Abstract Goosegrass [ Eleusine indica (L.) Gaertn.] is one of the most problematic grassy weeds in the world. It is considered to be an important weed in summer fallows and crops grown in the eastern region of Australia. To examine the seed germination ecology of two populations (Gatton and Ingham) of E. indica and their response to postemergence herbicides in Australian conditions, experiments were carried out in the laboratory and screenhouse. Seedling survival, spike production, and plant biomass of both E. indica populations declined markedly with the application of postemergence herbicides such as butroxydim, clethodim, glufosinate, haloxyfop, and propaquizafop, whereas the application of paraquat failed to control the Ingham population. A dose–response study verified the presence of paraquat resistance in the Ingham population. In this regard, it was observed that the paraquat doses required to achieve a 50% reduction in survival and plant biomass were 27 and 21 times greater in the Ingham population compared to the Gatton population, respectively. Higher alternating temperatures (35/25 and 30/20 C) resulted in greater germination of both populations than lower alternating temperatures (20/10 and 25/15 C). At 20/10 C, the Ingham population failed to germinate; however, about 15% germination in the Gatton population was observed. At the lowest alternate temperature range (15/5 C), neither population germinated. The germination of both populations of E. indica was severely reduced under completely dark conditions compared with the alternating light/dark period. Germination was more tolerant of salt and water stress in the Ingham population compared with the Gatton population. Eleusine indica seedling emergence was comparable among populations, and the greatest emergence (83%) was observed for seeds buried at a depth of 2 cm but then declined dramatically, and no seedlings emerged from an 8-cm burial depth. The information acquired from this study could be used in developing effective management strategies for E. indica .
{"title":"Herbicide response and germination behavior of two goosegrass (<i>Eleusine indica</i>) populations in the Australian environment","authors":"Virender Singh Hooda, Bhagirath Singh Chauhan","doi":"10.1017/wsc.2023.51","DOIUrl":"https://doi.org/10.1017/wsc.2023.51","url":null,"abstract":"Abstract Goosegrass [ Eleusine indica (L.) Gaertn.] is one of the most problematic grassy weeds in the world. It is considered to be an important weed in summer fallows and crops grown in the eastern region of Australia. To examine the seed germination ecology of two populations (Gatton and Ingham) of E. indica and their response to postemergence herbicides in Australian conditions, experiments were carried out in the laboratory and screenhouse. Seedling survival, spike production, and plant biomass of both E. indica populations declined markedly with the application of postemergence herbicides such as butroxydim, clethodim, glufosinate, haloxyfop, and propaquizafop, whereas the application of paraquat failed to control the Ingham population. A dose–response study verified the presence of paraquat resistance in the Ingham population. In this regard, it was observed that the paraquat doses required to achieve a 50% reduction in survival and plant biomass were 27 and 21 times greater in the Ingham population compared to the Gatton population, respectively. Higher alternating temperatures (35/25 and 30/20 C) resulted in greater germination of both populations than lower alternating temperatures (20/10 and 25/15 C). At 20/10 C, the Ingham population failed to germinate; however, about 15% germination in the Gatton population was observed. At the lowest alternate temperature range (15/5 C), neither population germinated. The germination of both populations of E. indica was severely reduced under completely dark conditions compared with the alternating light/dark period. Germination was more tolerant of salt and water stress in the Ingham population compared with the Gatton population. Eleusine indica seedling emergence was comparable among populations, and the greatest emergence (83%) was observed for seeds buried at a depth of 2 cm but then declined dramatically, and no seedlings emerged from an 8-cm burial depth. The information acquired from this study could be used in developing effective management strategies for E. indica .","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135435725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cyperus rotundus L. is a globally distributed noxious weed that poses a significant challenge for control due to its fast and efficient propagation through the tuber, which is the primary reproductive organ. Gibberellic acid (GA3) has proved to be crucial for tuberization in tuberous plants. Therefore, understanding the relationship between GA3 and tuber development and propagation of C.roundus will provide valuable information for controlling this weed. This study shows that the content of GA3 decreases with tuber development, which corresponds to lower expression of bioactive GA3 synthesis genes (CrGA20ox, two CrGA3oxs) and two up-regulated GA3 catabolism genes (CrGA2oxs), indicating that GA3 is involved in tuber development. Simultaneously, the expressions of CrDELLAs and CrGID1 decline with tuber growth and GA3 decreasing, and Yeast two-hybrid (Y2H) assays confirm that the GA3 signaling is DELLA-dependent. Furthermore, exogenous application of GA3 markedly reduces the number and the width of tuber, and represses the growth of tuber chain, further confirming the negative impact that GA3 has on tuber development and propagation. Taken together, these results demonstrate that GA3 is involved in tuber development and regulated by the DELLA-dependent pathway in C. rotundus, and plays a negative role in tuber development and propagation.
