First Report of Powdery Mildew on Dipsacus sylvestris Caused by Sphaerotheca dipsacearum in North America

Common teasel (Dipsacus sylvestris) is a European species introduced into North America, and is now widely established and regarded as a noxious weed. In October 2005, a powdery mildew was observed on D. sylvestris in two locations in Pullman, Whitman Co., WA. Examination of diseased material confirmed that the causal agent was S. dipsacearum. This report provides the first documentation of S. dipsacearum on D. sylvestris in North America. Accepted for publication 20 April 2006. Published 7 June 2006.

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First Report of Powdery Mildew on Caragana arborescens in Minnesota and North Dakota Caused by Microsphaera (Erysiphe) palczewskii

Plant Health Progress ◽

10.1094/php-2006-0117-01-br ◽

2006 ◽

Vol 7 (1) ◽

pp. 59

Author(s):

Dean A. Glawe ◽

Robert W. Stack ◽

James A. Walla

Keyword(s):

North America ◽

Powdery Mildew ◽

North Dakota ◽

Rocky Mountains ◽

Causal Agent ◽

First Report ◽

Powdery Mildew Disease ◽

Caragana Arborescens ◽

First Time

In North Dakota and Minnesota, the authors encountered a powdery mildew disease of Caragana arborescens Lam. (Siberian pea tree) previously unreported from these states. The causal agent was determined to be Microsphaera palczewskii Jacz. This report documents for the first time the presence of M. palczewskii in North America east of the Rocky Mountains and includes information on the morphology, classification, and distribution of this species. Accepted for publication 4 January 2006. Published 17 January 2006.

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First Report of Powdery Mildew of Ligustrum japonicum (Japanese Privet) Caused by Microsphaera syringae (Erysiphe syringae) in North America

Plant Health Progress ◽

10.1094/php-2003-1210-01-hn ◽

2003 ◽

Vol 4 (1) ◽

pp. 27

Author(s):

Jennifer S. Falacy ◽

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Causal Agent ◽

King County ◽

First Report ◽

Ligustrum Japonicum ◽

First Time

Powdery mildew was collected from Japanese privet (Ligustrum japonicum Thunb.) in Seattle, King County, WA. The authors determined the causal agent to be Microsphaera syringae (Schw.) Magn. This report documents for the first time the occurrence of M. syringae on L. japonicum in North America, and presents information on the taxonomy and identification of this fungus. Accepted for publication 6 November 2003. Published 10 December 2003.

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First Report of Powdery Mildew of Poison-Hemlock Caused by Erysiphe heraclei in North America

Plant Health Progress ◽

10.1094/php-2009-0312-01-br ◽

2009 ◽

Vol 10 (1) ◽

pp. 48 ◽

Cited By ~ 1

Author(s):

Steven T. Koike ◽

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Causal Agent ◽

Piperidine Alkaloids ◽

First Report

Poison-hemlock is a widely distributed biennial especially known for its toxic piperidine alkaloids that can poison livestock that eat this plant. In 2008, a powdery mildew was observed on poison-hemlock growing in coastal California. The causal agent was determined to be Erysiphe heraclei DC., previously unreported on this host in North America. Accepted for publication 18 December 2008. Published 12 March 2009.

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First Report of Powdery Mildew of Scabiosa columbaria (Dove Pincushions) Caused by Erysiphe knautiae in North America

Plant Health Progress ◽

10.1094/php-2005-1024-01-br ◽

2005 ◽

Vol 6 (1) ◽

pp. 24

Author(s):

Dean A. Glawe ◽

Gary G. Grove

Keyword(s):

North America ◽

Powdery Mildew ◽

Host Species ◽

Causal Agent ◽

Perennial Species ◽

Powdery Mildew Fungus ◽

Diagnostic Features ◽

First Report ◽

Landscape Plant

Scabiosa columbaria L. (dove pincushions) is a perennial species introduced into North America, where it is grown as an ornamental landscape plant. Little information is available on pathogens attacking it in North America. Recently, the authors encountered a powdery mildew fungus on this host species in Washington and determined it to be Erysiphe knautiae Duby. This report describes the disease as well as diagnostic features and taxonomy of the causal agent. Accepted for publication 11 October 2005. Published 24 October 2005.

