BR - Black Rot
Scientific Name: Xanthomonas campestris
Type: Bacterium
Black Rot is a disease that affects the growth of arugula, broccoli, Brussels sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard, radishes, rutabaga, Swiss chard, tomatoes, turnips, and watercress. It survives in warm wet weather and affects cabbage throughout the United States. It is spread from one field to another field by water and wind. The bacteria can infect seeds and young seedlings. Young plants infected will turn yellow, drop lower leaves, and may die. Once the plant is infected there is no rescue treatment since the infection is systemic. Symptoms include the yellowing of the leaves in v-shape or wedge-shaped patches and blackening of the internal vein. Usually only a few of the outer leaves are affected. Since the disease is spread by water, anything that can be done to reduce leaf wetness will help reduce the spread of the disease. Water the plants in the morning, instead of the watering in the afternoon or night, so the leaves have time to dry before sunset. Increase space between the plants to maximize air flow and drying of the leaves. The disease is favorable when temperatures are 75-95 F and rain, heavy fogs, and dew are present. The bacteria does not spread when temperatures are below 50 F or during dry weather. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year, as the disease can survive in the soil for two years. Treating the infected area with fungicides can help manage the disease. The primary source of bacteria of black rot is infested seeds and in infested transplants. The best option is to use disease resistant varieties, disease-free seeds, and disease-free transplants.
FW – Fusarium Wilt
Scientific Name: Fusarium oxysporum
Type: Fungus
Fusarium Wilt is a fungal disease that affects the growth of cantaloupes & melons, cauliflower, eggplants, peas, peppers, squash, tomatoes, and watermelons. It is one of the most devastating of all soil-borne diseases. It attacks the roots of the plants and moves up the stems. Symptoms include stunting and wilting. Plants don’t always die, but it slows growth and reduces yields. Infected seedlings will damping off, wilt, and die. If you stick with fusarium wilt resistant tomato varieties you don’t have to worry. Many of the older heirlooms don’t have any resistance to the disease, so if you grow these then you should keep an eye out for it. The infected plants should be removed to avoid further infestation. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year, as the disease can survive in the soil for 7 years. The best option is to use disease resistant varieties.