Screening of Disease-Resistant Germplasm and Its Application in Off-Season Cultivation of <i>Leonurus japonicus var. hunanensis</i>

This study focused on screening and using the disease resistant germplasm resources of Leonurus japonicus var. hunanensis , and analyzed its main diseases in detail. Through field observation, common problems such as powdery mildew, downy mildew and root rot were identified, and their incidence and damage degree under off-season cultivation conditions were evaluated. In the process of off-season planting, due to the changes of temperature, humidity and management conditions, diseases are prone to outbreak, especially in warm and humid environment. The research team conducted field surveys in many planting areas and screened out a batch of disease resistant materials with good comprehensive properties. Among the selected materials with high resistance to powdery mildew, some still maintain a low incidence in high humidity environment, reducing the dependence on chemicals, reducing production costs and improving economic benefits. According to the performance of disease resistant materials, the cultivation mode and management methods were further adjusted. The planting density, water supply and fertilizer use were improved, and the planting environment was properly regulated. The use of disease resistant germplasm combined with optimized cultivation techniques can significantly reduce the occurrence of disease and improve the yield and the level of active ingredients of Leonurus japonicus var. hunanensis in off-season production. This not only improves the economic benefits, but also reduces the use of pesticides, helps to achieve the goal of green planting, and provides a reliable basis for the sustainable development of the industry.