Exploration of soft rot and prevention and control of diseases and insect pests in national orchid

If it is said that which two diseases of the national orchid make Lanyou the most distressing, I am afraid it must be wiredrawing and soft rot. The former is a viral disease, and if we have it, there will be no rule of law, while the latter, although there is no cure, why does it bother us so much?

1. Where does the disease come from?

For people to cure diseases, it is important to prescribe the right medicine to cure the disease, and so is the orchid. Let's first look at the source of soft rot: national orchid soft rot (Bacterial soft rot) is a bacterial disease, its pathogen is carrot soft rot Erbsiella (Erwivia carotovora). This conclusion is important to determine that the pathogen is bacteria, not fungi or anything else. There are 5 kinds of bacterial diseases of orchids, including 4 species of orchids and 3 species of vegetative organs of orchids, which are bacterial brown rot, national orchid soft rot and bacterial brown spot. Among the three diseases, only Guolan soft rot mentioned in the book can harm the pseudobulbs of plants, and its pathogen-Erbsiella can also cause soft rot of some plants.

two。 What is the medicine?

Orchids are too valuable. if you have a disease, we will prescribe medicine to cure it. If you are not sick, you should also prescribe medicine from time to time to prevent and prevent the disease. The leaves were black, and we used topiramate and carbendazim; the plants were soft-rotted, but we still sprayed them with these drugs, but we couldn't stop the disease, so we came to the conclusion: orchid soft rot-terminal disease! Soft rot is a bacterial disease, there are its special treatment drugs, namely: fungicides (alkaline CuSo4- broad-spectrum bacterial disease drugs, can be used in spray) and antibiotics (agricultural streptomycin). Of course, if we can find drugs specifically for the prevention and treatment of Orbsiella, the targeted treatment will be stronger and the effect will be better. And some of the drugs we use are not always good for bacteria, just like people don't have a cure for all diseases. When taking medicine, we should pay attention to choose the appropriate time of administration; when giving medicine, the liquid should be in direct contact with the site of the disease. if the adhesion ability of the solution is low, it can be improved by increasing its concentration; at the same time, improve the disease environment, adjuvant treatment.

3. The adverse consequences of drug use

(1) causing the death of a large number of non-plant pathogens. Just as when people are undergoing chemotherapy, the liquid kills not only cancer cells, but also normal cells, making people very weak after chemotherapy; when we catch a cold and have a fever, we eat antibiotics hurriedly and may be cured, but the medicine destroys the balance of bacteria in the intestines and stomach and often secretes after illness. The same is true in plants. Chemicals are highly targeted things that can solve key problems at once, but also destroy the overall balance, triggering a series of changes and adjustments until a new balance is reached again.

(2) pollution. For example, copper compounds have bad effects on people, plants and animals. our original intention of growing flowers is for a better life, whether it is commercial production or family entertainment, the loss of health is always bad.

(3) induce the change of resistance of pathogenic bacteria. As I have just said, the destruction of a balance will lead to the establishment of a new balance. Of course, the pathogens themselves will also devote themselves to "construction" in order to survive. This may be experienced by many people, that is, the adverse consequences of the abuse of antibiotics.

(4) if you use the right medicine, the disease may not be cured. Because it is possible that the solution does not have effective contact with pathogens, such as bacteria in plant tissue. I remember that some time ago, an orchid friend on Guolan asked why the drug was administered and planted in isolation immediately after the onset of soft rot, but it was still not effective, and in the end, the whole army was wiped out. Sometimes one or two plants may survive without ramet. This may be because the ramet after the disease increases the chance of wound infection, while bacterial diseases are more difficult to control than real bacterial diseases, and re-infection may have little effect only on plant surface spraying.

4. Go back to the starting point of everything and think again

Prevention is better than cure, comprehensive prevention is the key! As mentioned above, when a balance is broken, we try our best to fix it, so why don't we think about how to build a more stable balance so that it is not so easily disrupted:

(1) the enhancement of the physique of the plant itself. No matter from the purchase or later maintenance, the disease resistance of strong seedlings is always stronger.

(2) the selection of soil and matrix. The plant is root-based, and the soil and substrate are the survival of the root system. At this point, we have to repeat what we have just said: if a balance net is woven by multiple ropes, it will certainly be more difficult to break. The composition and physical and chemical properties of the soil matrix determine what kind of physiological and biochemical reactions can be carried out, what kind of fungi can inhabit it, and finally determine the type of plants and the direction of growth and development. Natural soil seems to be lack of nutrients and poor physical and chemical properties, but on the whole, it has coordinated all kinds of elements almost perfectly, of course, from a big point of view. It is not necessary for families to use natural soil to raise orchids, which is not conducive to sustainable development. Although the artificial humus soil does not have the same composition as the natural soil, its nutrient diversity and buffer capacity to the external environment are also stronger than that of the single component matrix. Of course, the single-component matrix is easy for us to regulate, and the plant growth and development may be faster, but don't forget that everything will rise and fall, not to mention that according to the normal curve, the peak position must also be unstable, and this peak can be used in plant growth rate. All in all, it is not easy to say what matrix is the best, different use purposes, each has its own advantages, people should apply it flexibly.

(3) Environmental factors should be regulated. Plant disease, if the pathogen, should also be assisted by the pathogenic environment of the pathogen. In general, a cold and humid environment is conducive to the disease, which requires us to take various measures to prevent it.

(4) rational use of chemical drugs. There is a limit to everything, and so is medicine. It is not impossible to use it, nor can it be used often. If medication is needed, attention should be paid to reducing the chances of contact with the skin. The types of drugs should also be used in conjunction with each other to prevent a single species from causing changes in the resistance of pathogens. This point also reflects the truth of "balance" mentioned just now.

Conclusion: when we encounter problems, we cannot just solve the immediate contradictions. Through in-depth understanding, we can often uncover the deeper problems and fully apply the same truth to all aspects and levels by analogy. Because in the final analysis, many things are one, whether it is a problem or a solution. (author: King of Plum Blossom)

(article reference: Chen Xinqi, Ji Zhanhe's "complete Book of Chinese Orchids", Mr. Wang Jinsheng's "Plant pathogenic Bacteriology", and special thanks to my plant pathology teacher for his inspiration! )