Notes on Raspberry Diseases: Raspberry leaf spot
Greenish black spots develop on the upper leaf surface of new leaves. These progress to whitish grey with a distinct margin and sometimes a shot hole in the centre. Severely infected leaves drop prematurely.
Period of Activity
The fungus infects only raspberries and overwinters on old leaves and canes. Young rapidly expanding leaves are infected. Infections occur throughout the summer especially during periods of wet weather.
Keep rows narrow and weeds controlled to improve drying of the plants in the row. Broad-spectrum fungicides applied to control botrytis grey mould, generally help to control leaf spot. Some varieties for example, Reveille, are particularly susceptible.
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