Aplicação de cobalto e molibdênio na cultura da soja

Abstract

The elements cobalt (Co) and molybdenum (Mo) are micronutrients of great importance for legumes, since they play a fundamental role in the fixation of atmospheric nitrogen assimilated by bacteria of the genus Bradyrhizobium. The objective of the present study was to evaluate the yield components of soybean as a function of different doses and time of application of cobalt and molybdenum via leaf. The experiment was conducted at the Celeste farm, located on the banks of BR - 163 in the municipality of Vera - Mato Grosso. The treatments consisted of the combination of five doses of the micronutrient (0, 50, 100, 150 and 300 mL ha -1 ) with two phenological application periods (V5, fifth node and fourth trifoliate flower and R2, full flowering), totaling 10 treatments. The agronomic characteristics evaluated were: dry mass of the nodules, number of nodules, number of pods per plant, grains per pod, mass of 100 grains and productivity. It is concluded that under the conditions of this experiment, the application of cobalt and molybdenum via leaf in V5 and R2 does not alter soybean nodulation. The application in the reproductive period (R2) provides a greater number of pods per plant and number of grains per pod, but does not affect productivity