ADUBAÇÃO COM BORO E ZINCO NA CULTURA DO MILHO

Abstract

The work aims to evaluate the effect of boron (B) and zinc (Zn) on corn under field conditions to determine the best dose of B for application in the planting line. The experiment was carried out at Fazenda Escola do Instituto Federal Goiano, Campus Iporá, in Iporá-GO, it used a randomized block experimental design, in a 6x2 factorial scheme, corresponding to six doses of B applied, without and with Zn fertilization, both performed at sowing. The B and Zn sources used were boric acid and zinc sulfate, respectively, and the corn hybrid MG711 PW. Each experimental plot consists of five lines of 4.0 m, spaced 0.5 m apart. When 50% + 1 of the plants reached the phenological stage R1 - growth and pollination, the growth variables were evaluated: stem diameter and plant height, together with the chlorophyll SPAD index. In the phenological stage R6 - physiological maturation, 20 ears were collected per plot to determine ear length, thousand grain mass and productivity. The maximum efficiency dose determined by adjusting the equation of degree two to estimate the maximum efficiency had its results subjected to analysis of variance and means were compared by Tukey test, for comparison of the fertilization means, without and with Zn, and regression equations for the effect of B doses. There is an interaction between B and Zn in the fertilization of corn grown in soil with a sandy loam texture and low levels of these micronutrients, when 1.0 kg of B and 2.0 kg of Zn ha-1 were applied, with an increase in productivity. The doses of maximum technical efficiency for grain yield are 3.29 and 4.31 kg of B ha-1 for treatments without and with Zn fertilization, respectively.