Weed Science最新文献

{"title":"Thiobencarb Resistance Mechanism is Distinct from Cyp81a-Based Cross-Resistance in Late Watergrass (Echinochloa phyllopogon)","authors":"N. G. Dimaano, T. Tominaga, S. Iwakami","doi":"10.1017/wsc.2022.4","DOIUrl":"https://doi.org/10.1017/wsc.2022.4","url":null,"abstract":"Abstract The genetic and molecular basis of resistance evolution in weeds to multiple herbicides remains unclear despite being a great threat to agriculture. A population of late watergrass [Echinochloa phyllopogon (Stapf.) Koso-Pol.] was reported to exhibit resistance to ≥15 herbicides from six sites of action, including thiobencarb (TB). While previous studies disclosed that the resistance to a majority of herbicides such as acetolactate synthase (ALS) and acetyl-CoA carboxylase inhibitors is caused by the overexpression of herbicide-metabolizing cytochrome P450s (CYP81A12 and CYP81A21), the resistance mechanisms to some herbicides remain unknown. Here, we analyzed the resistance segregation in the progenies between resistant and sensitive populations and performed a transgenic plant sensitivity assay to resolve whether TB resistance is endowed by the same CYP81A12/21-based cross-resistance mechanism or other unknown multiple-resistance mechanisms. In the F6 progenies, resistance to the ALS inhibitor bensulfuron-methyl cosegregated with the resistances to many other herbicides under the CYP81A12/21-based cross-resistance mechanism; however, TB resistance segregated independently. Furthermore, CYP81A12/21 failed to confer TB resistance in transgenic Arabidopsis thaliana L. Heynh, thus confirming that TB resistance in resistant E. phyllopogon is not endowed by the two P450s that are responsible for the metabolism-based cross-resistance. This study provides evidence that resistance in E. phyllopogon to herbicides with multiple sites of action is endowed by both P450-based and other uncharacterized non–target site based mechanisms. Our findings add another layer in the understanding of resistance evolution to multiple herbicides in E. phyllopogon. Identification of the key genes endowing TB resistance will be the future direction of this research.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"160 - 166"},"PeriodicalIF":2.5,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42436324","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}

{"title":"Biologically Effective Dose of Flumioxazin and Pyroxasulfone for Control of Multiple Herbicide–Resistant Waterhemp (Amaranthus tuberculatus) in Soybean","authors":"James Ferrier, N. Soltani, D. Hooker, D. Robinson, P. Sikkema","doi":"10.1017/wsc.2022.3","DOIUrl":"https://doi.org/10.1017/wsc.2022.3","url":null,"abstract":"Abstract Two studies were conducted to ascertain the biologically effective dose (BED) of flumioxazin and pyroxasulfone for multiple herbicide–resistant (MHR) waterhemp [Amaranthus tuberculatus (Moq.) Sauer] control in soybean [Glycine max (L.) Merr.] in southwestern Ontario, Canada, during 2016 and 2017. In the flumioxazin study, the predicted flumioxazin doses for 50%, 80%, and 90% MHR A. tuberculatus control were 19, 37, and 59 g ai ha–1 at 2 wk after application (WAA) and 31, 83, and 151 g ai ha–1, respectively, at 12 WAA. The predicted flumioxazin doses to cause 5% and 10% soybean injury were 129 and 404 g ai ha–1, respectively, at 2 wk after emergence (WAE), and the predicted flumioxazin doses to obtain 50%, 80%, and 95% of the weed-free control plot's yield were determined to be 3, 14, and 65 g ai ha–1, respectively. In the pyroxasulfone study, the predicted pyroxasulfone doses that provided 50%, 80%, and 90% MHR A. tuberculatus visible control were 25, 50, and 88 g ai ha–1 at 2 WAA and 41, 109, and 274 g ai ha–1 at 12 WAA, respectively. The dose of pyroxasulfone predicted for 80% reduction in MHR A. tuberculatus density was 117 g ai ha–1, and the doses of pyroxasulfone predicted for 80% and 90% reduction in A. tuberculatus biomass were 204 and 382 g ai ha–1, respectively. The predicted doses of pyroxasulfone that caused 5% and 10% injury in soybean at 2 WAE were 585 and 698 g ai ha–1, respectively. The predicted doses of pyroxasulfone required to obtain 50%, 80%, and 95% yield relative to the weed-free plots were 6, 24, and 112 g ai ha–1, respectively. Flumioxazin and pyroxasulfone applied preemergence at the appropriate doses provided early-season MHR A. tuberculatus control in soybean.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"243 - 248"},"PeriodicalIF":2.5,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43745747","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}

