(From International Agricultural Development, Jan/Feb 1994.) Chickpea leaves and pods exude extremely acidic (pH 2) droplets which repel most pests from attacking the plant. But recently the pod borer, which eats the contents of the pods, has become tolerant to the acid and has devastated crops in Asia. Pod borers have become resistant to many insecticides, and biological control is difficult because beneficial insects do not tolerate the acidic conditions.
Scientists at ICRISAT are breeding low-acid chickpeas and recommend wider planting which gives birds (like cattle egrets) paths to walk through the field to eat the caterpillars. Another creative way to control the pest is to intercrop the chickpeas with coriander, a commercial spice crop. Coriander has an umbel flower (like carrots or Queen Anne’s Lace) which serves as a “platform” for predator insects to enjoy nectar and sun and an acidfree home from which they can attack the pod borer. Research showed that using these techniques enables Indian farmers to quadruple their chickpea yields.