Study On The Effect Of Different Previous Crops On Alleviating The Occurrence Of Chinese Cabbage Clubroot

Chinese Cabbage(Brassica rapa L.ssp pekinensis Olsson)is a Brassica plant of Cruciferae.It plays an important role in vegetable production and cultivation and plays an important role in stabilizes the yield and supply of vegetables in China.In recent years,under the threat of Cruciferae root gall,the yield of Chinese cabbage has been greatly reduced or even lost,and the fields have been destroyed for planting,which has seriously affected the healthy and sustainable development of Alpine vegetables in China.Rotation is one of the effective measures to prevent the occurrence of root gall.Through pot and field experiments in the Taibai mountain vegetable-producing area,this study analyzed and compared the mitigation effects of different previous crop rotations on the occurrence of Chinese cabbage root gall disease.The main results are as follows:1.7 crops were cultivated with Chinese cabbage,compared with Chinese cabbage continuous cropping,The results of the pot experiment were as follows: garlic seedling,pepper,fresh corn,onion,kidney bean,green wheat,heading lettuce.The number of dormant spores of Rhizopus in soil was reduced by 48.49%,43.41%,38.46%,33.65%,25.96%,15.93% and 12.64% respectively;The results of field experiments were as follows: Pepper,onion,lettuce,garlic seedlings,kidney beans,green wheat,fresh corn.The number of dormant spores of Rhizoctonia in soil was reduced by 66.24%,57.47%,50.29%,46.41%,44.54%,39.08%,and 33.91% respectively.2.Compared with Chinese cabbage continuous cropping,7 crops were cultivated with Chinese cabbage for alternate cropping,which alleviated the occurrence of Chinese cabbage root gall to varying degrees.Among them,garlic seedlings and onions were used as the first crop,which had a significant effect.The disease index of Chinese cabbage root gall in pot experiment and field experiment decreased by 45.89,46.46,and 21.71,31.88 respectively.3.Compared with Chinese cabbage continuous cropping,the alternate cultivation of 7 crops and Chinese cabbage improved the nutritional quality of the following crop Chinese cabbage,enhanced the antioxidant enzyme activity of the following crop Chinese cabbage,and improved the stress resistance of the plant.With garlic seedlings as the first crop,the activities of antioxidant enzymes cat and SOD were increased104.59% and 46.19% respectively.4.7 crop rotation with Chinese cabbage can adjust the physical and chemical properties of soil,improve soil enzyme activity,balance soil nutrient structure,maintain soil fertility,and promote the balanced absorption of nutrients by the following crop Chinese cabbage.Compared with Chinese cabbage continuous cropping,the soil urease activity increased 18.55% when garlic seedlings were used as the first crop;The activity of soil acid phosphatase could be increased 20.53% and 19.39% with onion and pepper as the first crop,respectively.