VENTURELLI, Leonardo.; TESOURO, Omar.; MASIÁ, Gerardo.; FUICA, Adriana.
Resumo:
The aim of this work was to study the influence of coverage percentage, obtained by
using different spray nozzles, in glyphosate efficiency on weed control. Three nozzles models were
used: flat fan to 3 bar, low drift conventional to 3 bar and low drift air induction to 5 bar. It was
applied a carried volume equivalent to 45 L ha-1 and four glyphosate doses (SL 48%): 0.5, 1.0, 1.5 and
2.0 liters of product formulated by hectare, with three replications by treatment. It was measured the
coverage on leaves and water sensitive papers and also dead plants (Bromus unioloides HBK). The
results were analyzed statistically by means of analysis of variance with a factorial design. The
effectiveness of the evaluated spray nozzles varied according to the used dose of glyphosate. The
larger number of dead plants was obtained with the smaller plaguicide concentration using the air
induction nozzles that has a distribution spectrum with greater size of drop. Nevertheless, with the
higher doses, the results were similar in all the cases. It can be established a close relation between
dose, coverage and droplet size. The plants mortality only increases when low dose and bigger
droplets size are used.
