11 August 1995

Horrified at N timing

BRITAINS top oat breeder was "horrified" by the timing of nitrogen fertiliser on the crop at West-ward Arable Centres and on some commercial farms in the region.

They had all adopted the technique developed by Vic Jordan of Long Ashton Research Station – delaying nitrogen until late April/ early May. By then the crop was so short of nitrogen it looked "bright pink". But it quickly recovered and produced shorter straw, less likely to lodge and needing less spent on fungicides. The result was a good gross margin.

Demonstrating the oat variety trials at WAC, local agronomist Arthur Marshall said he avoided lodging in his commercial crops by delaying N and applying Cycocel at GS 32, about May 7 or 8. Others in the audience confirmed the success of delayed nitrogen.

But John Valentine, head of oats breeding at Aberystwyth, insisted they must be losing potential grain sites. At Aberystwyth the nitrogen went on in early to mid-March, to ensure plenty of grain sites and tillers. That approach was confirmed by research at ADAS Rosemaund in Herefordshire.

"We get Oat Mosaic Virus and we think the early N helps the plants to gallop through OMV infection later on," he said. &#42

Breeder John Valentine believes early nitrogen helps oats overcome mosaic virus. Delaying too long risks losing grain sites, he says.