The "four essentials" of "anticorrosion" of orchid cultivation in summer

As the saying goes: until it is difficult to raise, you will know the orchid. However, in the four seasons of the year, it is particularly difficult to raise orchids in summer, and it is difficult to prevent the "rot" in the hot summer. Experienced Lanyou all know that in the hot and humid summer, the frequent occurrence of soft rot and stem rot is a major heart disease of Lanyou! If "Belas" is the cancer of orchids, then "rot" is the number one killer of orchids. Orchid friends along the coast call orchid "rot disease" as "rotten head disease". Of course, it refers to the disease leading to orchid pseudobulb rot, but this disease often causes orchid friends to worry, and it seems that it not only refers to orchids. Comprehensive Lanyou experience, combined with their own practice, the author believes that summer orchid "anticorrosion" should grasp the following "four essentials".

First, identify "rot"

The basis of "anticorrosion" lies in "knowing rot". Understanding and mastering the causes and damage characteristics of soft rot and stem rot is the key element of prevention and control of "rot". Often there are orchid friends who can not distinguish the harm of soft rot and stem rot, resulting in the prevention and control work misses the point, can not get to the right point, thus missed the opportunity of diagnosis and treatment, and then suffered heavy losses. Then let's uncover the true face of "rot".

Soft rot: the pathological study of horticultural plants showed that the soft rot of Chinese orchid was a bacterial disease and the pathogen was Eucalyptus carrots. The disease first occurs from the new seedlings, and within a week, the orchid plants catch the disease and die, and the whole pot of grass is seriously poured; some orchid plants are strong, their own resistance is strong, and the disease appears to be mild, so that the whole pot will not die. It is characterized by waterlogged disease spot at the base of the stem or upper root of orchid grass, which is grayish yellow, and the plant tissue is sticky, wet and rotten, with a bad smell, and the disease spot spreads upward, downward, left and right, causing stem base and root and petiole to rot. Due to the brittleness of the tissue after the damage of the stem base, the orchid leaves are very easy to fall off, and the diseased plants in the late stage of the disease are dumped by themselves.

Stem rot: national orchid stem rot is a fungal disease, the pathogen is a semi-known fungus Sporospora fungi, the disease is a chronic attack from the father or the previous generation, the disease period is as long as one month or even half a year. After the plant was infected, the initial symptom was that the base of the stem turned brown, the leaves lost green and sagged slightly. After the disease developed rapidly, the whole plant withered and the leaves did not fall off. The cortex of the diseased stem was shrunk and the epidermis was spongy. After the disease extends to the root, it causes the root cortex to rot. In the late stage of the disease, some petioles are still tough, but they have been dehydrated and shrunk, and some petioles are yellowed, brittle and easy to break.

Second, strengthen ventilation

The key to the prevention and treatment of orchid disease in summer high temperature and humidity environment is ventilation, as the ancients said, "face ventilation is the first important point for orchid cultivation." If the orchid is like a person, if people are in a suffocated environment for a long time, they are also prone to depression and disease; if the orchid is not well ventilated, the orchid will be suffocated by steam, which can easily cause diseases such as soft rot and stem rot! The author set up two orchid shelves on the balcony, which are on the left and right sides of the living room doorway. The three pots of soft rot found this year are the golden dragon of Baodao, the big tribute of fish pillow and the mayor's red, all of which are located on the right side of the orchid rack. The main reason is that the ventilation condition of the orchid rack is not as good as that of the left one. Therefore, when creating an orchid environment, we should do everything possible to achieve ventilation and ventilation, keep the orchid garden clean and orderly, and the orchid pots should be placed in the air on the orchid rack. It should be noted that ventilation not only refers to the air flow of the balcony or orchid room under the blowing of the fan, but also needs to take into account the loose ventilation of the plant and the permeability of the orchid basin, and can not let the orchid root breathe blocked, otherwise it is also easy to cause disease. It is easy for orchid friends to find a phenomenon that it is generally difficult for offices to keep orchids well, because offices are often closed after work and on weekends, with poor ventilation and hot weather, which leads to blue disease. In order to raise orchids well in the office, it is the key to solve the problem of ventilation and ventilation of orchids.

