Tomato leaf mould is a common fungal disease of tomatoes growing under cover, in a greenhouse. It is rarely seen on outdoor plants. Once it becomes established, it can spread rapidly and cause significant losses.
Description
Symptoms are similar to the early stages of grey mould - yellowing leaves turning brown and dying - but no fuzzy grey mould development. The spread of the growth will vary depending on the stage to which the infection has developed.
Symptoms
Tomato leaf mould symptoms include extensive discolouration with leaves or fruit turning brown, and bleached white spots on flower petals.

Treatment and control
Remove and destroy all affected plant parts. For plants growing under cover, increase ventilation and, if possible, the space between plants.
Try to avoid wetting the leaves when watering plants, especially when watering in the evening,
Copper-based fungicides can be used to control diseases on tomatoes.