Pest control

Pest control

A pest is any organism that has as undersierable effect. In farming it may cause harm economically, or effect the health of crops of livestock
Pests can have a devastating effect on crops, especially in monocultures in which only crop is grown. Monoculture systems are simpler than natural ecoosystems and usually lack pest predators
Pests can equally have a damaging effect on livestock reared in crowded conditions. In crowed conditions, the high reproductive output of the parasite can lead to its rapid transmission from one host to another
Most pests cause significant economic harm only when their population reaches a certain level, called the economic injury level. To prevent fast-growing pest populations from reaching this level, control measures have to be started at a lower pest population level, called the economic damage threshold. Pests may be controlled chemically, biologically, by cultural methods, or by a combination of methods
Cultural methods of pest control; such as weeding, tillage, and crop rotation are amoung the most common. Crop rotaion often prevents the build up of pests that occur in monocultures, but it is only effective when a pest cannot attck successive crops.
Crop damage can also be minimised by growing the crop at a particular time in the life cycle of a pest. The crop is sowed or harvested at times when the pests can do least damage. Other cultural methods of pest control include; creating physical barriers; intercropping
Chemical control; toxic chemicals that control pest populations are called pesticides. These include; fungicides, herbicides, and insecticides. Contact pesticides kill pests without being eaten, systemic pesticides are taken into a plant and translocated within the plant, and enter the pest when it eats the plant or sap. Broad-spectrum pesticides, designed to affect a wide range of pests, may also kill harmless organisms or beneficial ones such as the predators of pests
Biological control; is the control of pests and weeds by other living organisms or by bioloigical agents. A predator or parasite is usually used to control the pest. The aim is not to eliminate the pest or weed, but to use the control organism to keep the pest or weed population below the economic injury level. Care must be taken to ensure that the control organism does not become a pest itslef.
1. Biological agents inlcude pheremones genetically engineered insecticides. Pheremones are chemicals released by the organism. Synthetic pheremones have been used to lure pests onto traps laces with insecticides

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