Chemical control:
-The use of chemicals may destroy some useful insects and other organisms
-Nearly all the chemicals used to control pests of crops are toxic to man and farm animals
-Some chemicals can cause water pollution
-Pests and disease may develop resistance to chemicals

Biological control:
-The new organisms introduced may start to attack crops which were before free from attack
-The new organisms introduced may also feed on some beneficial insects
Cultural method of control:
-Bush burning can spread fire to other farms
-The use of fire to control pests can also result in the killing of other beneficial organisms
-Use of fire can also result in the loss of organic matter in the soil
-The use of fire can also destroy the soil structure