PEST CONTROL
Clever Kenyan
pest control
! Push-pull planting ": Strategic intercropping and margin planting entices harmful bugs out of staple crops without pesticides
Smallholders struggling with insect infestations in their crops would do well to investigate the “ pushpull ” form of pest management . The principle is based on the use of repellent plants which are planted within the crop field and the use of “ trap ” plants which are planted in the veld margins around the crop field . A staple crop such as maize is vulnerable to stem borers . A secondary crop such as a Desmodium species is planted between the rows of the primary crop . A third crop such as Napier grass is planted on the edges of the land . So the approach relies on a combination of companion crops to be planted around and among the maize . The grasses are planted in the border around the maize fields where invading adult moths become attracted to chemicals emitted by the grasses themselves . Instead of landing on the maize plants , the insects head for what appears to be a tastier meal . These grasses provide the " pull " in the " push – pull " strategy . They also serve as a haven for the borers ' natural enemies . Napier grass has a particularly effective way of defending itself against the pests : once attacked by a borer larva , it secretes a sticky substance which physically traps the pest and limits its damage . The " push " in the scheme is provided by the intercropping plants that emit chemicals which repel stem borer moths and drive them away from the main crop . The best candidates discovered so far with the repellent properties are species of leguminous genus Desmodium . Desmodium is planted in between the rows of maize . Being a low-growing plant , it does not interfere with the crops ' growth and , furthermore , has the advantage of maintaining soil
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