Victor H. V. Ribeiro, C. Mallory-Smith, Jennifer A. Gourlie, Chad W. Shelton, Judit Barroso
Managing winter annual grass weeds has long been a challenge in the dryland soft white winter wheat-producing regions of the Pacific Northwest (PNW). The recent development of quizalofop-resistant (CoAXium) wheat varieties allows growers to use the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide quizalofop (QP) for postemergence grass control. Field experiments were conducted over two winter wheat growing seasons in 2021-2022 and 2022-2023 near Adams, OR, to evaluate QP efficacy on feral rye and for crop safety. Downy brome and jointed goatgrass control with QP were assessed in 2021-2022 and 2022-2023, respectively. Quizalofop treatments provided effective feral rye (≥ 95%), downy brome (≥ 87%), and jointed goatgrass (99%) control regardless of rates, adjuvants, and spray volumes tested. Spring-applied QP caused no winter wheat injury. Results indicate that the quizalofop-resistant wheat technology can help PNW wheat growers selectively control winter annual grasses.
{"title":"Feral rye (Secale cereale L.) control in quizalofop-resistant winter wheat in Oregon","authors":"Victor H. V. Ribeiro, C. Mallory-Smith, Jennifer A. Gourlie, Chad W. Shelton, Judit Barroso","doi":"10.1017/wet.2023.89","DOIUrl":"https://doi.org/10.1017/wet.2023.89","url":null,"abstract":"\u0000 Managing winter annual grass weeds has long been a challenge in the dryland soft white winter wheat-producing regions of the Pacific Northwest (PNW). The recent development of quizalofop-resistant (CoAXium) wheat varieties allows growers to use the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide quizalofop (QP) for postemergence grass control. Field experiments were conducted over two winter wheat growing seasons in 2021-2022 and 2022-2023 near Adams, OR, to evaluate QP efficacy on feral rye and for crop safety. Downy brome and jointed goatgrass control with QP were assessed in 2021-2022 and 2022-2023, respectively. Quizalofop treatments provided effective feral rye (≥ 95%), downy brome (≥ 87%), and jointed goatgrass (99%) control regardless of rates, adjuvants, and spray volumes tested. Spring-applied QP caused no winter wheat injury. Results indicate that the quizalofop-resistant wheat technology can help PNW wheat growers selectively control winter annual grasses.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"16 8","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949109","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}
Amit J. Jhala, Mandeep Singh, Lovreet S. Shergill, Rishabh Singh, M. Jugulam, D. Riechers, Z. A. Ganie, Thomas P. Selby, Rodrigo Werle, J. Norsworthy
The herbicides that inhibit very long chain fatty acid (VLCFA) elongases are primarily used for residual weed control in corn, barley, oat, sorghum, soybean, sugarcane, certain vegetable crops, and wheat production fields in the United States. They act primarily by inhibiting shoot development of susceptible species, preventing weed emergence and growth. The objectives of this review were to summarize (1) the chemical family of VLCFA-inhibiting herbicides and their use in the United States, (2) the VLCFA biosynthesis in plants and their site of action, (3) VLCFA-inhibitor resistant weeds and their mechanism of resistance, and (4) the future of VLCFA-inhibiting herbicides. After their re-classification as group 15 herbicides to include shoot growth-inhibiting herbicides (group 8), the VLCFA-inhibiting herbicides are currently represented by eight chemical families (benzofurans, thiocarbamates, α-chloroacetamides, α-oxyacetamides, azolyl-carboxamides, isoxazolines, α-thioacetamides, and oxiranes). On average, VLCFA-inhibiting herbicides are applied once a year in both corn and soybean in the United States with acetochlor and S-metolachlor being the most-used VLCFA-inhibiting herbicides in corn and soybean, respectively. The site of action of group 15 herbicides results from inhibition of the VLCFA synthase, encoded by several fatty acid elongase (FAE1)-like genes in VLCFA elongase complex in an endoplasmic reticulum. The VLCFA synthase is a condensing enzyme, and relies on a conserved, reactive cysteinyl sulfur in active site that performs a nucleophilic attack on either the natural substrate (fatty acyl-CoA) or the herbicide. As of August 2023, 13 weed species have been documented resistant to VLCFA-inhibitor, including 11 monocot weeds and two dicot weeds (Palmer amaranth and waterhemp). The isoxazolines (pyroxasulfone and fenoxasulfone) are the most recently (2014) discovered VLCFA-inhibiting herbicides. Although the intensity of VLCFA-inhibitor-directed discovery efforts has decreased over the past decade, this biochemical pathway remains a viable mechanistic target for the discovery and valuable component of herbicide premixes.
