Toxicity of insecticides used in sugarcane crop to the diazotrophic bacteria Herbaspirillum seropedicae

摘要: Although sugarcane crop responds to nitrogen fertilization, especially in ratoon, the use of mineral sources N is one factors great economic impact production. Studies indicate that diazotrophic bacteria can supply part need for this crop. The objective study was identify pesticides used cultivation do not affect growth or cause harm ability biological fixation (BNF) bacterium Herbaspirillum seropedicae. Five insecticides (imidacloprid, fipronil, thiamethoxam, endosulfan and carbofuran) were tested their respective commercial doses regarding on growth. parameters analyzed duration lag phase, generation time maximum cell density. nitrogenase activity H. seropedicae grown semi-solid medium also assessed. Endosulfan carbofuran hindered seropedicae, but did reduce BNF vitro. Carbofuran increased reduced phase its duration. Imidacloprid, fipronil thiamethoxam any toxic effects vitro