Light leaf spot is widespread
Light leaf spot is widespread
LIGHT leaf spot is unusually widespread in oilseed rape this winter, so growers should spray infected crops to prevent yield losses of up to 1t/ha (8 cwt/acre), says Du Ponts Andy Selley.
The NIAB/Du Pont disease monitoring service, available on www.niab.com, shows infected crops in most regions. "We have found it practically all over the country, from Gwent to Hants, Cheshire, Northumberland, Cambs, Yorks and Scotland," says Mr Selley.
With little curative activity available from fungicides they should be applied as soon as infection is identified or reported in the area, he maintains. On crops that received an autumn fungicide he suggests 0.4 litres/ha of Punch C (carbendazim + flusilazole) or if previously untreated 0.8 litres/ha.
"Even the cost of the higher rate, about £21-22/ha, can be recouped by the increase in oil content of the crop alone, not to mention the yield response." *