SPRAY ADJUVANT, FORMULATION, AND ENVIRONMENTAL-EFFECTS ON SYNERGISM FROM POST-APPLIED TANK MIXTURES OF SAN 582H WITH FLUAZIFOP-P, IMAZETHAPYR, AND SETHOXYDIM

The effect of adding a spray adjuvant to SAN 582B tank mixtures with f luazifop-P, imazethapyr, and sethoxydim was evaluated. SAN 582H synerg istically increased broadleaf signal-grass control with reduced rates of all three postemergence (POST) herbicides when no spray adjuvant wa s used and when crop oil concentrate was added. For example, broadleaf signal-grass control increased from 50% to 83% when SAN 582H was tank -mixed with 52 g ai/ha sethoxydim and crop oil concentrate. In another experiment, several formulations of SAN 582H, including blank solvent -only formulations (no SAN 582H), were evaluated in combination with a reduced rate of sethoxydim to determine the source of synergism from tank mixtures. The SAN 582H molecule, not the carrier solvents in form ulated product, was determined to be the source of synergism. The syne rgistic properties of SAN 582H were compared to other chloroacetamides , Synergism from acetochlor was similar to SAN 582H when applied POST with a reduced rate of either fluazifop-P, imazethapyr, or sethoxydim for grass control. Metolachlor also synergistically increased the cont rol of grasses with the POST herbicides; however, metolachlor caused c onsiderable phytotoxicity when applied alone and synergistic interacti ons were detected less frequently. The efficacy of sethoxydim mixed wi th SAN 582H was evaluated under different soil moisture conditions. Br oadleaf signalgrass control increased from 81% to 93% under dry, moist ure-stressed conditions when 210 g/ha sethoxydim was tank- mixed with SAN 582H.