T. R. Piskáčková, Karla Gage, Eugene P. Law, Lauren M. Schwartz-Lazaro, Joan M Campbell, Christine Taliga
Plant names carry a significant amount of information without providing a lengthy description. This is an efficient shorthand for scientists and stakeholders to communicate about a plant, but only when the name is based on a common understanding. It is standard to think of each plant having just two names, a common name and a scientific name, yet both names can be a source of confusion. There are often many common names that refer to the same plant, or a single common name that refers to multiple different species, and some plants are without a common name at all. Scientific names are based upon international standards; however, when there is not agreement in the taxonomy, two scientific names may be used to describe the same species. Weed scientists and practitioners can easily memorize multiple plant names and know that they refer to the same species, but when we consider global communication and far-reaching databases, it becomes very relevant to consider two sides of this shift: 1) A need for greater standardization (due to database management and risk of lost data from dropped cross-referencing) and 2) the loss of local heritage which provides useful meaning through various common names. In addition, weed scientists can be resistant to changing names that they learned or frequently use. The developments in online databases and reclassification of plant taxonomy by phylogenetic relationships have changed the accessibility and role of the list of standardized plant names compiled by the Weed Science Society of America (WSSA). As part of an attempt to reconcile WSSA and USDA common names for weedy plants, the WSSA Standardized Plant Names Committee recently concluded an extensive review of the Composite List of Weeds common names and had small changes approved to about 10% of the list of over 2800 distinct species.
{"title":"How are weeds named: A committee review of the WSSA composite list of names","authors":"T. R. Piskáčková, Karla Gage, Eugene P. Law, Lauren M. Schwartz-Lazaro, Joan M Campbell, Christine Taliga","doi":"10.1017/wsc.2024.35","DOIUrl":"https://doi.org/10.1017/wsc.2024.35","url":null,"abstract":"\u0000 Plant names carry a significant amount of information without providing a lengthy description. This is an efficient shorthand for scientists and stakeholders to communicate about a plant, but only when the name is based on a common understanding. It is standard to think of each plant having just two names, a common name and a scientific name, yet both names can be a source of confusion. There are often many common names that refer to the same plant, or a single common name that refers to multiple different species, and some plants are without a common name at all. Scientific names are based upon international standards; however, when there is not agreement in the taxonomy, two scientific names may be used to describe the same species. Weed scientists and practitioners can easily memorize multiple plant names and know that they refer to the same species, but when we consider global communication and far-reaching databases, it becomes very relevant to consider two sides of this shift: 1) A need for greater standardization (due to database management and risk of lost data from dropped cross-referencing) and 2) the loss of local heritage which provides useful meaning through various common names. In addition, weed scientists can be resistant to changing names that they learned or frequently use. The developments in online databases and reclassification of plant taxonomy by phylogenetic relationships have changed the accessibility and role of the list of standardized plant names compiled by the Weed Science Society of America (WSSA). As part of an attempt to reconcile WSSA and USDA common names for weedy plants, the WSSA Standardized Plant Names Committee recently concluded an extensive review of the Composite List of Weeds common names and had small changes approved to about 10% of the list of over 2800 distinct species.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268213","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}
Common milkweed (Asclepias syriaca L.) is widely planted as part of monarch butterfly (Danaus plexippus) conservation efforts. Vegetative propagation is an alternative to planting A. syriaca from seed, which offers advantages such as high emergence rates. The aim of this study was to determine the ideal planting depth and initial root segment length to vegetatively propagate A. syriaca. In a greenhouse trial with two runs, A. syriaca was grown from seed and then 3, 8 and 15-cm segments were harvested. These segments were then planted at depths of either 3, 8, or 15 cm. Planting depth did not impact A. syriaca growth, but an initial root segment length of 15 cm was associated with greater above- and belowground biomass and height in both runs of the experiment. Emergence rates were not impacted by either factor. Overall, A. syriaca was likely to establish regardless of the initial root segment length or planting depth, but plants grown from root segments of 15 cm were more vigorous than plants grown from shorter segments.
