Effect of Dandelion (Taraxacum mongolicum Hand.-Mazz.) Intercropping with Different Plant Spacing on Blight and Growth of Pepper (Capsicum annuum L.)

Intercropping of crops that can secrete bacteriostatic active substances can not only inhibit the occurrence of disease but also have an important effect on plant growth.However, the effects of dandelion intercropping on pepper blight control and pepper growth remain unclear.In this study, the control effect of dandelion on pepper blight was studied by inoculating the pepper leaves with Phytophthora infestans, and it also discusses the correlation of the occurrence of pepper epidemic disease with the pepper canopy environment, soil environment, pepper photosynthesis, and yield index.The results showed that best plant distance for dandelion intercropping was 20 cm (P20), and the control effect reached 43.31%.As compared to the CK, SOD enzyme, POD enzyme, and PAL enzyme were significantly up-regulated during the growth of pepper; chlorophyll content in pepper leaves was significantly increased; photosynthetic characteristics were significantly increased; stem diameter and yield of crop pepper were effectively improved; and the quality of the pepper product was better, but intercropping dandelion resulted in a significant decrease of nutrients in the soil environment of pepper, so a reasonable intercropping distance was needed.The correlation analysis shows that the incidence of pepper blight (A) was significantly positively correlated with soil temperature (Q), intercellular carbon dioxide (L), and canopy air temperature (O).The incidence of capsicum blight (A) was significantly negatively correlated with chlorophyll content (F), net photosynthetic rate (K), stomatal conductance (M), ww rate (N), soil sucrase activity (W), vitamin C (AB), and leaf PAL enzyme (J).Finally, it was deduced that intercropping dandelion could effectively control the occurrence of pepper blight while also demonstrating a complex interaction with the pepper growing environment.