Efeito do tratamento das sementes de soja com fungicidas e período de armazenamento na resposta da planta inoculada com Bradyrhizobium

Abstract

Chemical treatment and seeds inoculation with Bradyrhizobium are used frequently in soybean, however the interaction between these practices can reduce nitrogen biological fixation, plants growth and development. The aim of this study was to evaluate the response of soybean seeds treated with fungicides, with or without polymer, in two storage periods and inoculated with Bradyrhizobium using liquid or peat inoculant. Seeds were treated with: carbendazin + thiram or thiabendazole + thiram by film coating or without polymer, either previous to or after the six-month storage. At sowing the seeds were treated with peat or liquid inoculants, both containing strains of nitrogen fixing bacteria, Bradyrhizobium (SEMIA 5079 and SEMIA 5019), or were sown without inoculant. A randomized complete blocks design with three replications was used; nodules, chlorophyll content and pod number were evaluated. The inoculation of soybean seeds with peat inoculant revealed higher nodules number. The fungicides carbendazin + thiram and thiabendazole + thiram, independently of film coating, reduced the nodules number and carbendazin + thiram by film coating reduced the pod number in soybean plants.