Root Knot

Meloidogyne incognita, and other Meloidogyne sp.


Symptoms:
Infected plants are not vigorous, off color, and progressively decline. The decline becomes rapid as the fruit load increases. Roots are swollen and covered with galls.
Control:
The root knot nematode is very difficult to control. Crop rotation with a non-susceptible species is important, and avoiding planting tomatoes after other highly susceptible species (cotton, okra) is a primary control. Many tomato varieties are resistant, so variety selection is also important.

Texas Plant Disease Handbook