{"title":"Functionally Diverse Flax-Based Rotations Improve Wild Oat (Avena fatua) and Cleavers (Galium spurium) Management","authors":"D. Benaragama, W. May, R. Gulden, C. Willenborg","doi":"10.1017/wsc.2021.79","DOIUrl":"https://doi.org/10.1017/wsc.2021.79","url":null,"abstract":"Abstract Wild oat (Avena fatua L.) and false cleavers (Galium spurium L.) are currently a challenge to manage in less competitive crops such as flax (Linum usitatissimum L.). Increasing the functional diversity in crop rotations can be an option to improve weed management. Nonetheless, this strategy had not been tested in flax in western Canada. A 5-yr (2015 to 2019) crop rotation study was carried at three locations in western Canada to determine the effect of diverse flax-based crop rotations with differences in crop species, crop life cycles, harvesting time, and reduced herbicides on managing A. fatua and G. spurium. The perennial rotation (flax–alfalfa [Medicago sativa L.]–alfalfa–alfalfa–flax) under reduced herbicide use was found to be the most consistent cropping system, providing A. fatua and G. spurium control similar to the conventional annual flax crop rotation (flax–barley [Hordeum vulgare L.]–flax–oat [Avena sativa L.]–flax) with standard herbicides. At Carman, this alfalfa rotation provided even better weed control (80% A. fatua, 75% G. spurium) than the conventional rotation. Furthermore, greater A. fatua control was identified compared with a conventional rotation in which two consecutive winter cereal crops were grown successfully in rotation (flax–barley–winter triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)]–winter wheat [Triticum aestivum L.]–flax). Incorporation of silage oat crops did not show consistent management benefits compared with the perennial alfalfa rotation but was generally similar to the conventional rotation with standard herbicides. The results showed that perennial alfalfa in the rotation minimized G. spurium and A. fatua in flax-cropping systems, followed by rotations with two consecutive winter cereal crops.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"220 - 234"},"PeriodicalIF":2.5,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48053972","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}

{"title":"Editorial for Weed Science, Volume 70","authors":"W. Vencill","doi":"10.1017/wsc.2021.72","DOIUrl":"https://doi.org/10.1017/wsc.2021.72","url":null,"abstract":"","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"1 - 3"},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47611478","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}

{"title":"WSC volume 70 issue 1 Cover and Front matter","authors":"","doi":"10.1017/wsc.2022.1","DOIUrl":"https://doi.org/10.1017/wsc.2022.1","url":null,"abstract":"","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"f1 - f3"},"PeriodicalIF":2.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41792469","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}

{"title":"Surveys of Weed Management on Flooded Rice Yields in Southern Brazil","authors":"A. L. Silva, N. Streck, A. Zanon, G. G. Ribas, Bruno L. Fruet, A. Ulguim","doi":"10.1017/wsc.2021.77","DOIUrl":"https://doi.org/10.1017/wsc.2021.77","url":null,"abstract":"Abstract One of the main limiting factors for high yields of flooded rice (Oryza sativa L.) is the presence of weeds, especially herbicide-resistant weeds. The aim of this study was to evaluate the association of weed management practices adopted by flooded rice farmers in the state of Rio Grande do Sul (RS), Brazil, with grain yield. For this purpose, 324 interview surveys were administered to farmers who supplied information about the history of weed management and yields. The answers to the survey indicated that weedy rice (Oryza sativa L.) and Echinochloa spp. were the most important weeds that occurred in flooded rice areas in RS. Advanced growth stage of weeds and inadequate environmental conditions such as air temperature and relative humidity were listed as the main reasons for low weed control efficacy. Farmers achieved greater rice yields when they adopted rice–soybean [Glycine max (L.) Merr.] (9,140 kg ha–1 average yield) and herbicide site of action rotations (8,801 kg ha–1 average yield) along with tank mixes (8,580 kg ha–1 average yield) as specific management practices for resistant weed control. The use of glyphosate with residual herbicides in a tank mix in the rice spiking stage is the main factor related to greater yields. The postemergence applications and their relationship to delaying of flooding in rice is a factor that reduces rice yield when no spiking glyphosate application was made. Identification of the most important weeds in terms of occurrence and knowledge of the main agronomic practices adopted by farmers are essential so that recommendations for integrated management practices can be adopted in an increasingly accurate and sustainable manner in flooded rice areas in southern Brazil.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"249 - 258"},"PeriodicalIF":2.5,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49461468","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}

