Young, B.G., Bradley, K.W., Bernards, M.L., Hager, A.G., Hartzler, B.G., Johnson, W.G., Loux, M.M., Peterson, D., Sprague, C.L., Slack, C., Ott, E.J., Refsell, D., Dale, T.M., Cranmer, J.R., Kirfman, G.W. and Pawlak, J.A. (2010) Length of Residual Weed Control with V-10266 and Other Preemergence Soybean Herbicides. Proceedings of the North Central Weed Science Society, Lexington, 13-16 December 2010.

has been cited by the following article:

• TITLE: Two-Pass Weed Management with Preemergence and Postemergence Herbicides in Glyphosate-Resistant Soybean

  AUTHORS: Nader Soltani, Robert E. Nurse, Peter H. Sikkema

  KEYWORDS: Biomass, Weed Density, Glyphosate, Profitability Analysis, Soybean

  JOURNAL NAME: Agricultural Sciences, Vol.5 No.6, May 19, 2014

  ABSTRACT: There is little information on the efficacy and profitability of two-pass weed control strategies in soybean when a preemergence (PRE) residual herbicide is followed by glyphosate applied late postemergence (LPOST) under Ontario, Canada environmental conditions. Ten field trials were conducted during 2011-2013 in Ontario, Canada to determine the level of weed control, yield and net returns of various preemergence/postemergence programs in glyphosate-resistant soybean. Crop injury was 2% or less with the herbicides evaluated except for chlorimuron + flumioxazin (PRE) and pyroxasulfone + flumioxazin (PRE) which caused 4% and 7% visible injury in soybean, respectively. A single application of glyphosate resulted in variable weed control (73% - 98%) while the sequential application of glyphosate provided excellent weed control (98% - 100%). The control of all weeds 8 WAA after the LPOST glyphosate application was equivalent regardless of the PRE herbicide applied (96% - 100%). Soybean yield was equivalent to the weed free control regardless of the PRE herbicide applied. Soybean yield was lower than the sequential application of glyphosate with chlorimuron or pyroxasulfone/flumioxazin PRE fb glyphosate LPOST. Generally net return with the two-pass programs was equivalent to the sequential application of glyphosate. Net returns were lower than the sequential application of glyphosate with chlorimuron or s-metolachlor + flumetsulam followed by glyphosate LPOST. Based on these results, a sequential application of glyphosate or a two-pass program of a preemergence residual herbicide followed by glyphosate LPOST are the preferred weed management programs in glyphosate-resistant soybean. The two-pass programs have the potential to reduce selection pressure for glyphosate-resistant weeds.