East: Sclerotinia threat high in oilseed rape

Here in the arid east no rain is forecast for yet another week, although we can expect some lower temperatures. Personally, I have never experienced such a dry start to spring and apart from the early drilled cereals, crops are beginning to show stress symptoms.

Drought conditions, coupled with the large amount of Oakley wheat, have seen an explosion in yellow rust whether the crops had a T0 fungicide or not. Viscount, Duxford and Solstice have also been affected, although not as badly. This is not a happy situation and although we have the armoury to deal with it, it is just another cost regardless of how much wheat is worth.

I am also seeing a large amount of “blind” racemes on many oilseed rape crops. This is not a varietal issue, as some have claimed, as many varieties I have seen are affected. Later- drilled crops appear worst affected by the lack of uptake of nitrogen and higher diurnal ranges in temperature than earlier drilled, well established crops.

Pollen beetle are not a serious problem here although they have been difficult to control in many crops and resistance problems have really shown up this year with the need to use the newer insecticides. The early crops are flowering really well and right through the profile. Sclerotinia sprays are being applied even though conditions are dry.

Heavy dews are enough to allow apothecia to release spores, especially with the high temperatures we are currently experiencing. But with overnight temperatures remaining above 7C, the threat of developing sclerotinia remains. I have also seen more brassica seed weevil than in other years, so take into account the threshold of 1 weevil/plant and treat accordingly.

Sugar beet is generally very good, but the dry conditions are showing up problems in heavy land seed-beds with patchy germination. Some have just not chatted, but will when and if it ever rains. Weed control at the moment is very much biased towards the contact materials, but those involved with the Broadacre approach are scratching heads where uneven germination is a problem and high temperatures prevail.

See more