Experiments were conducted to determine the influence of various factors on asulam {methyl[(4-aminophenyl)sulfonyl] carbamate} toxicity to flax (Linum usitatissimum L.) and wild oats (Avena fatua L. # AVEFA). Asulam toxicity to both flax and wild oats generally increased as temperature, humidity, and soil moisture increased after treatment. Octoxynol {α-[p-1,1,3,3-tetramethyl butyl phenyl]-ω-hydroxypoly(oxyethylene)} in the spray solution increased asulam toxicity to both species in all environments. Octoxynol and trimethylenonypolyethoxyethanol (WK) enhanced asulam toxicity more than other adjuvants evaluated. Asulam toxicity to both flax and wild oats increased as octoxynol concentration in the spray increased. Flax tolerance to asulam generally increased with flax height at treatment. ‘Flor’ flax was the most asulam susceptible of six cultivars evaluated. A 2-mm simulated rainfall within 3 or 6 h after asulam treatment reduced toxicity to wild oats and flax, respectively.