{"title":"Impact of burial depth and root segment length on vegetative propagation of common milkweed (Asclepias syriaca)","authors":"Rebecca S. Stup, Anna S. Westbrook, A. DiTommaso","doi":"10.1017/wsc.2024.37","DOIUrl":"https://doi.org/10.1017/wsc.2024.37","url":null,"abstract":"\u0000 Common milkweed (Asclepias syriaca L.) is widely planted as part of monarch butterfly (Danaus plexippus) conservation efforts. Vegetative propagation is an alternative to planting A. syriaca from seed, which offers advantages such as high emergence rates. The aim of this study was to determine the ideal planting depth and initial root segment length to vegetatively propagate A. syriaca. In a greenhouse trial with two runs, A. syriaca was grown from seed and then 3, 8 and 15-cm segments were harvested. These segments were then planted at depths of either 3, 8, or 15 cm. Planting depth did not impact A. syriaca growth, but an initial root segment length of 15 cm was associated with greater above- and belowground biomass and height in both runs of the experiment. Emergence rates were not impacted by either factor. Overall, A. syriaca was likely to establish regardless of the initial root segment length or planting depth, but plants grown from root segments of 15 cm were more vigorous than plants grown from shorter segments.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266253","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}
Noah H. Reed, Thomas R. Butts, J. Norsworthy, J. Hardke, L. Barber, Nick R. Bateman, Aurelie M. Poncet, K. B. Kouamé
Furrow-irrigated rice (Oryza sativa L.) has become a popular option for rice production in Arkansas. Highly troublesome weeds like barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] are a major problem for producers in all rice production systems. Cultural tactics should become a priority to enhance crop growth and competitiveness. This research aimed to determine the effects of bed width (irrigation furrow spacing) and crop row spacing manipulation on E. crus-galli emergence and seed production in a furrow-irrigated rice system. Three bed widths (76-, 97-, and 152-cm) (whole plot factor) were used, and plots were drill-seeded in four crop row spacings (subplot factor) (13-, 19-, 25-, and 38-cm). The widest width of 152-cm had a slight increase in E. crus-galli density in the early rice life cycle but, by the end of the season, did not differ from the narrower bed widths. Conversely, a decrease in E. crus-galli seed production was observed as the bed width increased. Similar rice canopy coverage and yields occurred between all three bed widths. As for crop row spacing, as the width increased, E. crus-galli density also increased. The 13-cm crop row spacing had the lowest preflood E. crus-galli density, preharvest panicle count, and seed production. No effect of crop row spacing was observed on rice canopy coverage; however, the 13-cm crop row spacing produced the greatest rice yield. The 13-cm crop row spacing paired with the 152-cm bed width may be the optimum combination of ecological strategies in furrow-irrigated rice to reduce E. crus-galli seed production while maintaining rice growth and yield.
沟灌水稻（Oryza sativa L.）已成为阿肯色州水稻生产的一种流行选择。稗草[Echinochloa crus-galli (L.) P. Beauv.]等问题严重的杂草是所有水稻生产系统中生产者面临的主要问题。为提高作物的生长和竞争力，应优先采用栽培策略。本研究旨在确定床宽（灌溉沟距）和作物行距对沟灌水稻系统中 E. crus-galli 出苗和种子产量的影响。采用了三种床宽（76 厘米、97 厘米和 152 厘米）（全小区因子），并以四种作物行距（子小区因子）（13 厘米、19 厘米、25 厘米和 38 厘米）对小区进行了钻播。在水稻生命周期的早期，最宽的 152 厘米床面的 E. crus-galli 密度略有增加，但到季节结束时，与较窄的床面宽度没有区别。相反，随着稻床宽度的增加，E. crus-galli 的种子产量也有所减少。三种床宽的水稻冠层覆盖率和产量相似。至于作物行距，随着宽度的增加，E. crus-galli 的密度也在增加。13 厘米的作物行距在淹水前的 E. crus-galli 密度、收割前的圆锥花序数和种子产量都最低。作物行距对水稻冠层覆盖率没有影响，但 13 厘米作物行距的水稻产量最高。13 厘米的作物行距与 152 厘米的床宽可能是沟灌水稻生态策略的最佳组合，可在保持水稻生长和产量的同时减少 E. crus-galli 种子产量。
