Sunscald of tomato, pepper (bell pepper, chile pepper), fruit, watermelon, muskmelon, summer squash and other fruits occurs when green or ripening fruits are exposed to direct prolonged sunlight, especially during sunny, hot weather. Large, light colored blistered areas develop on the sides of fruits facing the sun. It is most prevalent on plants that have lost foliage due to insect feeding or disease. For example, early blight disease of tomatoes can cause a large number of leaves to die, exposing fruits to intense sunlight. The condition renders fruits inedible.
Remove affected fruits immediately and prevent the problem by growing strong, healthy plants with good foliage cover. Control insect and disease problems before they begin to defoliate plants.