Late drilling will benefit from autumn vigour

With a lot of remedial soil cultivation work to be done following such a wet autumn, the drilling window for winter oilseed rape is becoming later once again and growers are being reminded that that rape really benefits from good soil structure so it is worth getting the soil structure right. They are also being advised to consider drilling the conventional rape variety Alienor that has become recognised as showing strong autumn vigour.

Oilseed rape specialist Simon Kightley of NIAB has remarked on Alienor’s vigour and earliness. He noted that, when describing the NIAB demonstration plots at Cambridge last year when crops were drilled late, the conventional variety Es Alienor looked distinctly more leafy and green than anything else. "Most of the rape varieties showed a pretty uniform level of pigeon grazing damage and varying unhealthy shades of pale green to blue to purple – desperate for their first dose of nitrogen. Alienor was easily the first variety to get up and go in the spring."

"Farmers want varieties that grow well in the autumn and so create a strong plant populations going into the winter. Varieties of rape which demonstrate good winter vigour are able to grow through pigeon damage, a real practical benefit. Alienor shows significant crop vigour in the autumn and into the spring, ahead of most hybrids," claims Neil Groom, Technical Manager of Grainseed.

"Autumn establishment is critical if only to keep ahead of the pigeons. Vigour has often been talked about and hearsay claims hybrids are better, but work this season by TAG questions this. This work and many commercial crops show that some conventional lines actually have better vigour than most of the hybrids."

"When growers are selecting varieties of rape to drill this autumn, there should be a number of characteristics they take into account including vigour and maturity. Alienor is the earliest maturing conventional variety and this means that fits well into normal crop rotations and helps spread the workload at harvest – an advantage to growers with a large acreage to harvest and to drill up. It is an ideal partner variety to grow in combination with the low biomass variety Astrid," says Neil.

Low biomass is also an important criteria valued by many growers who have benefited from growing Castille and Es Astrid over the past five years. Alienor is a low biomass variety with an average height of just 147 cms, close to that of Castille at 144 cms.

Richard Fenwick, independent seed specialist, is concerned that some farmers may choose to grow the much taller hybrid rapes, with the incentive of yield, and warns growers to think beyond just yield and consider all the cost and management benefits of growing a low biomass variety with a strong agronomic package.

"Low biomass varieties such as Es Astrid and Es Alienor offer growers many benefits in terms of management and costs, not just savings on seed, fungicides, fuel and labour at harvest but the positive benefits of avoiding lodging and better throughput at harvest. A crop which is easier and cheaper to manage and to grow can often be more profitable at the end of the day. Some of the new hybrids are a lot taller and bulkier and, if growers chose to grow them, they must be prepared for the ensuing management issues, all of which will have a cost implication," says Richard.

Richard Fenwick advises rape growers to look at the whole package. "Yes, gross output must be the starting point, but you need a good balance between output and input. In particular you must cost out the positives and negatives on both sides of this equation. Only by careful consideration of all key variety characteristics can a sound choice be made."

"The cost implications of disease resistance should also be added into the equation. Alienor has the best combined disease resistance ratings of any conventional variety, with a 7.4 for Phoma and a 6.2 for Light leaf Spot, making this variety suitable to grow in all parts of the UK," reports Neil Groom.

Neil concludes that Alienor has a unique combination of yield and agronomic characteristics that make it well worth considering for planting this year anywhere in the UK for early harvesting.

"Its overall package allows much easier and less costly inputs without compromising on yield, plus great ease of management. We are advising growers to think about planting 20% of their winter rape area down to early varieties like Alienor and so spread the risk next harvest.