COMPARING TECHNIQUES FOR QUANTIFYING HALOXYFOP ABSORPTION AND TRANSLOCATION IN JOHNSONGRASS (SORGHUM-HALEPENSE)

In comparing laboratory techniques, absorption and translocation of C- 14-haloxyfop was not affected by droplet size or treatment area. Treat ment with haloxyfop prior to application of C-14-haloxyfop resulted in 27% less translocation of radiolabel from the treated leaf and 43% le ss acropetal translocation compared with plants receiving only the rad iolabeled herbicide. Leaf washing with distilled water, distilled wate r plus haloxyfop, distilled water plus surfactant, distilled water plu s haloxyfop plus surfactant, 100% ethanol, 100% methanol, or methanol: water (1:1 v/v) removed similar amounts of radiolabel, while chlorofor m removed more. Considering some of the differences found with these t echniques, pretreatment with nonlabeled herbicide should be routine pr actice and water used as the standard solvent.