{"title":"Effects of Bed Width and Crop Row Spacing on Barnyardgrass (Echinochloa crus-galli) Emergence and Seed Production in Furrow-Irrigated Rice","authors":"Noah H. Reed, Thomas R. Butts, J. Norsworthy, J. Hardke, L. Barber, Nick R. Bateman, Aurelie M. Poncet, K. B. Kouamé","doi":"10.1017/wsc.2024.29","DOIUrl":"https://doi.org/10.1017/wsc.2024.29","url":null,"abstract":"\u0000 Furrow-irrigated rice (Oryza sativa L.) has become a popular option for rice production in Arkansas. Highly troublesome weeds like barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] are a major problem for producers in all rice production systems. Cultural tactics should become a priority to enhance crop growth and competitiveness. This research aimed to determine the effects of bed width (irrigation furrow spacing) and crop row spacing manipulation on E. crus-galli emergence and seed production in a furrow-irrigated rice system. Three bed widths (76-, 97-, and 152-cm) (whole plot factor) were used, and plots were drill-seeded in four crop row spacings (subplot factor) (13-, 19-, 25-, and 38-cm). The widest width of 152-cm had a slight increase in E. crus-galli density in the early rice life cycle but, by the end of the season, did not differ from the narrower bed widths. Conversely, a decrease in E. crus-galli seed production was observed as the bed width increased. Similar rice canopy coverage and yields occurred between all three bed widths. As for crop row spacing, as the width increased, E. crus-galli density also increased. The 13-cm crop row spacing had the lowest preflood E. crus-galli density, preharvest panicle count, and seed production. No effect of crop row spacing was observed on rice canopy coverage; however, the 13-cm crop row spacing produced the greatest rice yield. The 13-cm crop row spacing paired with the 152-cm bed width may be the optimum combination of ecological strategies in furrow-irrigated rice to reduce E. crus-galli seed production while maintaining rice growth and yield.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141120535","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}
Hayley L. Brackenridge, Nikita Konstantinov, Lisa H. Han, S. Yakimowski
Palmer amaranth (Amaranthus palmeri S. Watson), a dioecious wind-pollinated plant, is one of the most troublesome crop weeds in the United States and is spreading northwards. The prodigious production of seed contributes to establishment of populations and spread across the landscape. Sexual reproduction via outcrossing is likely the primary mode of seed production for this dioecious plant. However, A. palmeri may also be capable of autonomous asexual seed production (apomixis), which could be beneficial during colonization. We conducted two studies of female isolation from pollen to investigate the propensity for autonomous seed production in 19 populations across eastern North America. In the first we observed low frequency seed production on many isolated females. Using flow cytometry of seed samples (FCSS) we primarily found patterns of ploidy consistent with sexual reproduction; no significant differences in ploidy between seeds produced on isolated females (putative apomicts) and non-isolated females (putatively sexual) were detected. We also investigated patterns of DNA content and found no evidence for polyploidy in 153 samples, which is often observed in apomictic species. The second female isolation trial utilized sex-specific molecular markers to identify and remove males prior to flowering, and we observed zero seed production. Overall, we did not detect evidence in support of apomixis in these populations of A. palmeri, suggesting that apomixis is unlikely to have played a role in the northward advance of this species in eastern North America. We also investigated whether there is variation between females and males in size and secondary reproductive traits. We found evidence for sexual dimorphism in three of six traits investigated: females are taller at senescence, produce longer secondary branches, and more axillary flowers than males. Differences in cost of reproduction and strategies for pollen release vs. pollen capture are likely factors shaping the evolution of sexual dimorphism in this wind-pollinated dioecious plant.
