17 August 2001
Trials show rape likes space

By Andrew Blake

OILSEED rape establishment trials, carried out by direct-drill guru Jim Bullock, have revealed the crop prefers to be drilled at a low seed rate in wide rows.

Mr Bullock, a keen advocate of direct-drilling for the past three years, has been putting various establishment techniques to the test on his Worcestershire farm

The best yield was achieved from direct drilling a low seed rate in wide rows (36cm) after double harrowing.

This method also cost the least, at just 14.80/ha, compared to the most expensive plot at 63/ha.

But he warns that crops drilled wide at a low seed rate must be sown early, so that crop competition helps smother weeds, and that slug control is essential.

In the plots, slug pellets were applied at sowing and again at emergence. “Anything less than this was most unsatisfactory,” notes Mr Bullock.

He reports that the winning plot looked quite thin through the winter, but it compensated in the spring and produced a good yield.

Emergence was initially best in disced plots, but the crop grew too thick and lodged in July, and it was expensive to keep weed-free.

“As there was no time to create a stale seed-bed before drilling, these plots required extra sprays to control vast numbers of wheat volunteers and later charlock.”

He says a lower seed rate would have benefited most of the plots. “The high seed rate (6kg/ha) in the wide row produced a mass of small plants along the row.”

Broadcasting produced surprisingly good results, but its risky: “Autumn 2000 was so wet the system worked well, but in a dry year it could be less reliable.”

The one-acre tramline trials were sown on 6 September and examined 10 different methods of establishment. Straw was removed on every plot bar one.

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