Hannah E. Symington, Nader Soltani, Allan C. Kaastra, David C. Hooker, Darren E. Robinson, Peter H. Sikkema
Waterhemp is a summer annual, broadleaf weed with high fecundity, short seed longevity in the soil, and wide genetic diversity. Populations have evolved resistance to five herbicide modes of action (Groups 2, 5, 9, 14, and 27), which are present across southern Ontario; this has increased the challenge of controlling this competitive weed species in corn, the most important grain crop produced worldwide, and the highest value agronomic crop in Ontario. Acetochlor is a Group 15 soil-applied residual herbicide that has activity on many grass and broadleaf weeds but has yet to be registered in Canada. The objective of this study was to ascertain whether mixtures of acetochlor with flumetsulam, dicamba, atrazine, isoxaflutole/diflufenican, or mesotrione + atrazine applied preemergence would increase the control of multiple herbicide-resistant (MHR) waterhemp in corn. Five field trials were conducted between 2022 and 2023. No corn injury was observed. Acetochlor applied alone controlled MHR waterhemp 97% 12 weeks after application (WAA). All herbicide mixtures controlled MHR waterhemp similarly at ≥98% 12 WAA; there were no differences among herbicide mixtures. Flumetsulam, dicamba, and atrazine provided lower MHR waterhemp control than all other herbicide treatments and did not reduce density or biomass. Acetochlor reduced waterhemp density 98%, while the acetochlor mixtures reduced density similarly at 99 to 100%. This study concludes that the acetochlor mixtures evaluated provide excellent waterhemp control; however, control was not greater than acetochlor alone. Herbicides herbicide mixtures should be used as a best management practice to mitigate the evolution of herbicide resistance.
{"title":"Control of multiple herbicide-resistant waterhemp (Amaranthus tuberculatus) with acetochlor-based herbicide mixtures in corn","authors":"Hannah E. Symington, Nader Soltani, Allan C. Kaastra, David C. Hooker, Darren E. Robinson, Peter H. Sikkema","doi":"10.1017/wet.2024.16","DOIUrl":"https://doi.org/10.1017/wet.2024.16","url":null,"abstract":"Waterhemp is a summer annual, broadleaf weed with high fecundity, short seed longevity in the soil, and wide genetic diversity. Populations have evolved resistance to five herbicide modes of action (Groups 2, 5, 9, 14, and 27), which are present across southern Ontario; this has increased the challenge of controlling this competitive weed species in corn, the most important grain crop produced worldwide, and the highest value agronomic crop in Ontario. Acetochlor is a Group 15 soil-applied residual herbicide that has activity on many grass and broadleaf weeds but has yet to be registered in Canada. The objective of this study was to ascertain whether mixtures of acetochlor with flumetsulam, dicamba, atrazine, isoxaflutole/diflufenican, or mesotrione + atrazine applied preemergence would increase the control of multiple herbicide-resistant (MHR) waterhemp in corn. Five field trials were conducted between 2022 and 2023. No corn injury was observed. Acetochlor applied alone controlled MHR waterhemp 97% 12 weeks after application (WAA). All herbicide mixtures controlled MHR waterhemp similarly at ≥98% 12 WAA; there were no differences among herbicide mixtures. Flumetsulam, dicamba, and atrazine provided lower MHR waterhemp control than all other herbicide treatments and did not reduce density or biomass. Acetochlor reduced waterhemp density 98%, while the acetochlor mixtures reduced density similarly at 99 to 100%. This study concludes that the acetochlor mixtures evaluated provide excellent waterhemp control; however, control was not greater than acetochlor alone. Herbicides herbicide mixtures should be used as a best management practice to mitigate the evolution of herbicide resistance.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"30 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frank D’Amico, Thierry Besançon, Alyssa Koehler, Lovreet Shergill, Melissa Ziegler, Mark VanGessel
Common ragweed is a troublesome weed in many crops. Farmers and crop advisors in the coastal Mid-Atlantic region have reported inadequate control of common ragweed in soybean with glyphosate and other herbicide modes of action. To determine if herbicide resistance was one of the causes of poor herbicide performance, twenty-nine accessions from four states (DE, MD, NJ, VA) where common ragweed plants survived herbicide applications and produced viable seeds were used for greenhouse screening. Common ragweed seedlings from those accessions were treated with multiple rates of cloransulam, fomesafen, or glyphosate, applied as a single postemergence (POST) herbicide application. All accessions except one demonstrated resistance to at least one of the herbicides applied at twice the effective rate (2X), seventeen accessions were two-way resistant (glyphosate- and cloransulam-resistant; glyphosate- and fomesafen-resistant) and three-way resistance was present in eight accessions collected from three different states. Based on the POST study, five accessions were treated preemergence (PRE) with acetolactate synthase (ALS)-inhibiting PRE herbicides, and two accessions were treated with protoporphyrinogen oxidase (PPO)-inhibiting herbicides. All accessions treated PRE with the ALS-inhibitors chlorimuron or cloransulam demonstrated resistance at the 2X rates. Both accessions treated PRE with the PPO-inhibitor sulfentrazone, had survivors at the 2X rate. When the same accessions were treated PRE with fomesafen, one had survivors at the 2X rate, and one had survivors at the 1X rate. Results from these tests confirmed common ragweed with three-way resistance to POST herbicides is widespread in the region. In addition, this is the first confirmation that common ragweed accessions in the region are also resistant to ALS- or PPO-inhibiting herbicides when applied PRE.
