Push-pull entails mixing plants that repel insect pests (“push”) and planting diversionary trap plants around a crop perimeter that attracts the pests away from the crop (“pull”). In this case, stemborers are attracted to Napier grass (Pennisetum purpureum), a trap plant, and are repelled from the main cereal crop using Desmodium, a legume intercrop. Desmodium roots exude a chemical that effectively controls the parasitic Striga weed by preventing germination. Desmodium also improves soil fertility through nitrogen fixation, natural mulching, improved biomass and control of erosion.
As part of the research and development strategy, the International Centre of Insect Physiology and Ecology (ICIPE) directly involved thousands of smallholder farmers to test and experience the push–pull technology on their own farms. As a result mutual trust developed and the resulting improved communication process led to faster adoption of the technology. ‘Push-pull technology’ is now an innovative system of soil, pest and weed management on mixed cereal- livestock farms that has now been adopted by approximately 30,000 smallholders in Kenya, Uganda and Tanzania.