Desmodium is planted as an intercrop between the maize or millet and its smell repels the stemborer moths - Push. The ability of the soil to absorb and store moisture is improved, nitrogen is fixed and so soil fertility is improved. In addition, desmodium decimates the striga weed and so increases yields.
Napier grass is planted as a border crap and it draws the moths away from the field - Pull. The moth larvae then perish on the sticky leaves of the napier grass. Both napier grass and desmodium are also a welcome source of healthy animal fodder.