How to prevent and control the injury of clomazone

1. Prevention of phytotoxicity: There are many reasons why pesticides cause phytotoxicity to crops. Except some pesticides are sensitive to crops or some special pesticides (mostly herbicides), the main reason is that pesticides are not used strictly in accordance with the prescribed methods and technologies, or because of the influence of weather conditions. Therefore, the key to prevent phytotoxicity lies in the scientific and correct use of pesticides. (1) Before using pesticides, you should read the instructions carefully, especially the column of "Precautions", and make clear the object of use and prevention, application method, dosage and application time. Then, combined with the characteristics of pesticides, local usage habits and test data, you should make clear the "safety factor" of pesticides and determine the maximum dosage. Safety factor: it is the ratio of the minimum effective concentration of pesticides to the maximum tolerable concentration of crops, that is, the minimum effective concentration of pesticides to control pests and diseases and the maximum tolerable concentration of crops.

The smaller the k value, the safer the pesticide is to crops, that is, it is not easy to cause phytotoxicity; The greater the value of k, the less safe it is. For some newly introduced or doubtful drugs in terms of variety and quality, before large-scale use, it is best to take the calculated maximum dose as a pre-test and confirm that there is no acute phytotoxicity before large-scale use. (2) Correctly mastering the use methods and techniques of chemicals is the most critical step to prevent phytotoxicity. Accurately weigh the dosage, accurately use the concentration and dosage: Carefully prepare and prepare: C, the water quality of diluted pesticides is better, especially the diluted water of emulsifiable concentrate pesticides should be rivers, lakes and seas, not well water and sewage. D, pesticide mixture should be scientific and reasonable, continuous use should pay attention to the interval. (3) Fully understand the sensitivity of different crops, different growth parts and different growth periods to pesticides. (4) According to the characteristics of pesticides, it is particularly important to correctly grasp the weather conditions such as application time and temperature of herbicides, which is not only related to the efficacy, but also more important to avoid the occurrence of phytotoxicity. (5) Strictly manage the water layer to reduce the occurrence of phytotoxicity. This kind of pesticide for controlling weeds in rice field requires keeping shallow water layer, such as butachlor, oxadiazon and butachlor mixture. Generally, it is required to keep the water layer of paddy field 3-5 cm 5-7 days after pesticide application, which can not only give full play to the efficacy, but also reduce the occurrence of phytotoxicity. Too deep a water layer is unfavorable. If oxadiazon is applied to rice fields, the water layer is too deep and the heart leaves are submerged, which is also prone to phytotoxicity. 6) Pay attention to the quality of pesticides and insecticides. In a word, pesticides can effectively control diseases, insects and weeds of various crops. Improper application, unclear control objectives and unclear pesticide characteristics may all cause phytotoxicity. Although this is a contradiction, as long as we have a comprehensive understanding of the performance of pesticides used, the degree of drug resistance and physiological characteristics of crops, and the laws of diseases, pests and weeds, we can use these understandings to actively improve the quality of pesticides.