The Origin and Prevention Methods of the Orchid Cancer Virus, Bairas

Plant diseases caused by viral infection are called viral diseases, also known as toxin diseases; the English name is "VIRUS," transliterated as Bairas. According to records from the Hualien District of Taiwan, China, there are currently at least 25 viruses infectingorchids, belonging to 9 virus groups. Cymbidium mosaic virus,Cymbidiumringspot virus, andorchidfleck virus are the three most common. This disease is a virus that cannot currently be cured, and it is infectious and hereditary, so orchid enthusiasts call it theorchid's"cancer" and "AIDS." After a orchid plant is infected with the virus, it causes systemic infection throughout the entire plant, making the orchid grow slowly, with spots on the leaves or irregular sunken yellow faded patches, and sometimes necrotic streak spots. They generally occur at the base, middle, or part of the tip of the leaf, first appearing as milky white reticular streak spots of varying length, thickness, and irregular boundaries; the boundaries of the spots often resemble gradually spreading water stains, and the spot tissue is chlorotic and transparent on both sides. In the early stage, the spot tissue has no discolored dots; in the middle stage, there is a sunken feeling on the back and a few light brown spots appear, spots within spots; in the late stage, the color deepens to a sun-scorched appearance, while wrinkle lines appear, the leaf edges curl backward and lose their luster, then gradually dry up, and finally the plant dies. The dreaded Bairas virus is infectious, and it will also 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 famousorchid growerswith large operations inadvertently introduced diseased seedlings, and in less than two years the orchid seedlings became covered in spots, a sight too horrible to behold. This year some orchid growers in Guangdong and Sichuan suffered losses because of this, ranging from several hundred thousand to over a million yuan. Truly, "three years of skill to grow them well, a quarter of an hour to kill them." Insect bites, crawling, pots, substrate, friction and compression of leaf surfaces, orchid seedlings displayed, stacked, and transported together, soaking pots for watering, and reuse of old planting material can all spread the Bairas virus. Especially during division and repotting in spring and autumn, the cutting tools used, such as scissors, when cutting diseased orchid plants will inevitably be contaminated with the sap of the diseased plant; when the tool cuts other orchid seedlings 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 season, tools are used frequently, which often causes the virus to spread rapidly within an orchid garden. Some orchid gardens use tiered arrangement; when watering the upper layer of orchids, the leftover water flows down to the lower layer, and the virus on the roots also spreads everywhere with the water. Although this method of transmission is slower, its impact cannot be ignored. The way it spreads in large quantities is through tissue culture in scientific research departments to cultivateorchidseedlings, which often causes massive infection because the original stock is congenitally infected with the virus and this is overlooked. This is like the relationship between mother and baby; once it happens, it can be a catastrophe. In addition, when orchids are grown in rural areas and flower and horticultural farms, because other crops and tobacco, sweet pepper, chili pepper, adzuki bean, and pea, as well as ornamental plants such as daylily and lily, are infected with the Bairas virus (CMT), transmission through aphid vectors cannot be ignored either. Because viral diseases cannot be controlled with drugs, only strengthening virus diagnosis and prevention can prevent the occurrence of viral damage. Besides seeking help from local plant quarantine departments once abnormalities appear, the following preventive work should be done routinely. 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 virus-infected orchids are prevalent, and do not buy seedlings mixed and stored together 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 they may enter 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 edible rice vinegar at 250 times dilution for disinfection. After potting, spray the leaf surfaces and leaf backs once with diluted "Virus Bik" solution, and use this solution to water the roots once every 10-15 days, for more than 10 consecutive times each. Thereafter, spray once each quarter with medical aspirin at 1000 times dilution. This effectively suppresses the proliferation and spread of the virus. 3. Do not reuse the same cutting tool. When necessary, tools can be treated with a high-temperature flame, or soaked in 10% bleach or 2% formalin for 60 minutes for disinfection. It is best to prepare several knives for exchange use when dividing plants, and put them immediately into disinfectant solution after use, just as medical scissors are kept in disinfectant solution at all times. 4. When dividing plants, your own hands must also be disinfected with disinfectant solution. 5. Do not excessively pursue high propagation rates and high growth rates by overdoing 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 according to need; do not fertilize blindly, lest the result be the opposite of what is desired. Orchid gardens with sufficient space are best managed with natural cultivation. High temperature and high humidity are the main causes of viral damage. 6. Prevent insects from occurring in the garden, especially aphids. 7. In scientific research tissue culture, carry out virus testing before meristem propagation. 8. For pollen propagation, do not use virus-carrying orchids as the male parent. Although the Bairas virus is an incurable disease, it is not absolutely impossible to treat. Experts and orchid growers in various regions have made certain progress in treating Bairas-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 a strong constitution. Place diseased orchids in a naturally ventilated place, adjust light, temperature, and humidity well, create good ecological conditions, and provide suitable fertilizer and pesticide spraying to strengthen the plants and improve their antiviral ability. 2. Drug treatment: 1. Among finished pesticides, Virus Bik at 500 times dilution is an effective medicine; add edible rice vinegar at 250 times dilution, which has very strong penetrating function, to lead the medicine directly to the diseased parts; 2. Apply heat-clearing and detoxifying Chinese medicinal materials: Isatis root, Daqingye, honeysuckle, skullcap, Andrographis paniculata, Gardenia jasminoides, Paris polyphylla, etc.; select 3-5 kinds and combine them into a formula, and use them alternately each month. First use the infusion, then the decoction, and finally spread the medicinal residue with the medicinal liquid, preferably at 10-100 times dilution; 3. Spray once each quarter with analgesic aspirin at 1000 times dilution. Apply the medicine by both drenching and spraying, spraying to treat the aboveground parts and drenching to treat the underground parts. For all-around treatment, spray once every 7 days and drench once every 10-15 days. After 10-15 consecutive times, change to once every half month or once a month, and persist for one year to consolidate the curative effect. 3. Support the healthy and dispel the pathogenic: gradually increase the amount of light, provide more natural ventilation, let the plants receive more dew, fertilize normally, drench once every half year with 2 trace element fertilizers and plant growth biotin, and spray once every half month with a medium-concentration foliar fertilizer, such as Plant Power 2003, Gaolida, Gaole, and Aishi brand foliar fertilizer. By persistent effort according to these methods, short-term curative effects can be obtained, or at least the spread can be controlled. Sichuan Province Orchid Association "Guolan" Editorial Department - Laozhuang