EB – Early Blight
Scientific Name: Alternaria solani
Type: Fungus
Early Blight is a soil-borne disease that affects the growth of tomatoes. This disease is most common in North America. The symptoms include collar rust on the stems, circular dark spots appear on the leaves, rings surround the spots with a yellow halo, and tomatoes crack at the stem. The leaves may die and fall off the plant resulting in extensive defoliation, exposing the tomatoes to sun scald. Black spots may appear on the tomatoes. The disease can cause substantial yield loss and total crop loss. It is spread by wind and water. The infected plants should be removed and burned to avoid further infestation. The virus can live in plant debris and in the soil. The disease is favorable when temperatures are 82-86 F and usually occur when moisture and humidity are very high. Plan on using a 2 to 3 year crop rotation and avoid planting in the same location, year after year, and can survive in the soil for 1 year. Fungicides can help manage the disease. Stake plants to improve air circulation. Use drip irrigation to keep foliage dry and avoid overhead irrigation. The best option is to use virus-free seeds and disease resistant varieties