帕尔默苋（Amaranthus palmeri S. Watson）是一种雌雄异株的风媒植物，是美国最棘手的作物杂草之一，并正在向北蔓延。种子的大量生产促进了种群的建立和在地表的蔓延。通过杂交进行有性繁殖可能是这种雌雄异株植物生产种子的主要方式。不过，棕榈苣苔也能自主进行无性生殖（apomixis），这在殖民过程中可能是有益的。我们进行了两项雌株与花粉隔离的研究，以调查北美东部 19 个种群的自主种子生产倾向。在第一项研究中，我们观察到许多被隔离的雌性个体的种子生产频率较低。利用种子样本流式细胞术（FCSS），我们主要发现了与有性生殖一致的倍性模式；在隔离雌性（假定无性生殖）和非隔离雌性（假定有性生殖）上生产的种子之间，没有发现显著的倍性差异。我们还调查了 DNA 含量的模式，在 153 个样本中没有发现多倍体的证据，而多倍体在无性繁殖物种中经常出现。第二次雌性隔离试验使用了性别特异性分子标记，在开花前识别并移除雄性，我们观察到种子产量为零。总体而言，我们没有在这些棕榈蓟马种群中发现支持无性繁殖的证据，这表明无性繁殖不太可能是该物种在北美东部向北推进过程中扮演的角色。我们还研究了雌性和雄性在体型和次级生殖特征方面是否存在差异。我们发现，在所调查的六个性状中，有三个存在性二态性：雌性比雄性衰老时更高、产生的次生分枝更长、腋生花更多。繁殖成本的差异以及花粉释放与花粉捕获策略的不同很可能是影响这种风媒异株植物性二形进化的因素。
{"title":"Investigating sexual and asexual modes of reproduction in Palmer Amaranth (Amaranthus palmeri)","authors":"Hayley L. Brackenridge, Nikita Konstantinov, Lisa H. Han, S. Yakimowski","doi":"10.1017/wsc.2024.28","DOIUrl":"https://doi.org/10.1017/wsc.2024.28","url":null,"abstract":"\u0000 Palmer amaranth (Amaranthus palmeri S. Watson), a dioecious wind-pollinated plant, is one of the most troublesome crop weeds in the United States and is spreading northwards. The prodigious production of seed contributes to establishment of populations and spread across the landscape. Sexual reproduction via outcrossing is likely the primary mode of seed production for this dioecious plant. However, A. palmeri may also be capable of autonomous asexual seed production (apomixis), which could be beneficial during colonization. We conducted two studies of female isolation from pollen to investigate the propensity for autonomous seed production in 19 populations across eastern North America. In the first we observed low frequency seed production on many isolated females. Using flow cytometry of seed samples (FCSS) we primarily found patterns of ploidy consistent with sexual reproduction; no significant differences in ploidy between seeds produced on isolated females (putative apomicts) and non-isolated females (putatively sexual) were detected. We also investigated patterns of DNA content and found no evidence for polyploidy in 153 samples, which is often observed in apomictic species. The second female isolation trial utilized sex-specific molecular markers to identify and remove males prior to flowering, and we observed zero seed production. Overall, we did not detect evidence in support of apomixis in these populations of A. palmeri, suggesting that apomixis is unlikely to have played a role in the northward advance of this species in eastern North America. We also investigated whether there is variation between females and males in size and secondary reproductive traits. We found evidence for sexual dimorphism in three of six traits investigated: females are taller at senescence, produce longer secondary branches, and more axillary flowers than males. Differences in cost of reproduction and strategies for pollen release vs. pollen capture are likely factors shaping the evolution of sexual dimorphism in this wind-pollinated dioecious plant.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141122211","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}
Pâmela Carvalho-Moore, J. Norsworthy, Tristen H. Avent, D. Riechers
Weed resistance to herbicides has increased exponentially during the past 30 to 40 years, consequently reducing the number of effective products available to control certain species and populations. Future efforts should target not only the discovery of new protein binding sites and the development of new molecules, but also the revival of old molecules with reduced efficacy due to widespread herbicide resistance. The addition of herbicide synergists that inhibit metabolic pathways or enhance intrinsic plant stress is a possible solution to ameliorate the negative effects caused by the lack of new herbicide chemistries. Glutathione S-transferase (GST) enzymes are involved with numerous herbicide detoxification reactions and plant stress responses. This review approaches the potential use of natural and synthetic GST-inhibitors to enhance herbicidal activity or induce crop safety to provide effective, sustainable weed management strategies in the future.
