Symptoms: generally, the disease occurs on the leaves. At the beginning, some small dark brown spots appear. At the later stage, the surrounding color becomes darker, the center part is gray white, and there will be dark green mold on the surface. At the later stage, when it is serious, the leaves curl up and become dry.
Prevention and control: in the early stage of the disease, the diseased leaves can be removed in time, the plants can be cultivated and managed, the disease resistance ability can be enhanced, and the rain and shade can be prevented in time. Water timely after planting, strengthen ventilation management and reduce indoor humidity. In the early stage of the disease, Bordeaux solution, zineb, chlorothalonil and other chemicals can be sprayed.
Symptoms: the leaves turn brown and dry after infection, and the petals shrink, seriously affecting the ornamental.
Prevention and control: pay attention to the spacing when planting, and the soil should be well drained. Before seeds are sown, they need to be disinfected, which can be soaked with carbendazim. After the onset of the disease, 50% times of zinc or 80% new Wan Sheng right wet powder 600 times liquid spray can be used. Note that the back of the blade should be evenly sprayed.
Symptoms: at the early stage of the disease, it presents slight mottling, which often leads to plant dwarf, degeneration and ornamental decline.
Prevention and control: pay attention to the field health management at ordinary times, timely remove the diseased plants and reduce the source of infection.