豚草是许多作物中的一种令人头疼的杂草。据大西洋中部沿海地区的农民和作物顾问报告，草甘膦和其他除草剂对大豆中的豚草控制不力。为了确定除草剂抗性是否是除草剂效果不佳的原因之一，我们使用了来自四个州（德克萨斯州、马里兰州、新泽西州和弗吉尼亚州）的 29 个品种进行温室筛选。用氯酯磺草胺、福美双或草甘膦等多种除草剂处理这些品种的豚草幼苗，并在出苗后（POST）施用一次除草剂。除一种除草剂外，所有品种都对至少一种除草剂产生了抗性，抗性的有效剂量为 2 倍（2X），17 个品种具有双向抗性（草甘膦和氯酯磺草胺抗性；草甘膦和福美双抗性），从三个不同州收集的 8 个品种具有三向抗性。根据萌芽前研究，有五个品种使用乙酰乳酸合成酶（ALS）抑制型萌芽前除草剂进行萌芽前处理，两个品种使用原卟啉原氧化酶（PPO）抑制型除草剂进行萌芽前处理。所有使用 ALS 抑制剂氯嘧磺隆或氯酯磺草胺进行 PRE 处理的品种在使用 2 倍剂量时都表现出抗性。使用 PPO 抑制剂磺草酮进行预处理的两个品种在 2 倍剂量下都有存活。在用福美双进行预处理时，一个品种的存活率为 2 倍，另一个品种的存活率为 1 倍。这些试验结果证实，该地区普遍存在普通豚草对 POST 除草剂的三重抗性。此外，这也是首次证实该地区的豚草品种在预处理时也对 ALS 或 PPO 抑制性除草剂具有抗性。
{"title":"Common ragweed (Ambrosia artemisiifolia L.) accession in the Mid-Atlantic region resistant to ALS-, PPO-, and EPSPS-inhibiting herbicides","authors":"Frank D’Amico, Thierry Besançon, Alyssa Koehler, Lovreet Shergill, Melissa Ziegler, Mark VanGessel","doi":"10.1017/wet.2024.11","DOIUrl":"https://doi.org/10.1017/wet.2024.11","url":null,"abstract":"Common ragweed is a troublesome weed in many crops. Farmers and crop advisors in the coastal Mid-Atlantic region have reported inadequate control of common ragweed in soybean with glyphosate and other herbicide modes of action. To determine if herbicide resistance was one of the causes of poor herbicide performance, twenty-nine accessions from four states (DE, MD, NJ, VA) where common ragweed plants survived herbicide applications and produced viable seeds were used for greenhouse screening. Common ragweed seedlings from those accessions were treated with multiple rates of cloransulam, fomesafen, or glyphosate, applied as a single postemergence (POST) herbicide application. All accessions except one demonstrated resistance to at least one of the herbicides applied at twice the effective rate (2X), seventeen accessions were two-way resistant (glyphosate- and cloransulam-resistant; glyphosate- and fomesafen-resistant) and three-way resistance was present in eight accessions collected from three different states. Based on the POST study, five accessions were treated preemergence (PRE) with acetolactate synthase (ALS)-inhibiting PRE herbicides, and two accessions were treated with protoporphyrinogen oxidase (PPO)-inhibiting herbicides. All accessions treated PRE with the ALS-inhibitors chlorimuron or cloransulam demonstrated resistance at the 2X rates. Both accessions treated PRE with the PPO-inhibitor sulfentrazone, had survivors at the 2X rate. When the same accessions were treated PRE with fomesafen, one had survivors at the 2X rate, and one had survivors at the 1X rate. Results from these tests confirmed common ragweed with three-way resistance to POST herbicides is widespread in the region. In addition, this is the first confirmation that common ragweed accessions in the region are also resistant to ALS- or PPO-inhibiting herbicides when applied PRE.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"43 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140071247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elisabeta Lika, Chelsea Sutherland, Savannah Gleim, Stuart J. Smyth
The sustainable management of herbicides is critical to modern agriculture and the environment. This article examines the evolution and environmental implications of herbicide use in Saskatchewan agriculture. It quantifies changes in herbicide use and their environmental impacts by analyzing farm-level herbicide use data from 1991-1994 and 2016-2019 through the Environmental Impact Quotient. Results confirm significant reductions in both the environmental and toxicological impacts of herbicides used, underlining the pivotal shift from tillage-based weed control to herbicide-resistant cropping systems. The environmental impact of the top five herbicides used from 2016-19 is 65% lower than those used from 1991-94, with a 45% reduction in the active ingredient applied per acre. Despite increased herbicide usage due to more crop acres being seeded, the findings highlight a marked improvement in the sustainability of herbicide use, affirming the importance of technological advancements in agriculture. This research contributes valuable insights into long-term trends in herbicide use, offering a practical framework for informed decisions aligning with sustainable agricultural practices as well as reduced biodiversity impacts.
