Apoor start hid the true potential of conventional oilseed rape variety Aspire – which came back in time to pip other hybrid varieties for yield on a Suffolk farm.
“It yielded half a tonne more than any other variety on the farm,” says Tom Jewers, of Woodhall Farm, Rattlesden. “Based on this we will be using Aspire to replace our previous mainstays of Cabernet and Campus.”
Growing oilseed rape remains high risk as well as high reward, so Mr Jewers tries to limit exposure as much as possible. While disease resistance is key, a good agronomic strategy can help the crop too, he says.
In the battle against cabbage stem flea beetle (CSFB), Mr Jewers has found that rape plants should not drilled too close together. He aims for 20 plants/m2 irrespective of the crop being a hybrid or conventional variety.
“We try to drill as early as possible so the crop has a chance to get away before CSFB numbers build. By creating more space the crop has a chance to grow thicker stems which are just that bit more resistant to the pest.”
Reflecting on his decision-making process, Mr Jewers says one of the most important traits he looks for in a variety is still its resistance package – particularly to turnip yellows virus (TuYV). He was interested when Amalie was introduced as the first variety with TuYV resistance. An open-pollinated conventional rape with good gross out-put potential, it combines good lodging and excellent disease resistance as well as high oil content.
Although official figures showed Amalie to be behind on yield, Mr Jewers decided to trial it on farm.“It out-yielded everything else – showing us that it was likely that our yields had been held back by TuYV,” he says.
For the past few years, Mr Jewers has also grown companion crops. Having started on a small scale, they are now grown across the whole farm. Mixes of berseem clover and buckwheat are killed off over winter having given the rape a good start, he says.
Benefits from companion crops have been general and sometimes inconsistent. One year they seemed to deter flea beetle. In another year, they seemed to deter pigeons. More consistently, they appear to deter slugs.
Normally the oilseed rape is planted by direct drilling. But this year, Mr Jewers has had to undertake remedi- al work from wheelings in the previous barley crop. “If you have an issue with your soil you have to go in to repair it,” he explains.
“This means that some of the crop went into a loosened seedbed on 27 July, although we were concerned that it may be more vulnerable to flea beetle. At the moment it is markedly forward from mineralising the nitrogen (N) from the cultivated soils.
“Oilseed rape crops are a big risk, but the rewards can be equally as great, and there are no other break crops that we can grow on the farm that offer the same margins. Ultimately it is a case of trialling things to find out what works for you on your farm.”
Farmed area: 390ha (265ha home farm, 125ha contract farmed)
Soil: Hanslope medium clay soil
Seed rate: 40 seeds/m2