Absorption, Translocation, and Metabolism of Foliar-Applied Imazaquin in Soybeans (Glycine max), Peanuts (Arachis hypogaea), and Associated Weeds

Absorption of foliar-applied14C-imazaquin {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid} 72 h after treatment was higher than 90% for soybean [Glycine max(L.) Merr. ‘Braxton’], peanut (Arachis hypogaeaL. ‘Florunner’), common cocklebur (Xanthium strumariumL. # XANST), sicklepod (Cassia obtusifoliaL. # CASOB), and Florida beggarweed [Desmodium tortuosum(SW.) # DEDTO]. Both symplasmic and apoplasmic translocation of the herbicide were evident. Imazaquin half-life was 4.4 days in soybean, 5.3 days in peanut, 9.6 days in Florida beggarweed, 12.7 days in sicklepod, and 39.8 days in cocklebur. Tolerance of these species to foliar-applied imazaquin as determined in greenhouse studies with 21-day-old seedlings was as follows: soybean = peanut > Florida beggarweed > sicklepod > cocklebur. Tolerance was directly correlated to imazaquin halflife within the tissue of the respective species.