{"title":"Very long chain fatty acid-inhibiting herbicides: Current uses, site of action, herbicide-resistant weeds, and future","authors":"Amit J. Jhala, Mandeep Singh, Lovreet S. Shergill, Rishabh Singh, M. Jugulam, D. Riechers, Z. A. Ganie, Thomas P. Selby, Rodrigo Werle, J. Norsworthy","doi":"10.1017/wet.2023.90","DOIUrl":"https://doi.org/10.1017/wet.2023.90","url":null,"abstract":"\u0000 The herbicides that inhibit very long chain fatty acid (VLCFA) elongases are primarily used for residual weed control in corn, barley, oat, sorghum, soybean, sugarcane, certain vegetable crops, and wheat production fields in the United States. They act primarily by inhibiting shoot development of susceptible species, preventing weed emergence and growth. The objectives of this review were to summarize (1) the chemical family of VLCFA-inhibiting herbicides and their use in the United States, (2) the VLCFA biosynthesis in plants and their site of action, (3) VLCFA-inhibitor resistant weeds and their mechanism of resistance, and (4) the future of VLCFA-inhibiting herbicides. After their re-classification as group 15 herbicides to include shoot growth-inhibiting herbicides (group 8), the VLCFA-inhibiting herbicides are currently represented by eight chemical families (benzofurans, thiocarbamates, α-chloroacetamides, α-oxyacetamides, azolyl-carboxamides, isoxazolines, α-thioacetamides, and oxiranes). On average, VLCFA-inhibiting herbicides are applied once a year in both corn and soybean in the United States with acetochlor and S-metolachlor being the most-used VLCFA-inhibiting herbicides in corn and soybean, respectively. The site of action of group 15 herbicides results from inhibition of the VLCFA synthase, encoded by several fatty acid elongase (FAE1)-like genes in VLCFA elongase complex in an endoplasmic reticulum. The VLCFA synthase is a condensing enzyme, and relies on a conserved, reactive cysteinyl sulfur in active site that performs a nucleophilic attack on either the natural substrate (fatty acyl-CoA) or the herbicide. As of August 2023, 13 weed species have been documented resistant to VLCFA-inhibitor, including 11 monocot weeds and two dicot weeds (Palmer amaranth and waterhemp). The isoxazolines (pyroxasulfone and fenoxasulfone) are the most recently (2014) discovered VLCFA-inhibiting herbicides. Although the intensity of VLCFA-inhibitor-directed discovery efforts has decreased over the past decade, this biochemical pathway remains a viable mechanistic target for the discovery and valuable component of herbicide premixes.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"44 22","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949854","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}
Michael W. Marshall, Mitchell B. Williams, Michael A. Jones
A significant proportion of the forested production area in South Carolina is managed using aerial applications of imazapyr. Cotton injury from off-target movement of imazapyr has been observed in South Carolina. Field experiments were conducted at the Edisto Research and Education Center (EREC) in 2021 and 2022 and at the Pee Dee Research and Education Center (PDREC) in 2022 to evaluate the response of cotton at two growth stages to imazapyr at 0.1, 0.05, 0.025, 0.0125, and 0.00625X of the normal use rate of 0.84 kg ae ha-1. Vegetative cotton injury was 86 and 74% at 0.1 and 0.05X imazapyr rates 28 days after application (DAA). Cotton heights ranged from 23 to 93 cm across all three locations (EREC 2021, EREC 2022, and PDREC 2022). Yields at EREC 2021 were reduced by 79, 48 and 31% at the 0.1, 0.05, and 0.025X rates, respectively. Similar reductions from imazapyr were observed at EREC 2022 and PDREC 2022. Reproductive cotton visual injury 28 DAA ranged from 95 to 64% for the 0.1 to 0.0125X rates, respectively. Reproductive cotton height reductions were 59% of the untreated control 28 DAA at 0.1X rate. Seed cotton yields ranged from 0 to 2880 kg ha-1 across three locations in 2021 and 2022. Seed cotton yield was lowest at the 0.1 to 0.025X imazapyr rates. Cotton exposure to imazapyr at the vegetative and reproductive growth stages resulted in plant injury, height, and yield reductions, especially at the higher rates of imazapyr. The highest reduction in cotton growth and yield was observed after exposure at the reproductive growth stage across the imazapyr rates. In summary, the magnitude of cotton response to imazapyr depends on crop growth stage and imazapyr concentration at the time of exposure with the greatest impact occurring at the reproductive growth stage.
{"title":"Response of Cotton at Different Growth Stages to Imazapyr","authors":"Michael W. Marshall, Mitchell B. Williams, Michael A. Jones","doi":"10.1017/wet.2023.93","DOIUrl":"https://doi.org/10.1017/wet.2023.93","url":null,"abstract":"\u0000 A significant proportion of the forested production area in South Carolina is managed using aerial applications of imazapyr. Cotton injury from off-target movement of imazapyr has been observed in South Carolina. Field experiments were conducted at the Edisto Research and Education Center (EREC) in 2021 and 2022 and at the Pee Dee Research and Education Center (PDREC) in 2022 to evaluate the response of cotton at two growth stages to imazapyr at 0.1, 0.05, 0.025, 0.0125, and 0.00625X of the normal use rate of 0.84 kg ae ha-1. Vegetative cotton injury was 86 and 74% at 0.1 and 0.05X