The following is a listing of tomato problems caused by environmental stress. Rot - The blossom end of the fruit blackens and becomes leathery. The problem is caused by a lack of calcium in the fruit due to variable soil moisture conditions. Prevention involves keeping the soil evenly moist. Mulches are helpful in this regard.
Fruit is perfectly safe to eat.
Sunscald - This appears as a white or yellowish spot on the part of the fruit facing the sun. To minimize this problem, never remove mature foliage from the plant. Catfacing - Misshapened, severely deformed fruit, more common on the large fruited or early varieties, resulting from incomplete pollination of the tomato flower due to cold conditions when flowering. To minimize damage plant tomatoes after weather warms, avoid using large fruited varieties, and harden tomato trans-plants by limiting water, not by lowering temperatures. Catfaced tomatoes are safe to eat Fruit cracking - May be expressed as either concentric cracks around the stem end of the fruit or as radial cracks radiating from the stem scar.