Publicação on-line; 36 ref.; 4 tables; 2 illus.; Summary (En)

ABSTRACT
Background: The use of commercial mix and tank mix with two or more
herbicides is a widespread practice. However, despite its several possible
benefits, little is known about its effect on the behavior of the molecules
in the soil, which can increase or reduce the leaching potential of these
molecules.
Objective: This study evaluated the leaching potential of the herbicides
diuron and sulfentrazone applied, using commercial mix and tank mix, in
soils with different textures.
Methods: The herbicides diuron (1,750 g ha-1) and sulfentrazone
(875 g ha-1) were applied in three soils with different textures (clayey,
medium, and sandy), using a commercial mix (Stone®) and a tank mix
(Herburon 500 BR + Boral®). Subsequently, the treated soils were
reconstituted in soil columns subjected to rainfall simulations with
accumulated rainfall volumes of 40, 80, and 120 mm; the leached
solutions were collected and analyzed by LC-MS/MS.
Results: The results indicated a low descending movement of diuron in
the three soils evaluated, when applied using commercial and tank mixes
with sulfentrazone. Higher rainfall volumes (80 and 120 mm) were
required to increase the diuron movement (≈20% of diuron applied).
Sulfentrazone showed a high leaching potential in the soils, whereas the
tank mix increased the leaching potential in sandy soil with the rainfall
depths of 80 and 120 mm.
Conclusions: The formulations did not affect the leaching potential of the
herbicides in clayey and medium soil. However, the tank mix promoted
greater leaching of the herbicides in the sandy soil when compared to the
commercial mix.


Keywords:
herbicide
leaching
commercial mix
tank mix.