Grey Mould - Botrytis - Plant Fungal Disease

Grapes affected by Botrytis - noble rot
picture used permission of Kassander der Minoer - published under GNU Free Documentation License, Version 1.2

Strawberry with Botrytis (the less than noble form)
picture used permission of Aardbei Lambada vruchtrot - published under GNU Free Documentation License, Version 1.2

Signs - Stems, fuits and flowers become covered with a velvety greyish, fungal growth (that looks particularly unpleasant)

Damage - A very common fungus which produces spores that are always around in the air. They attack plants through areas of damage. At first, small pale brown or white patches appear as the flowers start to rot.

Treatment - A fungal disease so one of the best ways of dealing with it is by good hygiene. Remove all dead leaves in autumn to prevent the spores from over wintering, burn the leaves or take them to the skip rather than use them for compost or you may well just perpetuate the problem.

Controlling this fungus is very difficult because it is so widespread so it's more a question of prevention rather than cure. Affected areas of the plants should be cut out and disposed of or burnt. Spraying with a fungicide is rarely of any use.

Improve ventilation where possible, open windows in frames and greenhouses, prune over-congested shrubs to aid air flow etc.

There is a form of Botrytis known as "noble rot", this form affects wine grapes that become infected when ripe and when conditions become very dry. These grapes then can produce a very fine and concentrated sweet wine. In some vineyards the spores are spayed over the grapes to infect them.

Chemical fungicides

Rose clear combined fungicide and insecticide Make sure you shake the bottle well before use as the active ingredients often settle to the bottom - take it from me I learned the hard way!

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