Assigned to the African and Hindustani Centers of Diversity, cowpea or cvs thereof as reported to exhibit tolerance to aluminum, drought, high pH, heat, laterite, low pH, nematodes, poor soil, shade, slope. Distribution Of ancient culture in Africa and Asia, and widespread in Africa, spreading by way of Egypt or Arabia to Asia and the Mediterranean. Now widely cultivated throughout the tropics and subtropics. Wild and cultivated forms readily cross. Can withstand considerable drought and a moderate amount of shade, but is less tolerant of waterlogging than soybean.
Some plants are indeterminant in growth, and continue to grow until killed by frost.
In the tropics, such indeterminate plants may be weak perennials and continue growing as long as conditions are favorable. In some determinate types, the later flower initiation, the higher up the stem it is, the more flowers, and the greater the ultimate seed yield providing the growing season is sufficiently long. Differences of as short as 12 min can affect flowering and seed yield. They tolerate heat and relatively dry conditions and can be grown with less rainfall and under more adverse conditions than Phaseolus vulgaris or P. lunatus. Night temperatures strongly affect many phases of the life cycle and differences in day temperature during reproductive growth markedly affect crop duration and yield.