Effectiveness of herbicides isolated or in mixture in control of the exotic plant invasive Urochloa subquadripara

Abstract

The objective of this study was to evaluate the efficacy of glyphosate, saflufenacil, imazamox, imazapyr and penoxsulam alone or in combination in the control of Urochloa subquadripara. To do so, in greenhouse, five plant pointers were transplanted into 2.5 liter boxes containing 5.0 cm of soil, washed coarse sand and organic compound (1:1:1; ratio). After 30 days, the herbicides with costal sprayer were applied at a constant pressure of 25 p.s.i. maintained by CO2, with consumption of syrup equivalent to 200 L ha-1. The evaluations were performed through efficacy notes at 3, 7, 15, 21, 30, 45 and 60 days after application (DAA). The herbicides glyphosate and imazamox, isolated, showed excellent control (100%) of U. subquadripara, whereas imazapyr and penoxsulam (48.0 g ha-1) presented satisfactory control with 80 to 85% control efficacy. The herbicides glyphosate, imazamox and imazapyr (isolated and mixed), saflufenacil + glyphosate (mixture) and penoxsulam + glyphosate (mixture) can be used in management programs of this invasive aquatic plant.