{"title":"Known and potential benefits of applying herbicides with glutathione S-transferase inhibitors and inducers – a review","authors":"Pâmela Carvalho-Moore, J. Norsworthy, Tristen H. Avent, D. Riechers","doi":"10.1017/wsc.2024.34","DOIUrl":"https://doi.org/10.1017/wsc.2024.34","url":null,"abstract":"\u0000 Weed resistance to herbicides has increased exponentially during the past 30 to 40 years, consequently reducing the number of effective products available to control certain species and populations. Future efforts should target not only the discovery of new protein binding sites and the development of new molecules, but also the revival of old molecules with reduced efficacy due to widespread herbicide resistance. The addition of herbicide synergists that inhibit metabolic pathways or enhance intrinsic plant stress is a possible solution to ameliorate the negative effects caused by the lack of new herbicide chemistries. Glutathione S-transferase (GST) enzymes are involved with numerous herbicide detoxification reactions and plant stress responses. This review approaches the potential use of natural and synthetic GST-inhibitors to enhance herbicidal activity or induce crop safety to provide effective, sustainable weed management strategies in the future.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141123097","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}
Tropical ageratum (Ageratum conyzoides L.) is a problematic weed frequently observed in association with commercially important crops in Australian agroecosystems. Knowledge of the germination response of A. conyzoides is crucial for proactively managing this weed species, especially when herbicide resistance is involved. Herbicide screening and metsulfuron dose-response experiments were conducted on two separate populations of A. conyzoides (referred to as Sugarcane and Roadside) in an open environment to identify a metsulfuron-resistant population. Based on the survival percentage in the metsulfuron dose-response experiment, the Sugarcane population was found to be 54 times more resistant compared to the metsulfuron-susceptible population (referred to as Roadside). Subsequent laboratory experiments were performed to investigate the differential germination response of the two populations. No germination or emergence difference was observed between the Sugarcane and Roadside populations under various thermal regimes (15/5 to 35/25 C with a 12/12-hour photoperiod), salinity levels (0 to 320 mM), osmotic potentials (0 to -1.6 MPa), and burial depths (1 to 4 cm). However, different environmental conditions significantly impacted the germination and emergence of A. conyzoides. Ageratum conyzoides germinated over a wide range of temperatures, with the highest germination rate (>90%) occurring at 30/20 C. With increasing levels of salinity, osmotic potential, and burial depth, the germination/emergence of A. conyzoides declined and was completely inhibited at 300 mM salinity, -0.8 MPa osmotic potential, and a 1 cm burial depth. The data generated from this study will be useful in developing a model-based approach to predict the occurrence of this weed species and thus aid in designing ecologically sustainable integrated weed management protocols.
{"title":"Germination attributes of metsulfuron-resistant and metsulfuron-susceptible tropical ageratum (Ageratum conyzoides) populations under various environmental conditions","authors":"Devanshi H. Desai, Het Samir Desai, B. S. Chauhan","doi":"10.1017/wsc.2024.31","DOIUrl":"https://doi.org/10.1017/wsc.2024.31","url":null,"abstract":"\u0000 Tropical ageratum (Ageratum conyzoides L.) is a problematic weed frequently observed in association with commercially important crops in Australian agroecosystems. Knowledge of the germination response of A. conyzoides is crucial for proactively managing this weed species, especially when herbicide resistance is involved. Herbicide screening and metsulfuron dose-response experiments were conducted on two separate populations of A. conyzoides (referred to as Sugarcane and Roadside) in an open environment to identify a metsulfuron-resistant population. Based on the survival percentage in the metsulfuron dose-response experiment, the Sugarcane population was found to be 54 times more resistant compared to the metsulfuron-susceptible population (referred to as Roadside). Subsequent laboratory experiments were performed to investigate the differential germination response of the two populations. No germination or emergence difference was observed between the Sugarcane and Roadside populations under various thermal regimes (15/5 to 35/25 C with a 12/12-hour photoperiod), salinity levels (0 to 320 mM), osmotic potentials (0 to -1.6 MPa), and burial depths (1 to 4 cm). However, different environmental conditions significantly impacted the germination and emergence of A. conyzoides. Ageratum conyzoides germinated over a wide range of temperatures, with the highest germination rate (>90%) occurring at 30/20 C. With increasing levels of salinity, osmotic potential, and burial depth, the germination/emergence of A. conyzoides declined and was completely inhibited at 300 mM salinity, -0.8 MPa osmotic potential, and a 1 cm burial depth. The data generated from this study will be useful in developing a model-based approach to predict the occurrence of this weed species and thus aid in designing ecologically sustainable integrated weed management protocols.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140999736","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. Šoštarčić, Mateja Pišonić, Laura Pismarović, Maja Šćepanović
Heat disinfection of soil can be used to reduce the content of the soil seed bank. However, species differ in the lethal temperature needed for seed destruction and mortality. Laboratory research was conducted on the seeds of two weed species, redroot pigweed (Amaranthus retroflexus L.) and yellow foxtail [Setaria pumila (Poir.) Roem. et Schult]. The soil samples were collected at the experimental station Šašinovečki Lug, Zagreb (45.850289°N; 16.180465°W), Croatia and exposed to linearly increasing constant temperatures of 40, 50, 60, 80, 100 and 120 C and exposure times of 30, 60 and 90 min in a laboratory oven. Weed seeds were then extracted from the soil using the sieve separation method and survival measured by germinating seeds on the filter paper. Germination counts were converted into percentages of mortality compared to untreated seeds. The results show that both temperature and exposure time significantly affected seed mortality of both weed species. A. retroflexus shows a greater susceptibility to high temperatures than S. pumila. Fitted three-parameter sigmoid model was used to define the relationship between temperature and exposure time needed for 50% (LT50) and 90% (LT90) seed mortality. The estimated LT50 values for A. retroflexus are 58.89 – 46.08 C over the 30 to 90 min exposure times; the estimated LT90 113.36 to 65.72 C for the same durations. The estimated LT50 values for S. pumila over the 30 to 90 min exposure times ranged from 91.33 to 75.15 C; the estimated LT90 ranged from 98.79 to 90.32 C over the same durations. The research results contribute to the knowledge about the thermal sensitivity of seeds. Estimating efficacy of soil heating treatments is essential when comparing the environmental, economic and social costs of alternatives to conventional weed control methods.