imazapyr rates 28 days after application (DAA). Cotton heights ranged from 23 to 93 cm across all three locations (EREC 2021, EREC 2022, and PDREC 2022). Yields at EREC 2021 were reduced by 79, 48 and 31% at the 0.1, 0.05, and 0.025X rates, respectively. Similar reductions from imazapyr were observed at EREC 2022 and PDREC 2022. Reproductive cotton visual injury 28 DAA ranged from 95 to 64% for the 0.1 to 0.0125X rates, respectively. Reproductive cotton height reductions were 59% of the untreated control 28 DAA at 0.1X rate. Seed cotton yields ranged from 0 to 2880 kg ha-1 across three locations in 2021 and 2022. Seed cotton yield was lowest at the 0.1 to 0.025X imazapyr rates. Cotton exposure to imazapyr at the vegetative and reproductive growth stages resulted in plant injury, height, and yield reductions, especially at the higher rates of imazapyr. The highest reduction in cotton growth and yield was observed after exposure at the reproductive growth stage across the imazapyr rates. In summary, the magnitude of cotton response to imazapyr depends on crop growth stage and imazapyr concentration at the time of exposure with the greatest impact occurring at the reproductive growth stage.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"28 14","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948244","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}
Daniel M. Adamson, Gustavo M. Sbatella, Andrew R. Kniss, Franck E. Dayan
Soil-applied herbicides are important for controlling weeds in many crops but risk damage to susceptible rotational crops if they persist. Field studies were conducted in Powell, Wyoming from 2015 through 2017 to evaluate the effect of reduced water availability on soil-applied herbicide dissipation. Eight soil-applied herbicides, applied to dry bean or corn, were exposed to three season-long irrigation treatments (100, 85, and 70% of estimated crop evapotranspiration [ETc]) by overhead sprinkler. Soil samples were collected to a depth of 10 cm from 0 to 140 d after application, and soil herbicide concentrations were quantified using gas or liquid chromatography and mass spectrometry. Herbicide concentrations were regressed over time to produce a soil half-life estimate for each herbicide and irrigation treatment. Reduced irrigation decreased dry bean yield by up to 77%, and corn yield by up to 50%. After adjusting for precipitation, the lowest irrigation treatment received 78% as much water as the full irrigation treatment in 2015 and 76% in 2016. This significantly increased the soil half-life of imazethapyr, but did not increase the soil half-life of atrazine, pyroxasulfone, saflufenacil, ethalfluralin, trifluralin, or pendimethalin. Reduced irrigation did not increase carryover injury to rotational crops from these herbicides one year after application. Instead, carryover response was determined by the inherent persistence of individual herbicides. Imazethapyr (0.1 kg ai ha-1) injured rotational sugar beet, and isoxaflutole (0.1 kg ai ha-1) injured rotational dry bean. Pyroxasulfone (0.2 kg ai ha-1), atrazine (2.0 kg ai ha-1), saflufenacil (0.1 kg ai ha-1) + dimethenamid-P (0.6 kg ai ha-1), ethalfluralin (0.8 kg ai ha-1), trifluralin (0.6 kg ai ha-1), and pendimethalin (1.1 kg ai ha-1) did not injure rotational crops regardless of irrigation treatment. Drought stress sufficient to cause up to 77% crop yield loss did not increase soil-applied herbicide carryover.
土壤施用除草剂对控制许多作物的杂草很重要，但如果杂草持续存在，可能会对易感轮作作物造成损害。2015年至2017年在怀俄明州鲍威尔进行了实地研究，以评估水分有效性降低对土壤施用除草剂消散的影响。将8种土壤除草剂分别施用于干豆或玉米上，通过顶置洒水器进行3个季节的灌溉处理(分别为作物蒸散量的100%、85%和70%[等])。施用后0 ~ 140 d采集土壤样品至10 cm深度，采用气相色谱或液相色谱和质谱法定量土壤除草剂浓度。除草剂浓度随时间回归，得出每种除草剂和灌溉处理的土壤半衰期估计。减少灌溉可使干豆产量减少77%，玉米产量减少50%。经降水调整后，2015年最低灌溉处理水量为充分灌溉处理水量的78%，2016年为76%。这显著增加了吡嗪的土壤半衰期，但没有增加阿特拉津、pyroxasulfone、氟虫酸、乙氟拉林、三氟拉林和戊二甲基灵的土壤半衰期。减少灌溉并没有增加施用一年后这些除草剂对轮作作物的结转伤害。相反，遗留反应是由单个除草剂的固有持久性决定的。Imazethapyr (0.1 kg / ha-1)对轮作甜菜有害，异草氟唑(0.1 kg / ha-1)对轮作干豆有害。吡唑酮(0.2 kg ai ha-1)、阿特拉津(2.0 kg ai ha-1)、氟虫腈(0.1 kg ai ha-1) +二甲酰胺- p (0.6 kg ai ha-1)、氟虫灵(0.8 kg ai ha-1)、三氟虫灵(0.6 kg ai ha-1)和二甲虫灵(1.1 kg ai ha-1)对轮作作物均无损害，无论灌溉方式如何。足以造成高达77%作物产量损失的干旱胁迫并没有增加土壤施用除草剂的携带性。
{"title":"Reduced irrigation impact on soil-applied herbicide dissipation and rotational crop response","authors":"Daniel M. Adamson, Gustavo M. Sbatella, Andrew R. Kniss, Franck E. Dayan","doi":"10.1017/wet.2023.85","DOIUrl":"https://doi.org/10.1017/wet.2023.85","url":null,"abstract":"Soil-applied herbicides are important for controlling weeds in many crops but risk damage to susceptible rotational crops if they persist. Field studies were conducted in Powell, Wyoming from 2015 through 2017 to evaluate the effect of reduced water availability on soil-applied herbicide dissipation. Eight soil-applied herbicides, applied to dry bean or corn, were exposed to three season-long irrigation treatments (100, 85, and 70% of estimated crop evapotranspiration [ETc]) by overhead sprinkler. Soil samples were collected to a depth of 10 cm from 0 to 140 d after application, and soil herbicide concentrations were quantified using gas or liquid chromatography and mass spectrometry. Herbicide concentrations were regressed over time to produce a soil half-life estimate for each herbicide and irrigation treatment. Reduced irrigation decreased dry bean yield by up to 77%, and corn yield by up to 50%. After adjusting for precipitation, the lowest irrigation treatment received 