Wet weather is causing strawberries to suffer from grey mould (Botrytis cinerea).
Grey mould, sometimes known as Botrytis blight, is caused by a fungus Botrytis cinerea which spreads in cool, rainy weather around 60 F. The disease is particularly damaging when rainy, drizzly weather continues over several days.
Symptoms of Grey Mould
The rot usually starts at a point of contact such as the soil or other fruits.
The strawberry turns brown and remains firm. White mould is sometimes seen, and the whole berry can rot.
Control of Grey Mould –
- Is by inspection and hygiene. Always take a paper bag when inspecting the strawberry plants & place infected fruit in the bag to avoid spreading the spores.
- Carry out inspections when the plants are dry & dew has dried, to avoid spreading the spores in ideal conditions.
- Avoid misting the plants, or overhead watering, if Botrytis is a problem.
- Give plants plenty of space, to allow air circulation and rapid drying of plants.
- In autumn, cut stalks at or below ground level & remove all strawberry plant debris from the garden. This is to prevent overwintering of the fungus as tiny, black sclerotinia in dead leaves and stalks.
- Fungicides are available to control Botrytis. Always follow the manufacturer’s instructions on the packet.
Many strawberries have just a patch of light brown rot. This can be cut off, and the remaining strawberry can be used to make Joanna’s strawberry sponge!
Grey Mould on strawberries is a particular problem in wet weather.