Rice is an important food crop in China, and it is also a crop that has been seriously affected by pests and diseases. The annual incidence of pests and diseases is more than 1.6 billion mu. Rice is also the crop with the most doses of pest control in China. Therefore, it is especially important to promote the scientific reduction of rice. Change the extensive prevention and control methods in the past, scientifically use high-efficiency, low-toxic pesticide varieties, adopt combination drugs, reduce dosage and improve drug application techniques, etc., which can effectively improve the level of prevention and control of rice science drugs. 1. China's rice pests and diseases are aggravated In recent years, the occurrence of rice pests and diseases in China has been expanding, and the frequency of recurrence has increased. Rice leaf roller and rice planthopper have occurred in the southwestern China and other rice areas, and the secondary or new pests and diseases have been aggravated. The damage of rice pests such as rice water weevil, dry tip nematode disease, southern rice black-streak dwarf disease, and rice leaf dwarf disease has increased year by year. Affected by continuous rainy weather, rice blast, sheath blight, rice smut, leaf sheath spoilage and other late-stage diseases aggravated, resulting in different levels of yield loss. Climate change, rice variety layout, no-tillage and mechanical harvesting, planting structure and fertilizer management, and drug resistance are some of the major causes of serious pest and disease in rice. The increase of high temperature and high humidity weather is conducive to the occurrence and prevalence of pests and diseases, especially for pests and diseases to move to high latitudes. At present, hybrid rice is widely cultivated in large areas, lacking excellent disease-resistant and insect-resistant varieties, and is also conducive to large-scale outbreaks and epidemics of many important pests and diseases. The no-tillage method improved the survival rate of the overwintering insect source; the rice piles in the mechanical harvesting and retaining field were higher, and the number of overwintering insects such as aphid-like drillworms and gray planthoppers was increased. High-yield cultivation measures such as close planting, high-fertilization, especially partial nitrogen application, and one-to-one contracting system and planting diversification have resulted in different planting periods and varieties, and the formation of a large number of bridge fields is conducive to the spread of pests and diseases. In addition, pests and diseases are resistant to the outbreak of the main agent, and it can also cause outbreaks and cockroaches of this pest. 2, scientific medicine is expensive in "temperate" Due to the recurrence and frequent occurrence of rice pests and diseases, the compounding preparations, especially the high-efficiency pesticides, are too many and too chaotic, and the cultivation system of one household has caused the farmers to blindly and use pesticides seriously. A number of new products, such as rice blast, Kangkun, pymetrozine, and enemies, have been promoted and applied in production. These agents have novel mechanism, high control effect and long-lasting effect. We must change the past drug use patterns and habits. Guide farmers to use these new drugs in a controlled and scientific manner. At the same time, paddy fields are a relatively stable ecosystem, and the self-regulation of rice paddy ecosystems should be fully utilized to protect farmland ecosystems. There are several basic principles to be cautious when using pesticides: Focus on ecological regulation. Rice has strong photosynthesis and good self-repairing ability, and should fully exert its own repairing effect. At the same time, we will effectively protect the natural enemies of rice fields, exert their natural control functions, and apply drugs strictly according to the prevention and treatment indicators. Rational use of drugs. According to the action mechanism of the pesticide, the appropriate application period is selected. For example, the insecticidal effect is slow, the effect period is long, and the effect on the nymph of rice planthopper is good, but the buprofezin with poor effect on adult insects should be used in the lower nymph stage of the last generation of the main genus of rice planthopper to reduce the rice locust. The number of populations that are harmful to reduce the pressure of prevention and control; while pymetrozine with high systemic activity, long-lasting effect, and effective for both adults and nymphs, it should be used in the local rice blast. Alternate medication. According to the mechanism of action, the drug classification is carried out, and the agents with no cross-resistance or different action mechanism are alternately used between the upper and lower generations or between the two drugs before and after, so as to avoid the continuous use of a certain agent and delay the development of resistance. For example, chlorpyrifos, nitenpyram, chlorpyrifos, etc. can be used for controlling rice brown planthopper; chlorantraniliprole, avermectin, emamectin, indoxacarb, furfuran can be used for controlling rice leaf roller Acylhydrazine, chlorfluazuron, etc.; for the control of rice blast can use tricyclazole, rice blast, spring leimycin and other agents. Limit medication. In order to delay the development of resistance to pests and diseases, the principle of restricting the use of drugs for novel and highly effective pharmaceutical products (ie, limiting the number of uses during a growing period). For example, the activator of chlortetracycline, chlorantraniliprole, is mainly used to control the main damage of rice leaf roller and stem borer. It is recommended to use it once per growing season. Pyridine-imine heterocyclic insecticide The pymetrozine is mainly used to control the main damage generation of rice brown planthopper, whitebacked planthopper, and gray planthopper, and it is recommended that rice be used for 1 to 2 times per growing season (one type of planthopper is used only once). Suspend medication. Agents that have developed high resistance to pests and diseases and agents with cross-resistance must be suspended. For example, the brown planthopper has a very high level of resistance to imidacloprid, so it is not suitable to control rice brown planthopper with imidacloprid; Zhejiang, Jiangsu, Hunan, and sorghum have suspended high levels of resistance to insecticides and triazophos. Zolphos and insecticides prevent and control bismuth. Safe medication. Paddy fields are a special ecosystem with many natural enemies and good control of pests. It is necessary to use selective pesticides, and it is forbidden to use pesticides that are highly toxic to natural enemies in rice fields, such as enemy killing, to prevent the killing of natural enemies and to cause pests to re-crack. Disclaimer: Some articles on this website are transferred from the Internet. If legal rights of third parties are involved, please inform this website. phone ZHEJIANG SHENDASIAO MEDICAL INSTRUMENT CO.,LTD. , https://www.shendasiaomed.com