AGRONOMIC PERFORMANCE AND PRODUCTIVITY OF SOYBEAN CULTURE WITH CO-INOCULATION OF BRADYRHIZOBIUM E AZOSPIRILLUM BRASILENSE

Abstract

SOYBEAAN IS ONE OF THE MOST IMPORTANT CROPS IN THE WORLD ECONOMY. IN BRAZIL, THE INOCULATION OF SOYBEAN SEEDS WITH ATMOSPHERIC NITROGEN-FIXING BACTERIA IS ESSENTIAL, AND IT DOES NOT REQUIRE THE NEED FOR ADDITIONAL FERTILIZATION WITH NITROGEN, GENERATING AN ECONOMY OF APPROXIMATELY 3 MILLION DOLLARS FOR THE COUNTRY. THE USE OF AZOSPIRILLUM BRASILENSE HAS BEEN USED IN CONJUNCTION WITH BRADYRHIZOBIUM IN ORDER TO OPTIMIZE NODULATION AND GENERATE POSITIVE RESPONSES IN GRAIN YIELD AND QUALITY. THUS, THE OBJECTIVE OF THIS WORK WAS TO EVALUATE THE AGRONOMIC PERFORMANCE AND PRODUCTIVITY OF THE SOYBEAN CULTIVAR CO-INOCULATED WITH THE RHIZOBIUM BRADYRHIZOBIUM AND THE PLANT GROWTH PROMOTING BACTERIUM AZOSPIRILLUM BRASILENSE, APPLIED IN LEAF AREA. THE EXPERIMENT WAS CARRIED OUT AT THE FAZENDA BELA VISTA LOCATED IN THE MUNICIPALITY OF SANTA ISABEL (GO), USING A COMPLETELY RANDOMIZED EXPERIMENTAL DESIGN WITH FOUR REPLICATES, THE DATA OBTAINED WERE SUBMITTED TO ANALYSIS OF VARIANCE AND THE MEANS COMPARED BY THE SCOTT-KNOTT TEST. THE TREATMENTS CONSISTED OF: 1) WITNESS 4 DOSES OF INOCULANT; 2) 4 DOSES OF INOCULANT + 2 DOSES OF A. BRASILENSE; 3) 6 DOSES OF INOCULANT + 2 DOSES OF A. BRASILENSE; 4) 8 DOSES OF INOCULANT + 2 DOSES OF A. BRASILENSE; AND 5) 10 DOSES OF INOCULANT + 2 DOSES OF A. BRASILENSE, THE INOCULANT BEING APPLIED TO 50 KG-1 OF SEEDS AND AZOSPIRILLUM BRASILENSE VIA LEAF WITH DOSE PER HA-1. SEEDING WAS DONE IN DECEMBER 2016, MANUALLY. PLANT HEIGHT; NUMBER OF LEAVES; LEAF AREA INDEX; DRY MASS OF LEAVES, BRANCHES, ROOTS AND NODULES; NODULATION OF PRIMARY AND SECONDARY ROOTS AND SOYBEAN YIELD. IT WAS CONCLUDED THAT: WITH LINEAR INCREASE IN THE DOSAGE OF THE BRADYRHYZOBIUM INOCULANT + 2 DOSES OF A. BRASILENSE, THERE WAS A LINEAR INCREASE OF LEAF AREA AND ROOTS AND THAT THE USE OF AZOSPIRILLUM BRASILENSE SHOWED AN INCREASE IN THE NUMBER OF NODULES PRESENT IN THE MAIN AND SECONDARY ROOTS. FOR GRAIN YIELD, THE DOSAGES WITH 8 AND 10 INOCULANT DOSES PER 50 KG-1 OF SEEDS + 2 DOSES OF A. BRASILENSE SPRAYED IN V2 / V3 PER HA-1, OBTAINED THE BEST SOYBEAN YIELDS.