: Oilseed rape crops this time last year were mainly at the early green bud stage and under attack from pollen beetle. This year crops are a lot more advanced but forecasts for temperatures to rise above 16 degrees at the weekend could see a return of large numbers of pollen beetles. Note that once crops have started to flower control of this pest is no longer necessary. Yellow rust although present in some crops of Oakley has yet to develop significantly in other varieties. Brown rust on the other hand seems to be becoming more prevalent but still confined to the south and east.
Pollen beetle: new thresholds for control
Brown rust: in east, south and north east - keep monitoring
Net-blotch and Rhynchosporium: developing in the North East
: New thresholds proposed for pollen beetle control in oilseed rape suggest that the thicker the crop the lower the threshold per plant is for controlling pollen beetle, for the HGCA information sheet see: http://www.hgca.com/document.aspx?fn=load&media_id=7698&publicationId=8521
Winter Oilseed Rape
Pollen beetle (photo courtesy of Farming Online)
South East: All crops now at early green bud with crops of Alienor even showing some yellow buds.
Phoma: no significant renewed spotting seen to date.
Light Leaf Spot: was being found widely at around 10-20% infection levels in most crops/varieties in last two weeks and particularly those that only had one autumn Phoma/PGR spray applied.
Pollen beetle: only very low levels have been found so far and well below threshold levels - warm weather forecast for next 7 days may cause a surge in numbers. Hoping that there will be far fewer problems this year as crops are more advanced and generally very even in development.
Weed control: most crops beyond the growth stage for further weed control.
Eastern Counties: Crops rapidly moving into stem extension with flower buds proud. Camelot noticeably early. Some variability between fields and varieties. Most forward crops have had growth regulator applied this week.
Light leaf spot: visible but levels have remained low in North West Norfolk.
Pollen Beetle: very few pollen beetle seen in the crop to date but with temperatures increasing and some sunny intervals we will need to inspect crops especially on warm sunny still afternoons.
Weed control: all applications completed.
East Midlands: Most crops very forward with GAI of 2+ in some forward crops. Even later crops are growing rapidly and in most their flower buds are now showing above the crop.
Light Leaf Spot: just odd pieces but nothing of concern yet.
Pollen Beetle: Some pollen beetles found in flowers of bolters and spring rape volunteers which are in flower but generally not a lot seen yet.
West Midlands: Crops really lifting off now, many with buds above the crop/extending also signs of early flowers on buds that extended some weeks ago.
Phoma: no new infections.
Light Leaf Spot: very low levels which have not developed.
Pollen beetle: not an issue as yet, will start to keep an eye on the backward crops as temperatures start to climb.
Weed control: all herbicide applications made.
North East: All crops are 'buds proud' now and just a tinge of yellow in the most forward. Crops have good colour and grew very quickly during recent warm spell. They have slowed a little now but are at least 10-14 days ahead of last year.
Light Leaf Spot: a few lesions can be seen in crops now but the level is not causing concern.
Phoma: no further infections seen.
Pollen Beetle: none seen yet.
Weed control: all herbicide applications made.
Yellow rust in Oakley (photo courtesy Farming Online).
South East: All crops now responding to applied Nitrogen and have grown rapidly in last few weeks of mild weather. Crops range from late tillering to GS29 (late October+ sowings) to early stem extension GS 30-31 (September sowings) with leaf 4 up to 75% emerged now, particularly on Gallant/Solstice. Even seen tip of leaf 3 emerging in one particularly strong crop of Solstice.
Brown rust: just beginning to reappear now, particularly in September crops of Claire, Cordiale, Gallant, Target and Solstice.
Mildew: very little sign to date of any fresh pustules.
Yellow rust: no foci or leaf pustule stripes seen, but remain vigilant particularly on varieties that may be prone to the Warrior race.
Septoria: most lower leaves now completely senesced due to Septoria infection.
Weed control: where blackgrass present all spring applications of herbicide have now been completed.
