DIY Trials Prompt 2004 OSR Re-Think

Home-grown, field-scale OSR variety trials have caused Gavin Davies to revise his 2003 planting plans at Chivers Farms near Cambridge at the eleventh hour to make space for a variety that has surprised him roundly by outperforming his first choice, Winner to the tune of a good 0.5 t/ha.

Rather than putting his entire 400 ha of winter rape down to Winner and Recital as originally planned this autumn, the trials experience has persuaded arable farms manager, Gavin to devote fully 20% of his 2004 crop to low biomass newcomer, Caracas.

"Every year we look at a range of interesting varieties in 1 ha 24-metre strip trials grown to our standard commercial practice across a single field," he explained. "We do this because we invariably find small-scale research trials very unreliable in predicting actual OSR performance.

"We assess performance using the combine yield monitor, so we don't get the absolute accuracy of a plot combine. What we do get, though, is a very good indication of the relative yield of different varieties under our own regime. Which is what we really need.

"This year's trial went in 10 days later than I would have liked in mid-September, so it was more of a challenge. And all the varieties fared well despite the tough conditions. I have to say the Caracas didn't look anything special right up to harvest. But the combine told a different story, giving us a very pleasant surprise.

"It produced 0.5t/ha more than any of the other varieties, around 5 t/ha as against 4.5 t from next placed, Winner. In reality, accounting for the yield monitor effect, I reckon we're looking at yields nearer 4.5 t/ha and 4.0 t/ha respectively. Which is particularly encouraging in a challenging season that left our farm OSR average around 0.4 t/ha down on last year at 3.6 t/ha."

Even so, with all establishment non-plough based since 2001, wheat workload priorities meaning no fungicides were used on any of the rape this season, and the shortness of the crops allowing everything to be direct-combined, this performance produced tidy overall margins for the Chivers Farms team.

"Our OSR has to be able to look after itself if we run out of time," Gavin Davies pointed out. "After all, our 1000 ha of wheat has the first call on our resources. So disease resistance and all-round vigour are important considerations. That's why we've shied away from popular varieties like Royal with poor phoma ratings. Blackgrass control in the wheat is our Number One priority and, like last autumn, oilseed rape fungicide applications sometimes have to go by the board.

"The excellent disease rating of Caracas is an obvious attraction with our system," he added. "As is the guarantee of consistent direct combinability. At the end of the day, though, it's the variety's yield performance that has really impressed us. So much so that we've made an exception to our rule of only trying a small amount of a new variety in its first season and ordered 80 ha-worth of Caracas seed for this autumn."