Investigations were carried out to study the effect of diflferent concentrations of NAA on nodulation, nitrogen fixation and economic yield in Trifolium alexandrianum L. (berseem). The results showed significant enhancement in nitrogen fixation on treatment with 0.025 mM and 0.05 mM concentrations of NAA, with the latter concentration being more effective. There was also a concurrent increase in nodulation, nitrogen content and related metabolic processes.
