Chemical control dates back again 4500 years, with the Sumerians using Sulphur substances as insecticides. In Of india the Rig Veda, which is around 4000 years old mentions the utilization of dangerous plants for pest control. But chemical management became widespread with industrialization and mechanization of agriculture in 18th and 19th century, and the creation of insecticides Pyrethrum and Derris Today substance pest control is the dominant form of pest control. But its aftereffects have led people to think about alternatives in the form of traditional and biological pest control.
Long lasting synthetic compounds which affect the nervous system of insects on contact are applied as insecticides. Examples of best insecticides are the chlorinated hydrocarbons DDT, Chlordane and Toxaphene, even though DDT has been banned. Organophosphate insecticides include Malathiom, Parathion and Dimethoate. 2, 4- dichlorophenoxyacetic acid is the most effective herbicide, used to kill broad leaved weeds.