Grey Mould on oion leafs

QuestionsGrey Mould on oion leafs
Royston Harris Staff asked 10 years ago

The onions on our alottment the leafs turn GREY and floury like powder. What is it and is there a cure for this problem.

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Ask Gerry
Gerry Daly


Onion leaf rot is caused by a range of opportunistic fungi, such as grey mould, cladosporium and downy mildew in conditons of high humidity and highly rich feeding, especially high nitrogen, owing to manure or compost.

There is no cure as such, just to try to change the conditions for subsequent years, but applying some potash and spacing the onion plants more to allow more air circulation.

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