78% as much water as the full irrigation treatment in 2015 and 76% in 2016. This significantly increased the soil half-life of imazethapyr, but did not increase the soil half-life of atrazine, pyroxasulfone, saflufenacil, ethalfluralin, trifluralin, or pendimethalin. Reduced irrigation did not increase carryover injury to rotational crops from these herbicides one year after application. Instead, carryover response was determined by the inherent persistence of individual herbicides. Imazethapyr (0.1 kg ai ha<jats:sup>-1</jats:sup>) injured rotational sugar beet, and isoxaflutole (0.1 kg ai ha<jats:sup>-1</jats:sup>) injured rotational dry bean. Pyroxasulfone (0.2 kg ai ha<jats:sup>-1</jats:sup>), atrazine (2.0 kg ai ha<jats:sup>-1</jats:sup>), saflufenacil (0.1 kg ai ha<jats:sup>-1</jats:sup>) + dimethenamid-P (0.6 kg ai ha<jats:sup>-1</jats:sup>), ethalfluralin (0.8 kg ai ha<jats:sup>-1</jats:sup>), trifluralin (0.6 kg ai ha<jats:sup>-1</jats:sup>), and pendimethalin (1.1 kg ai ha<jats:sup>-1</jats:sup>) did not injure rotational crops regardless of irrigation treatment. Drought stress sufficient to cause up to 77% crop yield loss did not increase soil-applied herbicide carryover.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"93 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538833","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}
: Florpyrauxifen-benzyl (FPB) is an important postemergence rice herbicide. This study tested the potential for seed production in an FPB-resistant barnyardgrass population. A barnyardgrass population (NL) collected from a rice field in eastern China was highly resistant to FPB with a GR50 dose (the FPB dose causing a 50% reduction in fresh weight of aboveground parts) of 50.2 g ai ha−1. No significant differences in the percentages of surviving seedlings after treatment with different doses of the herbicide were found between F1 lines collected from F0 plants surviving a 36 g ai ha−1 FPB treatment and those collected from non-treated control F0 plants. Additionally, no significant differences were found in the rate of surviving seedlings after treatment with varying doses of FPB among the F2 lines collected from F1 plants that survived varying doses of FPB. At a constant temperature of 30 C, seeds from different F1 and F2 lines showed germination percentages of 85%‒92.0% and 68.3%‒89.0%, respectively. In the absence of competition, plants from the NL population surviving 0–144 g ai ha−1 FPB showed no significant differences in plant height, dry weight of aboveground parts, effective accumulated temperature (EAT) from sowing to seed maturation, seed production per plant, or 1000-seed weight. In the susceptible population (HJ), plants surviving 18 g ai ha−1 FPB showed no significant differences compared to the non-treated control plants of the same population for the above variables. This is the first report of FPB-resistant barnyardgrass in China. Barnyardgrass seedlings that survived FPB application showed a higher potential for accumulating in the soil seedbank and negatively affecting rice.
氟吡虫胺苄(FPB)是一种重要的水稻苗期除草剂。本研究测试了一个抗fpb的谷仓草种群的种子生产潜力。从中国东部稻田收集的一个禾草种群(NL)对赤霉病具有高度抗性，GR50剂量(赤霉病剂量导致地上部分鲜重减少50%)为50.2 g / ha - 1。F0植株经36 g ha - 1 FPB处理后的成活率与未处理的对照F0植株的成活率无显著差异。此外，在不同剂量的FPB处理后，从F1植株收集的F2系中，发现不同剂量FPB处理后的成活率没有显著差异。在30℃恒温条件下，不同F1系和F2系的种子发芽率分别为85% ~ 92.0%和68.3% ~ 89.0%。在没有竞争的情况下，存活0 ~ 144 g / h的NL群体植株在株高、地上部分干重、播种至种子成熟的有效积温、单株产量和千粒重方面均无显著差异。在易感群体(HJ)中，存活18 g ha - 1 FPB的植株与未处理的对照植株相比，上述变量均无显著差异。这是中国首次报道抗fpb的稗草。在FPB处理下存活的稗草幼苗在土壤种子库中积累的潜力较大，对水稻产生负面影响。
{"title":"Echinochloa crus-galli seedlings surviving florpyrauxifen-benzyl applications have a greater potential to produce resistant seeds","authors":"Guoqi Chen, Xiangxin Zhuang, Aatiqa Masoom, Yang Chen, Yunhua Gu, Jiahao Zhang","doi":"10.1017/wet.2023.87","DOIUrl":"https://doi.org/10.1017/wet.2023.87","url":null,"abstract":": Florpyrauxifen-benzyl (FPB) is an important postemergence rice herbicide. This study tested the potential for seed production in an FPB-resistant barnyardgrass population. A barnyardgrass population (NL) collected from a rice field in eastern China was highly resistant to FPB with a GR<jats:sub>50</jats:sub> dose (the FPB dose causing a 50% reduction in fresh weight of aboveground parts) of 50.2 g ai ha<jats:sup>−1</jats:sup>. No significant differences in the percentages of surviving seedlings after treatment with different doses of the herbicide were found between F<jats:sub>1</jats:sub> lines collected from F<jats:sub>0</jats:sub> plants surviving a 36 g ai ha<jats:sup>−1</jats:sup> FPB treatment and those collected from non-treated control F<jats:sub>0</jats:sub> plants. Additionally, no significant differences were found in the rate of surviving seedlings after treatment with varying doses of FPB among the F<jats:sub>2</jats:sub> lines collected from F<jats:sub>1</jats:sub> plants that survived varying doses of FPB. At a constant temperature of 30 C, seeds from different F<jats:sub>1</jats:sub> and F<jats:sub>2</jats:sub> lines showed germination percentages of 85%‒92.0% and 68.3%‒89.0%, respectively. In the absence of competition, plants from the NL population surviving 0–144 g ai ha<jats:sup>−1</jats:sup> FPB showed no significant differences in plant height, dry weight of aboveground parts, effective accumulated temperature (EAT) from sowing to seed maturation, seed production per plant, or 1000-seed weight. In the susceptible population (HJ), plants surviving 18 g ai ha<jats:sup>−1</jats:sup> FPB showed no significant differences compared to the non-treated control plants of the same population for the above variables. This is the first report of FPB-resistant barnyardgrass in China. Barnyardgrass seedlings that survived FPB application showed a higher potential for accumulating in the soil seedbank and negatively affecting rice.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"2 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538799","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}
