Efeito de diferentes formula??es de glifosate no manejo de plantas daninhas na cultura do cafeeiro

摘要

An study was carried out in a commercial one-year-old coffee crop following undercutting, aiming to evaluate the efficiency of different glyphosate salts, that is, potassic, isopropylamine and diamonium in managing weeds in coffee tree crop. The treatments consisted of 10 different managements corresponding to three sequential applications of herbicides, that could be performed with or without the same products. The control efficiency of the weed species were verified at 15, 30, 41, 58, 75, 84, 116 and 140 days after beginning the management (DAM). The management with sequential application of 720 g.ha-1 ac.eq. of potassic salt glyphosate and diamonium salt glyphosate, as well as the management with diuron and paraquat (150 + 300 g.ha-1 a.i., respectively, with added Agral 0.1% v/v) at the third application or at the second and third applications, with the second application performed at 41 days after the first application, and the third one at 54 days after the second application, were all efficient in controlling Brachiaria plantaginea and Bidens pilosa, but inefficient in controlling Euphorbia heterophylla and Commelina diffusa. The management with 720 g.ha-1 ac.eq. of isopropylamine salt glyphosate at the first application, and latter at the second and third ones with the tank mixture of 720 g.ha-1 ac.eq. of isopropylamine salt glyphosate + 30 g.ha-1 a.i. of carfentrazone-ethyl, showed to be effective in controlling Brachiaria plantaginea and Bidens pilosa from 7 to 140 DAM and the Commelina diffusa from 58 to 140 DAM. However, Euphorbia heterophylla were moderately controlled over this period.