Compatibility among fungicide treatments on soybean seeds through film coating and inoculation with Bradyrhizobium strains

Abstract

This research evaluated the development of soybean plants grown in a greenhouse, from seeds that were treated with fungicide, film coated and inoculated with Bradyrhizobium. Seeds from the soybean cultivar ‘Vencedora’ were submitted to treatments disposed in a factorial 5 x 3 x 2 design. The seeds were treated with Derosal Plus® with polymer; Tegran® with polymer; Derosal Plus® without polymer, Tegran® without polymer; and without fungicide and without polymer. After the chemical treatment, the seeds were inoculated with peat or liquid inoculants, and without inoculant. The chemical treatments were used either previous to or after the six months of storage. Seed inoculation was performed with CPAC15 and BR29 strains, immediately before sowing in Leonard pots (two seedlings per pot). The plants at R2 stage were evaluated through the number and dry matter weight of nodules, the shoot dry matter weight, and the chlorophyll content. The results indicated that the treatments with Derosal Plus or Tegran-associated or not with the polymer, and independent of the application time-did not affect nodule establishment and development, or nitrogen fixation when the seeds were inoculated. Liquid and peat inoculants applied to the seeds were equally efficient in the formation of nodules in soybean plants; however, the liquid inoculant promoted higher shoot dry matter weight.