Pesticides in current use

As previously mentioned, there are various ecological hazards associated with the repeated use of pesticides on crops, as they are mostly potent chemical poisons, but so far as can be seen agriculture will continue to rely heavily on their use for the forseeable future in the continuing battle with insect pests. What is important is that these poisons be used judicially; essentially this means the minimum dosage, and the fewest applications, for the maximum effect. This entails a high level of understanding, both of the chemicals themselves and the basic principles of pest control.

Historically the development of chemical control of insect pests started with the extensive cultivation of cotton in Egypt and the Sudan when insect damage threatened the success of this valuable crop. To this day cotton is still subjected to serious pest depradation – 1400 species of pests are recorded worldwide, and the present annual expenditure on pesticides is around £1.5 billion. Many cotton crops are still sprayed at weekly intervals for 15 weeks.