BS issues powdery mildew warning to protect 2002 crop
BS issues powdery mildew warning to protect 2002 crop
Maximising returns from
the sugar beet crop was
the theme of a British
Sugar/BBRO field day in
East Anglia last week.
Edward Long reports
WITH one of the highest ever forecasts of powdery mildew on beet this year growers are being urged to spray to protect yield.
"The forecast says 64% of the 160,000ha of beet are threatened and with yield losses of 7-25%, a lot is at stake," warns British Sugars Simon Fisher.
"Last year 70% of the crop was sprayed despite a much lower disease threat. We hope even more will be treated this year." Typically there is more than a 7% yield boost from fungicide, he says. But there are physiological benefits to be had too. "There is a 6% yield increase even in the absence of disease."
BS says triazoles should not be applied if there is less than four weeks between treatment and harvest, as time is needed to achieve a pay-back. "As long as there is sufficient time crops in the south should be given a blanket treatment within 7-10 days of disease being spotted, otherwise the yield benefits could be lost. In the north growers should wait for warning cards before taking action."
Triazole costs range from £13/ha to £15/ha, giving a net return after treatment of £10-£65/ha. "The cost of not treating is often £50-£200/ha," says Mr Fisher.
• See p56 for more on beet fungicides. *
Above left: Powdery mildew is set to be more severe than last year, warns BSs Simon Fisher. Above right: Tramlining beet saves seed, boosts spraying workrates and does not cut yield, says BSs Ed Gilbert. Left: headland beet rarely yields well, so replace it with wildlife-friendly set-aside, say FECs Marek Nowakowski (left) and Mike May of IACR Brooms Barn.