North: How late to drill oilseed rape?

Dry weather in early September has finally allowed progress to be made harvesting crops.  Wheat yields are only going to be memorable for the wrong reasons, having looked so good in early June. The only small consolation is that a lot of wheat has been combined at low moisture contents so drying costs are much lower, but that is about the only positive. Most will be glad to get this wheat harvest out of the way and start afresh.

August drilled oilseed rape crops have established fairly well despite some less than ideal seedbeds. The question ‘how late can I drill oilseed rape?’ has been asked many times, to which up until mid-September will be fine. After this point the success of crop establishment becomes less certain but is possible if seedbed conditions are good and temperatures remain warm.

Slugs have been a serious problem and have in some instances been severe enough to cause fields to be redrilled. Flea beetle activity, particularly on wold land, will need watching as seed dressings such as Cruiser and Modesto begin to wear off. Apply a pyrethroid insecticide if flea beetle damage begins to threaten the crop.

A large flush of cereal volunteers are emerging with the rape plants and will soon begin to become competitive. Applying a graminicide such as propaquizafop or fluazifop-P-butyl will provide good control.

Black-grass is emerging over a more protracted period and a graminicide will be applied where resistance to the fop and dim herbicides is not high. The timing of this herbicide is often narrow due to waiting for the black-grass to emerge, while not letting the cereal volunteers become too competitive against the oilseed rape.

Wheat drilling has started, but take note of the thousand grain weights on the seed bags as they are often very low this year. Drilling by weight alone with no regard to the thousand grain weight is likely to be mean excessively thick crops that will be prone to lodging. With the herbicide battle against black-grass becoming increasingly difficult, it is welcoming to see many more adopting cultural control methods, such as delayed drilling.

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