{"title":"The effect of temperature and exposure time on redroot pigweed (Amaranthus retroflexus) and yellow foxtail (Setaria pumila) seed mortality in the natural soil seed bank","authors":"V. Šoštarčić, Mateja Pišonić, Laura Pismarović, Maja Šćepanović","doi":"10.1017/wsc.2024.27","DOIUrl":"https://doi.org/10.1017/wsc.2024.27","url":null,"abstract":"\u0000 Heat disinfection of soil can be used to reduce the content of the soil seed bank. However, species differ in the lethal temperature needed for seed destruction and mortality. Laboratory research was conducted on the seeds of two weed species, redroot pigweed (Amaranthus retroflexus L.) and yellow foxtail [Setaria pumila (Poir.) Roem. et Schult]. The soil samples were collected at the experimental station Šašinovečki Lug, Zagreb (45.850289°N; 16.180465°W), Croatia and exposed to linearly increasing constant temperatures of 40, 50, 60, 80, 100 and 120 C and exposure times of 30, 60 and 90 min in a laboratory oven. Weed seeds were then extracted from the soil using the sieve separation method and survival measured by germinating seeds on the filter paper. Germination counts were converted into percentages of mortality compared to untreated seeds. The results show that both temperature and exposure time significantly affected seed mortality of both weed species. A. retroflexus shows a greater susceptibility to high temperatures than S. pumila. Fitted three-parameter sigmoid model was used to define the relationship between temperature and exposure time needed for 50% (LT50) and 90% (LT90) seed mortality. The estimated LT50 values for A. retroflexus are 58.89 – 46.08 C over the 30 to 90 min exposure times; the estimated LT90 113.36 to 65.72 C for the same durations. The estimated LT50 values for S. pumila over the 30 to 90 min exposure times ranged from 91.33 to 75.15 C; the estimated LT90 ranged from 98.79 to 90.32 C over the same durations. The research results contribute to the knowledge about the thermal sensitivity of seeds. Estimating efficacy of soil heating treatments is essential when comparing the environmental, economic and social costs of alternatives to conventional weed control methods.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140999516","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}
Mirella F. Ortiz, Scott J. Nissen, Franck E. Dayan
Eurasian watermilfoil (Myriophyllum spicatum L.) is an invasive aquatic plant that can hybridize with the native Northern watermilfoil (Myriophyllum sibiricum Kom.). These milfoil hybrids (M. spicatum × M. sibiricum) are becoming more prevalent in many lakes where the invasive and the native milfoil co-occur. Hybrid plants are more vigorous than either parent with a faster growth rate and lower sensitivity to some herbicides. The aquatic herbicides, endothall and 2,4-D, provide two effective modes of action (MOA) for management of the hybrids. For more than a decade, these two herbicides have been used in combination as an effective control option and a resistance management strategy. How this combination impacts herbicide movement and efficacy is unknown. Therefore, the objective of this research was to determine the activity of endothall and 2,4-D combined compared to activity applied alone. Absorption and translocation of endothall, 2,4-D and the combination was determined in hybrid plants over a 96-h time course. Endothall bioaccumulation was not impacted when these herbicides were applied in combination; however, 2,4-D accumulation increased by 80%, relative to when 2,4-D was applied alone. Endothall translocation from shoots to roots decreased by almost 50% when applied in combination with 2,4-D (alone = 16.7% ± 2.6; combination = 9.2% ± 1.2). Shoot-to-root translocation of 2,4-D also decreased when the two herbicides were applied in combination (24.8% ± 2.6 when applied alone to only 3.93% ± 0.4 when in the presence of endothall). This research demonstrates that combining herbicides can significantly impact herbicide activity in plants. Future research is needed to determine if this reduced translocation negatively impacts operational effectiveness when these herbicides applied in combination.
