Publicação on-line; 29 ref.; 6 tables; 1 illus.; Summary (En)

ABSTRACT
Background: The use of electrostatic spray has the potential to optimize
pesticide applications; however, further studies are required to verify its
effectiveness.
Objective: The objective of this work was to evaluate the electrostatic
application system for the chemical control of weeds with glyphosate and
adjuvant in different carrier volumes.
Methods: The physicochemical properties of the spray solution,
charge/mass relations, spray deposition on weeds, losses to the soil,
effectiveness of weed control, and spray drift were evaluated. The field
experiment was designed to have randomized blocks with four
replications in a 2x2x2+2 factorial: the presence or not of electrostatic
spray; with and without adjuvant (soybean lecithin + propionic acid); two
carrier volumes (50 and 90 L ha-1); a control without applications and a
conventional spray rate (150 L ha-1) for additional treatments. The study
was performed in duplicate.
Results: The electrostatic system energized the droplets during the
application of glyphosate and adjuvant; however, this did not influence
the deposition on the weeds, the losses to the soil, and the drift. The
adjuvant improved the effectiveness of weed control in various situations,
changed the spray solution properties, and reduced the losses due to
drift.
Conclusions: The adjuvant used proved to be an important tool in
application technology. The effectiveness of weed control, in general, was
not influenced by the electrostatic system.

Keywords:
spray adjuvant
spray drift
spray rate
glyphosate
physicochemical properties