In vegetable gardens with poor soil, water management is difficult in hot weather. Blossom end rot is common on tomatoes and squash shrivel on the vine. Blossom end rot is a black sunken spot on the bottom (blossom end) of tomato and pepper fruits and is caused by irregular moisture. The fruit is safe to use when the black area is cut off.
During flowering and fruit development, beans have the highest water requirement of any vegetable. If water is not available, beans will drop blossoms or produce curved, tadpole-shaped pods. Eggplant also has a relatively high moisture requirement and responds well to irrigation during periods of high temperatures.
For more information, see the following Colorado State Extension fact sheet(s).