COMPATIBILITY OF INSECTICIDES THIAMETOXAM AND IMIDACLOPRID WITH Bradyrhizobium

Abstract

Protection against pests and diseases, carried out through the application of phytosanitary products of chemical origin on seeds, can affect the biological fixation of N2, which is why this work aimed to evaluate the effect of the insecticide Cruiser 700 WS (thiamethoxam) on the nodulation in soybean plants of the IAC 18 cultivar. The experiments were carried out in a greenhouse. Soybean seeds were treated with Cruiser at the following concentrations: (50, 100 and 200g / 100Kg seeds) and with Gaucho (Imidacloprid - 200g / 100Kg seeds). After chemical treatment, the seeds were inoculated with the strains SEMIA 5079 (CPAC 15) and SEMIA 5080 (CPAC 7), components of the BIOMAX® product at the recommended concentration of 250g / 100Kg of seeds with at least 1x109 viable cells/g . The treatments that served as controls were represented by seeds inoculated with Bradyrhizobium and without inoculation. Three hours after preparing the material, the seeds were placed in pots (3 per pot) containing low fertility soil. After ten days, thinning was carried out, leaving only one plant per pot and after 45 days, the plants were removed from the soil to determine the number of nodules. Throughout this period, the plants were irrigated when necessary. The data were subjected to analysis of variance and the means were compared using the Tukey test at a 5% probability level. The insecticides tested, regardless of concentrations, did not affect nodulation.