Tomatoes, Diseases of in Virginia
Bacterial Diseases: (Bacterial Canker, Bacterial Speck, Bacterial Spot, and Bacterial Wilt)
 | No economic thresholds have been established, but treatment is recommended if initial symptoms of these diseases have been observed. Apply a fungicide every 7 days if the threat of disease is present. |
| The use of certified plants is critical, especially in areas where
bacterial disease is not yet established. |
| A crop rotation of 2-3 years between tomato plantings may help manage the
causal agents of bacterial canker, speck and spot, but not bacterial wilt. |
Late Blight:
| Blight forecasting systems can be very effective in identifying proper
timing of fungicide sprays. |
| If cool, wet conditions prevail, a preventative fungicide application is
recommended every 7 days. |
| Resistance management should be practiced when selecting a fungicide. |
Leaf Spots: (Early Blight, Septoria Leaf Spot, Gray Leaf Spot)
| No economic thresholds have been established. Preventative fungicideapplications are the best means of leaf spot control, especially in areas where this disease has been a problem. |
| Good sanitation practices and crop rotation can help prevent leaf spotestablishment. |
Wilts: (Fusarium Wilt and Verticillium Wilt)
| No effective chemical or biological controls are currently available. |
| Cultural practices such as good sanitation and the use of resistant tomatocultivars should be used if the disease has previously been a problem. Crop rotations are not usually very effective given the persistence of the fungi in the soil. |
Gray mold, powdery mildew, Southern blight, timber rot (Sclerotinia) and post-harvest rots often show up under unusual conditions such as weather or
result from poor cultural practices. Fruit rots (Pythium and Phytophthora) may also occur from time to time.
Consult the Commercial Vegetable Production Guide (456-420) for fungicide recommendations.
Reference(s):
|
