Vegetable clubroot is a common major disease. It mainly harms the roots, resulting in finger-shaped, short rod-shaped or spherical tumors of different sizes on the main roots or lateral roots. In severe cases, there are dozens of tumors strung together on the fibrous root. After getting sick, it will cause a significant reduction in production or even no harvest.

Cruciferae vegetable clubroot is a fungal disease. Rhizopus likes acidic soil. Generally speaking, cruciferous crops, acid soil fields and low-lying wet fields with poor drainage are the most serious diseases, and fields with excessive nitrogen application are the most serious diseases.

Comprehensive control measures should be taken to control clubroot. It is best to implement rice-upland rotation or rotation with non-cruciferous crops for 3~5 years, combined with deep tillage, which can effectively reduce the occurrence of diseases. In addition, lime can be added to reduce soil acidity, thus reducing the incidence.

Chemical control technology is as follows:

First, do a good job in seed disinfection. Soak the seeds with warm water at 55℃ for15min before sowing, then soak the seeds with 10% cyazofamid suspension for 10min, and sow after cleaning.

The second is disinfection of seedbed. The seedbed can be sprayed with 500 times solution of 50% sodium sulfamate soluble powder or 10% cyazofamid suspension 1000~ 1500 times solution, and the soil spraying depth is about 15 cm.

The third is seedling sterilization. Before transplanting the seedlings, soak the roots with appropriate concentration of lime water (65,438+05%) or 65,438+00% cyazofamid suspension (65,438+0,500 ~ 2,000 times) or use it as root-fixing water to prevent pathogens from invading the roots.

The fourth is to disinfect the fields before transplanting. The drugs used are fluazinam and benomyl. Sprayed soil is an effective drug to control clubroot in fluazinam, but it will inhibit the growth of seedling roots at high concentration, so it is not suitable for centralized pesticide treatment such as root irrigation. Generally, 60% fenpropathrin is sprayed 750 times, which is used to disinfect soil in the field, and the effect can reach 70%~80%.

The fifth is the prevention and treatment of spraying drugs after the onset. After the symptoms of clubroot appear in cruciferous vegetables in the field, 10% cyazofamid suspension 1500~2000 times solution can be used to irrigate the roots, or 800 times solution of 75% chlorothalonil wettable powder, or 20% quinazolol wettable powder 1000 times solution can be used to control the diseased plants.