NITROGEN AND DRY-MATTER ACCUMULATION IN W HEAT PLANTS INOCULATED WITHAZOSPIRILLUM-BRASILENSE

Aiming at assessing the effect of inoculation with two strains of Azos pirillum brasilense, 245 and JA04, under the forms of powder and granu late inoculant on dry matter production, total N accumulation, and gra in production of wheat plants of cultivar BR 23, a trial was carried o ut under field conditions. Inoculated treatments and inoculated treatm ents plus 15 kg N.ha(-1), absolute control, and 60 kg N.ha(-1) (15 kg N.ha(-1) at sowing and 45 kg N.ha(-1) at tillering) were distributed i n blocks at random with four replications. Dry matter and total N accu mulation, as well as grain production, were evaluated 20 days after an thesis and at maturity. Straw biomass variation between both evaluatio ns was positive for all inoculated treatments, while such variation wa s negative in the non-inoculated treatments, indicating straw biomass accumulation instead of loss in the treatments with inoculation. Inocu lation promoted a greater absorption of N at post-anthesis stage perio d, in which a higher availability of N did not contribute to an increa se in grain production. Powder peat inoculant of strain JA04, plus 15 kgN.ha(-1) at sowing, replaced nitrogen fertilization of 45 kg N.ha(-1 ), applied as topdressing, without any negative effect on yield.