Carry-over of granular and emulsifiable concentrate formulations of trifluralin in Saskatchewan

Abstract

The field persistence of trifluralin from fall treatments of both emulsifiable concentrate (EC) and granular formulations was investigated at two sites in Saskatchewan over a 2-yr period. At both locations, there were no significant differences (P = 0.05) in trifluralin persistence from fall applications of either formulation. In addition, the carryover of trifluralin residues in farmers’ fields following fall and spring applications of EC and granular formulations was monitored at several Saskatchewan locations to determine their persistence under typical farming practices. Trifluralin residue data indicated that following fall applications, the percent carry-over to the first spring was 83 ± 21(15 fields sampled) and 37 ± 15 (28 fields sampled) to the second spring; and that following spring applications, the percent carry-over to the next spring was 33 ± 12 (14 fields sampled). Key words: Field studies, persistence, formulations, trifluralin, herbicide