How to Fix It
What it looks like:
The plants look healthy, and the fruit develops normally. As tomatoes ripen, yellow patches form on the red skin. Yellow patches turn white and paper-thin, creating an unpleasant appearance and poor taste.
What causes it:
As the name implies, the sun’s rays have actually scalded the tomato.
What to do about it:
Tomato cages, or a wire support system that surrounds the plants, give the best branch support while shading the developing tomatoes naturally. Sunscald usually occurs on staked plants that have been too-vigorously pruned, exposing many of the tomatoes to the sun’s rays. Leaving some foliage and branches provides shade during the hottest part of the day.