Eficácia de uma nova formula??o de glifosato para o controle de grama-seda (Cynodon dactylon), em pomar de citros.

摘要

The aim of this experiment was to evaluate the performance of the potash glyphosate formulation, compared with sulphosate and aminic glyphosate formulation, used with commercial patterns, applied in orange orchard of Pera-rio variety, on the bermudagrass The experiment was conducted in Taiúva - SP, on ultisol. The treatments were: potash glyphosate (ZAPP Qi) at 1.05, 2.10 and 2.50 Kg a.e./ha, sulphosate (ZAPP) and aminic glyphosate formulation (ROUNDUP CS) at 1.98 and 2.16 Kg a.e./ha, respectively, along writh the control without weed. The herbicides were applied in postemergency with costal sprayer, constant pressure (2,5 kg/cm2), with six nozzles DG 11002. The equivalent spray volume was 200 L/ha. The best results were obtained with 2.50 kg a.e./ha rate of potash glyphosate guarantying smaller regrowth of the bermudagrass. However, the 2.10 kg a.e./ha rate guarantied as good control as sulphosate at 1.98 and glyphosate at 2.16 kg a.e./ha.