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Does a Diflufenzopyr Plus Dicamba Premix Synergize Russian Knapweed (Acroptilon repens) Control with Auxinic Herbicides?

  • Stephen F. Enloe (a1) and Andrew R. Kniss (a2)


Diflufenzopyr is a synergist that improves broadleaf weed control when mixed with certain auxinic herbicides. In nonagricultural settings, it is only available in a premix with dicamba, which is labeled for noncrop sites, pasture, hay, and rangeland. Our objectives were to determine the influence of diflufenzopyr + dicamba when applied with auxinic herbicides for Russian knapweed control. Studies were conducted near Ethete, WY, from 2005 to 2008 in a pasture heavily infested with Russian knapweed. Treatments were applied in the fall (September) and included aminopyralid, clopyralid, clopyralid + 2,4-D, clopyralid + triclopyr, and picloram at standard and reduced rates, with and without diflufenzopyr + dicamba. At 12 and at 24 mo after treatment (MAT), diflufenzopyr + dicamba did not influence Russian knapweed control when applied with standard rates of aminopyralid, clopyralid, clopyralid + 2,4-D, clopyralid + triclopyr, or picloram. All of these treatments except clopyralid + 2,4-D consistently provided ≥ 80% control 24 MAT. Reduced-rate herbicide interactions with diflufenzopyr + dicamba were also not significant at 12 MAT. However, at 24 MAT, aminopyralid applied with diflufenzopyr + dicamba controlled Russian knapweed 83% compared with 59% when aminopyralid was applied alone. Russian knapweed control with all other reduced-rate treatments, except picloram, fell below 80%. These results indicate that diflufenzopyr + dicamba does not generally improve Russian knapweed control at 12 or 24 MAT with either standard or reduced rates of typical fall, auxinic herbicide treatments.


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Anonymous 2004. Overdrive® herbicide product label. BASF Publication No. NVA 2004-04-078-0262. Ludwigshafen, Germany BASF. Accessed: December 8, 2008.
Anonymous 2008. Curtail® herbicide product label. Dow AgroSciences Publication No. D02-033-014. Indianapolis, IN Dow. Accessed: December 8, 2008.
Bowe, S., Landes, M., Best, J., Schmitz, G., and Graben, M. 1999. BAS 662 H: an innovative herbicide for weed control in corn. Proc. Brighton Conf. Weeds 1:3540.
Enloe, S. F., Kyser, G. B., Dewey, S. A., Peterson, V. F., and DiTomaso, J. M. 2008. Russian knapweed (Acroptilon repens) control with low rates of aminopyralid on range and pasture. Invasive Plant Sci. Manag 1:385389.
Enloe, S. F., Lym, R. G., Wilson, R., Westra, P., Nissen, S., Beck, G., Moechnig, M., Peterson, V., Masters, R. A., and Halstvedt, M. 2007. Canada thistle (Cirsium arvense) control with aminopyralid in range, pasture, and noncrop areas. Weed Technol 21:890894.
Dewey, S. A., Jenkins, M. J., and Tonioli, R. C. 1995. Wildfire suppression—a paradigm for noxious weed management. Weed Technol 9:621627.
Duncan, C. A. and Jachetta, J. J. 2005. Introduction. Pages 17. In Duncan, C. L. and Clark, J. K. Invasive Plants of Range and Wildlands and their Environmental, Economic, and Societal Impacts. Lawrence, KS Weed Science Society of America.
Franssen, A. S. and Kells, J. J. 2007. Common dandelion (Taraxacum officinale) control with postemergence herbicides in no-tillage glufosinate-resistant corn. Weed Technol 21:1417.
Lym, R. G. and Deibert, K. J. 2005. Diflufenzopyr influences leafy spurge (Euphorbia esula) and Canada thistle (Cirsium arvense) control by herbicides. Weed Technol 19:329341.
Ni, H-W., Wehtje, G., Walker, R. H., Belcher, J. L., and Blythe, E. K. Turf tolerance and Virginia buttonweed (Diodia virginiana) control with fluroxypyr as influenced by the synergist diflufenzopyr. Weed Technol 20:511519.
Whaley, C. and VanGessel, M. J. 2002. Effect of fall herbicide treatments and stage of horsenettle (Solanum carolinense) senescence on control. Weed Technol 16:301308.


Does a Diflufenzopyr Plus Dicamba Premix Synergize Russian Knapweed (Acroptilon repens) Control with Auxinic Herbicides?

  • Stephen F. Enloe (a1) and Andrew R. Kniss (a2)


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