The relation between growth and leaf nitrogen concentration in Nandi setaria and some other tropical grasses

Abstract

Abstract The relative growth rate of tops (RT) of Nandi setaria (Setaria anceps cv. Nandi), kikuyu (Pennisetum clandestinum). pangola (Digitaria decumbens) and Biloela buffel grass (Cenchrus ciliaris cv. Biloela) in pot experiments was a curvilinear function of the % N in the blades of the youngest fully‐expanded leaves on vegetative tillers (leaf N). The mean RT's differed significantly between grasses, but the response curves did not deviate significantly from being parallel. The mean quadratic curve for vegetative growth of Nandi setaria predicted increasing RT as leaf 11 rises from below 1 to about 3%, and near‐maximum RT between 3 and 6% N.