{"title":"Tuber Development and Propagation Are Inhibited by GA3 on DELLA-dependent Pathway in Cyperus rotundus","authors":"Chengcai Wei, Dan-Li Fan, Shu-yu Liu, Shan-Chi Yi, Shi-Xian Yu, Guo-Chao Zhao, Xiao-Liang Liu, W. Tang","doi":"10.1017/wsc.2023.47","DOIUrl":"https://doi.org/10.1017/wsc.2023.47","url":null,"abstract":"\u0000 Cyperus rotundus L. is a globally distributed noxious weed that poses a significant challenge for control due to its fast and efficient propagation through the tuber, which is the primary reproductive organ. Gibberellic acid (GA3) has proved to be crucial for tuberization in tuberous plants. Therefore, understanding the relationship between GA3 and tuber development and propagation of C.roundus will provide valuable information for controlling this weed. This study shows that the content of GA3 decreases with tuber development, which corresponds to lower expression of bioactive GA3 synthesis genes (CrGA20ox, two CrGA3oxs) and two up-regulated GA3 catabolism genes (CrGA2oxs), indicating that GA3 is involved in tuber development. Simultaneously, the expressions of CrDELLAs and CrGID1 decline with tuber growth and GA3 decreasing, and Yeast two-hybrid (Y2H) assays confirm that the GA3 signaling is DELLA-dependent. Furthermore, exogenous application of GA3 markedly reduces the number and the width of tuber, and represses the growth of tuber chain, further confirming the negative impact that GA3 has on tuber development and propagation. Taken together, these results demonstrate that GA3 is involved in tuber development and regulated by the DELLA-dependent pathway in C. rotundus, and plays a negative role in tuber development and propagation.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43494728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taseer Ahmad, K. Jabran, Z. A. Cheema, A. Bajwa, Muhammad Farooq
In modern agriculture, weed problems are predicted to worsen and become more complicated as a result of increasing invasiveness, herbicide resistance, and increased emphasis on high-input methods. Weeds cause huge economic yield losses that range from $100 million to $26 billion globally. The knowledge of weed science has offered success in the past through effective, reasonably priced, and secure technologies; specifically synthetic herbicides to effectively control weeds in agroecosystems. Weed science is accepted and adopted by most universities with teaching, research, and/or extension programs in agriculture. Globally, approximately 7% of all the universities offering agriculture education have specified weed science departments focusing on weed biology, ecology and weed management. Some universities also offer weed science degree programs or at least certain courses in their degrees related to associated disciplines such as plant protection, agronomy and ecology. Although substantial advancements have been made in weed science, such as a separate weed science discipline, specialized journals and specific weed science societies and conferences in weed science discipline worldwide, still, there are lots of constraints (for example, lack of trained weed scientists) and barriers to adoption of new weed-science technologies. Slow modernization in weed science research and low funding has slowed the progress of weed science. New curricula in the weed science discipline should focus on the role of biochemistry, evolutionary biology, molecular biology and genetics in weed science research.
