Could anyone suggest any treatments for grey mould. My normal approach
is to simply cut out the affected parts of plants but in the last two
weeks of cold damp weather I have found that my greenhouse won't open
up automatically and even with the door left open there isn't enough
ventilation to keep the grey mould down all of which means that
cutting out the affect parts of plants is a little drastic.

e.g. If I see grey mould trying to establish itself on the main stem
of a tomato plant is there any treatment I could use to selectively
treat that part before it becomes too established?

TIA