‘Big data’ highlights benefits of hybrid barley as previous crop to oilseed rape
Arable farmers seeing continued opportunities for planting winter oilseed rape next summer, in light of promising oilseed prices, should finalise this autumn’s preceding crop plans carefully, in order to get the best from the oilseed rape crops that will follow them.
That is the message from Syngenta arable seed specialist, Mark Bullen, who says oilseed rape has always benefited from planting early – firstly to achieve its full yield potential, but also to help it better withstand pest problems, such as cabbage stem flea beetle and slugs.
But with the loss of neonicotinoid seed treatment chemistry against flea beetle, it has brought a greater need to plan its fit in rotations well ahead, he says, so it can be established early enough against flea beetle attack.
“The better established that oilseed rape is, the more flea beetle feeding damage it can withstand,” explains Mr Bullen. “Most oilseed rape should be planted by the third week of August. You don’t want it to drift into September.
“Without neonicotinoid chemistry against flea beetle, it has pretty much ruled out planting oilseed rape after second wheat for many growers. Winter barley has found favour as the obvious earlier-harvested alternative. But even then, we have found differences in oilseed rape yields when planted after different types of winter barley,” he adds.
Pointing to results of an independent study commissioned by Syngenta, which examined five years’ of data from over 100,000 hectares of winter wheat and barley, Mr Bullen says the average harvest date for winter barley was found to be around a month earlier than that of second wheat.
Moreover, on average, hybrid barley was harvested earlier than conventional feed barley, he adds.
More interestingly still, he says, when yields of the following oilseed rape crops were examined, the average yield for oilseed rape planted after a second wheat was 0.28 t/ha higher. Oilseed rape yields also benefited after hybrid barley over conventional winter barley, avergaing 4.22 t/ha compared to 4.13 t/ha.
“We’re not entirely sure where this extra oilseed rape yield came from after the hybrid,” admits Mr Bullen. “It could have been because oilseed rape crops were more advanced after being planted earlier after hybrid barley, or it could have been because the earlier-harvested hybrid barley allowed more time for preparing better seedbeds.
“Whatever the reason, these big data results show a clear positive trend. On top of the extra oilseed rape yield, the hybrid barley crop itself was also found to yield on average 0.61 t/ha more than the conventional barley,” he adds.
Separately, Mr Bullen says hybrid barley in trials has also been found to be more competitive against black-grass than conventional winter barley and winter wheat. So it could also provide a cleaner entry for oilseed rape, which itself is already a useful break crop in black-grass situations, he adds.