{"title":"A global perspective of education in weed science","authors":"Taseer Ahmad, K. Jabran, Z. A. Cheema, A. Bajwa, Muhammad Farooq","doi":"10.1017/wsc.2023.49","DOIUrl":"https://doi.org/10.1017/wsc.2023.49","url":null,"abstract":"\u0000 In modern agriculture, weed problems are predicted to worsen and become more complicated as a result of increasing invasiveness, herbicide resistance, and increased emphasis on high-input methods. Weeds cause huge economic yield losses that range from $100 million to $26 billion globally. The knowledge of weed science has offered success in the past through effective, reasonably priced, and secure technologies; specifically synthetic herbicides to effectively control weeds in agroecosystems. Weed science is accepted and adopted by most universities with teaching, research, and/or extension programs in agriculture. Globally, approximately 7% of all the universities offering agriculture education have specified weed science departments focusing on weed biology, ecology and weed management. Some universities also offer weed science degree programs or at least certain courses in their degrees related to associated disciplines such as plant protection, agronomy and ecology. Although substantial advancements have been made in weed science, such as a separate weed science discipline, specialized journals and specific weed science societies and conferences in weed science discipline worldwide, still, there are lots of constraints (for example, lack of trained weed scientists) and barriers to adoption of new weed-science technologies. Slow modernization in weed science research and low funding has slowed the progress of weed science. New curricula in the weed science discipline should focus on the role of biochemistry, evolutionary biology, molecular biology and genetics in weed science research.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45206132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicholas D. Warren, E. Hobbie, Janet Chen, Richard G. Smith
The extent to which weed species vary in their ability to acquire and use different forms of nitrogen (N) (inorganic and organic) has not been investigated but could have important implications for weed survival and weed-crop competition in agroecosystems. We conducted a controlled environment experiment using stable isotopes to determine the uptake and partitioning of organic and inorganic N (amino acids, ammonium, and nitrate) by seven common weed and non-weed species. All species took up inorganic and organic N, including as intact amino acids. Concentrations of 15N derived from both ammonium and amino acids in shoot tissues were higher in large crabgrass [Digitaria sanguinalis (L.) Scop.] and barnyardgrass [Echinochloa crus-galli (L.) P. Beauv] than in common lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), and sorghum-sudangrass [Sorghum bicolor (L.) Moench x S. bicolor ssp. drummondii (Nees ex Steud.) de Wet & Harlan]. In contrast, the concentration of 15N derived from nitrate was higher in wild mustard (Sinapis arvensis L.) shoots than in wild oat (Avena fatua L.) shoots. Root concentration of 15N derived from ammonium was lower in sorghum-sudangrass compared to other species except for A. retroflexus and A. fatua, while root concentration of 15N derived from nitrate was lower in A. retroflexus compared to other species except for C. album and S. arvensis. Discriminant analysis classified species based on their uptake and partitioning of all three labeled N forms. These results suggest that common agricultural weeds can access and use organic N and differentially take up inorganic N forms. Additional research is needed to determine whether species-specific differences in organic and inorganic N uptake influence the intensity of competition for soil N.
