"[Push-pull] technology is appropriate and economical to the resource-poor smallholder farmers in the region as it is based on locally available plants, not expensive external inputs, and fits well with traditional mixed cropping systems in Africa. To date it has been adopted by over 96,535 smallholder farmers in East Africa where maize yields have increased from about 1 t/ha to 3.5 t/ha, achieved with minimal inputs. The technology involves intercropping maize with a repellent plant, such as desmodium, and planting an attractive trap plant, such as Napier grass, as a border crop around this intercrop. Gravid stemborer females are repelled or deterred away from the target crop (push) by stimuli that mask host apparency while they are simultaneously attracted (pull) to the trap crop, leaving the target crop protected."
Source: “A Platform Technology for Improving Livelihoods of Resource Poor Farmers,” African Insect Science for Food and Health, last modified 2014, accessed July 31, 2014, http://www.push-pull.net/3.shtml.