Further observations on the utility of N2-fixing micro-organisms in the phyllosphere of cereals

Abstract

SUMMARYThe utility of spraying some Na-fixing micro-organisms on rice (cv. Masuri and IR-26) and wheat (cv. Sonalika) leaves grown both in N2-less sand culture and under field conditions was examined. All the growth variables studied, including dry weight, chlorophyll content and N content of plants, were enhanced appreciably in N-less sand culture and under field conditions. The yield of rice cv. IR-26 per unit area was more than doubled or nearly so with Pseudomonas azotocolUgans, Ps. azotogensis, Klebsiella pneumoniae KUPBR2, K. pneumoniae KUP4, KUP6D, KUP7D, Azospirillum brasilense, Xanthobacter fiavus and K. rubiacearum. When rice cv. Masuri was used the grain weight was doubled by A. brasilense, Ps. azotocolUgans, Ps. azotogensis, KUPBR2, and KUP6D. Grain N content was increased appreciably in mostcases. The organisms also reduced acetylene to ethylene in the phyllosphere. In wheat cv. Sonalika grown in N-less sand culture, KUP4, KUPBR2, Ps. azotocolligans, A. brasilense, X. flavus, and KUP6D each doubled the N content of plants. Under field conditions Ps. azotocolligans gave the highest grain yield although grain yield was doubled by a large number of strains. N content of grains was also increased appreciably, the best result being given by KUP4.