杂草物种在获取和利用不同形式的氮（无机和有机）的能力方面的差异程度尚未得到调查，但可能对农业生态系统中的杂草生存和杂草作物竞争具有重要意义。我们使用稳定同位素进行了一项受控环境实验，以确定七种常见杂草和非杂草对有机和无机氮（氨基酸、铵和硝酸盐）的吸收和分配。所有物种都吸收无机和有机氮，包括完整的氨基酸。来源于芽组织中铵和氨基酸的15N的浓度在大型蟹甲草[Digitaria sanganalis（L.）Scop.]和Barnyardrass[Echinochloa crus galli（L.）P.Beauv]中高于常见的羔羊草（Chenopodium album L.）、复根猪草（Amaranthus retroflexus L.）和高粱苏丹草[Saughum bicolor（L.）Moench x S.bicolor ssp.drummondii（Nees ex Steud）。)de Wet&Harlan]。相反，野生芥菜（Sinapis arvensis L.）芽中来源于硝酸盐的15N浓度高于野生燕麦（Avena fatua L.）芽。与除A.retroflexus和A.fatua外的其他物种相比，高粱苏丹草中铵源性15N的根浓度较低，而A.retroflus中硝酸盐源性15氮的根浓度低于除C.album和S.arvensis外的其他品种。判别分析根据物种对所有三种标记N形式的吸收和分配对物种进行分类。这些结果表明，常见的农业杂草可以获得和利用有机氮，并不同程度地吸收无机氮。还需要进一步的研究来确定物种在有机和无机氮吸收方面的差异是否会影响对土壤氮的竞争强度。
{"title":"Relative uptake of organic and inorganic nitrogen by common weed species","authors":"Nicholas D. Warren, E. Hobbie, Janet Chen, Richard G. Smith","doi":"10.1017/wsc.2023.48","DOIUrl":"https://doi.org/10.1017/wsc.2023.48","url":null,"abstract":"\u0000 The extent to which weed species vary in their ability to acquire and use different forms of nitrogen (N) (inorganic and organic) has not been investigated but could have important implications for weed survival and weed-crop competition in agroecosystems. We conducted a controlled environment experiment using stable isotopes to determine the uptake and partitioning of organic and inorganic N (amino acids, ammonium, and nitrate) by seven common weed and non-weed species. All species took up inorganic and organic N, including as intact amino acids. Concentrations of 15N derived from both ammonium and amino acids in shoot tissues were higher in large crabgrass [Digitaria sanguinalis (L.) Scop.] and barnyardgrass [Echinochloa crus-galli (L.) P. Beauv] than in common lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), and sorghum-sudangrass [Sorghum bicolor (L.) Moench x S. bicolor ssp. drummondii (Nees ex Steud.) de Wet & Harlan]. In contrast, the concentration of 15N derived from nitrate was higher in wild mustard (Sinapis arvensis L.) shoots than in wild oat (Avena fatua L.) shoots. Root concentration of 15N derived from ammonium was lower in sorghum-sudangrass compared to other species except for A. retroflexus and A. fatua, while root concentration of 15N derived from nitrate was lower in A. retroflexus compared to other species except for C. album and S. arvensis. Discriminant analysis classified species based on their uptake and partitioning of all three labeled N forms. These results suggest that common agricultural weeds can access and use organic N and differentially take up inorganic N forms. Additional research is needed to determine whether species-specific differences in organic and inorganic N uptake influence the intensity of competition for soil N.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46551927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weed management is a significant challenge that must be addressed both globally and in Australia, where traditional methods of control have become limited. The avoidance of mechanical practices has resulted in reduced erosion but has also led to an increased reliance on chemicals and a subsequent increase in rates of herbicide resistance. To address this challenge, alternative forms of weed management, such as electric weed control (electro-weeding), need to be considered. Electric weed control functions by transferring electrical current through the target plant following electrode contact, causing its cells to burst and either killing the plant or suppressing its growth. However, a multitude of variables, such as electrical power and speed of application, weed morphology and site-specific environmental conditions, can impact the use of electric weed control and its efficacy. While electric weed control holds promise and despite its recent global popularity with numerous companies producing machinery, the applicability, efficacy, and risks of using electric weed control internationally and in Australia have yet to be thoroughly analysed. Given the existing knowledge gaps, this review provides a comprehensive overview of the theory and recent advancements in electric weed control. Additionally, the review discusses the potential for resistance development and safety risks associated with electric weed control and presents an overview of modern machines and their application in various settings. It also highlights the need for further research to determine the applicability and efficacy of implementing this new weed control method before widespread adoption and integration into pest management strategies.
