[Effects of weeds on crops and their ecological control in ecological agriculture of Chinese materia medica].

Weeds is one of the important parts of agricultural ecosystem of Chinese materia medica. Weeds is a double-edged sword with advantages and disadvantages for the cultivated medicinal plants. In this study, we firstly analyzed the positive and negative effects of weeds on the yield and quality of Chinese materia medica. We then explored the possible mechanisms for the weeds' positive effects from the aspects of interspecific relationship, soil microecological environment, light environment, natural control of pests and so on. We also summarized three basic principles of weed control, that is, "making medicinal plants and weeds coexist harmoniously, achieving the overall optimum growth of medicinal plants", "prevention first, integrated control" and "preserving beneficial weeds and increasing their beneficial effects, removing harmful weeds and control their adverse effects". Finally, we introduced several common weed ecological control technology in field of the cultivated medicinal plants in China, including technology of controlling weeds by no-tillage, stral mulch, rotation, alternative herbs, competitive crops, and allelopathy. This study is aimed to apply the ecology theory to guide weed management and control, so as to achieve the goal of advantages promotion and disadvantages elimination of weeds to cultivated medicinal plants, making weeds into treasure and to promote the sustainable and healthy development of Chinese medicinal materials production and the protection of weed diversity.