Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska
Abstract Orange hawkweed is a perennial European plant that has colonized roadsides and grasslands in south-central and southeast Alaska. This plant is forming near-monotypic stands, reducing plant diversity, and decreasing pasture productivity. A replicated greenhouse study was conducted in 2006 an...
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Online Access: | http://dx.doi.org/10.1614/ipsm-d-10-00020.1 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1939729100001802 |
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crcambridgeupr:10.1614/ipsm-d-10-00020.1 2023-05-15T15:13:57+02:00 Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska Seefeldt, Steven S. Conn, Jeffery S. 2011 http://dx.doi.org/10.1614/ipsm-d-10-00020.1 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1939729100001802 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Invasive Plant Science and Management volume 4, issue 1, page 87-94 ISSN 1939-7291 1939-747X Plant Science journal-article 2011 crcambridgeupr https://doi.org/10.1614/ipsm-d-10-00020.1 2022-04-07T08:58:02Z Abstract Orange hawkweed is a perennial European plant that has colonized roadsides and grasslands in south-central and southeast Alaska. This plant is forming near-monotypic stands, reducing plant diversity, and decreasing pasture productivity. A replicated greenhouse study was conducted in 2006 and repeated in 2007 to determine the efficacy of six herbicides (aminopyralid, clopyralid, picloram, picloram + chlorsulfuron, picloram + metsulfuron, and triclopyr) for orange hawkweed control. Based on results of the greenhouse trials, replicated field studies were conducted at two sites each year in 2007 and 2008 with three rates each of aminopyralid and clopyralid to determine efficacy of orange hawkweed control and impacts on nontarget native vegetation. In the field, only aminopyralid at 105 g ae ha −1 (0.1 lb ae ac −1 ) and clopyralid at 420 g ae ha −1 controlled orange hawkweed consistently, with peak injury observed 1 yr after treatment. Control with clopyralid was slightly less than that provided by aminopyralid at all observation times, except at Homer, AK, in 2007, where there was a near-monotypic stand of orange hawkweed, and clopyralid did not remove all orange hawkweed plants. Aminopyralid controlled clover ( Trifolium spp.), seacoast angelica ( Angelica lucida ), arctic daisy ( Chrysanthemum arcticum ), common hempnettle ( Galeopsis tetrahit ), and willow ( Salix spp.) in the treated areas. Other plant species, such as grasses and some annual forbs, recovered or increased following control of the hawkweed. Clopyralid had less impact on nontarget species with most recovering the year after treatment. In a pasture system, where grasses are preferred to forbs and shrubs, aminopyralid has an advantage because it controls a broader array of forbs compared with clopyralid. In natural areas, where the desire to retain biodiversity and the aesthetics of multiple forb species mixed with grasses and willows is preferred, clopyralid will leave greater species diversity than aminopyralid. Article in Journal/Newspaper Arctic Alaska Cambridge University Press (via Crossref) Arctic Invasive Plant Science and Management 4 1 87 94 |
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Cambridge University Press (via Crossref) |
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English |
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Plant Science Seefeldt, Steven S. Conn, Jeffery S. Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
topic_facet |
Plant Science |
description |
Abstract Orange hawkweed is a perennial European plant that has colonized roadsides and grasslands in south-central and southeast Alaska. This plant is forming near-monotypic stands, reducing plant diversity, and decreasing pasture productivity. A replicated greenhouse study was conducted in 2006 and repeated in 2007 to determine the efficacy of six herbicides (aminopyralid, clopyralid, picloram, picloram + chlorsulfuron, picloram + metsulfuron, and triclopyr) for orange hawkweed control. Based on results of the greenhouse trials, replicated field studies were conducted at two sites each year in 2007 and 2008 with three rates each of aminopyralid and clopyralid to determine efficacy of orange hawkweed control and impacts on nontarget native vegetation. In the field, only aminopyralid at 105 g ae ha −1 (0.1 lb ae ac −1 ) and clopyralid at 420 g ae ha −1 controlled orange hawkweed consistently, with peak injury observed 1 yr after treatment. Control with clopyralid was slightly less than that provided by aminopyralid at all observation times, except at Homer, AK, in 2007, where there was a near-monotypic stand of orange hawkweed, and clopyralid did not remove all orange hawkweed plants. Aminopyralid controlled clover ( Trifolium spp.), seacoast angelica ( Angelica lucida ), arctic daisy ( Chrysanthemum arcticum ), common hempnettle ( Galeopsis tetrahit ), and willow ( Salix spp.) in the treated areas. Other plant species, such as grasses and some annual forbs, recovered or increased following control of the hawkweed. Clopyralid had less impact on nontarget species with most recovering the year after treatment. In a pasture system, where grasses are preferred to forbs and shrubs, aminopyralid has an advantage because it controls a broader array of forbs compared with clopyralid. In natural areas, where the desire to retain biodiversity and the aesthetics of multiple forb species mixed with grasses and willows is preferred, clopyralid will leave greater species diversity than aminopyralid. |
format |
Article in Journal/Newspaper |
author |
Seefeldt, Steven S. Conn, Jeffery S. |
author_facet |
Seefeldt, Steven S. Conn, Jeffery S. |
author_sort |
Seefeldt, Steven S. |
title |
Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
title_short |
Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
title_full |
Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
title_fullStr |
Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
title_full_unstemmed |
Control of Orange Hawkweed ( Hieracium aurantiacum ) in Southern Alaska |
title_sort |
control of orange hawkweed ( hieracium aurantiacum ) in southern alaska |
publisher |
Cambridge University Press (CUP) |
publishDate |
2011 |
url |
http://dx.doi.org/10.1614/ipsm-d-10-00020.1 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1939729100001802 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Alaska |
genre_facet |
Arctic Alaska |
op_source |
Invasive Plant Science and Management volume 4, issue 1, page 87-94 ISSN 1939-7291 1939-747X |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1614/ipsm-d-10-00020.1 |
container_title |
Invasive Plant Science and Management |
container_volume |
4 |
container_issue |
1 |
container_start_page |
87 |
op_container_end_page |
94 |
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