Take care when interpreting data to support oilseed rape seed choices. Individual performance is driven by many factors and it’s easy to slip up and pick varieties that, contrary to their glossy literature, disappoint.

That advice came during discussions at the initial meeting of the recently formed Sigma Oilseed Rape Professional Growers Team*.

The Sigma initiative aims to find out why, despite breeders’ best efforts, the UK’s on-farm yield remains stubbornly static, and how it can be raised.

“The average potential mid-UK yield using the best current varieties is around 6.5t/ha,” said ADAS’s John Spink. That was in trials, so on-farm output could be expected to be slightly less, perhaps 6t/ha (2.4t/acre).

And provided plant breeding advances continued, the country got enough light and rainfall to produce more than 9t/ha (3.6t/acre), Mr Spink suggested. “But nationally the average is only 3.2t/ha.”

Outlining the Sigma Team’s objectives, NK Seeds’ Nigel Padbury explained that the idea was to challenge many growers’ perception that there was little they could do to improve output.

“Very often I’ve had conversations with farmers, for example about green area index, and they say they really can’t do anything about it. We want to challenge that and really test all the theories about growing the crop in a practical way on farms.”

The aim, through dialogue with participating farmers from all regions, was to produce the “ultimate growers’ guide”, he said. “We need to move things forward.”

* Feedback from all parties interested in raising UK output would be encouraged via a dedicated FWi forum.