MOACIR RIBEIRO NETO1, ISABEL CRISTINA MENDONÇA CARDOSO JAKOBY, PEDRO HENRIQUE DE MEDEIROS BUSO, MANUEL BERMUDEZ, MARTIN DIAZ-ZORITA AND EDSON LUIZ SOUCHIE
Abstract
This work aimed to establish the contribution of soybean seed inoculation with B. elkanii at sown or anticipated under field crop production in regions of Brazil. Forty five soybean trials were conducted, during six agricultural harvests: 2010/11, 2011/2012, 2012/13, 2013/14, 2014/15 and 2015/16, in three Brazilian States: Goiás, Mato Grosso and Paraná. In each place, four soybean management treatments were established, in a randomized block design, with four repetitions: 1) seeds without inoculation of rhizobia; 2) fertilization with 200 kg ha-1 N at planting, without inoculation of rhizobia; 3) seeds inoculated with rhizobia at planting; 4) seeds with inoculant applied between 30 and 45 days before planting. The plant populations between 15 and 30 days after emergence (DAE) were evaluated, as well as the number of nodules in the main root and the total nodules, at 45 DAE. Pre-inoculation of soybean seeds between 30 and 45 days before planting is as effective as the inoculation of rhizobia at sowing, when combined with the use of fungicides and insecticides. The treatment of soybean seeds with bacterial protection additives is a new alternative to farmers, since providing greater efficiency in the use of machines and labor.