Rape variety hit by podding problems

24 August 2001

Rape variety hit by podding problems

THE NFU is considering legal action against oilseed rape breeder CPB Twyford after growers claimed more than 10% of this years Gemini variety area suffered podding problems.

Yields from the varietal association hybrid have dipped as low as 1.5t/ha (12cwt/acre), with one web-site showing the variety running 1.1t/ha (9cwt/acre) below the average of all reported varieties.

All 82 complaints, representing 2366ha (5850 acres) of the estimated 18,000ha (44,500 acres) of Gemini grown, have been investigated, says CPB Twyford.

Company director Theo Labuda now admits such types can be risky to grow. "Growing a varietal association is more of a risk than growing an in-bred. But the potential benefit is much greater.

"We have sorted out 18 cases and the growers have gone away happy. In some cases there were no problems at all." Indeed, one initially aggrieved Hants producer found Gemini to be his highest yielder, he adds.

"But there are three or four others where we are concerned that it appears there was a very limited amount of pollination and we are still investigating what happened."

But compensation payouts are being resisted. "We are trying to keep our merchants and customers as happy as we can, but it would be crazy to offer compensation just because growers got low yields."

Suggested causes include a glitch in mixing the two seed components, leaving too few pollinating plants in the field, and sulphur deficiency after the wet winter.

An NIAB report for the HGCA recognises the possibility that some seed may have gone out with reduced or missing pollinator. No pollinators could be found in either of the crops investigated, while selective winter-kill seems unlikely, it concludes.

Mr Labuda says it is improbable that faulty seed blending led to poor yields.

And ARC director Mike Carver disputes the sulphur theory. "The way podding appears in layers points to poor pollination and maybe a lack of pollen, rather than sulphur being completely to blame."

He is aware of many commercial crops of Gemini with problems, including a 60ha (150 acre) block in Lincs. "I have always had fears about varietal association hybrids offering reliable yields. This season underlines that there is an inherent problem."

One grower told farmers weekly that he will not grow Gemini again after two years of disappointment. Last year the variety achieved only 1.2t/ha (10cwt/acre) at Martin Holmes Drylands Farm, Molash, Kent.

After a "financially very fair" settlement with the breeder, he grew it again. But poor podding led to a yield 0.6t/ha (5cwt/acre) less than Apexs 3.7t/ha (30cwt/acre).

"Thats certainly not good enough against an outdated variety like Apex. I have found it unreliable due to pollination problems of an uncertain nature." &#42


&#8226 Complaints from 13% of area.

&#8226 All investigated – some twice.

&#8226 Resolution in 22% of cases.

&#8226 Yields as low as 1.5t/ha (12cwt/acre).

&#8226 Causes still being explored.

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