Use of Pesticides

Use of Pesticides

Until 1940’s the following chemicals were used to control pests:
(1) Elements fungicides (S, Cu, Hg, organomercury) against fungal diseases.
(2) Copper sulphate, sodium aresenite and ferrous sulphate against weeds.
(3) Nature insecticides e.g. pyrethrum and nicotine, against beetles and aphids.
(4) Tar oil, petroleum, etc., against and red spider mite eggs.
(5) Lead arsenate against caterpillars.
Even these chemicals were sparingly used. The applications to cereals used to be confined to seed treatment with organomercury to kill-borne pathogens.
The organochlorine insecticides and herbicides became quite widespread in the mid and late 1950s and a large variety of these dangerous compounds were being used in the 1960s in USA, UK, and other developed countries. The British Govt. approved over 150 chemicals for use as pesticides/herbicides by 1970.