As harvest progresses almost a week earlier than normal and land is cleared, many growers will be looking to get their OSR crops into the ground – but don’t be tempted to drill until there is enough moisture, warns Limagrain UK.

The dry summer has meant that crops have ripened early, but it also means that there is very little moisture in the soils, says says Liam Wilkinson, arable development officer at Limagrain.

“Whilst some areas have seen some rain recently – many have not had any – and even where it has rained, it needs to be a serious amount to restore moisture levels to where they need to be to sustain a rapidly emerging rape crop,” he points out.

With not much rain in the early August forecast, many will be worrying about compromising establishment by holding off drilling until conditions improve.

Conditions, not dates

Liam’s advice is to look at and be guided by seedbed conditions rather than calendar dates.

“It’s possible to get good yields from later drilled rape, when sown into the right conditions. In fact, they often outperform some of the earlier drilled crops – and many later drilled crops have been winners in the YEN awards” he says.

“Last year we saw crops of LG Antigua drilled mid-September up in the Lincolnshire Wolds achieve yields of over 6t/ha, so there is definitely high yield potential for crops drilled into September in the right conditions.”

Variety choice

Choosing the correct variety for this drilling window is key to success, he adds. “If you are drilling in September, the focus should be on speed of autumn growth and vigour, so hybrids are a first choice because they are quick to get going and they accumulate biomass very quickly.

“Vigour is also important to get the crop established and putting roots down, but the speed of development for reaching over wintering biomass as quickly as possible is key.”

A variety in this situation will also benefit from a canopy in order to withstand potential pest problems, as well as harsh winter conditions, says Liam.

“Tried and tested varieties such as Aurelia and Ambassador have performed consistently in this slot, both on farm and in trial for a number of years now.

“More recent additions of LG Aviron, LG Auckland and LG Antigua to the AHDB Recommended List strengthens the variety options available to growers, when drilling later than planned.”

Seed rates

With vigorous varieties, seed rates should target 25-30 plants/m2, which is normally around 50 seeds/m2, and Liam recommends that growers assess seedbed conditions and adjust seed rates accordingly to account for field losses, particularly if conditions deteriorate.