Kumar, VipanJha, Prashant2015-09-032015-09-032015-05Kumar, Vipan, and Prashant Jha. "Influence of herbicides applied postharvest in wheat stubble on control, fecundity, and progeny fitness of Kochia scoparia in the US Great Plains." Crop Protection 71 (May 2015): 144-149. DOI:https://dx.doi.org/10.1016/j.cropro.2015.02.016.0261-2194https://scholarworks.montana.edu/handle/1/9235Field, greenhouse, and laboratory experiments were conducted at the Montana State University Southern Agricultural Research Center, Huntley, MT, USA, in 2012 and 2013, to evaluate the effectiveness of various postharvest-applied herbicides on late-season control, fecundity, seed viability, and progeny fitness of Kochia scoparia (kochia) in wheat stubble. Paraquat + atrazine, paraquat + linuron, and paraquat + metribuzin applied at the early bloom stage were the most effective postharvest treatments for late-season control (100%) at 28 d after treatment (DAT), biomass reduction (70–73%), and seed prevention of K. scoparia, and did not differ from glyphosate, glufosinate, saflufenacil + 2, 4-D, saflufenacil + atrazine, tembotrione + atrazine, or topramezone + atrazine treatments. Dicamba alone, dicamba + 2, 4-D, or diflufenzopyr + dicamba + 2, 4-D applied at the early bloom stage were ineffective, with <70% late-season control, <45% biomass reduction, and <55% seed reduction of K. scoparia. In the absence of a postharvest herbicide, uncontrolled kochia plants at a density of 8–10 plants m−2 contributed >100,000 seeds m−2. Addition of atrazine to dicamba improved late-season control (80%) and seed reduction (78%) compared to dicamba alone, and reduced seed viability and 100-seed weight. There was no significant effect of any of the dicamba-containing herbicides applied at the early bloom stage on K. scoparia progeny fitness, including height, width, primary branches, and shoot dry weight of seedlings at 42 d after planting (DAP). The effective postharvest-applied herbicides investigated in this research should be utilized to prevent late-season K. scoparia seed bank replenishment in wheat, and as a component of herbicide resistance management program for the containment of glyphosate- and/or acetolactate synthase (ALS)-inhibitor-resistant K. scoparia in wheat-based crop rotations in the US Great Plains.Article