In the seedling stage, the stem base is soaked in water and develops rapidly, which often leads to sudden collapse and seedling death. In adult stage, leaves are susceptible to diseases, resulting in irregular waterlogging spots, obvious wheel lines, but not obvious edges, brown or purple-brown, and a small amount of white mold grows on the spots when wet.
The stem shrinks in water, sometimes breaks, and has white mold. After being infected, the flower organs are brown and rotten. The fruit suffered the most, and began to appear circular spots in water immersion. The edge was not obvious, and it was slightly sunken, yellow-brown to dark brown. The pulp of the affected part is dark brown and rotten, and there are white flocculent hyphae on the surface of the affected part under high humidity conditions, and the diseased fruit is easy to fall off or shrink into hard fruit.
Second, the onset conditions
The optimum growth temperature is 30℃, and the mycelium develops well when the air relative humidity is above 95%. In the high temperature range, the humidity in the shed is an important factor to determine whether the disease occurs or not. In addition, continuous cropping, high groundwater level, poor drainage, close planting, poor ventilation, or rain behind the reserve, or dripping water from the canopy are all easy to induce the disease. Fusarium wilt of eggplant and cotton is a fungal disease. It is mainly spread through soil and rain. High temperature and humidity, abundant rain, high plant density, poor ventilation and light transmission, low terrain, sticky soil, easy to get sick.