Absorption and Translocation of Sethoxydim with Additives

Experiments were conducted to determine 14 C absorption and translocation by oat ( Avena sativa L. ‘Lyon’) foliarly treated with 14 C-sethoxydim {(2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one)} and various additives. Safflower ( Carthamus tinctorius L.), soybean [ Glycine max (L.) Merr.], linseed ( Linum usitatissimum L.), and sunflower ( Helianthus annuus L.) oil all similarly increased foliar absorption and translocation of 14 C more than palm oil ( Elaeis quineensis Jacq.) but less than petroleum oil, when applied without an emulsifier. An emulsifier in the oil additive tended to enhance 14 C absorption and translocation more in soybean oil than petroleum oil so that 14 C absorption and translocation were similar with both oils containing emulsifiers. Absorption and translocation of 14 C tended to increase more with an increase in emulsifier concentration in soybean oil than in petroleum oil but not beyond 15% with either oil. Percentage of 14 C absorbed and translocated from 14 C-sethoxydim applied to oats increased as the amount of soybean oil applied increased from 2.3 to 4.6 L/ha, but the increase was less for sethoxydim at 0.87 kg ai/ha than at 0.03 or 0.17 kg ai/ha.