Knowledge about diseases and insect pests of orchids

In the prevention and control of orchid diseases and insect pests, many orchids often do not have their own orchid diseases, insect diagnosis accurate circumstances, but eager to use medicine, such prevention and control, the efficacy is not good. The diagnosis is not accurate, which is the root cause of serious orchid diseases and insect pests.

The main problems in orchid pest control are as follows:

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

In the prevention and control of orchid diseases and insect pests, many orchids often do not have their own orchid diseases, insect diagnosis accurate circumstances, but eager to use medicine, such prevention and control, the efficacy is not good. The diagnosis is not accurate, which is the root cause of serious orchid diseases and insect pests.

two。 The occurrence conditions of orchid diseases and insect pests are complex, which is the objective reason for the serious occurrence of orchid diseases and insect pests.

Because of the variety of orchid cultivation methods and the different conditions of orchid farmers, the environmental conditions of orchid cultivation are different; because different orchid farmers have different orchid cultivation techniques, the strength and weakness of orchids are not the same. Because of these differences, the environmental conditions for the occurrence of orchid diseases and insect pests are very complex, which provides very good conditions for the occurrence of orchid diseases and insect pests.

From the point of view of the stem rot of orchids, it is impossible to make an accurate diagnosis if the false bulbs of orchids rot alone. For experienced people, they must also see the real object, separate the tissue of the disease department and make appropriate indoor training before they can draw a preliminary conclusion with the help of instruments. In general, orchid friends can diagnose pests only with the help of orchid disease and insect atlas, but if orchid diseases are diagnosed, the conclusion may not be very accurate. Otherwise, orchid stem rot (rot) would not have occurred so seriously in the country.

3. We do not know enough about the characteristics, action mechanism and control objects of pesticides.

For orchid disease prevention agents, many orchids only know carbendazim and methyl topiramate. When planting orchids, orchid plants are disinfected with these two kinds of drugs to prevent orchid disease. Orchids still use two kinds of drugs to prevent and cure orchids after getting sick. In this way, we often suffer losses in years when orchid disease is serious. This is because the two drugs themselves are the same as benzimidazole fungicides, long-term use, bacteria are easy to develop resistance, and resistance to one of them, then resistance to the other accordingly.

Therefore, when using a certain pesticide, the action mechanism and control object of the pesticide must be clearly defined in order to have the corresponding effect. In terms of the action mechanism of fungicides, it is necessary to make clear whether the drug mainly plays a role in prevention, treatment, or eradication of germs, and whether the drug has internal absorption, contact effect and other knowledge. in order to have targeted medication.

In fact, the use of pesticides in orchid pest control is very particular. It is necessary to find out what diseases and pests and what chemicals are needed to control them. For example, if you use fungus pesticides to control bacterial diseases of orchids, the general effect is very poor or ineffective; while the same diseases caused by fungi, it does not mean that all fungal control agents are effective, and must be targeted in order to improve the control effect. This is the basic requirement for the prevention and control of orchid diseases.

Here, it should be emphasized that a small number of fungicides, such as copper-containing fungicides, have a certain control effect on diseases caused by fungi, bacteria and viruses, but these broad-spectrum fungicides are generally mainly used for prevention. in the peak period of the disease, no matter what disease, the control effect is generally not high, such broad-spectrum agents to control orchid diseases, often easy to cause heavy losses.

4. Pay more attention to diseases and insect pests in the middle and upper parts of orchids, but not enough on pseudobulbs and roots.

From the practice of orchid planting, many orchid friends do not pay enough attention to pseudobulb diseases and root diseases and insect pests, but in fact, the latter two are the most destructive to the death of orchid plants. Generally speaking, most orchid friends take measures after they have diseases and insect pests in orchids and have shown symptoms. For diseases and insect pests in the middle and upper parts of orchids, first aid usually has a certain effect, but 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 orchid friends is the problem of pests in the orchid basin. There are many kinds of pests in the basin, and the harm is actually serious, which needs to be controlled in time (I have another special article to discuss).

5. Lack of systematic preventive measures and untimely application of drugs

In the practice of raising orchids, we often see that some people apply this kind of medicine today, but tomorrow they hear others say that it is good, and then change it to another one. As a result, the control effect is often not satisfactory. Therefore, in order to achieve better control effect against orchid diseases and insect pests, the same pesticide with good control effect must be used continuously, the disease should be applied at least 3 times (once in 7-10 days) and insect pests should be applied at least twice in a row in order to achieve better control effect. In the period of prevention and control, we must grasp the application of pesticides when the number of insect pests is small, that is, the disease must be treated early and small, while the disease must be kept in mind the principle of prevention and application as soon as possible. If the orchid has become sick, we must grasp the critical period of continuous application in the early stage of the disease. In addition, in the prevention of diseases and insect pests, drugs can be used in advance according to the common local diseases and insect pests (under the premise of correct diagnosis), keeping in mind that the high temperature and humidity season of the year (5-9 months) is the peak period of orchid diseases and insect pests, which needs to be prevented in time.

