Phenological changes in photosynthetic rate, transpiration rate and stomatal conductance and their relationship with seed yield in cowpea (Vigna unguiculata (L.) Walp)

Results of field experiment conducted during kharif seasons of 1999 and 2000 under rainfed condition with cowpea genotypes beloliging to different growth habit indicated that the determinate genotypes had higher values of photosynthetic rate (Pn), transpiration rate (TR), stomatal conductance (sq, as compared to indeterminate genotypes. It was also observed that all these parameters were maximum at flowering stage and declined at pod development stage. The genotypes KM-S and KM-4 among the determinate and C-44 and C-22 among indeterminate had higher seed yield and also showed higher values for Pn and SC.