Detailed Explanation of Prevention Methods and Treatment Examples for Bearus Disease

Diseased orchid names and quantities: "Baoshan" one group with two shoots; "Ruiyu" one group with two shoots; "Baosui Yinzui" four groups with eight shoots. Source of diseased orchids: imported. Onset time: June 1992 Symptoms: When leaves were examined against sunlight, irregular lesions were found. The condition of each shoot in each group differed and could be specifically classified as: (1) viral incubation period; (2) relatively mild condition; (3) severe condition. Tentative diagnosis: "Bearus Disease" CultivationGrower's psychological state: tasteless to eat, a pity to discard. Orchid doctor's opinion: treat with full effort Prescription: (1) Isolate and observe, surgically remove diseased leaves when necessary. (2) Change the environment and potting medium. Medicine (organic fertilizer) supplied internally, herbal medicine applied externally. I. Isolation, Observation and Surgical Removal Method The orchid shed should be inspected frequently. If any pot of Chinese orchid is found to be infected with "Bearus" disease, it should be isolated immediately, and the sunken, spreading diseased leaves should be removed. If severe lesions are found on the pseudobulbs, they should also be removed at the same time. The removed diseased leaves and diseased pseudobulbs should be gathered immediately and burned. After excision, the diseased orchid should be placed in a traditional orchid shed with good ventilation. The scissors used for the operation must be strictly sterilized. When excising diseased orchids, any places that have come into contact with people's hands should also be washed clean with soapy water before touching other healthy Chinese orchids. II. Strengthening the Foundation and Cultivating the Vital Essence Method This method is intended to allow Chinese orchids to absorb more and better organic elements, strengthen their constitution, and improve their immunity. This method can be divided into two steps. Step one: first change the potting medium. Imported Chinese orchids, including those from Taiwan, China, Hong Kong, China, Macao, China and other places, basically use tree fern, longan bark, sphagnum moss, magic soil, expanded clay pellets and other potting media. These media are greatly beneficial to the breathing of Chinese orchid roots, but they themselves do not contain organic fertilizer (except that longan bark produces brief and weak organic matter when it is about to rot). Terrestrial Chinese orchids have relatively active growth functions at 18-28 degrees, but their absorption of organic fertilizer is also very slow. At excessively high or low temperatures (below 13 degrees or above 35 degrees, Chinese orchids are basically in a dormant state), applying too much organic fertilizer is instead harmful to the growth of Chinese orchids. Therefore, potting media should be used to help adsorb part of the organic fertilizer, which is then released by the medium for the orchid roots to absorb. This would be relatively ideal. Unfortunately, the above-mentioned media cannot achieve this. At present, on the issue of potting media, basically everyone uses their own method and follows their own path. This is also correct, because temperatures and humidity differ from place to place, and sources of potting media differ, so one should adapt measures to local conditions. Below I will discuss the potting media I use and my analysis of them: (1) Potting medium from the middle to the bottom of the orchid pot: use charcoal granules or granules of ancient blue bricks. Charcoal itself is organic fertilizer. Can charcoal absorb rot and prevent rot? Unfortunately, its water absorption is a bit too strong, so the bottom potting medium should be controlled at about 20%. Granules of ancient blue bricks (each granule 0.6-1.2 cm) are better for lining the bottom of the pot, because ancient blue bricks were made from relatively good clay, fired with firewood and mountain grass, and have undergone years of weathering. Their water absorption is moderate, and they can also be used with some fermented organic fertilizer. The amount per pot can account for 40%-70% of the total potting medium. Here I would like to mention in passing that if modern red brick granules are used, they are not so ideal, because modern red bricks contain much coarse sand and are basically fired with coal powder mixed in during preparation. Their fiery nature has not dissipated, and their sulfur content is extremely heavy, which is not conducive to the growth of Chinese orchids. (2) Potting medium from the middle to the surface of the orchid pot: Botanists divide the world'sorchidsinto two major parts: terrestrial orchids and epiphytic orchids. Chinese orchids are basically terrestrial orchids. What is called "terrestrial" means "soil," so soil should be used forcultivationand there is nothing wrong with that. After many years of trial, the author finds that traditional pond mud granules are relatively ideal, but the selection of pond mud is a very important step. One should choose village-side fish ponds with a long history (several decades is best), deeper water, and relatively fertile water quality. Fry ponds are superior, and adult fish ponds are second, because fry farmers put in peanut cakes, bean cakes and other feed every day to feed the fry. The fry eat part of it, and another part sinks to the bottom of the pond. After fermentation, it cultivates many zooplankton, phytoplankton and organic debris. Such pond mud is retrieved, dried in the sun, and kept for later use. When using it, crush it into 1-2 cm granules and sieve out the powder, which should not be used. In an orchid pot it will not dissolve for 2-3 years. This kind of pond mud contains a large amount of organic