East Africa: Small-scale farmers use “push-pull” approach to control pests without chemicals (Africa Science News Service)

| January 28, 2008

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On fields across East Africa, crops are being protected by an invisible barrier. Instead of applying chemical pesticides, farmers are applying a scientific discovery. They are using special plants that actually keep pests away.It’s called the push-pull method of pest control. Farmers plant “push” plants between crop rows to keep pests away. These plants – such as Desmodium – naturally release chemicals that repel unwanted insects.

They also plant “pull” plants around the perimeter of fields where they plant their valuable crops. These plants – such as Napier grass – attract and trap the pests.

The method was developed by the International Centre for Insect Physiology and Ecology in Kenya. Already, thousands of farmers in Uganda, Tanzania, and Kenya have tried it.

It is a welcome alternative for small-scale farmers who cannot afford commercial pesticides. In fact, they have found it even more effective than pesticides. In trials, the push-pull method has proven very effective in reducing pest damage to maize, as well as helping to control the Striga weed. Compared to traditional methods of pest control, it can triple or quadruple farmers’ yields.

And the push-pull plants don’t go to waste, either. When they have done their job of keeping crops safe, they are also harvested. Most farmers use them to feed cattle.

Researchers have also tried planting traditional crops, like beans, among the push-pull plants.

And there may be more ways to use the push-pull method. Researchers are exploring how the technique could keep unwanted insects away from livestock.

In the future, it may even fight sleeping sickness by keeping the tsetse fly away from people.