Yam is a preferred food and a food security crop in some sub-Saharan African countries. Unlike cassava, sweet potato, and aroids, one can store yam tubers for periods of up to 4 or even 6 months at ambient temperatures. Nutritional information Yams constitute a multi-species crop. Though they can be similar in size and shape to sweet potatoes, yams are not as rich in vitamins A and C as sweet potatoes. However yams tend to be higher in protein and minerals like phosphorus and potassium.
Most yams contain an acrid principle that is dissipated in cooking.
D. rotundata and D. alata are the edible species most widely diffused in tropical and subtropical countries. D. esculenta, grown on the subcontinent of India, in southern Vietnam, and in the South Pacific islands, is one of the most nutritious yams. IITA scientists work in collaboration with NARS to ensure that farmers achieve a sustainable increase in the productivity of yam-based systems through the adoption of improved technologies. These technologies include improved varieties as well as strategies for management of pests, soil and vegetation. The available plant genetic resources in IITA's gene banks and elsewhere have contributed to IITA's success in improving yams for farmers to use.