Effect of disease on photosynthesis, nutrition, and nodulation of leguminous forage

Disease is one of the main limiting factors in pasture production. Many diseases can reduce pasture production and affect pasture quality, leading to plant death in severe cases, but often leading to premature senescence and degradation of the pasture. It can also cause livestock poisoning, and reduce livestock production performance. This article summarizes the effects of diseases, such as downy mildew, rust, powdery mildew, brown spot, and root rot, on the photosynthesis, nutrient composition, and root nodules of leguminous forage, such as alfalfa (Medicago sativa), erect milkvetch (Astragalus adsurgens), and common vetch (Vicia sativa). In general, infection by pathogens can destroy the normal structure of leaves and nodules, reduce photosynthesis and nitrogen fixation capacity of forage, and cause metabolic dysfunction of the plants. Plant metabolic dysfunction and synthesis and release of pathogenic virulence substances also alter plant nutrients. The mechanism of the effects of disease on the physiological growth, nutrient composition, nodule formation, and nitrogen fixation of leguminous herbage was analyzed to provide a reference for research and the prevention and control of leguminous diseases in the future. Furthermore, there are prospects for research in this field combined with the needs of the country's industries, and suggestions are made for future research.