Pesticide.

Pesticides are chemical substances used to combat pests harmful to agriculture, forest crops and their products (unprocessed pesticides are called primary drugs), including auxiliary substances that enhance the effectiveness of these agents (e.g., fillers that dilute solids, emulsions that allow insoluble liquids and water to disperse evenly, and solvents that dissolve liquid primary drugs). Hundreds of thousands of tons of pesticides are put into farmland, orchards, forests and grasslands every year. According to the different functions of pesticides, there are various classification methods. Generally divided into insecticides, fungicides,
herbicides
, rodenticides, anti-pythons and plant growth regulators, the first three categories of production and use of the largest. According to the composition of pesticides can be divided into chemical pesticides, plant pesticides and bio-pesticides, of which chemical pesticides are the main. In chemical pesticides, there are two types of inorganic
and
organic pesticides. Long-term single use of a pesticide, will produce resistance, so pesticides should be reasonably rotated. The main research target of pesticides is a new variety with low toxicity and high efficiency.