Cover crops and residual herbicides reduce selection pressure for Palmer amaranth resistance to dicamba‐applied postemergence in cotton

Hand, Lavesta C.; Randell, Taylor M.; Nichols, Robert L.; Steckel, Lawrence E.; Basinger, Nicholas T.; Culpepper, A. Stanley

doi:10.1002/agj2.20886

Cited by 8 publications

(3 citation statements)

References 72 publications

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“…Currently, weed scientists are actively studying how cover crops, deep tillage, in-row cultivation, varying row spacings, hand weeding, and weed seed destruction at harvest can be used to lessen herbicide selection pressure (Bell et al 2016; Bunchek et al 2020; Hay et al 2019; Price et al 2012; Walsh et al 2012; Wiggins et al 2016). For example, a cereal rye ( Secale cereale L.) cover crop reduced selection pressure to postemergence herbicides on A. palmeri in a cotton system by 77% during the early season and by 65% for the entire season (Hand et al 2021). This cover crop also reduced the number of plants present after the first postemergence application by 43%, thereby further reducing herbicide selection pressure from a second postemergence application.…”

Section: Resistance Management Principles For Sustainable Weed Manage...mentioning

confidence: 99%

Discovery, mode of action, resistance mechanisms, and plan of action for sustainable use of Group 14 herbicides

et al. 2023

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Protoporphyrinogen oxidase (PPO) inhibiting herbicides remain an important and useful chemistry 60 years after their first introduction. In this review, based on topics introduced at the WSSA 2021 symposium titled “A History, Overview, and Plan of Action on PPO Inhibiting Herbicides”, we discuss the current state of PPO inhibiting herbicides. Renewed interest in the PPO inhibiting herbicides in recent years, due to increased use and increased resistance cases, has led to refinements in knowledge regarding the mechanism of action of PPO inhibitors. Herein we discuss the importance of the two isoforms of PPO in plants, compile a current knowledge of target site resistance mechanisms, discuss non target site resistance cases and review crop selectivity mechanisms. To effectively study and compare PPO inhibitor resistance cases, consistent and reproducible greenhouse screening and target site mutation assays are necessary. To this end we cover best practices in screening to accurately identify resistance ratios and properly interpret common screens for point mutations. The future of effective and sustainable PPO inhibitor use relies on development of new chemistries that maintain activity on resistant biotypes and the promotion of responsible stewardship of PPO inhibitors both new and old. We present the biorational design of the new PPO inhibitor trifludimoxazin to highlight the future of PPO inhibitor development and discuss the elements of sustainable weed control programs using PPO inhibitors as well as how responsible stewardship can be incentivized. The sustained use of PPO inhibitors in future agriculture relies on the effective and timely communication from mode of action and resistance research to agronomists, extension workers, and farmers themselves.

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Section: Resistance Management Principles For Sustainable Weed Manage...mentioning

confidence: 99%

Discovery, mode of action, resistance mechanisms, and plan of action for sustainable use of Group 14 herbicides

et al. 2023

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“…The likelihood of this phenomenon is proportional to weed population size and the selection pressure imposed by herbicide (Menalled et al 2016; Neve et al 2014). Using ancillary practices that both limit selection pressure and maintain small population size are essential to the ongoing challenge of weed management in the Southeast region (Hand et al 2021; Norsworthy et al 2012; Price et al 2016a). The deliberate use of varied practices that differ in the selection pressure that they impose on weeds is a central tenet of integrated weed management (IWM) approaches (Harker 2013; Menalled et al 2016; Neve et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Do cover crops suppress weeds in the U.S. Southeast? A meta-analysis