Matthew B. Bertucci, Thomas R. Butts, Koffi Badou-Jeremie Kouame, Jason K. Norsworthy
Two low-dose dicamba exposure trials were conducted on container-grown peach trees in Fayetteville, AR. Peach trees were ‘July Prince’ scions grafted onto ‘Guardian’ rootstock and were transplanted into 19 L containers and received experimental dicamba treatments in each year. Container trials were initiated in 2020 and repeated on new trees in 2021. In the repeated application trial, dicamba was applied at 5.6 g ae ha-1 (1/100× field rate) in five sequences: an untreated control receiving no herbicide, one treatment receiving only initial application, and three treatments receiving initial application plus sequential applications at the same rate occurring 14 d, 28 d, 14 d + 28 d after initial treatment (DAT). A separate trial assessed peach tree responses to dicamba applied at 11.2 g ae ha-1 (1/50× field rate) using a selection of nozzles with differing droplet spectrum characteristics: Turbo TeeJet® Induction (TTI11002), Air Induction Turbo TeeJet® (AITTJ60-11002), AIXR TeeJet® (AIXR11002, air induction extended range), XR TeeJet® (XR11002, extended range flat fan), and XR TeeJet® (XR1100067, extended range flat fan). Peach tree height, tree cross sectional area (TCSA) and leaf chlorophyll content were not reduced in response to any sequence of dicamba application or nozzle selection. Repeated applications of dicamba at 1/100× rate did not increase peach injury after 28 DAT. By 84 DAT, no effect of nozzle type on peach tree injury was discernable, and all treatments caused below 4% injury. No dicamba or dicamba metabolites were observed in leaf samples collected at 14, 69, or 85 DAT from trees treated with XR1100067 nor in untreated controls. While peach tree injury was observed throughout the experiment, dicamba residues were only detected consistently in 2020 from leaf samples of trees treated with dicamba at 1/50× rate using TTI1102, AITTJ60-11002, AIXR11002, and XR11002 nozzles.
在AR州费耶特维尔的容器栽培桃树上进行了两项低剂量麦草畏暴露试验。桃树是“七月王子”接穗嫁接到“守护者”砧木上，移植到19升的容器中，每年接受麦草畏试验处理。容器试验于2020年启动，并于2021年在新树上重复。在重复施用试验中，麦草畏按5.6 g / hm -1(1/100倍田间施用量)分5个顺序施用:未处理对照不施用除草剂，1个处理只施用初施，3个处理在初施后14 d、28 d、14 d + 28 d以相同的施用量连续施用(DAT)。另一项试验评估了桃树对11.2 g / ha-1(1/50倍场率)麦草畏的反应，使用具有不同液滴光谱特征的喷嘴:Turbo TeeJet®感应(TTI11002)、Air Induction Turbo TeeJet®(AITTJ60-11002)、AIXR TeeJet®(AIXR11002，空气感应扩展范围)、XR TeeJet®(XR11002，扩展范围平风扇)和XR TeeJet®(XR1100067，扩展范围平风扇)。不同施用麦草畏和喷嘴的桃树高、树横截面积(TCSA)和叶片叶绿素含量均不受不同施用顺序的影响。以1/100倍剂量重复施用麦草畏对28天后的桃损伤无显著影响。84个DAT时，喷管类型对桃树伤害无明显影响，所有处理的伤害均在4%以下。在XR1100067处理的树木和未处理的对照中，在14、69或85 DAT采集的叶片样本中未观察到麦草畏或麦草畏代谢物。虽然整个试验过程中都观察到桃树的伤害，但在2020年，使用TTI1102、AITTJ60-11002、AIXR11002和XR11002喷嘴以1/50的比例处理的树木叶片样品中，麦草畏残留的检测结果一致。
{"title":"Peach Tree Response to Low-Dosages of Dicamba as Repeated Applications or with Various Spray Nozzles","authors":"Matthew B. Bertucci, Thomas R. Butts, Koffi Badou-Jeremie Kouame, Jason K. Norsworthy","doi":"10.1017/wet.2023.80","DOIUrl":"https://doi.org/10.1017/wet.2023.80","url":null,"abstract":"Two low-dose dicamba exposure trials were conducted on container-grown peach trees in Fayetteville, AR. Peach trees were ‘July Prince’ scions grafted onto ‘Guardian’ rootstock and were transplanted into 19 L containers and received experimental dicamba treatments in each year. Container trials were initiated in 2020 and repeated on new trees in 2021. In the repeated application trial, dicamba was applied at 5.6 g ae ha<jats:sup>-1</jats:sup> (1/100× field rate) in five sequences: an untreated control receiving no herbicide, one treatment receiving only initial application, and three treatments receiving initial application plus sequential applications at the same rate occurring 14 d, 28 d, 14 d + 28 d after initial treatment (DAT). A separate trial assessed peach tree responses to dicamba applied at 11.2 g ae ha<jats:sup>-1</jats:sup> (1/50× field rate) using a selection of nozzles with differing droplet spectrum characteristics: Turbo TeeJet® Induction (TTI11002), Air Induction Turbo TeeJet® (AITTJ60-11002), AIXR TeeJet® (AIXR11002, air induction extended range), XR TeeJet® (XR11002, extended range flat fan), and XR TeeJet® (XR1100067, extended range flat fan). Peach tree height, tree cross sectional area (TCSA) and leaf chlorophyll content were not reduced in response to any sequence of dicamba application or nozzle selection. Repeated applications of dicamba at 1/100× rate did not increase peach injury after 28 DAT. By 84 DAT, no effect of nozzle type on peach tree injury was discernable, and all treatments caused below 4% injury. No dicamba or dicamba metabolites were observed in leaf samples collected at 14, 69, or 85 DAT from trees treated with XR1100067 nor in untreated controls. While peach tree injury was observed throughout the experiment, dicamba residues were only detected consistently in 2020 from leaf samples of trees treated with dicamba at 1/50× rate using TTI1102, AITTJ60-11002, AIXR11002, and XR11002 nozzles.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"11 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538874","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}