{"title":"Exploring the potential of electric weed control: A review","authors":"Miranda J. Slaven, Maximilian Koch, C. Borger","doi":"10.1017/wsc.2023.38","DOIUrl":"https://doi.org/10.1017/wsc.2023.38","url":null,"abstract":"\u0000 Weed management is a significant challenge that must be addressed both globally and in Australia, where traditional methods of control have become limited. The avoidance of mechanical practices has resulted in reduced erosion but has also led to an increased reliance on chemicals and a subsequent increase in rates of herbicide resistance. To address this challenge, alternative forms of weed management, such as electric weed control (electro-weeding), need to be considered. Electric weed control functions by transferring electrical current through the target plant following electrode contact, causing its cells to burst and either killing the plant or suppressing its growth. However, a multitude of variables, such as electrical power and speed of application, weed morphology and site-specific environmental conditions, can impact the use of electric weed control and its efficacy. While electric weed control holds promise and despite its recent global popularity with numerous companies producing machinery, the applicability, efficacy, and risks of using electric weed control internationally and in Australia have yet to be thoroughly analysed. Given the existing knowledge gaps, this review provides a comprehensive overview of the theory and recent advancements in electric weed control. Additionally, the review discusses the potential for resistance development and safety risks associated with electric weed control and presents an overview of modern machines and their application in various settings. It also highlights the need for further research to determine the applicability and efficacy of implementing this new weed control method before widespread adoption and integration into pest management strategies.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46348981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Annika V. Rowland, Uriel D. Menalled, C. Pelzer, L. Sosnoskie, A. DiTommaso, M. Ryan
No-till planting organic soybean [Glycine max (L.) Merr.] into rolled-crimped cereal rye (Secale cereale L.) can have several advantages over traditional tillage-based organic production. However, suboptimal cereal rye growth in fields with large populations of weeds may result in reduced weed suppression, weed-crop competition, and soybean yield loss. Ecological weed management theory suggests that integrating multiple management practices that may be weakly effective on their own can collectively provide high levels of weed suppression. In 2021 and 2022, a field experiment was conducted in central New York to evaluate the performance of three weed management tactics implemented alone and in combination in organic no-till soybean planted into both cereal rye mulch and no mulch: 1) increasing crop seeding rate, 2) inter-row mowing, and 3) weed electrocution. A nontreated control treatment that did not receive any weed management and a weed free control treatment were also included. Cereal rye was absent from two of the five fields where the experiment was repeated; however, the presence of cereal rye did not differentially affect results and thus data were pooled across fields. All treatments that included inter-row mowing reduced weed biomass by at least 60% and increased soybean yield by 14% compared to the nontreated control. The use of a high seeding rate or weed electrocution, alone or in combination, did not improve weed suppression or soybean yield relative to the nontreated control. Soybean yield across all treatments was at least 22% lower than the weed free control plot. Future research should explore the effects of the tactics tested on weed population and community dynamics over an extended period. Indirect effects from inter-row mowing and weed electrocution should also be studied, such as the potential for improved harvestability, decreased weed seed production and viability, and the impacts on soil organisms and agroecosystem biodiversity.