et al. 2023

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Cover crops (CCs) have shown great potential for suppressing annual weeds within agronomic cropping systems across the US. However, the weed suppressive potential of CCs may be moderated by environmental and management factors that are specific to certain geographic areas and their associated characteristics. This may be particularly true within the Southeast (SE) region of the US where higher mean annual temperature and precipitation generate favorable conditions for both cover crop (CC) and weed growth. To understand the effects of this regional context on CCs and weeds, a meta-analysis examining paired comparisons of weed biomass and/or weed density under CC and bare ground conditions from studies conducted within the SE was conducted. Data were identified and extracted from 28 journal articles in which weed biomass and/or weed density were measured and cash crop yield data if they were provided. Fourteen studies provided 142 comparisons for weed biomass, 23 studies provided 139 comparisons for weed density, and 22 studies, pooled over both weed response variables, provided 144 comparisons for cash crop yield. CCs had a negative effect on weed density (p = 0.0016), but no effect on either weed biomass (p = 0.16) or cash crop yield (p = 0.88). The mean relative reduction in weed density under CCs was 44 percent. Subsequent analyses indicated that CC biomass was the key factor associated with this reduction. Weed density suppression was linearly related to CC biomass; a 50 percent decrease in weed density was associated with 6.6 Mg ha-1 of CC biomass. Edaphic, geographic, and other management factors had no bearing on this suppressive effect. This highlights the importance of generating adequate CC biomass if weed suppression is the primary objective of cover crop use, and the potential for CCs to reduce weed density over diverse soil, climate, and farm management conditions.

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“…Residual herbicides, when applied at PRE and POST timings with dicamba, provide greater A. palmeri control than dicamba applications without residual herbicides (Inman et al, 2016). PRE + POST herbicide programs of dicamba, when combined with high cover crop biomass, provide greater A. palmeri control (Wiggins et al, 2017;Hand et al, 2021;Grint et al, 2022). However, reduced sensitivity to dicamba has been reported recently in A. palmeri populations of the High Plains regions of Texas (Garetson et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Herbicide programs, cropping sequences, and tillage-types: a systems approach for managing Amaranthus palmeri in dicamba-resistant cotton

Vulchi,

Nolte,

McGinty

et al. 2023

Front. Agron.

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Herbicide-resistant Amaranthus palmeri poses a significant threat to cotton production in the US. Tillage, cover crops, crop rotations, and dicamba-based herbicide programs can individually provide effective control of A. palmeri, but there is a lack of research evaluating the above tactics in a system for its long-term management. Field trials were conducted near College Station and Thrall, TX (2019–2021) to evaluate the efficacy of dicamba-based herbicide programs under multiple cropping sequences and tillage types in a systems approach for A. palmeri control in dicamba-resistant cotton. The experimental design used was a split–split plot design. The main plots were no-till cover cropping, strip tillage, and conventional tillage. The subplots were cotton:cotton:cotton (CCC) and cotton:sorghum:cotton (CSC) sequences for 3 years within each tillage type, and sub-subplots were a weedy check (WC), a weed-free check (WF), a low-input program without residual herbicides (LI), and a high-input program with residual herbicides (HI). Using HI under the CSC sequence was the only system that provided >90% control of A. palmeri for 3 years across all tillage types and locations. By 2021, A. palmeri densities in the CSC sequence at College Station (4,156 plants ha−1) and Thrall (4,006 plants ha−1) are significantly low compared to the CCC sequence (31,364 and 9,867 plants ha−1, respectively) when averaged across other factors. Similarly, A. palmeri densities in HI at College Station (9,867 plants ha−1) and Thrall (1,016 plants ha−1) are significantly low compared to LI (25,653 and 13,365 plants ha−1, respectively) when averaged across other factors. We also observed that the CSC sequence reduced A. palmeri seed bank by at least 40% compared to the CCC sequence at both College Station and Thrall when averaged across other factors. Over 3 years, we did not observe significant differences between LI and HI for cotton yields at College Station (1,715–3,636 kg ha−1) and Thrall (1,569−1,989 kg ha−1). However, rotating cotton with sorghum during 2020 improved cotton yields by 39% under no-till cover cropping in 2021 at Thrall. These results indicate that using dicamba-based herbicide programs with residual herbicides and implementing crop rotations can effectively manage A. palmeri in terms of seasonal control, densities, and seed bank buildup across tillage types and environments.

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Cover crops and residual herbicides reduce selection pressure for Palmer amaranth resistance to dicamba‐applied postemergence in cotton

Cited by 8 publications

References 72 publications

Discovery, mode of action, resistance mechanisms, and plan of action for sustainable use of Group 14 herbicides

Discovery, mode of action, resistance mechanisms, and plan of action for sustainable use of Group 14 herbicides

Do cover crops suppress weeds in the U.S. Southeast? A meta-analysis

Herbicide programs, cropping sequences, and tillage-types: a systems approach for managing Amaranthus palmeri in dicamba-resistant cotton

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