Disease control for green peppers: how to identify symptoms and use pesticides scientifically

Disease control for green peppers refers to the management process of adopting comprehensive agricultural, physical, chemical and biological measures against the fungal, bacterial and viral diseases that commonly occur during the growth of green peppers, in order to reduce losses and safeguard quality. Green peppers favor a warm, humid environment, but under conditions of high temperature and high humidity diseases spread easily, so control work needs to run through the entire process from seedling raising and transplanting to harvest.

Common green pepper diseases in production include Phytophthora blight, anthracnose, gray mold, viral disease, powdery mildew and bacterial leaf spot. Phytophthora blight mostly starts at the base of the stem or on the fruit, with the diseased part becoming water-soaked and rapidly soft-rotting; anthracnose mainly affects the fruit, producing sunken brown lesions on the surface; gray mold often infects flowers and young fruit under low temperature and high humidity; viral disease shows as mosaic, crinkling and plant stunting, and is mostly spread by virus-transmitting vectors such as aphids.

Control should adhere to the principle of prevention first and integrated management. When planting, disease-resistant varieties can be selected, crop rotation practiced, and continuous cropping with solanaceous crops avoided; before sowing, seed disinfection and seedbed treatment should be done well; after transplanting, plant at a reasonable density, maintain ventilation and light penetration, adopt high-ridge cultivation and pay attention to drainage to reduce humidity. After disease occurs, promptly remove diseased leaves and fruit and carry them out of the field for disposal, then choose the appropriate pesticide according to the type of disease, taking care to rotate chemicals to delay the development of resistance and strictly observing the pre-harvest interval.

In daily management, attention should also be paid to balanced fertilization, avoiding excessive nitrogen fertilizer that causes excessive vegetative growth and lowers disease resistance; watch weather changes and spray protective chemicals in advance before and after continuous rain. In protected cultivation, ventilate promptly to reduce humidity inside the greenhouse, which can noticeably reduce the occurrence of high-humidity diseases such as gray mold.