{"title":"Quantifying changes in the environmental impact of in-crop herbicide use in Saskatchewan","authors":"Elisabeta Lika, Chelsea Sutherland, Savannah Gleim, Stuart J. Smyth","doi":"10.1017/wet.2024.15","DOIUrl":"https://doi.org/10.1017/wet.2024.15","url":null,"abstract":"The sustainable management of herbicides is critical to modern agriculture and the environment. This article examines the evolution and environmental implications of herbicide use in Saskatchewan agriculture. It quantifies changes in herbicide use and their environmental impacts by analyzing farm-level herbicide use data from 1991-1994 and 2016-2019 through the Environmental Impact Quotient. Results confirm significant reductions in both the environmental and toxicological impacts of herbicides used, underlining the pivotal shift from tillage-based weed control to herbicide-resistant cropping systems. The environmental impact of the top five herbicides used from 2016-19 is 65% lower than those used from 1991-94, with a 45% reduction in the active ingredient applied per acre. Despite increased herbicide usage due to more crop acres being seeded, the findings highlight a marked improvement in the sustainability of herbicide use, affirming the importance of technological advancements in agriculture. This research contributes valuable insights into long-term trends in herbicide use, offering a practical framework for informed decisions aligning with sustainable agricultural practices as well as reduced biodiversity impacts.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"38 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140071097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Casey H. Arnold, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Nick R. Bateman, Chad W Shelton
Herbicide-resistant barnyardgrass and weedy rice control, without crop injury, is a challenge for rice producers in the United States. Herbicides, such as oxyfluorfen, that were not initially labeled for rice, are now being evaluated as a new tool for weed control. The Roxy® trait allows for the use of oxyfluorfen in rice for weed control preemergence and postemergence. Experiments were initiated in 2021 and 2022 to evaluate 1) the effectiveness of preemergence- and postemergence-applied oxyfluorfen on barnyardgrass and weedy rice, 2) the sensitivity of oxyfluorfen-resistant rice to oxyfluorfen as a function of application timing, and 3) the influence of soil moisture on oxyfluorfen-resistant rice sensitivity to oxyfluorfen. In the field, a rate response was observed for oxyfluorfen applied to weedy rice when averaged over application timings of 1-leaf, 2-leaf, 3-leaf, and tillering, with oxyfluorfen at 1,680 g ai ha-1 resulting in 81 and 72% control 7 d after application (DAA) in 2021 and 2022, respectively. Under greenhouse conditions, barnyardgrass and weedy rice control averaged by the rate of oxyfluorfen was ≥85 and ≥70%, respectfully, 7 DAA for the 1-, 2-, and 3-leaf rice growth stage timings. Preemergence applications of oxyfluorfen under 100% soil saturation resulted in 75% injury to oxyfluorfen-resistant rice, greater than all other soil moisture at 7 DAA. All postemergence applications of oxyfluorfen resulted in 63 to 70% injury to oxyfluorfen-resistant rice at 7 DAA, regardless of soil moisture. Barnyardgrass and weedy rice control with oxyfluorfen are achieved with timely applications; however, injury to oxyfluorfen-resistant rice is likely.
{"title":"Oxyfluorfen-Resistant Rice Tolerance and Weed Control when using Oxyfluorfen","authors":"Casey H. Arnold, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Nick R. Bateman, Chad W Shelton","doi":"10.1017/wet.2024.6","DOIUrl":"https://doi.org/10.1017/wet.2024.6","url":null,"abstract":"Herbicide-resistant barnyardgrass and weedy rice control, without crop injury, is a challenge for rice producers in the United States. Herbicides, such as oxyfluorfen, that were not initially labeled for rice, are now being evaluated as a new tool for weed control. The Roxy<jats:sup>®</jats:sup> trait allows for the use of oxyfluorfen in rice for weed control preemergence and postemergence. Experiments were initiated in 2021 and 2022 to evaluate 1) the effectiveness of preemergence- and postemergence-applied oxyfluorfen on barnyardgrass and weedy rice, 2) the sensitivity of oxyfluorfen-resistant rice to oxyfluorfen as a function of application timing, and 3) the influence of soil moisture on oxyfluorfen-resistant rice sensitivity to oxyfluorfen. In the field, a rate response was observed for oxyfluorfen applied to weedy rice when averaged over application timings of 1-leaf, 2-leaf, 3-leaf, and tillering, with oxyfluorfen at 1,680 g ai ha<jats:sup>-1</jats:sup> resulting in 81 and 72% control 7 d after application (DAA) in 2021 and 2022, respectively. Under greenhouse conditions, barnyardgrass and weedy rice control averaged by the rate of oxyfluorfen was ≥85 and ≥70%, respectfully, 7 DAA for the 1-, 2-, and 3-leaf rice growth stage timings. Preemergence applications of oxyfluorfen under 100% soil saturation resulted in 75% injury to oxyfluorfen-resistant rice, greater than all other soil moisture at 7 DAA. All postemergence applications of oxyfluorfen resulted in 63 to 70% injury to oxyfluorfen-resistant rice at 7 DAA, regardless of soil moisture. Barnyardgrass and weedy rice control with oxyfluorfen are achieved with timely applications; however, injury to oxyfluorfen-resistant rice is likely.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"134 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juliano Bortoluzzi Lorenzetti, Maikon Tiago Yamada Danilussi, Alfredo Junior Paiola Albrecht, Arthur Arrobas Martins Barroso, Leandro Paiola Albrecht, André Felipe Moreira Silva, Guilherme Rossano dos Santos, Giuzeppe Augusto Maram Caneppele
