Crescimento e concentração de nutrientes na parte aérea de eucalipto sob efeito da deriva do glyphosate

Abstract

Glyphosate is often used to control weeds in eucalypt plantation, but it may cause plant intoxication because of drift, and the symptoms may be similar to those of some nutrients lack. This study aimed to evaluate eucalypt growth and nutrients concentration in aerial tissue under effect of simulated drift of glyphosate. It was applied 0; 43.2; 86.4; 172.8; 345.6 and 691.2 g ha-1 of glyphosate equivalent acid 60 days after planting. The percentage of intoxication in relation to the control was evaluated 7, 15, 30 and 50 days after application (DAA), and plant height and stem diameter were obtained 50 DAA. To determine concentration of P, K, Ca, Mg, Zn, Fe, Mn, Cu and B, leaves from apical and medium portion were collected in each plant, and the rest of ground tissue of the plants were used to determine dry biomass. Plants submitted to 86.4; 172.8; 345.6 and 691.2 g ha-1 of glyphosate showed symptoms of intoxication by herbicide and plants submitted to 345.6 and 691.2 g ha-1 showed high content of Ca, Mg, Fe, Mn and B in leaves. The results indicated that there is no relation between symptoms of intoxication by glyphosate and the lack of nutrients in eucalypt, but specific studies need to be driven for a better understanding of the effect of the glyphosate on the nutrients of the soil and in the plants.