Low winter temperatures, most of the activity and toxicity of plant diseases and insect pests in the hidden and static state. Use of chemical pesticides in winter, in addition to choose right pesticides, also pay attention to the following six o clock.
　　One is to choose the sunny day high temperature period drug use. Because of pests at high temperature in winter, its take food intake and respiration intensity is greater than the cold weather, liquid spray to the worm, was taken to the drugs, the body also is conducive to play a role of poison.
　　The second is increasing doses. Pests pesticides kill the amount is not constant. At room temperature, the lower the temperature, the lower the amount of pests in the death of, so it is necessary to appropriately increase the dose in winter, can prevent pests after a drug cant die. Farmers friends may according to the high or low temperature to determine the dose, but generally not more than 50% of the regular dose. The pesticide should strictly according to the diluted times when winter water, do not arbitrarily increase or decrease the dosage of the water.
　　Three is a reasonable choice for winter use of pesticides. In general, stomach poison and contact insecticide is affected by temperature, systemics and fumigant is affected by temperature. Such as DiShaSi, dichlorvos, dimethoate and methamidophos can significantly affect the insecticidal effect at low temperature. And deltamethrin, phoxim, lime sulfur compounds such as pesticides, in a relatively low temperature application can still play a good insecticidal effect. Winter low temperature season use of herbicides, the display effect is much longer time than high temperature application, therefore, to wait after medication, as long as the liquid spray to, generally do not need new spraying.
　　Fourth, we need to extend the crop security clearances. The pesticide, winter slow to the degradation of pesticides, the commend the residual phase of pesticides in crops is relatively longer, plant diseases and insect pests prevention and control of vegetable crops in winter, should pay special attention to extend the pesticide safety interval, to ensure human health.
　　Five must pay attention to the water with a very dilute solution of medicine a barrel. Can add a small packet of "YaoYinZi" or "vegetable oil" dose of 15 g, or acidic substances, etc., as the adhesive. But vegetables when applying pesticide, cannot use.