{"title":"喷洒西部豚草控制剂的牧场中的植被和动物产量","authors":"Keith Harmoney, John Jaeger, Jacob Hadle","doi":"10.1002/cft2.20279","DOIUrl":null,"url":null,"abstract":"<p>Western ragweed (<i>Ambrosia psilostachya</i> DC) is one of the most common perennial, native forbs of western US rangelands. Cattle consume small quantities of western ragweed in their diets when present in the forage sward, and forage nutritive value tends to be greater than the associated grass component in those swards. Yet, many producers view western ragweed as an undesirable forb in rangelands. We conducted a study over two years to compare vegetative and stocker animal productivity in pastures that were either sprayed with dicamba at 6 oz/acre (0.19 lb a.i./acre) for western ragweed control or were left unsprayed. Pastures started the study with high western ragweed densities (>9 western ragweed plants/ft<sup>2</sup>) before pasture treatment, and spraying with dicamba significantly reduced western ragweed density and yield compared to unsprayed pastures (0.2 vs. 3.5 ragweed plants/ft<sup>2</sup>, and 0 vs. 206 lb/acre, respectively). Grass production and total vegetation production were similar between treatments. Crude protein and total digestible nutrients of western ragweed was greater than grass at all mid-season and end of season sampling dates both years. Stocker animal gain was not different between pastures sprayed for ragweed control and pastures left unsprayed in either year, nor when averaged over the two years (189 vs. 188 lb/head, sprayed vs. unsprayed, respectively). Beef production per acre was also similar. The spray treatment was an added expense that did not result in greater total forage, grass, or animal production. With natural fluctuations in western ragweed population densities due to weather patterns, producers will likely experience little benefit from spraying for western ragweed alone in pasture.</p>","PeriodicalId":10931,"journal":{"name":"Crop, Forage and Turfgrass Management","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Vegetation and animal production in pastures sprayed for western ragweed control\",\"authors\":\"Keith Harmoney, John Jaeger, Jacob Hadle\",\"doi\":\"10.1002/cft2.20279\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Western ragweed (<i>Ambrosia psilostachya</i> DC) is one of the most common perennial, native forbs of western US rangelands. Cattle consume small quantities of western ragweed in their diets when present in the forage sward, and forage nutritive value tends to be greater than the associated grass component in those swards. Yet, many producers view western ragweed as an undesirable forb in rangelands. We conducted a study over two years to compare vegetative and stocker animal productivity in pastures that were either sprayed with dicamba at 6 oz/acre (0.19 lb a.i./acre) for western ragweed control or were left unsprayed. Pastures started the study with high western ragweed densities (>9 western ragweed plants/ft<sup>2</sup>) before pasture treatment, and spraying with dicamba significantly reduced western ragweed density and yield compared to unsprayed pastures (0.2 vs. 3.5 ragweed plants/ft<sup>2</sup>, and 0 vs. 206 lb/acre, respectively). Grass production and total vegetation production were similar between treatments. Crude protein and total digestible nutrients of western ragweed was greater than grass at all mid-season and end of season sampling dates both years. Stocker animal gain was not different between pastures sprayed for ragweed control and pastures left unsprayed in either year, nor when averaged over the two years (189 vs. 188 lb/head, sprayed vs. unsprayed, respectively). Beef production per acre was also similar. The spray treatment was an added expense that did not result in greater total forage, grass, or animal production. With natural fluctuations in western ragweed population densities due to weather patterns, producers will likely experience little benefit from spraying for western ragweed alone in pasture.</p>\",\"PeriodicalId\":10931,\"journal\":{\"name\":\"Crop, Forage and Turfgrass Management\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2024-04-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Crop, Forage and Turfgrass Management\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/cft2.20279\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"AGRONOMY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Crop, Forage and Turfgrass Management","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cft2.20279","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"AGRONOMY","Score":null,"Total":0}
Vegetation and animal production in pastures sprayed for western ragweed control
Western ragweed (Ambrosia psilostachya DC) is one of the most common perennial, native forbs of western US rangelands. Cattle consume small quantities of western ragweed in their diets when present in the forage sward, and forage nutritive value tends to be greater than the associated grass component in those swards. Yet, many producers view western ragweed as an undesirable forb in rangelands. We conducted a study over two years to compare vegetative and stocker animal productivity in pastures that were either sprayed with dicamba at 6 oz/acre (0.19 lb a.i./acre) for western ragweed control or were left unsprayed. Pastures started the study with high western ragweed densities (>9 western ragweed plants/ft2) before pasture treatment, and spraying with dicamba significantly reduced western ragweed density and yield compared to unsprayed pastures (0.2 vs. 3.5 ragweed plants/ft2, and 0 vs. 206 lb/acre, respectively). Grass production and total vegetation production were similar between treatments. Crude protein and total digestible nutrients of western ragweed was greater than grass at all mid-season and end of season sampling dates both years. Stocker animal gain was not different between pastures sprayed for ragweed control and pastures left unsprayed in either year, nor when averaged over the two years (189 vs. 188 lb/head, sprayed vs. unsprayed, respectively). Beef production per acre was also similar. The spray treatment was an added expense that did not result in greater total forage, grass, or animal production. With natural fluctuations in western ragweed population densities due to weather patterns, producers will likely experience little benefit from spraying for western ragweed alone in pasture.
期刊介绍:
Crop, Forage & Turfgrass Management is a peer-reviewed, international, electronic journal covering all aspects of applied crop, forage and grazinglands, and turfgrass management. The journal serves the professions related to the management of crops, forages and grazinglands, and turfgrass by publishing research, briefs, reviews, perspectives, and diagnostic and management guides that are beneficial to researchers, practitioners, educators, and industry representatives.