fertilizer and can be absorbed by Chinese orchids over a relatively long period. Step two: apply organic fertilizer. (1) Liquid organic fertilizer: use 5% peanut cakes or bean cakes, 40% human urine, 5% white clam shells (marine shellfish), add 50% clean water, add 6 pieces of dried tangerine peel, mix well, place in a container, cover and seal, and ferment for more than 4 months before use. When applying, dilute with 20 times clean water and pour it onto the parts below the pseudobulbs. After fertilizing, sprinkle a little clean water (also called rinsing). The principle of light application should be carried out (apply once per quarter for healthy Chinese orchids; for diseased orchids, apply three times per month). However, do not fertilize during the dormant period of Chinese orchids. Please remember this without fail; (2) Solid organic fertilizer: use 90% peanut cakes or bean cakes, 5% white clam shells (rich in calcium; if inland conditions are limited, cattle bone meal or other calcium sources can be used), mix well, process into powder or small granules, add 5% clean water, place in a container, seal for 4 months, then dry in the sun for later use. If maggots appear during fermentation, "trichlorfon" can be sprayed to kill them. Application method: scatter the solid fertilizer on the surface of the potting medium. Application amount: first examine the size of the orchid pot, the number of orchid plants per pot, the strength of the orchid body, water absorption conditions and so on to determine the amount to apply. For example: for a generally normal large orchid pot of the large-leaf Baosui type with more than 10 shoots per pot and relatively good absorption, 4-6 qian can be applied per pot each time. For those using orchid saucers (small pots), special attention should be paid to the amount; in principle, it is better to use less than more. At the same time, note that during the dormant period of Chinese orchids, water should be given sparingly or not at all, so as to avoid accelerating the dissolution of the solid organic fertilizer, which the Chinese orchid itself cannot absorb. Under such circumstances, root fertilizer burn often occurs. III. Herbal Treatment Method Sun-dried raw tobacco leaves (called "shengqie" in Xinhui, Taishan, Zhongshan, Gaohe and other places) can be used whole as medicine. The main vein bone of the tobacco leaf (abbreviated as tobacco bone) is one of China's ancient pesticides. Our ancestors applied it to mite diseases of vegetables, rust diseases of the fruits and leaves of mandarin oranges and sweet oranges, and so on. Production and use method: Soak about 5 percent tobacco bone in boiling water for 24 hours, remove the tobacco bone, filter the remaining medicinal liquid, and then spray it on the leaf surface and leaf underside, pseudobulbs and even orchid roots; it is required that every part of the whole orchid plant be covered with the medicinal liquid. Thirty minutes after spraying, the leaf surface of the Chinese orchid will appear lustrous and dazzling (the process of the action of the plant oil substances in the tobacco bone). When spraying, pay special attention: do not spray the medicinal liquid into the core of new shoots, and do not spray too much on the roots, otherwise it will affect the growth of the Chinese orchid. Using the same method as above, spray twice a day (four hours apart) for 10 consecutive days as the first course of treatment; stop for 10 days, then begin the second course, spraying for five consecutive days; stop for 10 days, then begin the third course, spraying again for five consecutive days. When spraying, it is best to choose a temperature between 18-26 degrees. Note that during the spraying period, rain must not wash it off, nor should clean water be sprinkled on the leaf surface, so as not to affect the efficacy. When watering is absolutely necessary, just water the surface of the potting medium. After three courses of treatment and about 40 days of observation, the clearly sunken lesions were basically controlled from spreading, and under sunlight or lamplight the irregular yellow-white spots were seen to gradually disappear. Fellow orchid growers, if this group of Chinese orchids is your beloved pet or the treasure of your collection, please continue with the fourth, fifth and sixth courses of treatment, and the effect will be even more ideal. Because tobacco leaves are a herbal medicine, they have no major side effects and are greatly beneficial to Chinese orchids. To ensure efficacy, the preparation is best made once every 2-3 days. If the preparation is used for too long, it will oxidize and deteriorate, causing part of the medicinal liquid to transform into organic fertilizer and reducing efficacy. But it can continue to be applied; do not waste it. The medicinal course required for "Bearus Disease" is relatively long, generally requiring 1-2 months of treatment, or even longer. If orchid growers lack the mental preparation for a "protracted war" and do not persist in systematic treatment (for example: frequently applying light applications of organic fertilizer, choosing potting media rich in organic elements, etc.), this often leads to recurrence of the disease. After two years of experiments with medicinal and comprehensive management of "Bearus Disease," the author does not dare to say that this disease has been completely cured, but it is basically possible to control the spread and transfer of the virus. Diseased orchids with relatively mild conditions can return to youth, causing their leaves to thicken, chlorophyll to increase, and luster to become bright. The new shoots that emerged in the springs of 1993 and 1994 have so far not been found to have viral inheritance, and they are full of vitality and growing robustly. (Li Guoming)