Experiments were conducted to determine the effect of triglycerides, free fatty acids (FFA), and fatty acid methyl esters (FAME) on the foliar absorption, translocation, and phytotoxicity of quizalofop. Absorption, translocation, and phytotoxicity of quizalofop in oats were greater when quizalofop was applied with FFA or FAME than with their respective triglycerides. Triglycerides and FFA generally enhanced quizalofop absorption and translocation more when they contained unsaturated than saturated fatty acids. Methylation of the fatty acids reduced differences among fatty acids, but methyl stearate and methyl linolenate enhanced absorption of quizalofop less than the other FAME for oats and yellow foxtail. Quizalofop absorption and phytotoxicity to oats were greater when applied with sunflower oil, sunflower oil FFA, and sunflower oil FAME than with the corresponding linseed oil derivatives. Emulsifier generally reduced differences between linseed oil and sunflower oil derivatives in their enhancement of absorption, translocation, and phytotoxicity of quizalofop.

Adjuvants were evaluated to determine the effect on increasing spray droplet size and reducing the amount of spray dispensed in small driftable size particles when applying water and paraffinic oil at ultralow volume. Spray solutions were applied with an air-assist system at liquid flow rates of 28 and 56 ml/min and atomized with 14, 28, 42, 56, and 84 kPa of air pressure. Water and paraffinic oil were applied alone and with two drift retardant adjuvants mixed individually in each. The two water soluble adjuvants were mixed at concentrations of 0.25, 0.50, 0.75, 1.0, and 2.0%; oil soluble adjuvants were applied at 0.125, 0.25, and 0.50%. Adjuvants used in water and oil were effective at increasing droplet size and reducing the amount of liquid dispensed in small driftable size particles. Effectiveness of the adjuvants decreased as air pressures increased, with water soluble adjuvants being more susceptible to air pressure. Volume median diameters > 200 μm with water could be achieved without adjuvants; whereas with oil, an adjuvant was required.

Spray droplet size of water and paraffinic oil was affected by air pressure, nozzle type, and liquid flow rate when applied with an ultralow volume (ULV), air-assist sprayer. Volume median diameters of water were generally larger than oil at constant air pressure and liquid flow rate. Droplet size decreased as air pressure increased, but increased as liquid flow rate increased. Volume median diameters of water droplets ranged from 41 to 838 μm and from 16 to 457 μm with oil when atomized at air pressures ranging from 14 to 84 kPa. Relative spans ranged from 1.2 to 18.0 and 2.0 to 7.2 for water and oil, respectively.