{"title":"Influence of Posttreatment Irrigation Timings and Herbicide Placement on Bermudagrass and Goosegrass (Eleusine indica) Response to Low-Dose Topramezone and Metribuzin Programs","authors":"Jonathan R. Brewer, Jordan C. Craft, S. Askew","doi":"10.1017/wsc.2021.80","DOIUrl":"https://doi.org/10.1017/wsc.2021.80","url":null,"abstract":"Abstract Immediate posttreatment irrigation has been proposed as a method to reduce hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] phytotoxicity from topramezone. Immediate irrigation is impractical, because it would take a turfgrass sprayer 10 to 15 min to cover an average golf course fairway or athletic field. There is also insufficient evidence regarding how posttreatment irrigation, immediate or otherwise, influences mature goosegrass [Eleusine indica (L.) Gaertn.] control from topramezone or low-dose topramezone plus metribuzin programs. We sought to investigate bermudagrass and E. indica response to immediate, 15-min, and 30-min posttreatment irrigation compared with no irrigation following topramezone at 12.3 g ae ha–1, the lowest labeled rate, or topramezone at 6.1 g ha–1 plus metribuzin at 210 g ai ha–1. We also evaluated placement of each herbicide and their combination on soil, foliage, and soil plus foliage to help elucidate the mechanisms involved in differential responses between species and herbicide mixtures. Responses were largely dependent on trial due to bermudagrass injury from high-dose topramezone being nearly eliminated by immediate irrigation in one trial and only slightly affected in another. When posttreatment irrigation was postponed for 15 or 30 min, topramezone alone injured bermudagrass unacceptably in both trials. Bermudagrass was injured less by low-dose topramezone plus metribuzin than by high-dose topramezone. All posttreatment irrigation timings reduced E. indica control compared with no posttreatment irrigation. The herbicide placement study suggested that topramezone control of E. indica is highly dependent on foliar uptake and that phytotoxicity of both bermudagrass and E. indica is greater from topramezone than metribuzin. Thus, posttreatment irrigation likely reduces topramezone rate load with a concomitant effect on plant phytotoxicity of both species. Metribuzin reduced 21-d cumulative clipping weight and tiller production of plants, and this may be a mechanism by which it reduces foliar white discoloration from topramezone.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"235 - 242"},"PeriodicalIF":2.5,"publicationDate":"2021-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46880823","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}

{"title":"Characterization and Inheritance of Dicamba Resistance in a Multiple-Resistant Waterhemp (Amaranthus tuberculatus) Population from Illinois","authors":"Lucas K. Bobadilla, Darci A. Giacomini, A. Hager, P. Tranel","doi":"10.1017/wsc.2021.76","DOIUrl":"https://doi.org/10.1017/wsc.2021.76","url":null,"abstract":"Abstract Waterhemp [Amaranthus tuberculatus (Moq.) Sauer] is one of the most troublesome agronomic weeds in the midwestern United States. The rapid evolution and selection of herbicide-resistance traits in A. tuberculatus is a major challenge in managing this species. An A. tuberculatus population, designated CHR, was identified in 2012 in Champaign County, IL, and previously characterized as resistant to herbicides from six site-of-action groups: 2,4-D (Group 4), acetolactate synthase inhibitors (Group 2), protoporphyrinogen oxidase inhibitors (Group 14), 4-hydroxyphenylpyruvate dioxygenase inhibitors (Group 27), photosystem II inhibitors (Group 5), and very-long-chain fatty-acid synthesis inhibitors (Group 15). Recently, ineffective control of CHR was observed in the field after dicamba application. Therefore, this research was initiated to confirm dicamba resistance, quantify the resistance level, and investigate its inheritance in CHR. Multiple field trials were conducted at the CHR location to confirm poor control with dicamba and compare dicamba treatments with other herbicides. Greenhouse trials were conducted to quantify the resistance level in CHR and confirm genetic inheritance of the resistance. In field trials, dicamba did not provide more than 65% control, while glyphosate and glufosinate provided at least 90% control. Multiple accessions were generated from controlled crosses and evaluated in greenhouse trials. Greenhouse dicamba dose–response experiments indicated a resistance level of 5- to 10-fold relative to a sensitive parental line. Dose–response experiments using F1 lines indicated that dicamba resistance was an incompletely dominant trait. Segregation analysis with F2 and backcross populations indicated that dicamba resistance had moderate heritability and was potentially a multigenic trait. Although dicamba resistance was predominantly inherited as a nuclear trait, minor maternal inheritance was not completely ruled out. To our knowledge, CHR is one of the first cases of dicamba resistance in A. tuberculatus. Further studies will focus on elucidating the genes involved in dicamba resistance.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"4 - 13"},"PeriodicalIF":2.5,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45460347","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}

