1. Agricultural Management
Crop rotation to be practised on a plot of land annually to control the pest's food supply, so as to terminate the great increase in a pest over the years. This is especially effective in controlling root nematodes (roundworms that live in the soil and feed on the roots) and other pests that do not have the ability to migrate appreciable distances.
Biodiversity provides stability. When a pest outbreak occurs, monoculture is most conducive to its rapid multiplication and spread. Other natural controls, even if present, may be overwhelmed by the avalanche of spreading pests. On the other hand, the spread of a pest outbreak and other natural controls may prove to be effective only if there is a mixture of crop species, some of which are not vulnerable to the attack. One approach that works effectively in the British Isles is to intersperse cultivated with uncultivated strips that are not treated with pesticides. Natural enemies of pests are maintained in the uncultivated strips.
2. Usage of physical barriers to impede pest attack
Leafhoppers, which are significant worldwide pests of cotton, soybeans, clover, alfalfa, beans and potatoes, can only damage plants with relatively smooth leaves. Thus, by cultivating some plants with hooked hairs on the leaf surfaces, will reduce the damage incurred by the leafhoppers, since these hooked hairs tend to trap and hold immature leafhoppers until they die. Similarly, the glandular hairs of plants that exude a sticky substance fatally entrap the alfalfa weevil larvae.
3. Introduction of natural enemies to control pest population
Scale insects that are potentially devastating to citrus crops have been successfully controlled by vedalia beetles (ladybirds), which feed on them.
Parasitic wasps used caterpillars as the hosts for their life cycles. The parasitic wasp deposits its eggs in a gypsy moth larva. The braconid wasp lays its eggs on the tomato hornworm, which is the larva of the sphinx moth. The wasp larvae feed on the caterpillar, and shortly before the caterpillar dies, they emerge and form cocoons.
Mealy bugs in Africa are controlled by a parasitic wasp that seeks out mealy bugs, paralyses them with a sting, and deposits eggs at hatch in the mealy bugs and eat their ways through the insects.
Japanese beetles are controlled by the bacterium, Bacillus thuringiensis, which produces toxic crystals when soil containing the bacterium is ingested by the larvae.
Rabbits in Australia are controlled by an infectious virus
4. Create better quality crops by cross-breeding the true-breeding crops with desirable qualities
Since the genes coding for the desirable qualities, such as taste and smell, are originally found in the species, thus the cross-breeding between two true-breeding crops will produce the desirable offspring that contains the genes for these qualities without any artificial alterations that might cause harm to the biological systems in future.
5. Surround GM crops with inert vegetation
- Since the pollen of the GM crops is the potential cause of genetic
pollution and the possible evolution of a super weed, thus surrounding the
GM crops with other plants that do not cross pollinate with them will reduce
the chance of the altered genes of the pollen to be expressed in their wild
cousins, as pollen grains of some crops cannot travel far due to their
- However, this technique can only be used for corns and potatoes that have
pollens that may spread over a distance of 1km. For Canola, its pollen can
travel over a large distance of 8km, thus reducing the effectiveness of this
technique to less than 10%.
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