{"title":"High seeding rates, inter-row mowing, and electrocution for weed management in organic no-till planted soybean","authors":"Annika V. Rowland, Uriel D. Menalled, C. Pelzer, L. Sosnoskie, A. DiTommaso, M. Ryan","doi":"10.1017/wsc.2023.45","DOIUrl":"https://doi.org/10.1017/wsc.2023.45","url":null,"abstract":"\u0000 No-till planting organic soybean [Glycine max (L.) Merr.] into rolled-crimped cereal rye (Secale cereale L.) can have several advantages over traditional tillage-based organic production. However, suboptimal cereal rye growth in fields with large populations of weeds may result in reduced weed suppression, weed-crop competition, and soybean yield loss. Ecological weed management theory suggests that integrating multiple management practices that may be weakly effective on their own can collectively provide high levels of weed suppression. In 2021 and 2022, a field experiment was conducted in central New York to evaluate the performance of three weed management tactics implemented alone and in combination in organic no-till soybean planted into both cereal rye mulch and no mulch: 1) increasing crop seeding rate, 2) inter-row mowing, and 3) weed electrocution. A nontreated control treatment that did not receive any weed management and a weed free control treatment were also included. Cereal rye was absent from two of the five fields where the experiment was repeated; however, the presence of cereal rye did not differentially affect results and thus data were pooled across fields. All treatments that included inter-row mowing reduced weed biomass by at least 60% and increased soybean yield by 14% compared to the nontreated control. The use of a high seeding rate or weed electrocution, alone or in combination, did not improve weed suppression or soybean yield relative to the nontreated control. Soybean yield across all treatments was at least 22% lower than the weed free control plot. Future research should explore the effects of the tactics tested on weed population and community dynamics over an extended period. Indirect effects from inter-row mowing and weed electrocution should also be studied, such as the potential for improved harvestability, decreased weed seed production and viability, and the impacts on soil organisms and agroecosystem biodiversity.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57585722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
African mustard (Brassica tournefortii Gouan), turnipweed [Rapistrum rugosum (L.) All.], and African turnipweed (Sisymbrium thellungii O.E. Schulz) are common broadleaf weeds in chickpea (Cicer arietinum L.) crops, particularly under dryland regions of eastern Australia. Information on crop yield losses and the seed production potential for these weeds are limited in chickpea. Field studies were conducted in the winter seasons of 2020 and 2021 in eastern Australia with different densities of the three weeds (B. tournefortii, R. rugosum, and S. thellungii) in chickpea. Based on the sigmoid model, chickpea yield was reduced by 50% at 11 plants m-2 of B. tournefortii. Based on hyperbola models, a 50% yield reduction of chickpea occurred at 5, and 25 plants m−2 of R. rugosum, and S. thellungii, respectively. Based on the linear model, B. tournefortii, R. rugosum, and S. thellungii produced a maximum of 448,000, 206,700, and 869,400, seeds m−2, respectively. At chickpea harvest, the low seed retention (<55%) of B. tournefortii and S. thellungii suggests limited opportunities for harvest weed seed control, and the seed rain of these weeds may enrich the weed seedbank in the soil. At crop harvest, the seed retention of R. rugosum was found to be greater than 90%, suggesting that it is a suitable candidate for harvest weed seed control. This study demonstrated that R. rugosum could cause a greater reduction in chickpea yield compared with B. tournefortii and S. thellungii. Furthermore, it is recommended to restrict seed rain of B. tournefortii and S. thellungii by not allowing the plants to produce seeds in order to reduce their weed seedbank in the soil. The information generated from this study could aid in strengthening integrated weed management in chickpea.
