Oilseed Rape

Hybrid winter oilseed rape drilled in mid October has demonstrated yields of more than 3.5t/ha indicating growers have no need to despair if the weather turns against them in the next few weeks, according to findings from an NK sponsored trial at Springdale Farms, Rudston, Driffield, in East Yorkshire.

Royal was among the hybrid varieties on trial and once again it showed an optimum yield of 3.58t/ha from a moderate input of 170kgN/ha. The exact same yield response to moderate nitrogen input was demonstrated by Royal in three consecutive years of trials at Springdale.

"The latest trials have demonstrated that hybrid vigour can be exploited to extend the cultivations window if necessary, however it is not a practice we would advocate on an annual basis," says NK's Nigel Padbury.

Springdale's Simon Meakin explains the crop germinated within 10 days of drilling in the middle of October and over wintered in the three to four leaf stage. "Hybrid vigour initiated in spring despite stem extension being delayed until early April, two to three weeks later than Springdale's winter oilseed rape drilled in late August, while flowering was 10 days later. The mature crop was approximately one foot shorter than normal, however we had no canopy problems and we were able to desiccate and direct cut, eliminating the need for swathing."

He adds: "While the crop did pose more of a challenge to manage during winter with extra vigilance required for pests and disease, drilling late provides farmers with more time to clean up the field in early autumn. Overall, the trial proved that if the weather conditions turn against planting in September, then hybrid varieties such as Royal, offer a great deal more flexibility than previously thought and they can turn in a highly respectable yield."

• At 4.77t/ha, hybrid Royal was among the highest yielding varieties in NK's Performance Evaluation Network trials staged at nearby Haywold, Driffield. NK's new long term initiative on the Yorkshire Wolds, is one of seven located in major oilseed rape growing areas throughout Britain. Each PEN trial site features 20 winter oilseed rape varieties; a mix of HGCA Recommended List 2005/06 varieties, National List Year II and Recommended List candidates.

PEN has been structured to enable growers for the first time to make direct local and national comparisons of the performance of National List Year II candidate varieties with existing commercial varieties - those on the current HGCA Recommended List. The initiative will extend the information available to growers beyond the HGCA Recommended List trial sites.

Further information on the NK PEN trials and results from all of the sites in the network can be found on the NK website www.oilseedrape.com