Prevent black spots on the leaves of orchids

Orchid maintenance requirements are relatively fine, a little carelessly will occur leaf black spots and so on. If the head is drenched when watering, it is easy to splash up the basin soil and stick to the leaves, making the leaves scorched. When fertilizing, the fertilizer liquid is stained on the leaves, if you do not immediately spray clear water to remove, it will make the leaves appear black spots and scorch. If you do not pay attention to sunshade in spring and summer, it will make orchid leaves yellow and scorched in the scorching sun. Placed in an environment with more soot, orchids are blackened by smoke. In addition, orchids are damaged by anthracnose, and black spots often occur in their leaves.

Orchid anthracnose is especially easy to occur in high temperature and poorly ventilated plum rain season or autumn rain season, sometimes even more serious. The symptoms are that only semicircular or round brown spots appear in the leaves at the beginning, and then gradually develop into black-brown spots, many lesions expand into strips of dark-brown spots, and later become grayish white in the middle of the spot, with many small black spots on it. The disease is common in the middle and upper parts of the leaves. When this disease is found, the diseased leaves should be cut off. When it is first found, in addition to improving ventilation, 50% carbendazim wettable powder can be sprayed 500 times, or topiramate wettable powder 500 times, once a week, 3 ~ 4 times in a row, can get better results. In order to prevent the infection of diseases and insect pests, orchids should not be too crowded and too dense, so as to avoid the intersecting of orchid leaves and keep a good environment of ventilation and light transmission. (Xu Rui)