Estefania G. Polli, Travis W. Gannon, Mathieu LeCompte, Ronald R. Rogers, Daniel D. Beran
2,4-D and dicamba are postemergence herbicides widely used to control broadleaf weed species in crop and non-crop areas in the United States. Currently, there are multiple formulations of 2,4-D and dicamba available in the market. Even though the active ingredient is the same, the chemical form may vary by formulation, which can influence the volatility potential of these herbicides. Therefore, the objective of this study was to evaluate the response of soybean, cotton, and tobacco plants exposed to vapor of 2,4-D and dicamba formulations alone or mixed in humidomes for 24 h. Humidome studies were conducted in an open pavilion at the Lake Wheeler Turfgrass Field Lab of the North Carolina State University in Raleigh, NC. Dicamba and mixture treatments injured and affected height of soybean. Injury varied from 55% to 70%, and average plant height was 8.8 cm lower when compared to the untreated control. 2,4-D treatments caused the lowest injury in soybean (≤ 21%), and differences among formulations were identified (dimethylamine > choline > dimethylamine-monomethylamine). However, soybean height was not affected by 2,4-D treatments. No differences between herbicide treatments were observed for cotton. The highest injury in tobacco was caused by dicamba dimethylamine (23.3%). Overall, the effect of 2,4-D and dicamba vapor was species-specific and formulation-dependent. Additionally, weather conditions in the humidomes possibly played a major role on the outcome of this study.
{"title":"Response of Soybean, Cotton, and Tobacco to Volatility of 2,4-D and Dicamba Formulations in Humidome","authors":"Estefania G. Polli, Travis W. Gannon, Mathieu LeCompte, Ronald R. Rogers, Daniel D. Beran","doi":"10.1017/wet.2023.86","DOIUrl":"https://doi.org/10.1017/wet.2023.86","url":null,"abstract":"2,4-D and dicamba are postemergence herbicides widely used to control broadleaf weed species in crop and non-crop areas in the United States. Currently, there are multiple formulations of 2,4-D and dicamba available in the market. Even though the active ingredient is the same, the chemical form may vary by formulation, which can influence the volatility potential of these herbicides. Therefore, the objective of this study was to evaluate the response of soybean, cotton, and tobacco plants exposed to vapor of 2,4-D and dicamba formulations alone or mixed in humidomes for 24 h. Humidome studies were conducted in an open pavilion at the Lake Wheeler Turfgrass Field Lab of the North Carolina State University in Raleigh, NC. Dicamba and mixture treatments injured and affected height of soybean. Injury varied from 55% to 70%, and average plant height was 8.8 cm lower when compared to the untreated control. 2,4-D treatments caused the lowest injury in soybean (≤ 21%), and differences among formulations were identified (dimethylamine > choline > dimethylamine-monomethylamine). However, soybean height was not affected by 2,4-D treatments. No differences between herbicide treatments were observed for cotton. The highest injury in tobacco was caused by dicamba dimethylamine (23.3%). Overall, the effect of 2,4-D and dicamba vapor was species-specific and formulation-dependent. Additionally, weather conditions in the humidomes possibly played a major role on the outcome of this study.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"2 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538836","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}
Jeanine Arana, Stephen L. Meyers, Emmanuel Cooper, Luis F. Medina, Josué Cerritos, Carlos A. López
Few published studies exist documenting banana pepper tolerance to clomazone. Therefore, field trials were conducted in 2022 at two Indiana locations [Meigs Horticulture Research Farm and the Pinney Purdue Agricultural Center (PPAC)] to evaluate crop safety in plasticulture-grown banana pepper. The experimental design was a split-plot in which the main plot factor was the clomazone rate (0, 840 and 1,680 g ai ha-1), and the subplot factor was cultivar (‘Pageant’ and ‘Sweet Sunset’). Clomazone was applied over-the-top of black polyethylene mulch-covered raised beds and their respective bare ground row middles one day prior to transplanting 12 pepper plants per subplot. Data collected included crop injury on a scale from 0% (no injury) to 100% (crop death) at 2, 4, and 6 wk after treatment (WAT), and plant stand. Two harvests were performed in which mature fruits were counted and weighed. Injury presented as interveinal bleaching only at PPAC 2 and 4 WAT. At this location 1,680 g ha-1 clomazone resulted in greater injury to ‘Sweet Sunset’ at 2 and 4 WAT (53 and 15%, respectively) than to ‘Pageant’ (19 and 3%, respectively), however, plant stand and yield were not affected by either clomazone rate. These results suggest that the clomazone rate range currently used for bell pepper (280 to 1,120 g ai ha-1) can be applied prior to transplanting plasticulture-grown banana pepper with minimal crop injury and without reducing yield.
