1 September 1995


A South Humberside farmer hit the yield jackpot this year with his first crop of hybrid oilseed rape. Robert Harris talked to him and a leading expert to find out how its done

MARTIN Robinson is wary of growing new varieties. He prefers to wait a couple of years to make sure they perform.

But when approached by local merchant Geoff Williams of Retford, Notts, to grow Synergy as part of a nationwide field test, he decided to try some.

"I dont mind having a small field of something different for interest. When you are farming 900 acres of conventional crops it makes a change."

He planted a quarter of the 36ha (90 acres) of heavy clay at Priory Farm, Goxhill, with Synergy and the rest with Apex. The heavy soil was ideal, says CPB Twyfords oilseed rape consultant Mike Pickford.

"Well-bodied soils gave the best yields this year in the dry conditions. Growers should select their best fields to make the most of Synergys yield potential. Dont expect 2t/acre on brash."

All the rape followed naturally regenerated set-aside, allowing plenty of time for seed-bed preparation. "We disced in May to remove cover, then moled and subsoiled." The ground was cultivated further before drilling on Aug 23.

"I like to drill early to get the crop moving," says Mr Robinson. "Two weeks after Aug 20 is a key time. Any later and plants struggle."

Mr Pickford agrees. "Drilling rape into a good seed-bed in August is critical to get it up and away. You then have good, strong plants going into the winter."

Mr Robinson drilled the recommended seed rate of 3.2kg/ha (2.85lb/acre). This gives hybrid plants enough space to express their vigour and ensures the pollinator variety, Falcon, which makes up 20% of the mix, is not crowded out by its more vigorous but sterile neighbours, explains Mr Pickford.

Mr Robinsons main concern was calibrating the drill accurately. "Luckily, we only had a teacup full when we finished, without altering the drill."

It is worth spending "an extra half hour" on calibration, Mr Pickford stresses. "Drilling between 3-4kg/ha is ideal, 7kg is too much and crops go flat. At 2kg, crops are too stiff and bolt upright."

Any doubts Mr Robinson had about resulting low plant numbers were quickly dispelled. "Both varieties emerged at the same time. But Synergy was more vigorous. Plants were about three times the size of the Apex going into winter, and ground cover was as good."