Surprisingly rapid ripening, uneven crops and serious harvesting delays and difficulties are leading to major seed shedding in many oilseed rapes, warns Openfields arable technical manager, David Leaper.

“The actual level of losses is very hard to quantify at this stage,” he explains. “But we’ve received widespread reports of large amounts of seed running off cutter bars in the past week, in particular. And there’s been far too much white haze for comfort across many crops ahead of combining, suggesting substantial pre-harvest losses as well.

“This really isn’t surprising given the unbelievable speed with which so many crops have gone from green and immature to extremely dry this season, putting intense pressure on the pods.
You only have to stand in them as the sun comes out to hear the tell-tale chorus of pod-popping.”

Weather delayed harvesting has made the problem worse, Leaper believes. As has uneven maturity from the very extended flowering period, and the intensity of local summer storms. Add to this the extra battering of reels set to lift and pick-up storm-tossed crops, and he sees largely unseen yield losses of a good 20 percent or more on the cards for many.

“This will go down as the second bad season in a row for seed shedding,” he predicts. “It will also be a season which underlines the value of varieties with genetic resistance to pod shatter.

“Pod shatter resistance is not a character most people have given much thought to until now. But our field-scale variety trials show just how significant it can be. Last season, for instance, we recorded just 1-2 volunteers/m² in blocks of the pod shatter resistant hybrid, DK Extrovert two weeks after harvest compared with up to 700/m² in some other varieties grown and harvested alongside it under precisely the same conditions.”

Pod shatter resistance derives from a superior balance between key genes determining the anatomy and functioning of the lignified layer which divides the OSR pod into two halves. Although yet to be highlighted in official variety lists, genetic studies confirm it is carried by a growing number of modern hybrids available in the UK.

“However it arises, after what we’ve seen this season and last I’m convinced it’s something more and more growers should be actively seeking in their variety mix to minimise seed shedding losses,” insists David Leaper.

“Alongside the pod-sticking products grower feedback suggests are also proving especially valuable this season, pod shatter resistance has an important role to play in improving OSR performance reliability in our increasingly uncertain climate.”