Co-inoculação de Bradyrhizobium japonicum e Azospirillum brasiliensis em diferentes cultivares de soja

Abstract

Recently the researches have verified beneficial effects in the co-inoculation of soybean plants with associative diazotrophic bacteria of the genus Azospirillum and with associative symbiotic bacteria of the genus Bradyrhizobium. However, several results are contradictory, and it is noticed that many of these alter the cultivars used, disregarding that this may be a factor that interferes with the result. Therefore, the objective of this work was to verify if the efficiency of co-inoculation is altered between different soybean cultivars. The experiment was carried out in a rural property, located in the municipality of São Luiz Gonzaga-RS, and implanted in a commercial agricultural field, under no-tillage system installed at fifteen years, having a history of inoculation with Bradyrhizobium. The experiment was conducted with a randomized block design with subdivided plots, with three replicates. The treatments consisted of five soybean cultivars (BMX Garra, Monsoy 6410, Nidera 6909, BMX Ponta, TMG 7063), forming the plots and two conditions of co-inoculation (with Bradyrhizobium and Azospirillum, and without Bradyrhizobium and Azospirillum). subplots. Sowing was performed on November 20, 2017. The height of plants in stage V5 and R3 was evaluated, counting the number of pods of two and three grains and subsequent analysis of the total dry mass of the shoot. The experiment was performed on April 14, 2018. The data were statistically analyzed by means of analysis of variance, with the help of the sisvar program, comparing the means by the Tukey test at a probability level of 5%. Co-inoculation showed efficiency for the Monsoy 6410 cultivar, increasing its productivity by 914 kg ha-1, in relation to the same cultivar without co-inoculation.