{"title":"Interference of Brassicaceae weeds (Brassica tournefortii, Rapistrum rugosum, and Sisymbrium thellungii) in Chickpeas","authors":"G. Mahajan, B. Chauhan","doi":"10.1017/wsc.2023.40","DOIUrl":"https://doi.org/10.1017/wsc.2023.40","url":null,"abstract":"\u0000 African mustard (Brassica tournefortii Gouan), turnipweed [Rapistrum rugosum (L.) All.], and African turnipweed (Sisymbrium thellungii O.E. Schulz) are common broadleaf weeds in chickpea (Cicer arietinum L.) crops, particularly under dryland regions of eastern Australia. Information on crop yield losses and the seed production potential for these weeds are limited in chickpea. Field studies were conducted in the winter seasons of 2020 and 2021 in eastern Australia with different densities of the three weeds (B. tournefortii, R. rugosum, and S. thellungii) in chickpea. Based on the sigmoid model, chickpea yield was reduced by 50% at 11 plants m-2 of B. tournefortii. Based on hyperbola models, a 50% yield reduction of chickpea occurred at 5, and 25 plants m−2 of R. rugosum, and S. thellungii, respectively. Based on the linear model, B. tournefortii, R. rugosum, and S. thellungii produced a maximum of 448,000, 206,700, and 869,400, seeds m−2, respectively. At chickpea harvest, the low seed retention (<55%) of B. tournefortii and S. thellungii suggests limited opportunities for harvest weed seed control, and the seed rain of these weeds may enrich the weed seedbank in the soil. At crop harvest, the seed retention of R. rugosum was found to be greater than 90%, suggesting that it is a suitable candidate for harvest weed seed control. This study demonstrated that R. rugosum could cause a greater reduction in chickpea yield compared with B. tournefortii and S. thellungii. Furthermore, it is recommended to restrict seed rain of B. tournefortii and S. thellungii by not allowing the plants to produce seeds in order to reduce their weed seedbank in the soil. The information generated from this study could aid in strengthening integrated weed management in chickpea.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47329902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
2,4-D is commonly used for sucker control in hazelnut (Corylus avellana L.). However, the use of 2,4-D for sucker control has been implicated in delaying natural abscission in hazelnut. Hazelnuts naturally abscise and are collected from the orchard floor. Delays in abscission may reduce nut quality due to the onset of the rainy season, increasing mold and mud in the nuts. The effect of basal-directed applications of 2,4-D on hazelnut abscission, yield, and quality was assessed. In the first study, four basal-directed applications of 2,4-D (1.06 kg ae ha-1) did not affect hazelnut abscission, yield, or quality compared to glufosinate (1.1 kg ha-1) or manual pruning. In a second 3 yr study, a single yearly simulated drift of 2,4-D to the tree canopy at 0.06 and 0.6 mg L-1 increased the growing degree d (GDD) requirement from 50 to 141 to reach 50% hazelnut abscission, compared to nontreated. This is the equivalent of 5 to 15 calendar d. No effect was observed in the third yr of the study when the simulated drift was not performed. No differences in abscission were observed with basal-directed applications of 2,4-D at rates up to 4.4 kg ha-1 when applied four times each season during all 3 yrs of the study. Simulated drift reduced hazelnut yield by up to 37% and reduced the percentage of marketable nuts during one yr of the study. No effect on average kernel weight was observed. However, 2,4-D drift did delay hazelnut abscission, highlighting the importance of drift control measures.
2,4- d通常用于榛子(Corylus avellana L.)的吸盘控制。然而，2,4- d用于吸盘控制已牵连到延迟自然脱落榛子。榛子自然脱落，从果园地面采集。由于雨季的到来，脱落的延迟可能会降低坚果的质量，增加坚果中的霉菌和泥。评价了碱基施用2,4- d对榛子脱落、产量和品质的影响。在第一项研究中，与草铵膦(1.1 kg ha-1)或人工修剪相比，四次基底定向施用2,4- d (1.06 kg ha-1)对榛子脱落、产量或质量没有影响。在第二个为期3年的研究中，与未处理的榛子相比，在0.06和0.6 mg L-1的浓度下，每年模拟向树冠漂移2,4- d，将生长度d (GDD)需求从50提高到141，以达到50%的榛子脱落。这相当于5到15个日历d。在研究的第三年，当不进行模拟漂移时，没有观察到任何影响。在所有3年的研究中，每个季节施用4次2,4- d，以高达4.4 kg ha-1的速率在基部定向施用时，没有观察到脱落的差异。在一年的研究中，模拟漂移使榛子产量减少了37%，并减少了可销售坚果的百分比。对平均粒重无影响。然而，2,4- d漂移确实延迟了榛子的脱落，突出了漂移控制措施的重要性。
{"title":"Hazelnut Abscission is Delayed by Simulated Drift of 2,4-D","authors":"Marcelo L. Moretti, L. L. De Souza","doi":"10.1017/wsc.2023.43","DOIUrl":"https://doi.org/10.1017/wsc.2023.43","url":null,"abstract":"\u0000 2,4-D is commonly used for sucker control in hazelnut (Corylus avellana L.). However, the use of 2,4-D for sucker control has been implicated in delaying natural abscission in hazelnut. Hazelnuts naturally abscise and are collected from the orchard floor. Delays in abscission may reduce nut quality due to the onset of the rainy season, increasing mold and mud in the nuts. The effect of basal-directed applications of 2,4-D on hazelnut abscission, yield, and quality was assessed. In the first study, four basal-directed applications of 2,4-D (1.06 kg ae ha-1) did not affect hazelnut abscission, yield, or quality compared