AbstractThe modern varieties of pigeonpea were domesticated from perennial wild species with a tall bushy startue (van der Maesen 1990). Although breeding efforts had been focused on the incorporation of the annual character compatible with the present cropping systems, perennial character persists in the growth habit. The growth feature related to the perennial character is represented by a low early growth vigor (Brakke and Gardner 1987). The lower net photosynthetic rate compared with that of sunflower, cotton, and other legumes at the same leaf age (Rawson and Constable 1981) may account for the slow growth. Although photosynthetic activities are controlled by many factors, including environmental, physical, and chemical factors, allocation of the fixed carbon into either starch or sucrose is one of the regulating mechanisms in photosynthetic pathways (Huber et al. 1990) which directly affects translocation of photosynthates and consequently whole plant growth.