Oilseed rape growers need to monitor crops closely for signs of wet weather diseases such as Botrytis and Alternaria on pods and upper leaves, ADAS has advised.

“It’s too late to prevent infection getting into the crop, but a fungicide now could stop leaf blotch spread and retain the all important green leaf for as long as possible,” said ADAS’s Peter Gladders.

Botrytis infection covering up to 10% of the leaf area has already appeared on crops in the eastern counties and Alternaria is also present – particularly in southern England, he said.

Recent showery conditions are likely to have contributed to increased Botrytis infection, added Syngenta field technical manager, Tom Mitchell.

He suggests applying Amistar (azoxystrobin) at the full 1.0 litre/ha rate on untreated crops as soon as possible.

See FWi’s Crop Watch for the latest reports from a team of agronomists around the country – updated every Tuesday.