26 January 1996

Direct drill still most profitable

DIRECT drilling into topped oilseed rape stubble gave the highest yields and proved the most profitable way to establish winter wheat in the first year of a "thought-provoking" demonstration at George Farm. Two plant populations (300 and 150/sq m) were assessed.

The result, with Brigadier hitting 12.2t/ha (4.9t/acre) at the high population, is "rather worrying" for Cotswolds-based Velcourt manager Mike Dewar, who relies on two combination drills on his similar land.

Compared to drilling there was surprisingly little penalty from broadcasting and power harrowing after discing. Indeed such plots outyielded those drilled after ploughing. But broadcast crops were "very patchy" in the autumn.

Mr Dewar stresses the results are from one year only. "But they suggest that the less cultivation we have done the higher the yield. They also suggest that in part we can substitute seed for cultivation and vice versa."

HGCA Research in Action demonstrations at George Farm showed:

&#8226 IACR-Rothamsted Sundial model for predicting nitrogen inputs very successful in providing highest yield.

&#8226 Early season stem-base disease control (full rate Sportak in March) boosted Soissons yield by 2.2t/ha (17.5cwt/acre).

&#8226 Omitting early nitrogen (as in crop canopy experiment) on brashland may be a mistake.

&#8226 French hybrid wheat very disease-prone, a single fungicide spray giving 23% yield rise.