Glyphosate for Orobanche aegyptiaca control in Vicia sativa and Brassica napus

Use of glyphosate in controlling Ovobanche aegyptiaca (broomrape), a parasi tic weed on dicotyledonous crops, was examined by determining glyphosate do se response and C-14-labeled glyphosate absorption, translocation, and meta bolism patterns in Vicia sativa (common vetch) that is tolerant of low leve ls of glyphosate and Brassica napus (oilseed rape) that has been geneticall y engineered to be glyphosate resistant. Glyphosate provided excellent supp ression of O. aegyptiaca growth in both V. sativa and B. napus. Absorption and translocation of C-14-glyphosate was similar between parasitized and no nparasitized V. sativa plants. C-14-Glyphosate was metabolized up to 32% in V. sativa, which could account for some of the tolerance of V. sativa to g lyphosate. Approximately 27% of translocated C-14-glyphosate accumulated in O. aegyptiaca attachments on V. sativa. Absorption and translocation patte rns of C-14-glyphosate were similar between parasitized and nonparasitized B. napus plants. Nearly one-third (31%) of the translocated radioactivity w as Found in O. aegyptiaca attachments on B. napus. No metabolism of C-14-gl yphosate was detected in B. napus.