to glufosinate (1.1 kg ha-1) or manual pruning. In a second 3 yr study, a single yearly simulated drift of 2,4-D to the tree canopy at 0.06 and 0.6 mg L-1 increased the growing degree d (GDD) requirement from 50 to 141 to reach 50% hazelnut abscission, compared to nontreated. This is the equivalent of 5 to 15 calendar d. No effect was observed in the third yr of the study when the simulated drift was not performed. No differences in abscission were observed with basal-directed applications of 2,4-D at rates up to 4.4 kg ha-1 when applied four times each season during all 3 yrs of the study. Simulated drift reduced hazelnut yield by up to 37% and reduced the percentage of marketable nuts during one yr of the study. No effect on average kernel weight was observed. However, 2,4-D drift did delay hazelnut abscission, highlighting the importance of drift control measures.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48223332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Ribeiro, J. Barroso, C. Brunharo, C. Mallory-Smith
This review summarizes what is currently known about herbicide resistance in Bromus spp. worldwide. Additional information on the biology and genetics of Bromus spp. is provided to further the understanding of resistance evolution and dispersal of the different species. Cases of herbicide resistance have been confirmed in Bromus catharticus Vahl., Bromus commutatus Schrad.; syn. Bromus racemosus L., Bromus diandrus Roth, Bromus japonicus Thunb.; syn. Bromus arvensis L., Bromus madritensis L., Bromus rigidus Roth; syn. Bromus diandrus Roth ssp. diandrus, Bromus rubens L., Bromus secalinus L., Bromus sterilis L., and Bromus tectorum L. in 11 countries. Bromus spp. populations have evolved cross and multiple-resistance to six herbicide sites of action: acetyl-coenzyme A carboxylase, acetolactate synthase, photosystem II, very long-chain fatty acid, 5-enolpyruvylshikimate-3-phosphate synthase, and 4-hydroxyphenylpyruvate dioxygenase inhibitors. Resistance mechanisms varied from target-site to non-target-site or a combination of both. Bromus spp. are generally highly self-pollinated, but outcrossing can occur at low levels in some species. Bromus spp. have different ploidy levels, ranging from diploid (2n = 2x = 14) to duodecaploid (2n = 12x = 84). Herbicide resistance in Bromus spp. is a global issue, and the spread of herbicide resistance alleles primarily occurs via seed-mediated gene flow. However, the transfer of herbicide resistance alleles via pollen-mediated gene flow is possible.
{"title":"Herbicide resistance in Bromus spp.: a global review","authors":"V. Ribeiro, J. Barroso, C. Brunharo, C. Mallory-Smith","doi":"10.1017/wsc.2023.42","DOIUrl":"https://doi.org/10.1017/wsc.2023.42","url":null,"abstract":"\u0000 This review summarizes what is currently known about herbicide resistance in Bromus spp. worldwide. Additional information on the biology and genetics of Bromus spp. is provided to further the understanding of resistance evolution and dispersal of the different species. Cases of herbicide resistance have been confirmed in Bromus catharticus Vahl., Bromus commutatus Schrad.; syn. Bromus racemosus L., Bromus diandrus Roth, Bromus japonicus Thunb.; syn. Bromus arvensis L., Bromus madritensis L., Bromus rigidus Roth; syn. Bromus diandrus Roth ssp. diandrus, Bromus rubens L., Bromus secalinus L., Bromus sterilis L., and Bromus tectorum L. in 11 countries. Bromus spp. populations have evolved cross and multiple-resistance to six herbicide sites of action: acetyl-coenzyme A carboxylase, acetolactate synthase, photosystem II, very long-chain fatty acid, 5-enolpyruvylshikimate-3-phosphate synthase, and 4-hydroxyphenylpyruvate dioxygenase inhibitors. Resistance mechanisms varied from target-site to non-target-site or a combination of both. Bromus spp. are generally highly self-pollinated, but outcrossing can occur at low levels in some species. Bromus spp. have different ploidy levels, ranging from diploid (2n = 2x = 14) to duodecaploid (2n = 12x = 84). Herbicide resistance in Bromus spp. is a global issue, and the spread of herbicide resistance alleles primarily occurs via seed-mediated gene flow. However, the transfer of herbicide resistance alleles via pollen-mediated gene flow is possible.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46647190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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