Oxygen uptake and oxidative phosphorylation were inhibited by 10–4 M of α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin) in isolated mitochondria of corn (Zea mays L., var. Dixie 18), Sorghum (Sorghum vulgare Pers., var. Early Hegari) and Soybean (Glycine max L., var. Lee). Little or no inhibition was detectable at 10–5 and 10–6 M in corn and sorghum. Data for 4-(methylsulfonyl)2,6-dinitro-N,N-dipropylaniline (nitralin) were more variable but similar. The effects on these processes do not seem to be related to the selectivity of trifluralin since it caused a greater reduction in oxygen and phosphate uptake in resistant species (soybean) than the susceptible species (sorghum).
