Exploration of the Potential Mechanism of Faba Bean–Wheat Intercropping to Control Faba Bean Fusarium Wilt Due to Allelopathic Plant Extracts

[Image: see text] We intensively studied faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) intercropping and found that this type of intercropping can effectively control the occurrence of faba bean wilt under field conditions. We conducted hydroponic experiments to explore the role of plant extracts in the process of soil-borne diseases and the mechanism of disease control of faba bean and wheat intercropping. In this experiment, three concentration gradients of faba bean and wheat stem, leaf, and root extracts were added to study the effects of faba bean and wheat extracts on faba bean growth, the physiological resistance of roots, and the growth of Fusarium oxysporum f. sp. fabae (FOF). Faba bean extracts significantly inhibited the growth of faba bean seedlings and the activity of root defense enzymes and significantly stimulated the growth of FOF at high concentrations. Compared with the treatment with faba bean extracts, wheat extracts significantly enhanced the growth of faba bean seedlings, increased the activity of defense enzymes, and inhibited the growth of FOF. Based on these results, we believe that wheat extracts can effectively alleviate the autotoxicity of faba beans and also control the occurrence of faba bean wilt in the field. This provides a theoretical basis for practical intercropping to reduce the damage caused by faba bean wilt.