Absorption, translocation, metabolism, and mode of action of buthidazole (3-[5-(1,1-dimenthylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone) as related to its selectivity between corn (Zea mays L.) and redroot pigweed (Amaranthus re...