All rights reserved. Most of these diseases can be controlled by chemical sprays or other means. But tomatoes can also develop several nonparasitic disorders that cannot be corrected with chemical sprays. Nonparasitic disorders, though not infectious and therefore not a threat to your entire garden, can distort plants and blemish fruits.
Nonparasitic disorders are the result of plant responses to abnormalities in environment.
In some cases these environmental factors are unknown. In other cases, the causes of abnormalities are known but are difficult to correct. 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.