Its common name, grey mould, alludes to the distinctive grey mould on the surface of infected tissues. At first, grey mushy spots appear on stems, leaves, flowers and fruits followed by an abundance of fuzzy grey spores. Rot then sets in. The disease is particularly prominent during warm humid weather.

Prevention

Provide adequate spacing between plants for good air circulation reducing humidity, enabling plants to dry quickly after getting wet. Prune overcrowded stems and branches to further improve air circulation. Thin bunches of grapes so they are not touching.

Avoid watering from above; install drip irrigation to prevent leaves and fruit from constantly getting wet.

Keep the soil beneath plants clean and free of debris as the fungal spores may occur here. Mulch low-growing plants, such as strawberries, to prevent water from splashing onto leaves and fruit. Spores are typically dispersed two ways: by water and air currents but can be spread via insects and garden tools as well. Disinfect tools between pruning cuts with a diluted bleach solution – one part bleach to 10 parts water.

Keep greenhouses well ventilated.

Treatment

Remove and destroy (bin or burn; do not compost) any diseased parts to prevent further spread.