What are the key points for the maintenance of orchids in autumn?

I. Raising orchids faces four major risks

In the process of orchid cultivation, orchid breeders often face various risks. In my opinion, the main risks come from the following four aspects: one is the risk of buying fake flowers, the other is the risk of orchid theft, the third is the risk of orchid price fluctuation, and the fourth is the risk of orchid being raised to death. In the above four orchid risks, the first three risks may not be encountered by everyone, and the fourth risk, every orchid owner has to face. According to the author's investigation results in recent years, in Dali Prefecture, from the survey of more than 110 orchid growers, there are no people who have not raised dead orchids, but there is a difference between more dead and less dead, and the better flowers and famous flowers are more likely to have problems. Only from April to August 2005 5 5 months of investigation, in Dali Prefecture, only because of the outbreak of orchid stem rot, and caused losses estimated at between 100 million yuan-500 million yuan, the specific loss, only know how much, simply can not be counted. However, one thing is certain: the loss must have been huge. This year, the stem rot of orchids in the whole province and the whole country is relatively serious (here refers to the stem rot in a broad sense, that is, the disease caused by the rot of pseudobulbs, including bacteria, fungi and other causes). If the losses in the whole province and the whole country are added together, the loss amount must be huge. Therefore, how to raise orchids well, but not to raise orchids to death, this is a major event that every orchid grower has to face. Why is there an outbreak of orchid disease? Why did it cause such a huge loss? The author thinks that the main reason is that orchid breeders take improper measures in the process of orchid pest control, and there are many problems in the long term. The main problems and countermeasures in orchid pest control investigated by the author for many years are summarized as follows.

II. Main problems existing in orchid pest control

1. Inaccurate diagnosis is the root cause of serious orchid diseases and insect pests.

When we go to the hospital to see a doctor, what we need most is for the doctor to diagnose the disease accurately before we can prescribe the right medicine. This is very understandable. However, in the prevention and control of orchid diseases and insect pests, many orchid friends often do not accurately diagnose what diseases and insects their orchids have, but rush to use drugs, such prevention and control, the efficacy is not good. Diagnosis is inaccurate, which is the root cause of orchid diseases and insect pests.

2. The complex conditions of orchid diseases and insect pests are the objective reasons for the heavy occurrence of orchid diseases and insect pests.

From the survey in recent years, there are 100 orchid people, there are roughly 100 kinds of orchid cultivation methods, which are mainly caused by the cultivation conditions of each person, experience and different views on different orchid cultivation methods. Because of the variety of orchid cultivation methods, orchid cultivation conditions vary greatly, resulting in different orchid cultivation environmental conditions; Because different orchid cultivation techniques are different, the orchids raised are different; Because of these differences, the environmental conditions for the occurrence of orchid diseases and insect pests are also very complex, providing good conditions for the occurrence of orchid diseases and insect pests, and finally causing various types of orchid diseases and insect pests, each different. From the perspective of stem rot of orchids alone, it is impossible to make an accurate diagnosis if the pseudobulb rot of orchids alone. For experienced people, it is also necessary to see the real thing, isolate the diseased tissue, and cultivate it properly in the room before they can draw preliminary conclusions with the help of instruments. Generally, orchid friends can diagnose pests only by means of orchid pest atlas. If they diagnose orchid diseases, the conclusion may not be very accurate. Otherwise, orchid stem rot (rot disease) would not have occurred so seriously in the country.

