Agricultural pesticide application technology is largely improved by reduction of waste and losses. With such objective, an experiment was conducted in order to evaluate the efficacy of a post-emergence contact herbicide applied with and without air-assisted sleeve boom in different spray volumes. The experiment was carried out in Ponta Grossa county, in a no-till black oats cover crop (Avena strigosa Schreb). The formulated mixture (SC) of paraquat and diuron at 400 + 200 g a.i ha-1 was applied with a sleeve boom sprayer, with and without air-assistance and five spray volumes: 0; 100; 200; 300 and 400 L ha-1. Treatments were placed in a 2 x 5 factorial arrangement in a randomized complete block design with four replications. Herbicide efficacy was evaluated by the ALAM rating system. Efficacy of paraquat + diuron sprayed at 100 L ha-1 without air-assistance was higher than the check treatment but significantly lower when compared to other herbicide treatments. Weed control efficacy with 100 L ha-1 and air-assistance was equivalent to the other carrier volumes. No significant differences were detected among the 200 to 400 L ha-1 carrier volumes, neither their interaction with and without air-assistance.
no-till; application technology; carrier volume