很少有发表的研究记录香蕉辣椒对氯马酮的耐受性。因此，我们于2022年在印第安纳州的两个地点(Meigs园艺研究农场和Pinney Purdue农业中心)进行了田间试验，以评估塑料栽培香蕉辣椒的作物安全性。试验设计为分块样区，主样区因子为氯马唑酮率(0,840和1,680 g / ha-1)，次样区因子为品种(' Pageant '和' Sweet Sunset ')。在每亩地移植12株辣椒前一天，将氯马唑酮施用于黑色聚乙烯地膜覆盖的栽培床及其各自的裸地行中部。收集的数据包括处理后2、4和6周(WAT)的作物伤害从0%(无伤害)到100%(作物死亡)，以及植株生长情况。进行了两次收获，对成熟的果实进行了计数和称重。损伤仅在PPAC 2和4 WAT时表现为静脉间白化。在这个位置，1,680 g ha-1氯马唑酮对“Sweet Sunset”在2 WAT和4 WAT时的伤害(分别为53%和15%)比对“Pageant”的伤害(分别为19%和3%)更大，但是，两种氯马唑酮浓度对植株的林分和产量都没有影响。这些结果表明，目前用于甜椒的氯丙唑酮用量范围(280 ~ 1120 g / ha-1)可以在塑料栽培的香蕉辣椒移栽前施用，对作物的伤害最小，且不会降低产量。
{"title":"Plasticulture Banana Pepper Response to Clomazone Applied Pretransplanting (PRE)","authors":"Jeanine Arana, Stephen L. Meyers, Emmanuel Cooper, Luis F. Medina, Josué Cerritos, Carlos A. López","doi":"10.1017/wet.2023.78","DOIUrl":"https://doi.org/10.1017/wet.2023.78","url":null,"abstract":"Few published studies exist documenting banana pepper tolerance to clomazone. Therefore, field trials were conducted in 2022 at two Indiana locations [Meigs Horticulture Research Farm and the Pinney Purdue Agricultural Center (PPAC)] to evaluate crop safety in plasticulture-grown banana pepper. The experimental design was a split-plot in which the main plot factor was the clomazone rate (0, 840 and 1,680 g ai ha<jats:sup>-1</jats:sup>), and the subplot factor was cultivar (‘Pageant’ and ‘Sweet Sunset’). Clomazone was applied over-the-top of black polyethylene mulch-covered raised beds and their respective bare ground row middles one day prior to transplanting 12 pepper plants per subplot. Data collected included crop injury on a scale from 0% (no injury) to 100% (crop death) at 2, 4, and 6 wk after treatment (WAT), and plant stand. Two harvests were performed in which mature fruits were counted and weighed. Injury presented as interveinal bleaching only at PPAC 2 and 4 WAT. At this location 1,680 g ha<jats:sup>-1</jats:sup> clomazone resulted in greater injury to ‘Sweet Sunset’ at 2 and 4 WAT (53 and 15%, respectively) than to ‘Pageant’ (19 and 3%, respectively), however, plant stand and yield were not affected by either clomazone rate. These results suggest that the clomazone rate range currently used for bell pepper (280 to 1,120 g ai ha<jats:sup>-1</jats:sup>) can be applied prior to transplanting plasticulture-grown banana pepper with minimal crop injury and without reducing yield.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"63 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538864","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}
Mandeep Singh, Vipan Kumar, Stevan Z. Knezevic, Suat Irmak, John L. Lindquist, Santosh Pitla, Amit J. Jhala
Corn resistant to aryloxyphenoxypropionates (FOPs) (Enlist™ corn) enables the use of quizalofop-p-ethyl (QPE) as a selective postemergence (POST) herbicide for control of glufosinate/glyphosate-resistant corn volunteers. Growers usually mix QPE with 2,4-D choline and/or glufosinate to achieve broad-spectrum weed control in Enlist™ corn. The objectives of this study were to (1) evaluate the efficacy of QPE applied alone or mixed with 2,4-D choline and/or glufosinate for control of glufosinate/glyphosate-resistant corn volunteers in Enlist™ corn and (2) determine the impact of application time (V3 or V6 growth stage of volunteer corn) of QPE-based treatments on volunteer corn control as well as Enlist™ corn injury and yield. Field experiments were conducted at South Central Agricultural Lab, Clay Center, NE in 2021 and 2022. Quizalofop-p-ethyl (46 or 93 g ai ha‒1) applied at V3 or V6 growth stage controlled volunteer corn ≥ 88% and ≥ 95% at 14 and 28 d after treatment (DAT), respectively. The QPE (46 g ai ha‒1) mixed with 2,4-D choline (800 g ae ha‒1) had 33% less expected control of V3 volunteer corn in 2021, and 8% less than expected control of V6 volunteer corn in 2022 at 14 DAT. Volunteer corn control was improved by 7%-9% using the higher rate of QPE (93 g ai ha‒1) in a mixture with 2,4-D choline (1,060 g ae ha‒1). The QPE mixed with glufosinate had an additive effect and interactions in any combinations were additive beyond 28 DAT. Mixing 2,4-D choline can reduce QPE efficacy on glufosinate/glyphosate-resistant corn volunteers up to 14 DAT when applied at the V3 or V6 growth stage; however, the antagonistic interaction did not translate into corn yield loss. Increasing the rate of QPE (93 g ai ha‒1) while mixing with 2,4-D choline can reduce antagonism.