3. Insufficient understanding of pesticide characteristics, mechanism of action and control objects

From the investigation, it can be seen that many orchid friends only know carbendazim and methyl thiophanate as disease prevention agents for orchids. When planting orchids, these two drugs are used for disinfection of orchids and prevention of orchid diseases. After orchids get sick, they are still used for prevention and control. In this way, they often suffer losses in the years when orchid diseases occur seriously. This is because the two drugs themselves are the same as benzimidazole fungicides, long-term use, bacteria easy to produce resistance, and one of them produces resistance, then the other also produces resistance. Therefore, when using a pesticide, it is necessary to clarify the mechanism of action and control objects of the pesticide in order to achieve the corresponding effect. In the mechanism of action of the fungicide, it is necessary to make clear whether the drug mainly plays a preventive role, a therapeutic role, or a role in eradicating germs. At the same time, it is necessary to understand whether the drug has an internal absorption effect or a contact killing effect, etc., so as to have targeted medication. In fact, the use of pesticides in orchid pest control is very particular. What pests and diseases, what chemicals need to be used to control them, this must be clear. For example, orchid bacterial diseases, if used to control fungi pesticides to control, the general effect is very poor or ineffective; and the disease is also caused by fungi, it is not to say that any fungal control chemicals are effective, must have targeted use, in order to improve the control effect, this is the basic requirement for the control of orchid diseases. Here, it is important to point out that there are a few pesticides such as copper-containing fungicides, such as killing, which have certain control effects on diseases caused by fungi, bacteria and viruses. However, such broad-spectrum fungicides are generally mainly used for prevention. When used at the peak of the disease, no matter what disease is prevented, the control effect is generally not high. To control orchid diseases with such broad-spectrum fungicides as the main control, it is often easy to cause heavy losses.

4. More attention was paid to diseases and insect pests in the middle and upper parts of orchids, but not enough attention was paid to pseudobulbs and root diseases and insect pests.

From the practice of planting orchids, many orchid friends pay insufficient attention to false bulb diseases and root diseases of orchids, and in fact, the latter two are the most destructive to the death of orchids; most orchid friends take measures only after they have been infected with diseases and diseases of orchids and have already shown symptoms. For diseases and diseases of middle and upper parts of orchids, first aid most of the time has certain effect, while for false scale diseases and root diseases, it is often too late. In addition, what needs to be paid attention to by the majority of Lanyou is the pest problem in the orchid basin. There are many kinds of pests in the basin. In fact, the harm is serious, so it needs to be controlled in time (I have another special article to discuss).

5. Lack of systematic preventive measures and late application

In the practice of orchid cultivation, we often see that some people apply this medicine today, listen to others say that medicine is good tomorrow, and change to another medicine. As a result, the prevention effect is often not ideal. Therefore, in order to achieve better control effect, the same pesticide with good control effect must be used continuously for a certain pest. The disease should be applied at least 3 times (once every 7-10 days) and the pest should be applied at least 2 times in order to achieve better control effect. In the control period, it is necessary to master the application of pesticides when the number of pests is small, that is, the early treatment and small treatment; and the disease must bear in mind the principle of prevention first, early application; if the orchid has developed, it must seize the early stage of the disease. This critical period of continuous application; In addition, in the prevention of diseases and insect pests, according to the local common diseases and insect pests (on the premise of correct diagnosis), medicine can be used in advance, bearing in mind that the high temperature and high humidity season (5-9 months) in a year is the peak period of orchid diseases and insect pests, so timely prevention is needed.

III. Response measures

1. Strictly implement disinfection measures for seedlings and plant materials

The newly introduced orchid seedlings must adopt corresponding disinfection and pest control methods to eliminate and reduce the transmission of diseases and insect pests as far as possible and cut off the transmission source. When planting orchids, disinfection treatment should be carried out on orchid seedling tools, planting materials and orchids pots. After many years of practice, the author thinks that besides orchids, the better measure is to carry out high temperature disinfection, which can kill germs and pests, and is more thorough. The specific method can be to put orchid cultivation articles, utensils, plant materials, etc. into boiling water for 10 minutes, or steam for 30-60 minutes after boiling water. Other methods such as sun exposure, frying and other methods can be used, but not necessarily can kill 100% of germs, pests and eggs. This is the first step in planting orchids, and it must be done well.

2. Regular pest prevention

In recent years, with the increase of large-scale and modern orchid growers, many famous orchid products have high value, so it is particularly important to do this well. In the middle of August 2005, the author saw on a well-known orchid website in China that a certain orchid friend died of stem rot due to orchid disease within 15 days, and more than 50 seedlings of Fulan famous product Cheng Mei were worth more than 600,000 yuan, which is a pity. Just imagine, except for a few big outdoor, the vast majority of Lanyou can withstand this kind of attack? Therefore, it is necessary to prevent orchid diseases and insect pests, especially destructive diseases. In terms of specific preventive measures, in Dali Prefecture, generally speaking, pest prevention is the main one in spring, disease prevention is secondary, disease prevention is the main one in summer with high temperature and humidity, pest prevention is secondary in autumn, and pest prevention is generally lighter in winter, so it can be selected and treated according to each person's situation. However, in winter, special attention should be paid to protecting the root system of orchids. If the humidity in the winter basin is high, orchids are most likely to rot. There is a proverb for cultivating orchids: winter roots, summer and autumn leaves, which is very reasonable.

