Upto three quarter of Kenyan farmers grow cereals for subsistence and commercial purposes. Yet 60 percent of their yields are lost to a voracious pest named stem borer. The moth like pests eats up entire leaf little by little. Young caterpillars feed on the tender leaves of the plant. They later feed at the growing point into the stem. Seriously attacked plants dry-up entirely or partly showing the so-called ‘dead heart’ symptom.
Early attacked plants are stunted in growth and the ears are poorly developed. Farmers have used dozens of pesticides to no avail. However a new low cost technique is now wiping the pest completely and increased maize yield six fold. The technique is called Push pull. All a farmer needs is to intercrop certain unique forage plants with cereals, which act as both a trap and a repellent for stem borers
The two plants being used are napier grass, which attracts the moths, and desmodium, which produces chemicals that repel stem borers.
The desmodium produces a scent that repels (push) the stem borer. The borer then gets attracted by the nappier grass scent and they lay eggs on the grass rather than on the maize stalk.
At the same time, the napier grass produces a sticky gel that traps the stem borer larvae on hatching. The effect is a significant reduction of larvae that would otherwise have matured to adulthood and attacked the maize and other cereals.
The napier grass is planted around the maize field to form a perimeter. The desmodium fodder is planted side by side with the maize.