Fungicide application technology for controlling the sugarcane orange rust

ABSTRACT With the epidemic onset of the sugarcane orange rust, fungicide applications of the Strobilurins and Triazoles groups have become necessary in susceptible varieties. This study aimed at evaluating the operational conditions of fungicide application in sugarcane (SP81-3250 variety), in relation to the spray deposition on the upper canopy and the effectiveness of the orange rust control. Treatments consisted of two application volumes (30 L ha-1 or 40 L ha-1) and three nozzle deflection angles (0 º, 90 º or 135 º), plus a ground application at the rate of 200 L ha-1, sprayed with a uniform flat spray nozzle of air induction. The ground application resulted in the smallest and the greatest spray deposition on sugarcane leaves and on the soil, respectively. The aerial application at the rate of 30 L ha-1, sprayed by hollow cone nozzles, at a deflection angle of 135 º, provided the best sugarcane orange rust control.