The identification method of dairy pesticide identification method found that there were precipitation and layered flocculation in pesticides. The vials could be placed in hot water and allowed to stand for 1 hour. If the precipitates were decomposed, the flocs disappeared, indicating that the pesticides were effective; otherwise , can not be used by craftsmen. In the shaking method, stratification occurred in the pesticide bottle, and the upper layer of oil floating in the lower layer precipitated, and the pesticide bottle was shaken with force to make the pesticide uniform, and then allowed to stand for 1 hour. If it was still stratified, the deterioration of the pesticide was proved to be invalid. If the stratification disappears, it means that it has not failed and can continue to be used. Powder pesticide identification method Suspension method: Take powder pesticides 50 grams, placed in a glass bottle, add a little water into a paste, add appropriate amount of water and mix well, place 10-20 minutes, good pesticide powder fine, less and Precipitation is slow; failure of pesticide particles is faster and more precipitation. Cautery method: Take 10-20 grams of powder pesticide, put it on a metal plate and put it on fire. If you take a white smoke, it means that the pesticide has not failed, otherwise it has become invalid. Observing method: If the powdered pesticide has agglomerated, it is not easily broken and proves to be invalid and can no longer be used. Wettable powder Pesticide identification method Take a glass of fresh water, and gently sprinkle a little of the pesticide on the surface of the water. After 1 minute, if the pesticide does not dissolve in the water, it means that the pesticide has gone bad. In addition, 1 gram of pesticide was sprinkled into a glass of water and stirred well. If sedimentation occurred quickly, the liquid surface appeared translucent, which also indicated that the pesticide had failed.