Arable Crop Watch - Ben Pledger - Farmers Weekly

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The little Oilseed rape that I have in the ground is growing well, mainly drilled around the middle of August after some welcome rains. Flea beetle pressure this season (I’m touching wood as I write this) has been relatively low in the Hertfordshire area, with early attacks being nipped in the bud at cotyledon stage with a mix of lambda-cyhalothrin, sulphur and a latex based sticker. On all bar one field, this has been the only treatment needed for the pest.

The next issue is the population of blackgrass flushing, in the crop. Fortunately, there is enough of a flush to suggest that it has germinated at the same time, and a well-timed application of clethodim will hopefully take it out.

The low dormancy of blackgrass is noted with the weed flushing well in both uncultivated stubbles and seed beds already prepared for cereal drilling. Although some seed drills in the area have started to get going, it is still way too early to start when there are seed-beds only just showing one-leafed blackgrass, with others only getting a rain at the weekend to get a chit of anything.

Seed treatments

As this is the last year for clothianidin based seed dressings, we will have to push further toward delayed drilling not only as part of our integrated blackgrass control, but also to reduce the potential of aphids bringing barley dwarf virus into crops.

Further to this, I can find aphids quite easily in volunteer cereals growing in stubbles planned for spring cropping. It is important to spray these stubbles off sooner rather than later to eliminate any green-bridge which may harbour pests for neighbouring winter crops.

On a final note, with the dry summer this year, seed quality is all over the place. I’ve heard of thousand grain weights for winter wheat ranging from 33g to 60g. Please take this variance into account when calculating seed rates for drilling this autumn.