Improved Cowpea Varieties and Intensive Cowpea-Cereals Cropping Systems for Enhanced Food Security and Nutrition in the Tropics.

Major cereals and food legumes evolved in pairs such as  ‘wheat-pea’ in the  Middle East; ‘rice-Vigna sp.’ in India; rice-soybean in China; ‘sorghum-cowpea’ in Africa; ‘maize-beans’ in Central America; and ‘cassava-peanut in South America and provided balanced diet to the early settlers who domesticated these crops thousands of years ago. Majority of population in the tropics still depend upon food legumes as a source of protein and minerals in their daily diets.  However, whereas the cereals production has increased manifold, the production of food legumes has remained stagnant causing widespread malnutrition. This is because bulk of the agriculture is now based on the green revolution led cropping systems involving cereals like wheat, rice and maize and food legumes have been pushed to marginal lands. How can the production of food legumes be increased? The only answer is to cultivate short duration food legumes in the existing niches in the cereal systems. The food legumes like chickpea, lentils, pigeon pea, field pea and beans mature in 120 days or more and compete with cereals for land. Therefore, substantial increase in the production of these legumes is not possible. However, cowpea has a maturity range from 60 to 120 days and its extra-early varieties (60-70 days maturity) fit well as a niche crop in various cereals based cropping systems. Through systematic breeding program, a number of photo-insensitive and heat tolerant ‘60-day cowpea’ varieties with pest resistance and erect growth habit have been developed which combine high yield potential with enhanced levels of protein, iron, zinc, calcium and potassium. On-station and on-farm trials of intensive systems involving ‘maize-double cowpea’, ‘sorghum-cowpea’, and ‘millet-cowpea’ strip cropping, and ‘wheat-cowpea-rice triple cropping have shown  up to 300% increase in total productivity compared to the traditional cropping systems.