III. Proper dry maintenance

Dry culture and wet culture are relative to the frequency and quantity of watering of Lanyou. The author made a rough survey of Lanyou and came to the conclusion that the novice is more wet and the veteran is more dry. This is consistent with the saying that "beginners are prone to waterlogging and veterans are easy to die from drought." In the orchid world, we often encounter arguments about "wet breeding" or "dry breeding", but unfortunately we are often unable to come to a conclusion. So generally speaking, which way is more suitable for orchid cultivation? The author believes that the choice of dry or wet, in addition to vary from person to person, the key lies in changing from time to time! As far as I am concerned, spring and autumn are slightly wet, while summer and winter are dry. The biggest advantage of dry farming in summer is that it can greatly reduce the occurrence of diseases such as soft rot and stem rot. Some Lanyou summed up as follows: "dry-raised disease is less, wet-raised disease is more." The author believes that dry management can increase the chances of solar sterilization in the plant environment and reduce the possibility of bacteria spreading in the wet and permeable plant environment. In addition, practice has proved that dry farming has the effectiveness of strong buds, promoting flowers and rooting. So, what are the standards for dry farming? How dry or dry is it appropriate to water it? The so-called "dry cultivation" is the management method of watering only one or two days after the basin soil is slightly dried. The practice of the ancients was to use thin pieces of bamboo to poke away the basin plants to look at the roots and see that the roots were dry and they could be watered. Some orchid friends do not pull away the basin mud, but look at the roots exposed on the basin surface and water them when they see that the roots on the basin surface are dry and shrunken, or apply buckle water, that is, they will be watered after two or three days. This method can also be used for reference.

IV. Symptomatic use of drugs

The principle to deal with orchid diseases is "combination of prevention and control, focusing on prevention and comprehensive management". In addition to the above-mentioned preventive measures of "strengthening ventilation" and "proper dry maintenance", my main prevention and control measures in orchid management are as follows: first, alternate use of drugs to control bacterial and fungal diseases in daily management, spraying or pouring to prevent the occurrence of rot. The second is to spread plant ash to prevent soft rot. In the summer plum rain season, using plant ash grain shell charcoal or quicklime, sprinkling basin surface can effectively prevent the occurrence of soft rot. The third is to close the disinfection when preparing the basin soil. According to the parasitic habit of bacteria and fungi in the basin soil, thoroughly eliminate virus was applied to each kind of plant material when preparing the plant material to ensure that it was clean and aseptic and did not leave any future problems.

Of course, in Yilan practice, no matter how strict prevention is, there will still be omissions, which leaves room for the growth of "rot". Once you find that the potted seedlings are sick, do not panic, think calmly about the treatment plan, and take decisive measures immediately. One is to remove the pot and clear the seedlings. Discard the pots and soil, remove and destroy the diseased seedlings, wash the healthy seedlings, and accurately judge whether it is soft rot or stem rot according to the symptoms of the disease. The second is thorough disinfection. If it is soft rot, use bacterial drugs to disinfect, you can choose a 1000-fold solution of carbendazim, agricultural streptomycin, chloramphenicol, potassium permanganate, benzoammonium and other drugs, soak for 30 minutes, then rinse with clean water and dry. If the stem rot, it is necessary to use fungal drugs disinfection, you can choose methyl thiophanate, Shigao, carbendazim, amicida, metalaxyl and other drugs in a 1000-fold solution. Third, replant and recuperate. After the plant is dried, put it back into the pot with new pot and new soil, put it in a cool and ventilated place to slow down the seedlings, and you can spray leaves or roots with fungicides regularly. For the sake of insurance, it is best to choose the method of dismantling and replanting rare seedlings in order to prevent the infection between orchid seedlings.