Prevention and treatment of Orchid virus

There are many works on the research of orchid virus, each of which has its own advantages. We think that raising orchids should pay great attention to environmental hygiene. We discussed that orchids like the sun, should be ventilated, soilless cultivation and granular medium cultivation as far as possible, less use and do not advocate the use of organic fertilizer and so on. With these conditions, the incidence of orchid disease will naturally be reduced, but in the process of biological growth, there are many factors that will cause the disease, we should have some preliminary knowledge to avoid the loss of orchids as far as possible.

The common diseases and common diseases of Cymbidium in Jiangsu and Zhejiang are Cymbidium leaf black spot, white silk disease, stem rot, anthrax, root rot, Bayas disease and so on. The direct cause is that harmful fungi, bacteria and viruses invade bluegrass and cause undue losses to orchid seedlings. Most of the indirect reasons are the poor sanitary conditions of the small environment. Poor ventilation and permeability, long-term retention of water in the basin, overuse of drugs, and long-term acidity of plants in the basin are also the causes of illness. Virus diseases may also occur if imported hormone-based fertilizers are often used to make nitrogen, phosphorus and potassium fertilizers out of balance. Because the virus system occurs in the cell, if the synthetic cell is too fast, and the lack of phosphorus and potassium factors, the immunity decreases, the virus protein body has the upper hand, destroying the normal growth of orchid leaves, so that the virus takes advantage of the deficiency.

We should have a clear understanding of blue disease, focusing on prevention, especially in spring and winter. Before leaving the house (shed) in spring and in winter, blue shelves, doors and windows, floors and walls are sprayed and cleaned with stone-sulfur mixture into methyl thiophanate and concentrated lime water. When changing and turning the basin, after the orchid basin is washed, it can be washed with 1% copper sulfate or potassium permanganate. Langen should not be cleaned if there is no serious damage. Orchid leaves should be sprayed with "chlorothalonil" or "carbendazim" and then planted in human aseptic culture medium. After getting on the shelf, in the windless season, the leaves should be sprayed in turn with topzine, stone-sulfur mixture, carbendazim, cephalosporin, etc. (choose one according to the situation) every two weeks. In the Huangmei season, the bluegrass in the middle and lower reaches of the Yangtze River can be combined with watering, fertilization and pest control at the same time to increase the times of control. Humidity is often in a high ratio, it is best to choose stone sulfur mixture to reduce the PH value.

Black spot is mostly caused by anthracnose fungi. Black spot is a common disease of Chunlan, Huilan, Qiulan and Orchid. It becomes small scars, dots and patches at first. If it is not treated in time, it can spread to the whole basin and even damage others. If it occurs in a high position, it can be cut off; if it occurs in the leaves, it can be coated with Topol or stone-sulfur mixture. In order to prevent spore germination, carbendazim or benzoate zinc should be sprayed at least twice on the whole grass and basin.

Stem rot is caused by white silk disease fungi that damage orchid stems. First of all, the diseased orchid had white filaments on the surface of the culture medium, and soon it could be seen that the upper part of the pseudocorm and the leaf base were yellow-brown water stains, which could be pulled up by hand, so it was also called twitching disease. If you find this disease, you should immediately turn the basin, wash the orchid basin with 1% sulfur, cut off the obviously infected bulbs, and the orchid should also be soaked for more than five minutes, then dry, apply "Dakening" on the diseased area, and change the cultivation medium.

Root rot disease, mostly occurs in the poor permeability of the basin orchid, you can see the root black-brown rot focus, or orchid root erosion leaving epidermis and root tendons. Many and half of the harmful orchids are eosinophilic blight fungi, which are caused by waterlogging in the basin, acidity for a long time and obstruction of orchid body circulation. Root rot is not easy to be detected in time, which is characterized by long-term lack of luster, no budding, long-term prosperity and shrinking head. After discovery, you should immediately turn the basin, clean up the rotten roots, scrape off the rotten part with your fingernails, and leave the central column tendons for support and water transport. Then clean it, disinfect it with potassium permanganate and then put it back on the basin.

Burning tip disease is a frequently-occurring disease of Cymbidium in the middle and lower reaches of the Yangtze River, especially for Yilan, first the plant shrinks locally, and then all are damaged, especially the old grass, the braided head is faster, so it is also called shrinking head disease. Most of them are caused by low humidity in Orchid Field and excessive water leakage in the basin. The treatment method is to cut off the necrotic part of the shrinking head, and then add topiramate, chlorothalonil, etc., pay attention to the basin and the environment is not easy to dry.

In short, the orchid basin should be checked frequently, early detection, early treatment, so as to avoid damage.

The use of drugs should be cautious. Can be used for pot grass commonly used topurazine, carbendazim and other sprinkler irrigation. Huakang No.2 produced by Huayi Company in Chengdu, Sichuan has obvious effect. Try to use sulfur mixture and Bordeaux solution as carefully as possible, but it has good disinfection effect on environment and appliances. Bluegrass is easy to occur in Huangmei days or high temperature in summer, so spray irrigation should be used frequently to sterilize pesticides. However, it is not suitable to apply human antibiotics to bluegrass, because it is not clear whether various antibiotics will damage the plant immune mechanism. (Guan Wenchang, Zhu Hexing)