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With the increasing aphid on rice in recent years, the application of organophosphorus pesticides in rice is also becoming more and more popular, and its use and concentration are also increasing. Due to improper use, it often causes certain phytotoxicity to rice growth, and even causes a large reduction in production. Based on my personal experience, I propose the following prevention and control measures. First, the main symptom of rice plant damage is that after the rice plant is damaged, it is light yellow, and the rust spots appear on the leaf surface. Sometimes the rust spot area accounts for more than half of the leaf surface. When using a manual sprayer, the walking route with the pest control is particularly obvious. It usually takes 7-10 days for the symptoms to gradually disappear. Second, the cause of damage to rice plants The main reasons for the use of organophosphorus pesticides are the following: (1) The amount of pesticides is too large and the concentration is too high. Some farmers use the organophosphorus pesticides at random to increase the dosage, the use of the acres reaches 150 grams or more, and even reaches 200-250 grams. In order to save labor, the water consumption is seriously insufficient, even less than 30 kilograms, so that the use of the drug concentration is greatly exceeded, resulting in phytotoxicity. (2) Improper selection of medication time. In general, the use of organophosphorus pesticides to control aphids, it is best to choose 8-10 in the morning or after 3 o'clock in the afternoon, try to avoid spraying at noon high temperature, otherwise it is easy to produce phytotoxicity. (3) A water-free layer when used in the field. Because of the high temperature season when controlling aphids, the transpiration of rice plants is large. At this time, there is a lack of water in the field, and the phytotoxicity is often aggravated. (4) There are too many varieties of mixed application. When more than two types of mixed application are applied, the rice plant will also cause phytotoxicity. Third, preventive measures (1) Strictly control the amount of drugs and the concentration of application. Generally speaking, the amount of organophosphorus pesticides used in rice should be strictly controlled below 150 grams, and the water consumption per mu should not be less than 40 kilograms. (2) Select the appropriate spraying time. Avoid high temperature noon medication. (3) When applying pesticides, there must be a water layer in the field, the concentration of which is not less than 10 cm. (4) The variety of mixed application should not be too much, and the general type of insecticide should not exceed 2 types.