Hybrids could deliver greater consistency of production than conventionals when used in stressful conditions and close rotations, suggests an independent trial of 31 oilseed rape varieties carried out by Agrivice Ltd in the South East of England.
Top of the pile was the DSV variety Compass recording both the highest yield and oil content with four out of the top five places going to hybrids. “2012 has been a difficult year for oilseed rape with many crops lodging and a high incidence of disease so the trials were a true test of standing power and a variety’s inherent ability to deliver its genetic potential against the odds,” says Agrivice managing director, Dan Robinson.
“In particular, with oilseed rape prices at £400/tonne allowing the crop to rival the gross margins of many wheat crops, we wanted to test varietal tolerance and see which were capable of delivering consistent performance in the stressful conditions of alternating years of wheat and rape.”
Compass not only achieved the best yield at 6.21 tonnes/ha – corrected to 9% moisture content – but also the highest oil content at 47.18%, giving it the highest gross output by some margin. The variety also achieved the lowest Verticillium wilt score in the trial of just 2.0 on a scale of 1 – 9. Further analysis carried out by Dr. Peter Gladders of ADAS revealed no incidences of dead stems on the variety due to the disease with others showing up to 90%.
All the varieties were sown on the 30th August 2011 and harvested on the 24th of July 2012. The site at Frostenden Hall Farm in Wrentham, Suffolk, is sandy clay loam with oilseed rape sown every two years in between wheats.
“We specifically sought a close rotation to try and split apart the varieties’ differences under increased stress, so we could see which ones coped with this the best in terms of both yield and susceptibility to Verticillium wilt,” Dan Robinson explains. “Although four of the top five performing varieties were hybrids and these delivered the best oil contents in the trial, there was wide variation in performance between different hybrids with some conventionals rivalling them for yield and disease resistance.”
According to Mike Mann of DSV, the results with Compass in the trial are consistent with those now being seen in the field across the UK underlining its position as highest oil producing variety in the current HGCA recommended lists.
“As harvest gets underway, we are getting many reports of how well Compass has stood up to the difficult growing season and how well it is yielding.
“It’s been a tough year for oilseed rape growers and the scientific community believes we’ve got more of these variable weather patterns to come in the future, so ‘genetic resilience’ – a variety’s ability to cope with widely varying growing conditions and environmental stress such as tighter rotations – is going to be of greater importance than ever in the years ahead.
“It is certainly something that is a top priority in the DSV breeding programme. This is not only evidenced by the consistency and stability of current varieties like Compass, but also the potential of the new semi-dwarf hybrid Troy and other varieties now coming through testing.”