The absorption, translocation, and metabolism of the methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} by three sunflower (Helianthus annuus L.) lines was determined at 10 and 30C. Sunflower absorbed up to 27% more 14C-diclofop while growing at 30C and 90 ± 5% relative humidity (RH) than at 10C and 40 ± 10% RH. Absorption of diclofop by susceptible (170415) and tolerant (296292 and Hybrid 894) sunflower lines was similar. Translocation of 14C out of the treated sunflower leaf was greater at 30 (1.3%) than 10C (0.5%) 192 h after treatment when averaged across sunflower lines. The diclofop-susceptible line exported more of the applied diclofop from the treated leaf to the shoot portion below the treated leaf than the tolerant lines. Metabolism of diclofop was more rapid at 30 than 10C; however, the three sunflower lines metabolized diclofop similarly.