Response measures:

1. Strictly carry out disinfection measures for seedlings and plant materials

For the newly introduced orchid seedlings, corresponding disinfection, sterilization and pest control methods must be taken to eliminate and reduce the spread of diseases and insect pests as far as possible, and cut off the source of transmission. When planting orchids, orchid seedling appliances, plant materials and orchid pots should be disinfected. After years of practice, the author believes that in addition to orchids, the better measure is to carry out high-temperature disinfection, high-temperature disinfection can kill bacteria and pests, and more thoroughly. Specific methods can be put orchid products, utensils, plants, etc., into boiling water for 10 minutes, or steam in the water after boiling for 30-60 minutes. Other methods, such as sun exposure and pan-frying, are fine, but they may not kill 100% of germs, pests and eggs. This is the first step in planting orchids, and we must go well.

two。 Regular prevention of diseases and insect pests

In recent years, with the increase of large-scale and modern orchids, many famous orchids are of high value, so it is particularly important to do this well. In mid-August 2005, the author saw on a well-known orchid website in China that a certain orchid friend died of stem rot in an orchid within 15 days, and more than 50 seedlings of Chengmei were worth more than 600,000 yuan, which is a pity. Just imagine that except for a few large families, can the vast majority of Orchid Friends withstand this kind of blow? Therefore, it is necessary to do a good job in orchid pest prevention, especially the prevention of destructive diseases. In terms of specific preventive measures, in Dali Prefecture, generally speaking, the prevention of insect pests is given priority to in spring, supplemented by diseases, while in summer with high temperature and humidity, disease prevention is given priority to and pest control is supplemented, while diseases and insect pests are prevented in autumn, and the occurrence of diseases and insect pests is relatively light in winter. can be picked and treated according to each person's situation. But in winter, we should pay special attention to protect the roots of orchids. If the humidity on the basin is high in winter, orchids are most prone to rot. There is a proverb for orchids to grow roots in winter and leaves in summer and autumn.

3. an antidote against the disease

As mentioned earlier, the fundamental reason why orchid diseases and insect pests are serious and difficult to control is that there is no right remedy to the case, and the main reason is that the diagnosis is incorrect. The solution is to do a good job in prevention and control of diseases and insect pests by yourself. for diseases and insect pests that you do not know or are not sure, you can seek advice from experienced people nearby, or you can also seek advice from experts engaged in this field. You must make an accurate diagnosis before you can prescribe the right medicine to the case. Nowadays, when many people talk about the stem rot of orchids, they have the feeling of blind people touching elephants and blowing each other.

4. Timely application of pesticide

This measure mainly includes two meanings: first, prevention and control should be timely, in addition to the usual prevention work, drugs should be used at the initial stage of the occurrence of orchid diseases and insect pests; second, as mentioned earlier, in view of the occurrence of diseases and insect pests, especially diseases, under the premise of accurate diagnosis, select the right medicament, apply the medicine continuously, disease at least 3 times (once in 7-10 days) and pest at least 2 times in order to ensure a certain control effect. Timely application of pesticide is an effective measure to reduce the occurrence of diseases and insect pests and reduce losses.

5. Correctly grasp the concentration of pesticides and spray them evenly.

At present, in the prevention and control of orchid diseases and insect pests, there are two incorrect uses for the use of pesticides: one is the use of too high concentration, such as some people in disease prevention, the direct use of commercial chemicals directly applied to the disease department without water. For orchids, this method is prone to drug damage (direct drug damage will lead to orchid plant death, indirect drug damage is to harm the leaves, growth points and orchid root fungi of orchids), for diseases and insect pests, it is easy to produce drug resistance, and the direct consequence is the use of the same agent in the future. the control effect is very poor or there is no control effect. Now many people say that the germicidal efficacy of methyl topiramate is poor because it has been used for too long and improper usage. Second, some orchid farmers are afraid to use pesticides to hurt their orchids, rarely use drugs or the concentration is too low, did not play a role in the prevention and control of diseases and insect pests. In fact, these two methods are unscientific, and the correct method should be to confirm that a certain drug is effective on certain diseases and insect pests according to the action mechanism, control objects and application methods of various pesticides, combined with their own or other people's successful experience. and after there is no drug harm, then use it. When spraying, the front, back and basin soil surface of the leaf should be sprayed in order to have a better control effect.

6. Alternate use of drugs

In view of the main diseases and insect pests in a certain place, different kinds of pesticides should be selected, and more than 3 effective pesticides should be selected for each kind of diseases and insect pests, at least once a month, in order to effectively reduce the drug resistance of diseases and insect pests and improve the control effect. at the same time, prolong the service life of some special pesticides. This measure should also attract the attention of the majority of orchid friends.

7. Strengthen ventilation

Jinze, Lanjia District, Guangdong Province in the Qing Dynasty, said: to raise orchids to face ventilation as the first meaning, ventilation as the priority of orchids, Yang multi-flower good, Yin multi-leaf good, this is the ventilation, in short, if there is no ventilation, then Yang more sun death, Yin more silting death, all die. This is the supreme exposition of cultivating orchids about ventilation, and it is the truth. This requires us to achieve: orchid environment should be ventilated, plants should be loosely ventilated, nutritious, and orchid pots should also be ventilated in order to raise orchids well. Ventilation plays an irreplaceable role in the cultivation of orchids and the prevention and control of diseases and insect pests, especially diseases.