Inoculação com azospirillum brasilense e adubação nitrogenada em cultivares de trigo

Abstract

Wheat (Triticum aestivum) is the second largest world production of grains, with great importance in food and feed. It needs more technologies that provide productivity increases at low cost. A newly available technology for the wheat crop is the seed inoculation with growth promoting bacteria and atmospheric nitrogen fixing. The study was divided into two chapters, the first to evaluate the influence of inoculation and its interaction with the chemical seed treatment on germination, vigor and initial growth of wheat cultivars. To this end, we conducted an experiment in Didactic Laboratory and Seeds Research in UFSM in 2013. The second chapter aimed to verify the contribution of Azospirillum brasilense bacteria for biological nitrogen fixation on yield components in the culture wheat in different cultivars, management of nitrogen fertilization, local, sowing dates and years of cultivation. For this, experiments were conducted in the years 2013 and 2014 in Santa Maria and Cruz Alta cities. Inoculation promoted the increase of the dry mass of wheat seedlings in cultivars FUNDACEP Bravo, TBIO Itaipu and BRS 331, seven days after sowing, not affecting the other variables. The chemical treatment of seeds with fungicide triadimenol reduced germination, emergence and early growth of wheat seedlings. Inoculation had a positive response to productivity and hectoliter mass (HM) in some cultivars, with a maximum increase of 21% productivity in genotype TEC 07-244, the second sowing date 2014, in Cruz Alta. For HM, there were significant increases, especially during 1, 2013 in Santa Maria, where the average was 75,6 and 77,2 kg hL-1, for non-inoculated and inoculated, respectively. The nitrogen was important to improve the yield of wheat components, providing great increases in productivity, with better increments per kg of N applied at the rate of 50 kg N ha-1.