Good cultural practices that ensure consistent plant growth will reduce the occurrence of abnormalities. Tomato varieties differ in susceptibility to these disorders under different environmental conditions. By trial and error you can find the best varieties for your location. The purpose of this fact sheet is to point out some common nonparasitic diseases of tomatoes and current knowledge about them. When certain tomato varieties are grown for maximum fruit production they often develop a physiologic disorder called leaf roll.
Symptoms are most prominent on leaves at the plant base.
Leaf roll does not noticeably check plant growth or yields. The initial symptom is a watersoaked spot at the blossom end of the fruit. This spot enlarges and becomes brown and leathery. Blossom-end rot is associated with a calcium deficiency, fluctuations in moisture, heavy applications of nitrogen fertilizer, and root pruning. The amount of calcium salt available to the plant decreases more rapidly in the presence of excessive salts such as potassium, magnesium, ammonium, and sodium.