Monitoring herbicide-resistant weeds makes it possible to study the evolution and spread of resistance, providing important information for management. The objective of this study was to map fleabane accessions in the states of Paraná (PR) and Mato Grosso do Sul (MS), Brazil, to identify herbicide-resistant accessions and their response to soybean pre-plant chemical burndown management strategies. Fleabane seeds were collected in agricultural areas in PR and MS, in 2018, 2019, and 2020. Initial screening was performed for glyphosate, chlorimuron, paraquat, 2,4-D, saflufenacil, and glufosinate efficacy. Subsequently, dose-response experiments were conducted. Field experiments were carried out in three locations, where accessions of multiple-resistant Sumatran fleabane were identified. Herbicides were used in single or sequential (seq.) applications at three plant heights (<5 cm, 5 to 10 cm, and >10 cm). After preliminary screening, accessions were classified as putative resistant (<80% control for all 4 replicates), segregated (<80% control for 1 to 3 replicates), or susceptible (>80% control for all 4 replicates). There was no evidence of resistance to glufosinate or saflufenacil in any of the 461 accessions, while 65 showed possible resistance or segregation only for glyphosate, 235 for glyphosate + chlorimuron, 79 to glyphosate + chlorimuron + paraquat, 59 to glyphosate + chlorimuron + 2,4-D, and 23 with 4-way resistance (glyphosate, chlorimuron, paraquat and 2,4-D). Of these 23 accessions, 7 were analyzed using dose-response curves (F2 generation), all from PR, confirming 4-way resistance to glyphosate, chlorimuron, paraquat, and 2,4-D. To control resistant Sumatran fleabane, an application should prioritize smaller plants. Despite resistance to 2,4-D, double mixtures containing this herbicide were among the most effective treatments in plants <5 cm in height. Sequential application is needed for plants >5 cm in height, it was recommended glyphosate + synthetic auxin followed by glufosinate or glyphosate + saflufenacil.
{"title":"Identification, mapping, and chemical control of fleabane resistant to glyphosate, chlorimuron, paraquat and 2,4-D","authors":"Juliano Bortoluzzi Lorenzetti, Maikon Tiago Yamada Danilussi, Alfredo Junior Paiola Albrecht, Arthur Arrobas Martins Barroso, Leandro Paiola Albrecht, André Felipe Moreira Silva, Guilherme Rossano dos Santos, Giuzeppe Augusto Maram Caneppele","doi":"10.1017/wet.2024.10","DOIUrl":"https://doi.org/10.1017/wet.2024.10","url":null,"abstract":"Monitoring herbicide-resistant weeds makes it possible to study the evolution and spread of resistance, providing important information for management. The objective of this study was to map fleabane accessions in the states of Paraná (PR) and Mato Grosso do Sul (MS), Brazil, to identify herbicide-resistant accessions and their response to soybean pre-plant chemical burndown management strategies. Fleabane seeds were collected in agricultural areas in PR and MS, in 2018, 2019, and 2020. Initial screening was performed for glyphosate, chlorimuron, paraquat, 2,4-D, saflufenacil, and glufosinate efficacy. Subsequently, dose-response experiments were conducted. Field experiments were carried out in three locations, where accessions of multiple-resistant Sumatran fleabane were identified. Herbicides were used in single or sequential (seq.) applications at three plant heights (<5 cm, 5 to 10 cm, and >10 cm). After preliminary screening, accessions were classified as putative resistant (<80% control for all 4 replicates), segregated (<80% control for 1 to 3 replicates), or susceptible (>80% control for all 4 replicates). There was no evidence of resistance to glufosinate or saflufenacil in any of the 461 accessions, while 65 showed possible resistance or segregation only for glyphosate, 235 for glyphosate + chlorimuron, 79 to glyphosate + chlorimuron + paraquat, 59 to glyphosate + chlorimuron + 2,4-D, and 23 with 4-way resistance (glyphosate, chlorimuron, paraquat and 2,4-D). Of these 23 accessions, 7 were analyzed using dose-response curves (F2 generation), all from PR, confirming 4-way resistance to glyphosate, chlorimuron, paraquat, and 2,4-D. To control resistant Sumatran fleabane, an application should prioritize smaller plants. Despite resistance to 2,4-D, double mixtures containing this herbicide were among the most effective treatments in plants <5 cm in height. Sequential application is needed for plants >5 cm in height, it was recommended glyphosate + synthetic auxin followed by glufosinate or glyphosate + saflufenacil.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"52 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Industrial hemp is a multipurpose crop cultivated for fiber, seed, human food, and animal feed. Hemp legalization in Texas creates a considerable potential to increase its acreage in semi-arid conditions; however, knowledge to grow hemp optimally in Texas is limited. Best management practices, including weed control, need to be evaluated for profitable hemp production. Since little is known about the herbicide tolerance of hemp, field studies were conducted to test several soil-residual herbicides with different modes of action for phytotoxicity to two hemp cultivars, Yuma and Jinma. The experimental units were randomized three times in a blocked split-plot design with hemp cultivars in the main plots and soil-residual herbicides in the subplots. Ethalfluralin, the mixture of sulfentrazone and S-metolachlor, prometryn, and S-metolachlor, resulted in 60 to 90% and 73 to 100% weed control as compared to nontreated control in 2021 and 2022, respectively. The highest hemp germination, stand count, and plant height were observed with ethalfluralin and S-metolachlor herbicides; however, no significant differences were observed for hemp germination and plant height compared to nontreated control. S-metolachlor, ethalfluralin, fomesafen, and prometryn resulted in similar hemp biomass compared to the nontreated control. Overall, the results indicate that hemp is tolerant to ethalfluralin, prometryn, and S-metolachlor, and these soil-residual herbicides were effective for weed control in hemp. The mixture of bicyclopyrone and S-metolachlor, metribuzin and S-metolachlor, and mesotrione should be avoided due to significant injury to hemp plants. Future research is needed to test the efficacy of different preemergence and postemergence herbicides that can be used in industrial hemp grown under different environments, making sure the delta-9-tetrahydrocannabinol (THC) content of the hemp is below the legal content restrictions.