摘要:抗芳基苯氧丙酸酯(FOPs)玉米(Enlist™玉米)使quizalofop-p-ethyl (QPE)作为一种选择性的苗期(POST)除草剂，用于控制抗草甘膦/草甘膦玉米志愿者。种植者通常将QPE与2,4- d胆碱和/或草铵膦混合使用，以实现对Enlist™玉米的广谱杂草控制。本研究的目的是(1)评估QPE单独施用或与2,4- d胆碱和/或草铵膦混合施用对Enlist™玉米中抗草铵膦/草甘膦玉米志愿者的控制效果;(2)确定施用时间(志愿者玉米的V3或V6生育期)对志愿者玉米的控制以及对Enlist™玉米的伤害和产量的影响。田间试验于2021年和2022年在东北克莱中心中南农业实验室进行。在V3或V6生育期施用quizalofp -p-ethyl(46或93 g / ha -1)，在处理后14和28 d (DAT)分别控制志愿者玉米≥88%和≥95%。QPE (46 g / ha -1)与2,4- d胆碱(800 g / ha -1)混合，在2021年V3志愿者玉米的预期控制减少33%，在2022年14 DAT时V6志愿者玉米的预期控制减少8%。在与2,4- d胆碱(1,060 g / / 1)混合的高QPE (93 g / / 1)中，志愿者的玉米控制能力提高了7%-9%。QPE与草甘膦混合具有加性效应，任何组合的相互作用都是加性的，超过28 DAT。混合2,4- d胆碱可使抗草铵膦/草甘膦玉米志愿者的QPE效果在V3或V6生长阶段降低至14dat;然而，拮抗作用并未转化为玉米产量损失。在与2,4- d胆碱混合时，增加QPE的比率(93 g / ha -1)可以减少拮抗作用。
{"title":"Interaction of quizalofop-p-ethyl with 2,4-D choline and/or glufosinate for control of volunteer corn in corn resistant to aryloxyphenoxypropionates","authors":"Mandeep Singh, Vipan Kumar, Stevan Z. Knezevic, Suat Irmak, John L. Lindquist, Santosh Pitla, Amit J. Jhala","doi":"10.1017/wet.2023.79","DOIUrl":"https://doi.org/10.1017/wet.2023.79","url":null,"abstract":"Corn resistant to aryloxyphenoxypropionates (FOPs) (Enlist™ corn) enables the use of quizalofop-p-ethyl (QPE) as a selective postemergence (POST) herbicide for control of glufosinate/glyphosate-resistant corn volunteers. Growers usually mix QPE with 2,4-D choline and/or glufosinate to achieve broad-spectrum weed control in Enlist™ corn. The objectives of this study were to (1) evaluate the efficacy of QPE applied alone or mixed with 2,4-D choline and/or glufosinate for control of glufosinate/glyphosate-resistant corn volunteers in Enlist™ corn and (2) determine the impact of application time (V3 or V6 growth stage of volunteer corn) of QPE-based treatments on volunteer corn control as well as Enlist™ corn injury and yield. Field experiments were conducted at South Central Agricultural Lab, Clay Center, NE in 2021 and 2022. Quizalofop-p-ethyl (46 or 93 g ai ha‒1) applied at V3 or V6 growth stage controlled volunteer corn ≥ 88% and ≥ 95% at 14 and 28 d after treatment (DAT), respectively. The QPE (46 g ai ha‒1) mixed with 2,4-D choline (800 g ae ha‒1) had 33% less expected control of V3 volunteer corn in 2021, and 8% less than expected control of V6 volunteer corn in 2022 at 14 DAT. Volunteer corn control was improved by 7%-9% using the higher rate of QPE (93 g ai ha‒1) in a mixture with 2,4-D choline (1,060 g ae ha‒1). The QPE mixed with glufosinate had an additive effect and interactions in any combinations were additive beyond 28 DAT. Mixing 2,4-D choline can reduce QPE efficacy on glufosinate/glyphosate-resistant corn volunteers up to 14 DAT when applied at the V3 or V6 growth stage; however, the antagonistic interaction did not translate into corn yield loss. Increasing the rate of QPE (93 g ai ha‒1) while mixing with 2,4-D choline can reduce antagonism.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135634004","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}
Abstract Limited research has been directed at evaluating the ability of single cover crop plantings to suppress weeds in crops beyond the initial field season. Thus, this experiment was conducted to investigate the ability of a second-year self-regenerated annual and second-year perennial cover crop planting to suppress weeds during the critical period for weed control (CPWC) in soybean. Whole plot treatments included: (1) conventional till, (2) no-till with cover crop residue, (3) living mulch + cover crop residue, and (4) living mulch + winter killed residue. Sub-plot treatments involved weed management intensity: a) no weed management (weedy), b) weeds manually removed through the CPWC (third node soybean stage; V3), and c) weeds manually removed until soybean canopy closure (weed-free). Overall, total annual cover crop biomass during the second field season was comparable to biomass obtained from direct seeded stands during the initial field season. All cover crop treatments reduced total weed biomass through the CPWC compared to conventional till. Soybean yield was low across all treatments in this experiment. Still, yield was similar between cover crop and conventional till treatments at one site-year, however, yields were lower in all cover crop treatments at the other site-year.
{"title":"Influence of cover cropping and conservation tillage on weeds during the critical period for weed control in soybean","authors":"Veronica Yurchak, Alan Leslie, Cerruti R.R. Hooks","doi":"10.1017/wet.2023.82","DOIUrl":"https://doi.org/10.1017/wet.2023.82","url":null,"abstract":"Abstract Limited research has been directed at evaluating the ability of single cover crop plantings to suppress weeds in crops beyond the initial field season. Thus, this experiment was conducted to investigate the ability of a second-year self-regenerated annual and second-year perennial cover crop planting to suppress weeds during the critical period for weed control (CPWC) in soybean. Whole plot treatments included: (1) conventional till, (2) no-till with cover crop residue, (3) living mulch + cover crop residue, and (4) living mulch + winter killed residue. Sub-plot treatments involved weed management intensity: a) no weed management (weedy), b) weeds manually removed through the CPWC (third node soybean stage; V3), and c) weeds manually removed until soybean canopy closure (weed-free). Overall, total annual cover crop biomass during the second field season was comparable to biomass obtained from direct seeded stands during the initial field season. All cover crop treatments reduced total weed biomass through the CPWC compared to conventional till. Soybean yield was low across all treatments in this experiment. Still, yield was similar between cover crop and conventional till treatments at one site-year, however, yields were lower in all cover crop treatments at the other site-year.","PeriodicalId":23710,"journal":{"name":"Weed Technology","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135635362","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}
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