rain on 27th/28th May combined with strong winds have resulted in some lodging on early drilled wheat, particularly on fields which continued
to grow during the spring drought.
Brown rust : still causing concern. Becoming obvious and beginning to develop on newer leaves of Alchemy, Robigus and Solstice.
Yellow rust : trace levels on Robigus.
Mildew : low levels at base of crop on Einstein.
Septoria : risk very high although still in latent period.
Eyespot : at low levels.
Wheat blossom midge : none seen. Recent weather (rain, low temperatures and high winds) will not allow flight/egg laying in evenings.
North East
Crop development: Most crops at full ear emergence, but later drilled at 25-50% ears emerged. No flowering seen yet so all crops at very vulnerable stage to OWBM damage. Field conditions are good, despite 23 mm rainfall in last 7 days making a total of 87 mm for May.
Last lot of rain has 'ruffled' many crops and there are small areas lodged in a few crops.
Brown rust : T2 application continues to give good control, but some infection still to be found in crops of Alchemy. Other varieties seem to be clear now. Will apply robust fungicide on Alchemy to maintain control.
Mildew : slight increase on light land.
Septoria : T2 has given good control but next 14 days will show how much re-infection has occurred following the heavy rain.
Eyespot : low levels, no increase.
Yellow rust : good control in all varieties so far, including Robigus, but need to continue checking up to T3.
Aphids : low levels present in crop canopies now.
Orange blossom midge : no panic over OWBM this week, but there is still time for them to flare up before most crops start flowering so there will be at least another 7 days of close monitoring.
Only low numbers being caught in pheromone traps. ie. 5-7 over 3 nights. Soil temperatures fell from 13°C to 10°C last weekend and will take a while to warm up again so immediate threat maybe over.
Winter barley
South East: All crops now at grains half full and await the combine in early to mid-July.
South West: Crops milky to cheesy ripe.
Midlands: Most forward crops grain watery ripe. Some nasty lodging on more fertile sites where manure used.
East: Typically at GS 63 - 65, mid flower. Low disease levels
North East: Flowering finished and grain fill just starting. A few small areas lodged, but generally crops standing well.
Spring Beans
Downy mildew on spring beans Photo Farming Online
South East: Crops are just beginning to flower, and have first signs of chocolate spot now developing.
South West: Early to mid flowering.
Bruchid beetle : first insecticide will be applied
with fungicide at mid flower followed by second dose 7 days later. Usual caution re bees advised.
Midlands: Crops now flowering - fungicide + bruchid beetle insecticide soon.
Downy mildew : starting to come into Fuego.
North East: Early flowering. Chocolate spot : at low levels. Considering a fungicide application next week to pre-empt disease development and to include insecticide for some Bruchid and further Weevil control.
Crop Report compiled by Farming Online from reports
received by members from the Association of Independent Crop Consultants
delivered to the industry by HGCA
This website was last updated on: 14/05/2008
© Crown Copyright Central Science Laboratory 2007
All risk predictions published by CropMonitor are provided in good faith and are NOT a substitute for
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