This is a fungus caused by Thanatephorus cucumeris (also
called Rhizoctonia solani) which
attacks brassica vegetable plants. It mainly attacks
cauliflowers and but other vegetable plants such as cabbage, lettuce
and brussels sprouts are also affected.
Wirestem normally attacks seedlings and causes the
stems to fail and the seedling to topple over. This fungus is
sometimes mis-diagnosed as grey mould because very soon
after being infected by wirestem they may well be infected by
Wirestem can also affect plants well after the
seedling stage. In these cases the signs are stems which are
harder than normal, shrunken and brownish in colour.
Treatment of Wirestem
Once wirestem has infected plants there is no treatment other
than removing and burning the infected plants. Avoiding wirestem
is easier, sow seeds more thinly, avoid over-watering and keep
the soil well-drained by incorporating well-rotted compost and
digging deeply and thoroughly to open up the soil.