{"title":"Impact of Soil-Residual Herbicides on Industrial Hemp (Cannabis sativa L.) Phytotoxicity and Biomass Yield in West Texas","authors":"Atinderpal Singh, Rupinder Saini, Arjun Kafle, Manpreet Singh, Sukhbir Singh","doi":"10.1017/wet.2024.13","DOIUrl":"https://doi.org/10.1017/wet.2024.13","url":null,"abstract":"Industrial hemp is a multipurpose crop cultivated for fiber, seed, human food, and animal feed. Hemp legalization in Texas creates a considerable potential to increase its acreage in semi-arid conditions; however, knowledge to grow hemp optimally in Texas is limited. Best management practices, including weed control, need to be evaluated for profitable hemp production. Since little is known about the herbicide tolerance of hemp, field studies were conducted to test several soil-residual herbicides with different modes of action for phytotoxicity to two hemp cultivars, Yuma and Jinma. The experimental units were randomized three times in a blocked split-plot design with hemp cultivars in the main plots and soil-residual herbicides in the subplots. Ethalfluralin, the mixture of sulfentrazone and <jats:italic>S</jats:italic>-metolachlor, prometryn, and <jats:italic>S</jats:italic>-metolachlor, resulted in 60 to 90% and 73 to 100% weed control as compared to nontreated control in 2021 and 2022, respectively. The highest hemp germination, stand count, and plant height were observed with ethalfluralin and <jats:italic>S</jats:italic>-metolachlor herbicides; however, no significant differences were observed for hemp germination and plant height compared to nontreated control. <jats:italic>S</jats:italic>-metolachlor, ethalfluralin, fomesafen, and prometryn resulted in similar hemp biomass compared to the nontreated control. Overall, the results indicate that hemp is tolerant to ethalfluralin, prometryn, and <jats:italic>S</jats:italic>-metolachlor, and these soil-residual herbicides were effective for weed control in hemp. The mixture of bicyclopyrone and <jats:italic>S</jats:italic>-metolachlor, metribuzin and <jats:italic>S</jats:italic>-metolachlor, and mesotrione should be avoided due to significant injury to hemp plants. Future research is needed to test the efficacy of different preemergence and postemergence herbicides that can be used in industrial hemp grown under different environments, making sure the delta-9-tetrahydrocannabinol (THC) content of the hemp is below the legal content restrictions.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"81 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Delaney C. Foster, Thomas C. Mueller, Lawrence E. Steckel
Palmer amaranth, which is resistant to glyphosate and protoporphyrinogen oxidase inhibitors, remains a threat to cotton and soybean production in Tennessee. This is partly due to the recent evolution of dicamba-resistant Palmer amaranth in West Tennessee, which further complicates weed management. Experiments were conducted in 2021 and 2022 to determine the best timing between sequential applications and in what order 2,4-D or dicamba should be used with glufosinate to control resistant Palmer amaranth. Palmer amaranth control increased when the interval between postemergence herbicide applications decreased from 21 to 7 days. At the 7-day interval in a dicamba-based system, the order of herbicides did not affect Palmer amaranth control. However, in a 2,4-D-based system, the greatest control was achieved when 2,4-D was applied first, followed by either 2,4-D or glufosinate. While weed height at the time of application had a significant effect on Palmer amaranth control with auxin herbicides, control was still unacceptable in the field at the labeled rates of dicamba or 2,4-D when applied to <10 cm tall weeds (48% and 53%, respectively). Neither dicamba nor 2,4-D provided acceptable control of the Palmer amaranth populations evaluated. Sequential applications separated by 7 days provided better weed control than those separated by 21 days. Given that the better 7-day sequential treatments provided less than 90% control and resulted in more than 64,000 surviving Palmer amaranth ha-1 suggests that relying solely on these herbicides for Palmer amaranth control is not a sustainable weed management strategy.
