Rape clubroot is a fungal disease, which not only harms rape, but also harms cruciferous families such as Chinese cabbage, radish, mustard, cabbage and cauliflower to varying degrees. The root of rape is mainly damaged by clubroot, which can be damaged at seedling stage, and when it is serious, the seedlings will die. In the early stage of adult stage, the overground part is not obvious, but it grows slowly and is short, and in severe cases, it is in a state of water shortage. The basal leaves wilt at noon and can recover sooner or later. In the late stage, the leaves turn yellow and wither until the whole plant dies. Below, Xiaobian will introduce how to prevent and treat rape clubroot.

1, select disease-resistant varieties and sow them in time.

Disease-resistant varieties, such as Brassica napus Huayou No.8 and Tietieqing, were selected and sowed at the end of September and the beginning of 10, with mild disease.

2. Implement crop rotation.

Because of the strong stress resistance of dormant sporangium, the rape field with serious disease should be rotated for 4-5 years. Rape and cruciferous vegetables can be planted instead of wheat and green manure within the specified rotation period.

3. Seedling raising and transplanting

It is an ideal measure to select disease-free plots to cultivate strong seedlings and transplant them after the five-leaf stage.

4, strengthen the seedbed and field disinfection.

Disinfect with sodium dihalide or pentachloronitrobenzene.

(1) During seedling raising, the seedbed can be disinfected, and sodium dichlorvos or quintozene10-20g of fine soil can be mixed with 5-6kg of fine soil to make medicinal soil and evenly spread;

(2) During direct seeding and transplanting in the field, 2-3kg of dichlorvos sodium or pentachloronitrobenzene and 40-50kg of fine soil are added per mu to prepare medicinal soil, and when sowing, the medicinal soil is first applied into a sowing ditch and then planted, or applied into a planting hole and then planted. When necessary, the roots can be irrigated with 800-1000 times solution of sodium dichlorvos or pentachloronitrobenzene, and each plant can be irrigated with 0.5 kg of liquid medicine.

5. Transforming acid soil

Combined with soil preparation, plant ash and other alkaline organic fertilizers or lime100-150kg per mu were added to the acid soil, and sand was mixed to transform the acid soil to alleviate the occurrence of clubroot.

6. Cultivation management

Strengthen the management of water slurry in the field, pay attention to ditching and drainage, and avoid flooding in the field. Sunny planting should be chosen. Production practice has proved that: sunny days of 1-2 weeks after planting can greatly reduce the incidence; If it rains during planting or shortly after planting, spraying 2% lime water can reduce the incidence, pay attention to collecting diseased plants, and cover them with lime in time to promote vegetable root rot and pathogen death. If compost is made from vegetable roots with bacteria, it must be fully decomposed before it can be applied to the field. Pay attention to the combined use of nitrogen, phosphorus and potassium, and do not apply nitrogen fertilizer in a partial way.

7. Chemical control

The key period of chemical control is the three-leaf stage of rape, and the control effect can reach more than 60% by using 500-fold solution of dihuang sodium salt and 200-fold solution of bacterial toxin 1 day1time for continuous control for 2-4 times. 50-75 kg of lime or 25-35 kg of sodium carbonate were applied in holes per mu during sowing period, and the disease prevention effect could reach about 60%. Plant ash acupoint application also has a certain preventive effect.