Produtividade com sementes pré-inoculadas de soja em períodos antes da semeadura

ABSTRACT-The practice of inoculation of soybean seeds with nitrogen-fixing bacteria represented a major advance in crop production, such as those of the genus Bradyrhizobium that are able to capture existing nitrogen in the atmosphere and convert it into N assimilable by plants. The pre-inoculation, which consists in inoculating the N-fixing bacteria in seeds with greater precedence to sowing, is a practice already used in some countries. However, the use of this technique depends on the ability of the bacteria to survive in the seeds and the type of treatment performed in the benefit. The objective of the study was to determine the "ideal" time between inoculation and sowing in soybean culture. The cultivar used was M 8372 IPRO, and pre-inoculation was done at five different dates; 1, 4, 6, 7 and 8 days before sowing. The experimental delineation was entirely casualised with four repetitions. The foliar area, chlorophyll content, number of leaves, number of grains per vage, weight of 1,000 grains and yield were determined. With the analysis of the results there was a difference in some characteristics. No statistical differences were observed between the production of treatment without inoculation with the rest, however, there were gains of up to 700 kg/ha with the inoculant, showing that pre-inoculation can bring economic gains if performed correctly.