Greenhouse Bean Disease Prevention and Control Methods and Key Technical Points
I. Symptoms of bean rust: It mainly affects the leaves, and in severe cases also affects the petioles and pods. In the early stage of the disease, small pale yellow spots appear on the underside of the leaves, later turning rusty brown, raised and forming small pustule-like blisters, then expanding into uredinia, and after the epidermis ruptures, reddish-brown powder is released. This is the urediniospore. II. Bean powdery mildew...
I. Symptoms of bean rust: It mainly affects the leaves, and in severe cases also affects the petioles and pods. In the early stage of the disease, small pale yellow spots appear on the underside of the leaves, later turning rusty brown, raised and forming small pustule-like blisters, then expanding into uredinia, and after the epidermis ruptures, reddish-brown powder is released. This is the urediniospore.
II. Symptoms of bean powdery mildew: It mainly affects the leaves, and can also infect stems, vines and pods. When leaves are infected, yellow-brown spots appear on the underside at first, and after expanding, they become purplish-brown spots covered with a thin layer of white powder. The pathogen is a fungus of the subphylum Ascomycota.
III. Integrated control methods: In the early stage of the disease, spray 70% thiophanate-methyl wettable powder at 500 times dilution, or 40% copper hydroxychloride wettable powder at 600 times dilution, 50% sulfur suspension concentrate at 300 times dilution, or Fenbiqing at 150 times dilution. Spray 2-3 times consecutively at 5-7 day intervals.