These are all soil borne diseases that enter through the root system and plug up or destroy the vascular tissue within the stems. Most frustrating is the fact that infected plants don t begin to die until mid-season. There are no sprays that will control the tomato wilt diseases. When dealing with them we must rely on resistant varieties if available, and rotating our planting sites from one area of the garden to another. There are several varieties that are resistant to Fusarium, our most common fungal wilt.
Bacterial wilt is another story.
This is the disease that causes sudden, rapid wilting of mature, bearing plants and it happens so fast that they retain their green color. Two varieties, Neptune and Capitan, are showing resistance to bacterial wilt. Though not readily available, several local gardeners have found a few sources of seed.