The disease survives for a long time in the soil and infects cabbage and other cruciferous plants via the soil. When the seeds are conditioned, the germ-carrying soil particles are attached to the seeds, which can lead to seed infection. The development temperature of the pathogen is 9-30℃, and the optimum temperature is 20-24℃. The suitable temperature for spore germination bud tubes and disease progression is 18-25°C. Acidic soil is favorable for the propagation of the pathogen, while alkaline soil with a pH value of 7.2 or more is difficult to propagate. Diseases caused by fungi. The fungus overwinters and summers with the roots in the soil, invades the host from young roots or wounds, and spreads by rain, irrigation water and agricultural tools. The incidence of the disease is low in dry years. Acidic soil disease is heavy, planting cruciferous plots and disease in successive years