Journal or Publishing Institution: Crop Protection
Study: http://www.sciencedirect.com/science/article/pii/S0261219404002789
Author(s): dos Santos, J.B., Ferreira, E.A., Kasuya, M.C.M., da Silva, A.A. and de Oliveira Procópio, S.
Article Type: Peer Reviewed Study
Record ID: 544
Abstract: Application of glyphosate to soybean plants, resistant to this herbicide, may be harmful to Bradyrhizobium, the symbiotic bacterium. This study compared the effect of two glyphosate commercial formulations, ZappQi® and Roundup Transorb® with the standard N-(phosphonomethyl) glycine on the growth of four Bradyrhizobium strains under laboratory conditions. Commercial formulations were applied at a concentration of 43.2 μg L−1 of a.e. and the strains were inoculated in yeast extract mannitol (YEM) broth used with or without a mixture of aromatics amino acids (phenylalanine, tyrosine, tryptophan). Herbicide effect on the growth of the Bradyrhizobium strains was assessed by optical density reading in a spectrophotometer. Roundup Transorb® had the biggest effects, probably, because of the presence of ethylamine as a surfactant. Pure glyphosate had minimal effects on Bradyrhizobiumstrains when aromatics amino acids have been added to YEM broth. Glyphosate application as Roundup Transorb® in the initial stage of soybean development may affect the nodulation process by Bradyrhizobium.
Keywords: Adjuvant, Aromatic amino acids, Rhizobium, Laboratory bioassay
Citation: dos Santos, J.B., Ferreira, E.A., Kasuya, M.C.M., da Silva, A.A. and de Oliveira Procópio, S., 2005. Tolerance of Bradyrhizobium strains to glyphosate formulations. Crop Protection, 24(6), pp.543-547.
