Rendimento e qualidade pós-colheita de grãos de soja transgênica e convencional, com a utilização de inoculantes e adubação nitrogenada

Abstract

Nitrogen (N) is the nutriente in larger amount absorbed by the soy crop, it can be supplied to the culture by bacteria of the genus Bradyrhizobium, present in inoculants. Worldwide, soybean is the main product for the production of oils, animal feed and even human consumption, so the quality of the grain produced is of extreme importance. Hence, it was aimed with this study to determine the yield, and physical and physiological peculiarity of grains, depending on the use of different types of inoculants and nitrogen fertilizer in transgenic and conventional soy cultivars. It was used block design at random with two cultivars (conventional and transgenic), four repetitions and tested four treatments: 1) peaty inoculant; 2) liquid inoculant; 3) fertilizing with mineral N (240 kg ha-1 N) and 4) without inoculate and without nitrogen fertilizer. The variables analyzed were: productivity (kg ha-1), humidity (%), mass of 1,000 grains (g), real specific bulk (kg m-3), apparent specific bulk (kg m-3), germination (%) and accelerated aging (%). The data were subjected to analysis of variance by F test and averages were compared by Tukey test at 5% probability. The results show that soy inoculation with liquid and peaty inoculants, provided a significant increasing in grain productivity. The conventional cultivar showed higher productivity than the transgenic cultivar. For the conventional soy the peaty inoculant was efficient, since it was noted a greater bulk of 1000 grains and larger actual specific bulk. In turn the inoculant showed high values when assessed in transgenic soy, as it had higher values for the apparent specific and real bulks, number of sprouted grains both in the germination test and the accelerated aging test. Therefore, it can be suggested the use of the conventional cultivar inoculated with peaty inoculant in order to ensure high productivity that may represent an alternative to the use of transgenic soybeans.