Twenty-nine diverse genotypes of cowpea (Vigna unguiculata) were grown in approximately 30 photothermal environments in Nigeria and Niger, with mean temperatures ranging from 19° to 30°C, photoperiods from 10 to 16 h d−1 and saturation deficits from 0.5 to 3.1 kPa. Twelve of these genotypes were insensitive to photoperiod. The time of flowering of these photoperiodinsensitive genotypes showed a similar response to temperature. Time to flowering was also delayed by mean pre-flowering saturation deficits greater than 1.5 kPa. The implications of these responses to temperature and saturation deficit for phenological adaptation in West Africa are discussed.
Craufurd, P.Q.; Qi, A.; Ellis, R.H.; Summerfield, R.J.; Roberts, E.H. Development in Cowpea ( Vigna unguiculata). II. Effect of Temperature and Saturation Deficit on Time to Flowering in Photoperiod-Insensitive Genotypes. Experimental Agriculture (1996) 32 (01) 13-28. [DOI: 10.1017/S0014479700025813]