{"title":"Impacts of Long-Term Composted Manure and Straw Amendments on Rice-Associated Weeds in a Rice–Wheat Rotation System","authors":"Pinglei Gao, Aimei Hong, Min Han, Minghan Song, Y. Duan, Haiyan Zhang, Yong Li, Yicheng Sun, Guojun Sun, Qigen Dai, W. Ran","doi":"10.1017/wsc.2021.75","DOIUrl":"https://doi.org/10.1017/wsc.2021.75","url":null,"abstract":"Abstract As part of a long-term experiment to determine the impacts of composted manure and straw amendments (replacing 50% of chemical fertilizer with composted pig manure, wheat straw return combined with chemical fertilizer, and setting no fertilizer and chemical fertilizer-only as controls) on rice-associated weeds in a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) rotation system, species richness, abundance, density, and biomass of weeds were assessed during years 8 and 9. Fertilization decreased the species richness and total density of rice-associated weeds but increased their total biomass. The species richness and densities of broadleaf and sedge weeds decreased with fertilization, while species richness of grass weeds increased only with straw return and density was not significantly affected. The shoot biomass per square meter of grass and broadleaf weeds was significantly higher with fertilization treatments than with the no-fertilizer control, while that of sedge weeds declined with fertilizer application. With fertilization, the densities of monarch redstem (Ammannia baccifera L.) and smallflower umbrella sedge (Cyperus difformis L.) decreased, that of Chinese sprangletop [Leptochloa chinensis (L.) Nees] increased, and those of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] and monochoria [Monochoria vaginalis (Burm. f.) C. Presl ex Kunth] were not significantly affected. Ammannia baccifera was the most abundant weed species in all treatments. Whereas composted pig manure plus fertilizer resulted in higher density of A. baccifera and lower shoot biomass per plant than chemical fertilizer only, wheat straw return plus chemical fertilizer caused lower density and shoot biomass of A. baccifera. Therefore, it may be possible that fertilization strategies that suppress specific weeds could be used as improved weed management program components in rice production systems.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"120 - 133"},"PeriodicalIF":2.5,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44206483","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}

{"title":"Toward Understanding the Impact of Nuisance Algae Bloom on the Reduction of Rice Seedling Emergence and Establishment","authors":"S. Ohadi, Guelta Laguerre, J. Madsen, K. Al‐Khatib","doi":"10.1017/wsc.2021.69","DOIUrl":"https://doi.org/10.1017/wsc.2021.69","url":null,"abstract":"Abstract California rice (Oryza sativa L.) production has been recently challenged by the early-season nuisance algae blooms. The algal community in rice is a complex of green algae (Nostoc spongiforme Agardh ex Bornet) and cyanobacteria species that can develop a thick algal mat on the surface of the water and interfere with the emergence and establishment of rice seedlings. The objective of this research was to determine the impact of algal infestation level on rice seedling emergence. A mesocosm study was conducted in 57-L tubs. Three levels of algal infestation (low, medium, and high) were produced by adding fertilizer (N:P) into the tubs at 0:0, 75:35, and 150:70 kg–1 ha. Sixty rice seeds (‘M-206’) were soaked for 24 h and spread into tubs filled with water. Photosynthetic active radiation (PAR), chlorophyll a concentration as the quantitative measure of algae, number of emerged rice seedlings, and their dry biomass were studied during the experiment. Results showed that algal infestation can directly change the amount of light received into the water. Minimum, maximum, and mean percentage of PAR inside the water declined as the algal infestation level increased. As a consequence, rice seedling emergence dropped under the high algal pressure. At very high algal infestation (i.e., chlorophyll a concentration of above 500 µg ml–1), rice seedling emergence was reduced up to 90%. Furthermore, rice seedling emergence was delayed under algal infestation. When algal infestation was low, time to 50% rice seedling emergence (t 50) ranged between 5 and 10 d, while at high algal infestation, t50 ranged between 12 and 20 d. Moreover, individual rice seedling biomass was reduced from 1 g to 0.01 g as algal infestation increased. The results from this study indicate that uncontrolled algae at the beginning of the rice-growing season could reduce rice seedling emergence, establishment, and rice stand. Given that algal infestation in fields has a patchy pattern, loss of rice stand in these patches could provide empty niches for other weeds to grow.","PeriodicalId":23688,"journal":{"name":"Weed Science","volume":"70 1","pages":"95 - 102"},"PeriodicalIF":2.5,"publicationDate":"2021-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44503893","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}