What is a "’push-pull’" strategy?
ICIPE and her partners have developed an effective, cheap and environmentally friendly technology known as ‘push-pull’ for the control of stemborers and suppression of striga weeds in maize.
It is a simple cropping strategy, where the farmers use Napier grass and desmodium legume (silverleaf and Greenleaf) for control of stemborer and striga weed in maize fields.
Desmodium is planted in between the rows of maize. It produces a smell that stemborer moths do not like. The smell “pushes” away the stemborer moths from the maize crop.
Napier grass is planted around the maize crop as a trap plant. Napier grass is more attractive to stemborer moths and it pulls the moths to lay their eggs on it. But Napier grass does not allow stemborer larvae to develop on it. When the eggs hatch and the small larvae bore into Napier grass stem, the plant produces sticky substance like glue, which traps them and they die. So, very few stemborer larvae survive and maize is saved in the ‘push-pull’ strategy.
In addition, a ground cover of desmodium, interplanted among the maize, reduces striga weed. It has been shown that nitrogen fixed by desmodium and chemicals produced by the roots of desmodium are responsible for suppressing the striga weed. Therefore, striga does not grow where desmodium is growing.
More stemborer moths are attracted to Napier grass as compared to maize
Napier leaves attacked by stemborer larvae and how the larvae are killed by the sticky substance produced from Napier grass