Fungicide sprays should be applied every seven to ten days beginning when the first fruit cluster develops. Make sure that you use the right fungicide spray material to control tomato blight diseases. Spray more often when it is cool and wet. The weather that we have experienced this summer allows these diseases to progress rapidly. If any of these diseases were a problem in the previous season, start spraying before the disease symptoms appear.
Early blight is the most common and wide spread tomato disease.
This blight is mainly a foliage disease, but can attack the fruit. The spots may be circular to irregular in shape. As the spot enlarges, concentric rings may form as a result of daily growth by the fungus in the leaf tissue. Early blight usually is seen on the older leaves and stems. The fungus then spreads upward to newer leaves.