It is necessary to play a good "combined fist" and master the key technical matters in the scientific use of rice drugs.

Rice is not only an important food crop in China, but also a crop seriously attacked by diseases and insect pests. The occurrence area of diseases and insect pests is more than 1.6 billion mu every year. Rice is also the crop with the largest amount of drugs used for pest control in China. Therefore, it is particularly important to promote the scientific reduction of pesticide use in rice. Changing the extensive control methods in the past, scientifically using varieties of pesticides with high efficiency and low toxicity, adopting combined pesticide use, reducing pesticide use and improving pesticide application technology can effectively improve the level of scientific pesticide prevention and control of rice.

1 the harm of rice diseases and insect pests is aggravated in China.

In recent years, the scope of rice diseases and insect pests in China has been expanding, and the frequency of rice diseases and insect pests has increased. Rice leaf roller and rice planthopper have occurred year after year in southwest China and other rice areas, and the harm of minor or new diseases and insect pests in the past has been aggravated. The harm of rice diseases and insect pests such as rice water weevil, dry tip nematode disease, southern rice black streaked dwarf disease and rice tooth leaf dwarf disease increased year by year. Under the influence of continuous overcast and rainy weather, rice blast, sheath blight, rice false smut, leaf sheath rot and other late diseases were aggravated, resulting in different degrees of yield loss.

Climate change, rice variety layout, no-tillage and mechanical harvesting, planting structure and fertilizer and water management, and drug resistance are the major causes of serious rice diseases and insect pests. The increase of high temperature and humidity is conducive to the occurrence and prevalence of diseases and insect pests, especially to the high latitudes.

At present, the large-scale popularization and planting of hybrid rice is lack of excellent disease-resistant and insect-resistant varieties, which is also conducive to the large-scale outbreak and epidemic of many important diseases and insect pests. The no-tillage method improved the survival rate of overwintering insect sources, and the rice stakes retained by mechanical harvesting were higher, which increased the number of overwintering insect sources such as borer borer pests and gray planthopper.

High-yield cultivation measures such as dense planting, high fertilizer, especially partial application of nitrogen fertilizer, household contract system and planting diversification, resulting in different sowing periods and varieties, and the formation of a large number of bridge fields are conducive to the spread of diseases and insect pests. In addition, the outbreak resistance of diseases and insect pests to attending agents will also cause the outbreak and rampant harm of this kind of diseases and insect pests.

(2) the value of scientific medication lies in "abstinence".

Due to the recurrence and frequent occurrence of rice diseases and insect pests, too many varieties of compound preparations, especially high-efficiency pesticides, and the household planting system, farmers are blind and misuse of pesticides. A number of new products, such as Rice Teng, Kangkuan, Pyrazidone and Nadimel, have been popularized and applied in production one after another. these agents have novel action mechanism, high control effect and long duration, so we must change the previous drug use patterns and habits. guide farmers to use these new agents in a controlled, scientific and rational manner.

At the same time, the paddy field is a relatively stable ecosystem, so we should give full play to the self-regulation role of the paddy ecosystem and protect the farmland ecosystem. Several basic principles should be grasped in the prudent use of pesticides:

Pay attention to ecological regulation and control. Rice has strong photosynthesis and good self-repair ability, so it is necessary to give full play to its own repair function. At the same time, we should earnestly protect the natural enemies in the rice field, give full play to their natural control role, and apply pesticides strictly according to the control targets.

Rational use of medicine. According to the action mechanism of pesticides, the appropriate control period was selected. For example, the insecticidal effect is slow, the persistence period is long, and the effect on rice planthopper nymphs is good, but the buprofezin with poor effect on adults should be used in the young nymphs of the previous generation of rice planthopper, so as to reduce the population number of the main damage generation of rice planthopper and reduce the control pressure. on the other hand, Pyrazidone, which has high endurance activity, long duration and effective to both adults and nymphs, should be used in the local main damage generation of rice planthopper.

Alternate medication. Implement the drug classification according to the action mechanism, and choose the agents with no cross-resistance or different action mechanisms between the previous and next generations or between the previous and later generations, so as to avoid the continuous use of a single agent and delay the development of resistance. For example, imidacloprid, chlorpyrifos and chlorpyrifos can be used to control rice brown planthopper, chlorobenzamide, avermectin, methylaminoavermectin, indenyl, furan hydrazide, fluazide and so on can be used to control rice brown planthopper. Tricyclazole, rice blast can be used to control rice blast, such as tricyclazole, rice blast and so on.

