White or yellow blisters will develop on the sides of the fruit that are facing the sun. With continued exposure to the sun, the damaged areas may become papery, flattened, and grayish white. Black mold may grow in the papery patch and cause the fruit to rot. Integrated Pest Management Strategies 1. Maintain healthy plants with plenty of foliage.
Water tomatoes thoroughly on a regular basis.
Fertilize with a low nitrogen or slow release fertilizer at planting and at full blossom. Mulch lightly when the soil has warmed. Cover exposed fruit with a lightweight material, such as shade cloth, in order to provide them with some shelter from intense sunlight. Practice controls for leaf diseases in order to prevent defoliation that leaves the fruits more vulnerable to sunscald. These practices may include crop rotation, proper sanitation, and the use of fungicides.