Absor??o de Subdoses Glyphosate aplicadas em diferentes locais de plantas de eucalipto

摘要

One of the biggest problems faced in reforestation areas with the eucalyptus crops are the weeds, whose management takes an important role among the cultural treatments and with direct responses in income and production costs. Preliminary works of research and field observations indicate a differential tolerance to glyphosate between local (leaves and stems) that this herbicide reaches. In this context, the objective of this work was to verify the intoxication and development of plants submitted to subdoses of glyphosate and its absorption in different application locals in the plant, simulating a drift. The experiment was conducted in a greenhouse, in a factorial arrangement, with four glyphosate subdoses (40, 80, 160 and 240 g ha-1),and three application sites (leaf, stem and whole plant) and a control without application of herbicide. The glyphosate herbicide caused phytotoxicity in the eucalyptus crop, which increased as subdoses increased and with the greater intensity in the applications on the stem and whole plant, reaching 75% at 14 days after application. The gain in height plant and diameter, dry mass in the aerial section and leaf section had significant reductions, which resulted in losses up to 58% in dry mass, 56% in leaf area and a difference by 6 cm in height.