3. right medicine

As mentioned above, the root cause of orchid diseases and insect pests is that there is no right medicine, mainly inaccurate diagnosis. The solution is to do a good job of prevention and control by oneself. For diseases and insect pests that one does not know or is not sure about, consult experienced people nearby, or consult experts engaged in this field. Make sure that the diagnosis is accurate before one can talk about the right medicine. Now many people talk about orchid stem rot, there are blind people feel the elephant, each blow each hit feeling.

4. Timely application

This measure mainly includes two meanings: one is to prevent and control in time, in addition to doing the usual prevention work, to apply drugs at the early stage of orchid diseases and insect pests; second, as mentioned above, aiming at the occurrence of diseases and insect pests, especially diseases, under the premise of accurate diagnosis, select the right chemicals, apply continuously, disease at least 3 times (once every 7-10 days), pest at least 2 times, in order to ensure a certain control effect. Timely application is an effective measure to reduce the occurrence of diseases and insect pests and reduce losses.

5. Correct control of pesticide concentration and uniform spraying

At present, there are two incorrect uses of pesticides for the control of orchid diseases and insect pests: one is to use too high a concentration, such as some people in the prevention of disease, direct use of commercial chemicals without mixing water directly applied to the disease. This method is easy to cause phytotoxicity to orchids (direct phytotoxicity means that the orchid plant dies, indirect phytotoxicity means that the leaves, growth points and root fungi of orchids are damaged). For pests and diseases, it is easy to produce drug resistance. The direct consequence is that the same pesticide is used later, and the control effect is very poor or no control effect. Now many people say that thiophanate-methyl bactericidal effect is very poor, the reason is that the use of time is too long and improper use caused. Second, some orchid growers are afraid to use pesticides to hurt their orchids, rarely use drugs or use concentrations too low, and do not play a role in preventing and controlling pests and diseases. The above two methods are actually unscientific, the correct method should be based on the mechanism of action of various pesticides, control objects and use methods, combined with their own or other successful experience, to confirm that a certain drug has an effect on a certain pest, and no harm, and then use. When spraying, the front and back of the leaves and the surface of the pot soil should be sprayed to have a better control effect.

6. alternate medication

For the main pests and diseases in a certain place, different kinds of pesticides should be selected. More than 3 effective pesticides should be selected for each pest and disease, at least once a month, in order to effectively reduce the resistance of pests and diseases, improve the control effect, and prolong the service life of a certain special pesticide. This measure should also attract the attention of the majority of Lanyou.

7. strengthen ventilation

Jin Ce of Lanjia District of Qing Dynasty of Guangdong said: Orchid cultivation takes surface ventilation as the first meaning, ventilation is the first task of planting orchid, Yang more flowers are good, Yin more leaves are good, this is for ventilation, if not ventilated, Yang more sun death, Yin more silted death, no death also. This is the supreme treatise on ventilation of cultivated orchids, which is the truth. This requires us to do: orchid cultivation environment to ventilation, plant material to loose ventilation, rich nutrition, orchid basin also to ventilation, in order to raise orchids. Ventilation plays an irreplaceable role in raising orchids and preventing diseases and insect pests, especially diseases. Every orchid keeper should pay attention to it.

Why do some orchids have roots growing out of the ground?

Orchids root arch out of the ground for two main reasons: small orchids basin, can not accommodate. If there is no pot change for three years; drought and water shortage for a long time, the pot soil is too full, the irrigation overflows, the pot soil is in a state of water shortage for a long time, suitable high tube orchid pots can be used, the planting soil must be replaced, and the watering must be poured until the bottom hole of the pot is out of water.