Are the fruits developing on your plants blackened and disfigured at the ends? It can be blossom end rot. I will show you how can you recognize and prevent this disease.
Photo by gezellig-girl.com
Blossom end rot attacks eggplant, pepper, squash and tomatoes. No, it can't transfer between plants or fruits. It's not a bacterial or fungal disease. It's a physiological problem caused by the low level of calcium in the fruit.
Low amount of calcium in the soil can be a culprit, but more often the plant has troubles with correct absorption of calcium. Irregular watering can cause such imbalance. Find out how to water tomato plants correctly.
At first, small watery spot appears on the blossom end of the fruit. If you are lucky, that is it. However, problem usually worsens. Spot enlarges, becomes sunken, leathery and black. On peppers it's tan - don't confuse it with white sun scald. Secondary infections lead to the destruction of the fruit.