Partitioning and utilization of carbon and nitrogen for dry matter and protein production in chickpea (Cicer arietinum L.)

Abstract

The partitioning of N and utilization of C in various processes in chickpea (Cicer arielinum L.) was studied at 10 d intervals from 35 to 135 d after sowing (DAS). Dry matter, C and N content of the plant increased throughout the study period. The maximum amounts of C and N were fixed during the flowering and early fruiting phase (75-115 DAS) and the minimum during the seed filling phase (115-135 DAS). Efficiency of nitrogen fixation in relation to net C utilization and respiratory output of the whole plant, nodules and nodulated root, varied widely, but was maximum during 75-115 DAS. The crop experienced severe respiratory losses, particularly during the vegetative phase, when 83% of the total fixed C was lost in respiration. The crop produced 54.6 g of glucose units, 2.36 g of seed dry matter and 495 mg of seed protein. Possible reasons for the poor efficiency of chickpea, in terms of photosynthate utilization for dry matter and protein production are discussed.