{"title":"Endothall and 2,4-D Activity in Milfoil Hybrid (Myriophyllum spicatum × M. sibiricum) when Applied Alone and in Combination","authors":"Mirella F. Ortiz, Scott J. Nissen, Franck E. Dayan","doi":"10.1017/wsc.2024.26","DOIUrl":"https://doi.org/10.1017/wsc.2024.26","url":null,"abstract":"\u0000 Eurasian watermilfoil (Myriophyllum spicatum L.) is an invasive aquatic plant that can hybridize with the native Northern watermilfoil (Myriophyllum sibiricum Kom.). These milfoil hybrids (M. spicatum × M. sibiricum) are becoming more prevalent in many lakes where the invasive and the native milfoil co-occur. Hybrid plants are more vigorous than either parent with a faster growth rate and lower sensitivity to some herbicides. The aquatic herbicides, endothall and 2,4-D, provide two effective modes of action (MOA) for management of the hybrids. For more than a decade, these two herbicides have been used in combination as an effective control option and a resistance management strategy. How this combination impacts herbicide movement and efficacy is unknown. Therefore, the objective of this research was to determine the activity of endothall and 2,4-D combined compared to activity applied alone. Absorption and translocation of endothall, 2,4-D and the combination was determined in hybrid plants over a 96-h time course. Endothall bioaccumulation was not impacted when these herbicides were applied in combination; however, 2,4-D accumulation increased by 80%, relative to when 2,4-D was applied alone. Endothall translocation from shoots to roots decreased by almost 50% when applied in combination with 2,4-D (alone = 16.7% ± 2.6; combination = 9.2% ± 1.2). Shoot-to-root translocation of 2,4-D also decreased when the two herbicides were applied in combination (24.8% ± 2.6 when applied alone to only 3.93% ± 0.4 when in the presence of endothall). This research demonstrates that combining herbicides can significantly impact herbicide activity in plants. Future research is needed to determine if this reduced translocation negatively impacts operational effectiveness when these herbicides applied in combination.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140999377","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}
Qian Yang, Wei Deng, Longwei Liu, Tian Wei, Xia Yang, Jin Zhu, Min Lv, Yongfeng Li
Digitaria ciliaris var. chrysoblephara (Fig. & De Not.) R.R. Stewart is an annual xeromorphic weed that severely infests direct-seeded rice fields in China. Herbicide resistance is emerging in D. ciliaris var. chrysoblephara owing to extensive and recurrent use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicide metamifop. In this study, a total of 53 D. ciliaris var. chrysoblephara populations randomly sampled from direct-seeded rice fields across Jiangsu Province were investigated for metamifop resistance and potential resistance-endowing mutations. Single-dose assays revealed that 17 (32.1%) populations evolved resistance to metamifop and 5 (9.4%) populations were in the process of developing resistance. Resistance index (RI) of metamifop-resistant populations ranged from 2.7 to 32.1. Amino acid substitutions (Ile-1781-Leu, Trp-2027-Cys/Ser, and Ile-2041-Asn) in ACCase genes were detected in resistant D. ciliaris var. chrysoblephara plants, and caused various cross-resistance patterns to ACCase-inhibiting herbicides. All of four resistant populations (YC07, YZ09, SQ03, and HA06), with different ACCase mutations, exhibited cross-resistance to the aryloxyphenoxypropionate (APP) herbicides cyhalofop-butyl (RIs, 10.0 to 19.9), fenoxaprop-P-ethyl (RIs, 53.7 to 132.8), and haloxyfop-P-methyl (RIs, 6.2 to 62.6), and the phenylpyrazoline (DEN) pinoxaden (RIs, 2.3 to 5.4), but responded differently to the cyclohexanedione (CHD) herbicides clethodim and sethoxydim. It is noteworthy that four post-emergence herbicides used for rice cropping, including bispyribac-sodium, pyraclonil, quinclorac, and anilofos, showed poor control effect against D. ciliaris var. chrysoblephara, suggesting few alternations for managing this weed in rice fields except ACCase inhibitors. In conclusion, this work demonstrated that the D. ciliaris var. chrysoblephara had developed resistance to ACCase-inhibiting herbicides in rice cultivation of China, and target-site amino acid substitutions in ACCase were primarily responsible for metamifop resistance.