{"title":"Spray Interval, Application Order, and Plant Height Influences Control of Dicamba-Resistant Palmer amaranth","authors":"Delaney C. Foster, Thomas C. Mueller, Lawrence E. Steckel","doi":"10.1017/wet.2024.9","DOIUrl":"https://doi.org/10.1017/wet.2024.9","url":null,"abstract":"Palmer amaranth, which is resistant to glyphosate and protoporphyrinogen oxidase inhibitors, remains a threat to cotton and soybean production in Tennessee. This is partly due to the recent evolution of dicamba-resistant Palmer amaranth in West Tennessee, which further complicates weed management. Experiments were conducted in 2021 and 2022 to determine the best timing between sequential applications and in what order 2,4-D or dicamba should be used with glufosinate to control resistant Palmer amaranth. Palmer amaranth control increased when the interval between postemergence herbicide applications decreased from 21 to 7 days. At the 7-day interval in a dicamba-based system, the order of herbicides did not affect Palmer amaranth control. However, in a 2,4-D-based system, the greatest control was achieved when 2,4-D was applied first, followed by either 2,4-D or glufosinate. While weed height at the time of application had a significant effect on Palmer amaranth control with auxin herbicides, control was still unacceptable in the field at the labeled rates of dicamba or 2,4-D when applied to <10 cm tall weeds (48% and 53%, respectively). Neither dicamba nor 2,4-D provided acceptable control of the Palmer amaranth populations evaluated. Sequential applications separated by 7 days provided better weed control than those separated by 21 days. Given that the better 7-day sequential treatments provided less than 90% control and resulted in more than 64,000 surviving Palmer amaranth ha<jats:sup>-1</jats:sup> suggests that relying solely on these herbicides for Palmer amaranth control is not a sustainable weed management strategy.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"282 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139981617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taylor Randell-Singleton, Lavesta C. Hand, Jenna C. Vance, Hannah E. Wright-Smith, A. Stanley Culpepper
Protoporphyrinogen oxidase- (PPO) inhibiting herbicides are used in over 40 agronomic and specialty crops across Georgia to manage weeds through residual and postemergence (POST) control. In 2017, a population of Palmer amaranth exhibiting reduced sensitivity to POST applications of PPO-inhibiting herbicides was identified by the University of Georgia. Seed were collected from the site along with a known sensitive population; distance between the samples was 200 m, increasing the likelihood of similar environmental and genetic characteristics. To quantify sensitivity for both preemergence (PRE) and POST uses, 21 greenhouse dose-response assessments were conducted from 2017 to 2022. After conducting initial rate response studies, 13 doses per herbicide were chosen for the POST experiment; field use rates of fomesafen (420 g ai ha-1), lactofen (219 g ai ha-1), acifluorfen (420 g ai ha-1), and trifludimoxazin (25 g ai ha-1) at rates ranging from 0 to 4X the field use rate for the susceptible population, and 0 to 40X for the suspect population were applied. Herbicide treatments included adjuvants and were applied to plants 8 to 10 cm in height. Relative resistance factors (RRF) were calculated for control ratings, mortality, and biomass, and ranged from 105 to 318, 36 to 1477, 215 to 316, and 9 to 49 for fomesafen, lactofen, acifluorfen, and trifludimoxazin, respectively. In the PRE experiment, herbicide applications included five to nine doses of fomesafen (1X=210 g ai ha-1), flumioxazin (1X=57 g ai ha-1), oxyfluorfen (1X=561 g ai ha-1), and trifludimoxazin (1X=38 g ai ha-1); doses ranged from 0 to 6X for the suspect population and 0 to 2X for the susceptible population. Visual control, mortality, and biomass RRF ranged from 3 to 5 for fomesafen, 21 to 31 for flumioxazin, 6 to 22 for oxyfluorfen, and 8 to 38 for trifludimoxazin. Results confirm that a Georgia Palmer amaranth population is resistant to PPO-inhibiting herbicides applied both PRE and POST.
{"title":"Confirming resistance to PPO-inhibiting herbicides applied preemergence and postemergence in a Georgia Palmer amaranth population","authors":"Taylor Randell-Singleton, Lavesta C. Hand, Jenna C. Vance, Hannah E. Wright-Smith, A. Stanley Culpepper","doi":"10.1017/wet.2024.12","DOIUrl":"https://doi.org/10.1017/wet.2024.12","url":null,"abstract":"Protoporphyrinogen oxidase- (PPO) inhibiting herbicides are used in over 40 agronomic and specialty crops across Georgia to manage weeds through residual and postemergence (POST) control. In 2017, a population of Palmer amaranth exhibiting reduced sensitivity to POST applications of PPO-inhibiting herbicides was identified by the University of Georgia. Seed were collected from the site along with a known sensitive population; distance between the samples was 200 m, increasing the likelihood of similar environmental and genetic characteristics. To quantify sensitivity for both preemergence (PRE) and POST uses, 21 greenhouse dose-response assessments were conducted from 2017 to 2022. After conducting initial rate response studies, 13 doses per herbicide were chosen for the POST experiment; field use rates of fomesafen (420 g ai ha<jats:sup>-1</jats:sup>), lactofen (219 g ai ha<jats:sup>-1</jats:sup>), acifluorfen (420 g ai ha<jats:sup>-1</jats:sup>), and trifludimoxazin (25 g ai ha<jats:sup>-1</jats:sup>) at rates ranging from 0 to 4X the field use rate for the susceptible population, and 0 to 40X for the suspect population were applied. Herbicide treatments included adjuvants and were applied to plants 8 to 10 cm in height. Relative resistance factors (RRF) were calculated for control ratings, mortality, and biomass, and ranged from 105 to 318, 36 to 1477, 215 to 316, and 9 to 49 for fomesafen, lactofen, acifluorfen, and trifludimoxazin, respectively. In the PRE experiment, herbicide applications included five to nine doses of fomesafen (1X=210 g ai ha<jats:sup>-1</jats:sup>), flumioxazin (1X=57 g ai ha<jats:sup>-1</jats:sup>), oxyfluorfen (1X=561 g ai ha<jats:sup>-1</jats:sup>), and trifludimoxazin (1X=38 g ai ha<jats:sup>-1</jats:sup>); doses ranged from 0 to 6X for the suspect population and 0 to 2X for the susceptible population. Visual control, mortality, and biomass RRF ranged from 3 to 5 for fomesafen, 21 to 31 for flumioxazin, 6 to 22 for oxyfluorfen, and 8 to 38 for trifludimoxazin. Results confirm that a Georgia Palmer amaranth population is resistant to PPO-inhibiting herbicides applied both PRE and POST.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"165 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139766222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tameka L. Sanders, Jason A. Bond, Tom. W. Allen, Drew Gholson, L. Jason Krutz, Eric P. Webster
