Improvement of growth, under field conditions, of wheat inoculated with Pseudomonas chlororaphis subsp aurantiaca SR1

Effects of inoculation of wheat (Triticum aestivum L.) with the rhizobacterium Pseudomonas chlororaphis subsp. aurantiaca strain SR1 (termed SR1) were studied at an experimental field site in Rao Cuarto, Argentina. Treatments involved SR1 inoculation with or without nitrogen/phosphorus fertilization. Inoculation produced a significant increase in plant height and root length in early growth stages. Inoculation plus fertilization with 40 kg ha(-1) urea/30 kg ha(-1) diamonic phosphate ("50% dose") gave a yield increase of 636 kg ha(-1) relative to control, and an increase of 472 kg ha(-1) relative to fertilization with 80 kg ha(-1) urea/60 kg ha(-1) phosphate without inoculation. SR1 inoculation without fertilization, compared to control, produced increases of 6% in weight of 1,000 grains, 13% in number of spikes per plant, and 30% in number of grains per spike. Inoculation plus 50% dose fertilization also improved these parameters. Results of the study indicate that inoculation of wheat with SR1 improves various growth and yield parameters, and allows reduced dosage of nitrogen/phosphorus fertilizers in the field.