Push–pull agricultural pest management

Push–pull technology was developed at the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya in collaboration with Rothamsted Research, UK.

The "push" in the intercropping scheme is provided by the plants that emit volatile chemicals (kairomones) which repel stemborer moths and drive them away from the main crop (maize or sorghum).

There is also an increase of approximately 100-fold in the total amounts of these compounds produced in the first hour of nightfall by Napier grass (scotophase), the period at which stemborer moths seek host plants for laying eggs, causing the differential oviposition preference.

[3] Recent large-scale field studies in East Africa show that maize grown in push–pull systems has higher levels of two benzoxazinoid glycosides, compounds known for their antiherbivore properties.

[7] Desmodium also controls the parasitic weed, Striga, resulting in significant yield increases of about 2 tonnes/hectare (0.9 short tons per acre) per cropping season.

[citation needed] In addition to benefits derived from increased nitrogen availability and competition for light, it was found that D. uncinatum strongly suppresses striga growth through allelopathy.

[8] These effects are thought to be related to isoflavanones produced in Desmodium roots, which can either promote the germination of striga seeds or inhibit seedling growth, depending on their structure.

[3] Other Desmodium species have also been evaluated and have similar effects on stemborers and striga weed and are currently being used as intercrops in maize, sorghum and millets.

[3][10][11][12] Push-pull agriculture leads to beneficial economic outcomes on the level of individual smallholder and subsistence farmers through larger income streams coming from the sale of surplus grain, desmodium seeds, fodder, and milk.

[14] Because push-pull technology was developed mainly outside of Sub-saharan Africa—where international agencies today aim to grow its impact the most—a lack of trust was initially faced.

[15] Push–pull technology was developed at the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya in collaboration with Rothamsted Research, UK.

[3] This strategy is based around the use of locally available plants, not costly industrial inputs, thus making it both more economically feasible and more culturally appropriate as this method is in many ways similar to traditional African practices of intercropping.

[3] For this reason, mass media campaigns have been launched, public meetings held, printed materials disseminated, and farmer-to-farmer and farmer field school programs established in order to overcome knowledge barriers to the implementation of push-pull technology.