What Is Orchid Cancer? Get to Know the Deadly Disease of Orchids

Plant diseases caused by viral infection are called viral diseases, also known as toxin diseases, with the English name "VIRUS," transliterated as Bailasi. According to documents from the Hualien District of Taiwan, China, at least 25 viruses infect orchids, belonging to 9 virus groups. Cymbidium mosaic virus, Cymbidium ringspot virus, and Orchid fleck virus are the three most common. This disease is a virus that currently cannot be cured, and it is contagious and hereditary, so orchid enthusiasts call it the "cancer" and "AIDS" of orchids. After a plant is infected with the virus, it causes systemic infection throughout the plant, making it grow slowly, with spots on the leaves or irregular sunken yellow faded patches, and sometimes necrotic streaks. It generally occurs at the base, middle, or part of the tip of the leaf, first showing milky white streaks of varying length and thickness, with irregular net-like streaks of different shapes and irregular boundaries. The boundaries of the spots often resemble gradually spreading water stains, and the spot body appears chlorotic and transparent on both sides. In the early stage, the spot body has no abnormal color dots; in the middle stage, there is a sunken feeling on the back, containing a small amount of light brown, spot-in-spot; in the late stage, the color deepens like sunburn scorch, while shrunken wrinkles appear, the leaf edges curl backward and lose luster, then gradually dry up, and finally death occurs. The dreaded Bailasi virus is contagious and will be passed on to the next generation of orchid plants. Although it may not cause disease immediately, it is like early-stage cancer. Some very famous orchid growers have accidentally introduced diseased seedlings, and in less than two years, the orchid seedlings became spotted and mottled, a sight too horrible to bear. This year, some orchid growers in Guangdong and Sichuan suffered losses because of this, ranging from several hundred thousand to over a million yuan. It is truly "three years of skill to grow well, a quarter of an hour to kill." Bites and crawling of pests, pots, substrate, friction and compression of leaf surfaces, orchids displayed together, stacked, transported, soaked pots for watering, and reuse of old planting material can all spread the Bailasi virus. Especially during division and repotting in spring and autumn, the knives and scissors used, when cutting diseased orchid plants, will inevitably be contaminated with the sap of diseased plants. When the tool cuts other orchid plants again, the virus in the sap originally on the tool can enter the cells through the wound and cause infection. During the spring and autumn repotting and division seasons, tools are used frequently, often causing the virus to spread rapidly within an orchid garden. Some orchid gardens use vertical arrangement; when watering the upper orchids, the leftover water flows to the lower layer, and the virus on the roots will also spread with the water. Although this method of transmission is slower, its impact cannot be ignored. A major route of transmission is the tissue culture method used by research departments to cultivate orchid seedlings, which often causes mass infection because the original stock is inherently virused and this is overlooked. This is like the relationship between mother and baby; once it happens, it can be catastrophic. In addition, when orchids are grown in rural areas and flower and horticultural farms, because other crops such as tobacco, sweet pepper, chili pepper, red bean, and pea, and flowers such as daylily and lily are infected with the Bailasi virus (CMT), transmission by aphid vectors cannot be ignored either. Since viral diseases cannot be controlled with drugs, only strengthening virus diagnosis and prevention can prevent the occurrence of viral damage. In addition to seeking help from local plant quarantine departments once abnormalities are found, the following preventive work should be done regularly. 1. Do not blindly pursue varieties, do not buy virus-infected orchid seedlings just because they are cheap, especially do not buy orchid seedlings from areas where virused orchids are prevalent, and do not buy seedlings mixed and stored with diseased seedlings. This is the most effective prevention method. 2. Newly purchased orchid seedlings must be carefully checked for whether they carry the virus before entering the garden. Do not bring in a daughter-in-law carrying infectious hepatitis. Before entering the garden, they must be soaked for 2 hours in a solution of "Virus Bik" at 500-700 times dilution plus 250 times edible rice vinegar for disinfection. After potting, spray the leaf surfaces and backs once with a diluted "Virus Bik" solution, and water the roots once every 10-15 days with this solution, for more than 10 consecutive times each. After that, spray once per season with medical aspirin at 1000 times dilution. This effectively inhibits the proliferation and spread of the virus. 3. Do not reuse the same cutting tool. When necessary, treat tools with a high-temperature flame, or soak them in 10% bleach or 2% formalin for 60 minutes for disinfection. It is best to prepare several knives for exchange use during division, and put them immediately into disinfectant after use, just like medical scissors kept in disinfectant at all times. 4. During division, your own hands must also be disinfected with disinfectant. 5. Do not force high reproduction and growth rates by excessive high-temperature and high-humidity management. Orchid seedlings must not be planted too densely. The orchid garden must have natural ventilation. Various fertilizers should be supplied as needed; do not fertilize blindly to avoid the opposite effect. Where the site permits, it is best to grow orchids naturally. High temperature and high humidity are the main causes of viral diseases. 6. Prevent insects in the garden, especially aphids. 7. For scientific research tissue culture, conduct virus testing before meristem propagation. 8. For pollen propagation, do not use virus-infected orchids as the father parent. Although the Bailasi virus is an incurable disease, it is not absolutely untreatable. Experts and orchid growers in various regions have made certain progress in treating Bailasi-diseased orchids. Some orchid friends have effectively controlled the virus after several years of treatment, which can be called success. The summarized methods are as follows: 1. Build up physical strength. Place diseased orchids in a place with natural ventilation, adjust light, temperature, and humidity well, create good ecological conditions, and appropriately supply fertilizer and spray medicine to strengthen the plants and improve antiviral ability. 2. Drug treatment: 1. Finished pesticide Virus Bik 500 times dilution is an effective medicine; add edible rice vinegar with extremely strong penetration at 250 times dilution to lead the medicine directly to the diseased part; 2. Apply heat-clearing and detoxifying Chinese medicinal materials: Isatis root, Folium Isatidis, honeysuckle, Scutellaria baicalensis, Andrographis paniculata, gardenia, Paris polyphylla, etc., choose 3-5 kinds to combine into a formula, and use alternately every month. First use the infusion, then the decoction, and finally sprinkle the medicinal residue with the liquid, preferably at 10-100 times dilution; 3. Spray once per season with analgesic aspirin at 1000 times dilution. Apply medicine by both watering and spraying: spray to treat the aboveground part, water to treat the underground part. For comprehensive treatment, spray once every 7 days, water once every 10-15 days, and after 10-15 consecutive times, change to once every half month or once a month, persisting for one year to consolidate the effect. 3. Support the healthy and remove the pathogenic, gradually increase light, provide more natural ventilation, more dew bathing, normal fertilization, water once every half year, comply with 2 trace element fertilizers and plant growth promoters, spray a medium-concentration foliar fertilizer once every half month, such as Plant Power 2003, Gaolida, Gaole, and Aishi brand foliar fertilizers. With unremitting efforts according to this method, short-term curative effects can be obtained, at least controlling its spread. Sichuan Province Orchid Association "National Orchid" Editorial Department - Laozhuang