Limit the use of drugs. In order to delay the development of drug resistance to diseases and insect pests, the principle of limiting the use of novel and efficient pesticides (that is, limiting the number of use in a growing period) was implemented. For example, chlorobenzamide, an activator of fenidin receptor, is mainly used to control the main harmful generation of rice leaf roller and Chilo suppressalis, which is recommended to be used once per growing season; pyridine methimine heterocyclic insecticide pyrimidine is mainly used to control the main harmful generation of brown planthopper, white-backed planthopper and gray planthopper.

Stop taking the medication. Agents that have developed high resistance to diseases and insect pests and agents with cross-resistance must be suspended. For example, rice brown planthopper has a very high level of resistance to imidacloprid, so it is not suitable to use imidacloprid to control rice brown planthopper; in areas where rice brown planthopper is resistant to triazophos and triazophos in Zhejiang, Jiangsu and Hunan, stop using triazophos and insecticide to control Chilo suppressalis.

Safe medication. Rice field is a special ecosystem with many kinds of natural enemies and has a good control effect on insect pests. It is necessary to use selective pesticides and prohibit the use of pesticides that are highly toxic to natural enemies in rice fields, such as enemy killing, so as to prevent killing natural enemies and causing pests to become rampant again.

(3) to master key technologies and get twice the result with half the effort.

To improve the level of scientific prevention and control of rice diseases and insect pests, the following measures can be taken.

Grasp green prevention and control. Pay attention to the agronomic measures of variety and cultivation for disease prevention, soil and seedling treatment, seed chemical treatment and seedling stage control, especially the unified field control of raising rice seedlings, and do a good job of "sending medicine", which can get twice the result with half the effort. It is necessary to integrate and popularize and apply a number of practical technologies. Including ecological regulation, light trapping, information disorientation, odor avoidance and bio-pesticides and other technologies and product applications, in the south of China, rice actively promotes raising ducks and crabs in rice fields, and popularizing environment-friendly technologies such as bio-pesticides. At the same time, actively popularizing and applying the whole-process solution of rice crops can reduce the number of pesticide application for 2 or 3 times.

Implement the combination of drugs. Through experiments and demonstrations, the best combination modes of two or more agents, such as the best time and the lowest dosage, were studied in order to reduce the cost and the use of pesticides.

Actively promote the use of reduced drugs. Adopt appropriate application method and time, select efficient, safe and environmentally friendly pesticide varieties, improve the control effect of diseases and insect pests, delay the development of resistance to rice diseases and insect pests, and reduce the cost of control per unit area.

We will vigorously carry out professional and unified defense rule. Specialized unified control is an effective way to solve the difficulties of disease prevention and control, improve the control effect and reduce pesticide pollution in every household, and it is also an effective measure to control the use of highly toxic pesticides and reduce poisoning by pesticide applicators. it is especially suitable for the occurrence of migratory, epidemic and fulminant rice diseases and insect pests. It is necessary to vigorously advocate and promote all kinds of specialized prevention and control organizations to actively carry out specialized unified control of rice diseases and insect pests, ensure the effect of control, and reduce production costs.

Promote high-efficiency pharmaceutical equipment and advanced spraying technology. In the middle and later stage of rice growth, the plant leaves are luxuriant, and the knapsack motor sprayer and high efficient wide-range long-distance mobile sprayer can be used to spray. This kind of sprayer has good droplet penetration, can reach directly to the middle and lower part of the plant, and has a good effect on the control of rice planthopper. Greatly improve the operation efficiency. In addition, the use of lower operating speed, small flow sprinkler, the implementation of low-capacity spraying to improve the utilization rate of pesticides.

Add auxiliaries. The waxy layer on the surface of rice leaves is thick, and the leaves belong to the natural super-hydrophobic biological surface. The contact angle of water droplets on the surface of rice leaves is large, which is not easy to be wetted and retained. When spraying pesticides, organosilicon auxiliaries can be added to the pesticides to improve the adhesion, diffusion and spreading ability of the liquid on the crop surface, and to improve the utilization rate and control effect of pesticides.

Actively promote the use of drugs in the panicle in the later stage. Diseases such as rice blast, rice false smut and leaf sheath rot often occur in the late growth stage of rice, which affect the yield and quality. Fungicides such as Baig, love seedlings and take diazepam can be vigorously popularized to control rice diseases in the later stage, increase 1000-grain weight and increase yield.