Digitaria ciliaris var. Chrysoblephara (Fig. & De Not.) R.R. Stewart 是一种一年生异型杂草，严重危害中国的直播稻田。由于乙酰-CoA羧化酶（ACCase）抑制性除草剂甲草胺的广泛和反复使用，D. ciliaris var. Chrysoblephara 对除草剂的抗性正在出现。本研究从江苏省各地的直播稻田中随机抽样选取了53个D. ciliaris var. Chrysoblephara种群，对其甲磺草胺抗性和潜在的抗性突变进行了调查。单剂量测定结果显示，17 个种群（32.1%）对甲氰菊酯产生了抗性，5 个种群（9.4%）正在产生抗性。甲胺磷抗性种群的抗性指数（RI）从 2.7 到 32.1 不等。在抗性 D. ciliaris var. Chrysoblephara 植株中检测到 ACCase 基因中的氨基酸取代（Ile-1781-Leu、Trp-2027-Cys/Ser 和 Ile-2041-Asn），并导致对 ACCase 抑制性除草剂产生不同的交叉抗性。四个抗性种群（YC07、YZ09、SQ03 和 HA06）都有不同的 ACCase 突变，它们对芳基氧基苯氧基丙酸酯（APP）除草剂氰氟草酯（RIs，10.0 至 19.9）、精噁唑禾草灵（RIs，53.7 至 132.8）表现出交叉抗性。但对环己二酮除草剂 clethodim 和 sethoxydim 的反应则不同。值得注意的是，用于水稻种植的四种芽后除草剂，包括双草醚、吡唑醚菌酯、喹草酮和苯胺磷，对 D. ciliaris var. Chrysoblephara 的控制效果不佳，这表明除了 ACCase 抑制剂外，几乎没有其他替代品可用于管理水稻田中的这种杂草。总之，该研究表明，在中国的水稻种植中，D. ciliaris var. Chrysoblephara对ACC酶抑制性除草剂产生了抗性，而ACC酶的靶位氨基酸取代是造成甲磺草胺抗性的主要原因。
{"title":"Resistance patterns and molecular basis to ACCase-inhibiting herbicides in Digitaria ciliaris var. chrysoblephara from China","authors":"Qian Yang, Wei Deng, Longwei Liu, Tian Wei, Xia Yang, Jin Zhu, Min Lv, Yongfeng Li","doi":"10.1017/wsc.2024.30","DOIUrl":"https://doi.org/10.1017/wsc.2024.30","url":null,"abstract":"\u0000 Digitaria ciliaris var. chrysoblephara (Fig. & De Not.) R.R. Stewart is an annual xeromorphic weed that severely infests direct-seeded rice fields in China. Herbicide resistance is emerging in D. ciliaris var. chrysoblephara owing to extensive and recurrent use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicide metamifop. In this study, a total of 53 D. ciliaris var. chrysoblephara populations randomly sampled from direct-seeded rice fields across Jiangsu Province were investigated for metamifop resistance and potential resistance-endowing mutations. Single-dose assays revealed that 17 (32.1%) populations evolved resistance to metamifop and 5 (9.4%) populations were in the process of developing resistance. Resistance index (RI) of metamifop-resistant populations ranged from 2.7 to 32.1. Amino acid substitutions (Ile-1781-Leu, Trp-2027-Cys/Ser, and Ile-2041-Asn) in ACCase genes were detected in resistant D. ciliaris var. chrysoblephara plants, and caused various cross-resistance patterns to ACCase-inhibiting herbicides. All of four resistant populations (YC07, YZ09, SQ03, and HA06), with different ACCase mutations, exhibited cross-resistance to the aryloxyphenoxypropionate (APP) herbicides cyhalofop-butyl (RIs, 10.0 to 19.9), fenoxaprop-P-ethyl (RIs, 53.7 to 132.8), and haloxyfop-P-methyl (RIs, 6.2 to 62.6), and the phenylpyrazoline (DEN) pinoxaden (RIs, 2.3 to 5.4), but responded differently to the cyclohexanedione (CHD) herbicides clethodim and sethoxydim. It is noteworthy that four post-emergence herbicides used for rice cropping, including bispyribac-sodium, pyraclonil, quinclorac, and anilofos, showed poor control effect against D. ciliaris var. chrysoblephara, suggesting few alternations for managing this weed in rice fields except ACCase inhibitors. In conclusion, this work demonstrated that the D. ciliaris var. chrysoblephara had developed resistance to ACCase-inhibiting herbicides in rice cultivation of China, and target-site amino acid substitutions in ACCase were primarily responsible for metamifop resistance.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140998137","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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