Kochia [Bassia scoparia (L.) A.J. Scott] is a summer annual tumbleweed that is tolerant of heat, drought, and salinity and capable of causing large yield losses in spring wheat (Triticum aestivum L). Increased incidence of glyphosate- and acetolactate synthase (ALS) inhibitor-resistant kochia in western Canada warrants investigation of alternative herbicides to manage these biotypes. Herbicides applied pre- or post-emergence in spring wheat were evaluated based on crop tolerance and control of ALS inhibitor-resistant kochia accessions with and without the glyphosate resistance trait in five environments near Lethbridge and Coalhurst, Alberta, from 2013 to 2015. The most effective and consistent treatments for kochia management included sulfentrazone applied pre-emergence and fluroxypyr/bromoxynil/2,4-D or pyrasulfotole/bromoxynil applied post-emergence. All of these treatments resulted in ≥90% visible control in all environments and ≥90% kochia biomass reduction compared with the untreated control in Lethbridge 2014 and 2015. MCPA/dichlorprop-p/mecoprop-p, dicamba/2,4-D/mecoprop-p, and dicamba/fluroxypyr resulted in acceptable control among environments (≥80% visible control in all environments and ≥80% kochia biomass reduction in Lethbridge 2014 and 2015); however, the latter two options caused unacceptable (>10%) wheat visible injury in Coalhurst 2014. Recent confirmations of auxinic herbicide-resistant kochia in western Canada—due, in part, to use of synthetic auxins to manage glyphosate-resistant kochia in small-grain cereals—will limit kochia management options. When implemented with non-chemical tools as part of an integrated weed management program, alternative herbicide modes of action like protoporphyrinogen oxidase inhibitors before and photosystem II or 4-hydroxyphenylpyruvate dioxygenase inhibitor(s) within spring wheat could mitigate selection for multiple herbicide-resistant kochia.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.