Eastern Counties: Crops range from 2 tillers after sugar beet to 10 tillers and some wheat at GS31. There are some very tall thick crops.
Brown rust: easily found in some crops. Varieties include Claire, Grafton, Hereford and most other varieties.
Yellow rust: quite a lot of rust in Oakley and Robigus, low levels in Viscount. Some seed treatments have been more effective than others making it more difficult to find.
Mildew: the more backwards crops showing quite a lot of mildew.
Eyespot: low levels in very forward crops. We are expecting high levels this year as early drilling was common and crops very thick.
Weed control: the mild winter has given rise to more cleavers this year than usual. Good autumn control of blackgrass but some cases with resistance. Cloddy, dry seedbeds have caused some poor control from pre - ems.
East Midlands: Forward crops at GS 30+ with vast majority at GS 29-30 and later crops at GS 29. All crops have had some Nitrogen with clients concerned by dry conditions and possible dry soils later on. Expect second application to be early to mid April depending on weather. Most crops have had 40 kg N and second wheat 50-60 kg N/ha. Soils dry on top with no wheeling damage in tramlines.
Brown rust: none seen.
Yellow rust: easily found in Oakley but none in other crops. No increase seen since last week - Gallant, Duxford and Solstice remain clean.
Mildew: levels remain very low even in varieties such as Gallant and no real concern.
Septoria: older leaves dying off in dry conditions but plenty of potential infection.
Eyespot: lower leaves dying off and in drier conditions there is less penetration.
Weed control: some larger flushes of cleavers.
West Midlands: Crops range from GS21 to GS31. T0 fungicide sprays planned for this coming week. Some drought stress signs beginning to show on light land and with no rain forecast for next two weeks things could start to get critical quickly.
Brown rust: none seen.
Yellow rust: still only traces in Oakley and Conqueror.
Mildew: pretty much everything has got more mildew on it to a lesser or greater degree.
Eyespot: some lesions seen in the base of Oakley.
Septoria: lots of septoria in the base of many crops.
Weed control: some big cranesbill in some fields.
North East: Despite the cool nights, longer days and plenty of sunshine has encouraged significant crop growth. Even the later sown crops are at GS 30 now, and the more forward are GS 31. Its dried up again after the rain at the beginning of March. There has been no rain locally for 11 days.
Brown Rust: low levels seen in the most susceptible varieties, such as Duxford and Grafton.
Yellow Rust: some crops of Oakley developed a severe level of infection last week. Also present in Santiago and Viscount but to a much lesser degree.
Mildew: only the most resistant varieties are clean such as Warrior and Viscount. All the rest have varying levels of infection.
Eyespot: the level of infection seen has the potential to become a significant problem in many crops.
Weed control: Cranesbill is the most common broad leaved weed and there are some severe infestations.
South East: Crops still mostly range in growth stage from GS29-30. All crops have tillered well this year.
Brown rust: pustules still very evident in many crops and getting active again - have seen one crop of Volume where only top 2-3 leaves are green and rest have largely senesced due to brown rust!
Eastern Counties: Most crops have at least 4 tillers. The most forward are up to 7 or 8 tillers and just below wellington boot height. Some looking as though could lodge.
Net-blotch: at treatable levels in some varieties such as Flagon and Cassata.
Brown rust: present in Carat and Pearl.
East Midlands: Generally crops at GS 29 and not moving forward much. Levels of mildew, net-blotch and Rhynchosporium all remain low in the dry conditions.
West Midlands: Crops range from late tillering to GS 30 it will be another week or two before T1 fungicides are needed. Very little Net-blotch or Rhynchosporium and no brown rust. Late sown light land crops losing bottom leaves to mildew + looking short of everything else as well. Applying manganese + magnesium + fungicide at earliest possible opportunity to these crops.
North East: All crops are at leaf sheath erect stage (GS 30 - 31).
Net-blotch and Rhynchosporium: remain at significant levels in most crops.