Rice in Mississippi is often in early seedling growth stages when paraquat-based herbicide treatments are commonly applied to corn, cotton, and soybean; therefore, off-target movement onto adjacent rice fields may occur. After an off-target movement event has occurred, weed management in the rice crop is still necessary. Field studies were conducted from 2019 to 2021 in Stoneville, MS, to evaluate rice injury and barnyardgrass control with labeled herbicides after exposure to a sub-lethal paraquat concentration. Labeled herbicide treatments were recommended rates of imazethapyr, quinclorac, propanil, bispyribac-sodium, cyhalopfop, and florpyrauxifen-benzyl applied following rice exposure to a sub-lethal concentration of paraquat. Rice injury was detected 7 and 28 d after treatment (DAT) with injury ≥ 35 and 14%, respectively, following all labeled herbicides. Florpyrauxifen-benzyl and imazethapyr injured rice the greatest 28 DAT. Following paraquat exposure, barnyardgrass control was similar for all labeled herbicide treatments 7, 14, and 28 DAT except with florpyrauxifen-benzyl and no labeled herbicide (paraquat alone) 7 DAT. Across all evaluations, barnyardgrass control was at least 12% greater following paraquat exposure and labeled herbicide treatments than with no paraquat exposure. The current research demonstrates that labeled herbicides applied following exposure to a sub-lethal concentration of paraquat resulted in <36% injury and provided as great as 95% control of barnyardgrass, depending on the herbicide treatment. Therefore, the labeled herbicides choice following rice exposure to a sub-lethal concentration of paraquat should be based on weed spectrum.
{"title":"Barnyardgrass (Echinochloa crus-galli) control and rice injury with labeled herbicides following exposure to sub-lethal concentrations of paraquat","authors":"Tameka L. Sanders, Jason A. Bond, Tom. W. Allen, Drew Gholson, L. Jason Krutz, Eric P. Webster","doi":"10.1017/wet.2024.8","DOIUrl":"https://doi.org/10.1017/wet.2024.8","url":null,"abstract":"Rice in Mississippi is often in early seedling growth stages when paraquat-based herbicide treatments are commonly applied to corn, cotton, and soybean; therefore, off-target movement onto adjacent rice fields may occur. After an off-target movement event has occurred, weed management in the rice crop is still necessary. Field studies were conducted from 2019 to 2021 in Stoneville, MS, to evaluate rice injury and barnyardgrass control with labeled herbicides after exposure to a sub-lethal paraquat concentration. Labeled herbicide treatments were recommended rates of imazethapyr, quinclorac, propanil, bispyribac-sodium, cyhalopfop, and florpyrauxifen-benzyl applied following rice exposure to a sub-lethal concentration of paraquat. Rice injury was detected 7 and 28 d after treatment (DAT) with injury ≥ 35 and 14%, respectively, following all labeled herbicides. Florpyrauxifen-benzyl and imazethapyr injured rice the greatest 28 DAT. Following paraquat exposure, barnyardgrass control was similar for all labeled herbicide treatments 7, 14, and 28 DAT except with florpyrauxifen-benzyl and no labeled herbicide (paraquat alone) 7 DAT. Across all evaluations, barnyardgrass control was at least 12% greater following paraquat exposure and labeled herbicide treatments than with no paraquat exposure. The current research demonstrates that labeled herbicides applied following exposure to a sub-lethal concentration of paraquat resulted in <36% injury and provided as great as 95% control of barnyardgrass, depending on the herbicide treatment. Therefore, the labeled herbicides choice following rice exposure to a sub-lethal concentration of paraquat should be based on weed spectrum.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139766130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjamin C. Westrich, William G. Johnson, Bryan G. Young
Preemergence (PRE) applications of mesotrione, a herbicide that inhibits 4-hydroxyphenolpyruvate dioxygenase (HPPD), have recently gained regulatory approval in appropriately traited soybean varieties. Giant ragweed is an extremely competitive broadleaf weed, and biotypes resistant to acetolactate synthase inhibitors (ALS-R) can be particularly difficult to manage with soil-residual herbicides in soybean production. This study investigated control of giant ragweed from PRE applications of cloransulam (32 g ai ha-1), metribuzin (315 g ai ha-1), and S-metolachlor (1600 g ai ha-1) in a factorial design with and without mesotrione (177 g ai ha-1) at two different sites over two years. Treatments with mesotrione were also compared with two commercial premix products: sulfentrazone (283 g ai ha-1) and cloransulam (37 g ai ha-1), and chlorimuron (19 g ai ha-1), flumioxazin (69 g ai ha-1), and pyroxasulfone (87 g ai ha-1). At 42 days after planting, control and biomass reduction of giant ragweed were greater in treatments with mesotrione than any treatment without mesotrione. Giant ragweed biomass was reduced by 84% in treatments with mesotrione, while treatments without mesotrione did not reduce biomass relative to the nontreated. Following these PRE applications, sequential herbicide treatments utilizing postemergence (POST) applications of glufosinate (655 g ai ha-1) plus fomesafen (266 g ai ha-1) and S-metolachlor (1217 g ai ha-1) resulted in at least 97% control of giant ragweed at 42 days after planting, which was greater than sequential applications of glufosinate alone in 3 of 4 site-years. PRE applications of mesotrione can be an impactful addition to soybean herbicide programs designed to manage giant ragweed, with the potential to improve weed control and delay the onset of herbicide resistance by providing an additional effective herbicide site of action.
