Monsanto has dismissed concerns about blind pods on its promising candidate winter oilseed rape variety DK Cabernet, pointing out that yields will not be affected.
Difficult planting and growing conditions mean that many oilseed rape crops struggled to get the nutrients required when they were setting pods, says the company’s Anne Williams.
“The combination of late drilling, shallow rooting and a dry spring meant that the crop’s need for magnesium and boron wasn’t met in some situations,” she notes.
This resulted in lower pods being aborted, she reports. “Growers have noticed blind sites at the bottom of plants, but we are confident that crops have more than made up for it by now.”
This phenomenon shows up more on taller, later-maturing varieties, which is why DK Cabernet has been the focus of attention, adds Mrs Williams.
Conventional type DK Cabernet leads the candidate varieties on gross output for the east and west region, with seed being sold ahead of the decision on its recommendation by a number of companies.
Simon Kightley of NIAB believes that blind pods are a feature of the growing season, not a varietal issue. “There have been more reports of the problem this year, but mainly from Norfolk and Suffolk, where it’s been very dry. That suggests it is a nutritional blip.”
Richard Elsdon of United Oilseeds agrees. “The oilseed rape plant produces between 50% and 100% more pod sites than it can set. Not all of them come to fruition.”
Philip Marr of Masstock points out that the problem has been seen before in the variety Lioness, when it was deficient in magnesium.
“Some varieties appear worse than others, which is why they get singled out. But if there’s a hold up in the plant’s uptake of either magnesium or boron, it shows at flowering. Boron is needed for pollen grain production.”
Sulphur deficiency can also lead to pod abortion, which is another factor relevant to this year, he says.
Poor root structure is to blame, adds Mr Marr. “As well as DK Cabernet, the hybrids Flash, Dimension and Hammer were showing blind pods earlier on. But harvest results are unlikely to be affected, as crops have grown on well since then.”