萌芽前（PRE）施用美索三酮（一种抑制 4- 羟基苯酚丙酮酸二氧酶 (HPPD) 的除草剂）最近获得了监管部门的批准，可用于适当性状的大豆品种。巨型豚草是一种竞争性极强的阔叶杂草，对乙酰乳酸合成酶抑制剂（ALS-R）产生抗性的生物型在大豆生产中尤其难以用土壤残留除草剂进行管理。本研究调查了在两个不同的地点，通过采用阶乘设计，在两年内预先施用氯酯磺草胺（32 g ai ha-1）、嗪草酮（315 g ai ha-1）和 S-甲草胺（1600 g ai ha-1），同时施用或不施用甲草胺（177 g ai ha-1）对巨豚草的控制情况。此外，还将使用介草酮的处理方法与两种商业预混料产品进行了比较：磺草酮（283 克/公顷）和氯虫苯甲酰胺（37 克/公顷），以及杀草隆（19 克/公顷）、氟吡氧乙酸（69 克/公顷）和吡唑醚菌酯（87 克/公顷）。在种植后 42 天，与未施用介草酮的处理相比，施用介草酮的处理对巨型豚草的控制和生物量的减少都更大。与未施用介草酮的处理相比，施用介草酮的处理大豚草生物量减少了 84%，而未施用介草酮的处理生物量没有减少。在施用这些预除草剂后，利用草铵膦（655 克活性成分/公顷-1）加福美双（266 克活性成分/公顷-1）和 S-甲草胺（1217 克活性成分/公顷-1）的出苗后（POST）除草剂进行连续除草处理，可在种植后 42 天控制至少 97% 的巨型豚草，在 4 个地点年中的 3 个地点年，控制效果优于单独施用草铵膦。在大豆除草剂计划中，在播种前施用介草酮可以有效控制大豚草，通过提供额外的有效除草剂作用点，有可能改善杂草控制并延缓除草剂抗药性的产生。
{"title":"Control of Giant Ragweed (Ambrosia trifida) in Mesotrione-Resistant Soybean","authors":"Benjamin C. Westrich, William G. Johnson, Bryan G. Young","doi":"10.1017/wet.2024.4","DOIUrl":"https://doi.org/10.1017/wet.2024.4","url":null,"abstract":"Preemergence (PRE) applications of mesotrione, a herbicide that inhibits 4-hydroxyphenolpyruvate dioxygenase (HPPD), have recently gained regulatory approval in appropriately traited soybean varieties. Giant ragweed is an extremely competitive broadleaf weed, and biotypes resistant to acetolactate synthase inhibitors (ALS-R) can be particularly difficult to manage with soil-residual herbicides in soybean production. This study investigated control of giant ragweed from PRE applications of cloransulam (32 g ai ha<jats:sup>-1</jats:sup>), metribuzin (315 g ai ha<jats:sup>-1</jats:sup>), and <jats:italic>S</jats:italic>-metolachlor (1600 g ai ha<jats:sup>-1</jats:sup>) in a factorial design with and without mesotrione (177 g ai ha<jats:sup>-1</jats:sup>) at two different sites over two years. Treatments with mesotrione were also compared with two commercial premix products: sulfentrazone (283 g ai ha<jats:sup>-1</jats:sup>) and cloransulam (37 g ai ha<jats:sup>-1</jats:sup>), and chlorimuron (19 g ai ha<jats:sup>-1</jats:sup>), flumioxazin (69 g ai ha<jats:sup>-1</jats:sup>), and pyroxasulfone (87 g ai ha<jats:sup>-1</jats:sup>). At 42 days after planting, control and biomass reduction of giant ragweed were greater in treatments with mesotrione than any treatment without mesotrione. Giant ragweed biomass was reduced by 84% in treatments with mesotrione, while treatments without mesotrione did not reduce biomass relative to the nontreated. Following these PRE applications, sequential herbicide treatments utilizing postemergence (POST) applications of glufosinate (655 g ai ha<jats:sup>-1</jats:sup>) plus fomesafen (266 g ai ha<jats:sup>-1</jats:sup>) and <jats:italic>S</jats:italic>-metolachlor (1217 g ai ha<jats:sup>-1</jats:sup>) resulted in at least 97% control of giant ragweed at 42 days after planting, which was greater than sequential applications of glufosinate alone in 3 of 4 site-years. PRE applications of mesotrione can be an impactful addition to soybean herbicide programs designed to manage giant ragweed, with the potential to improve weed control and delay the onset of herbicide resistance by providing an additional effective herbicide site of action.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"96 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：