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First Report of Powdery Mildew of Convolvulus arvensis (Field Bindweed) Caused by Erysiphe convolvuli var. convolvuli in North America

Plant Health Progress ◽

10.1094/php-2003-1021-01-hn ◽

2003 ◽

Vol 4 (1) ◽

pp. 31

Author(s):

Dean A. Glawe ◽

Gwenyth E. Windom ◽

Gary G. Grove ◽

Jennifer S. Falacy

Keyword(s):

North America ◽

Powdery Mildew ◽

Pacific Northwest ◽

Morphological Features ◽

Convolvulus Arvensis ◽

Powdery Mildew Fungus ◽

First Report ◽

The Pacific ◽

Field Bindweed ◽

Noxious Weed

Field bindweed (Convolvulus arvensis L.) is widespread in the Pacific Northwest where it is considered a noxious weed. During 2002, collections of a powdery mildew fungus attacking C. arvensis were made from Pierce, Spokane, Whitman, and Yakima counties, WA. Based on morphological features we determined the fungus to be Erysiphe convolvuli. Accepted for publication 22 September 2003. Published 21 October 2003.

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First Report of Powdery Mildew of Lycium chinense (Chinese Matrimony Vine) Caused by Arthrocladiella mougeotii in the Pacific Northwest

Plant Health Progress ◽

10.1094/php-2004-1208-01-hn ◽

2004 ◽

Vol 5 (1) ◽

pp. 16

Author(s):

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Medicinal Plant ◽

Pacific Northwest ◽

Morphological Features ◽

Lycium Chinense ◽

First Report ◽

Landscape Plant ◽

The Pacific ◽

Plant Grown

Chinese matrimony-vine (Lycium chinense Mill.) is a traditional medicinal plant grown in China and used as a perennial landscape plant in North America. This report documents the presence of powdery mildew on L. chinense in the Pacific Northwest and describes and illustrates morphological features of the causal agent. It appears to be the first report of a powdery mildew caused by Arthrocladiella in the Pacific Northwest. Accepted for publication 10 November 2004. Published 8 December 2004.

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First Report of Powdery Mildew of Platanus occidentalis caused by Microsphaera platani (Erysiphe platani) in Washington State

Plant Health Progress ◽

10.1094/php-2003-0818-01-hn ◽

2003 ◽

Vol 4 (1) ◽

pp. 33 ◽

Cited By ~ 2

Author(s):

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Native Species ◽

Washington State ◽

Eastern North America ◽

First Report ◽

Platanus Occidentalis

American sycamore (Platanus occidentalis L.) is a common native species in eastern North America and is planted widely as a landscape tree in other regions. During a survey of powdery mildew diseases in Washington State, the fungus Microsphaera platani Howe was found on American sycamore trees in Madison Park, Seattle. This report documents the presence of M. platani in Washington State and presents information on the fungus. Accepted for publication 30 July 2003. Published 18 August 2003.

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First Report of Powdery Mildew of Coreopsis Species Caused by Golovinomyces cichoracearum in the Pacific Northwest

Plant Health Progress ◽

10.1094/php-2006-0405-01-br ◽

2006 ◽

Vol 7 (1) ◽

pp. 57

Author(s):

Dean A. Glawe ◽

Gary G. Grove ◽

Mark Nelson

Keyword(s):

Powdery Mildew ◽

Pacific Northwest ◽

Causal Agent ◽

Diagnostic Features ◽

First Report ◽

The Pacific ◽

Powdery Mildew Disease ◽

Golovinomyces Cichoracearum

In 2005, the authors encountered a previously unreported powdery mildew disease of Coreopsis verticillata L. (whorled tickseed) ‘Zagreb’ and C. auriculata L. (lobed tickseed) ‘Nana’ in central Washington and determined the causal agent to be Golovinomyces cichoracearum (DC.) VP Gelyuta. This report documents the occurrence of G. cichoracearum on Coreopsis species in the Pacific Northwest, and describes diagnostic features of the disease and causal agent. Accepted for publication 2 March 2006. Published 5 April 2006.

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First Report of Leaf Smut of Gaillardia × grandiflora Caused by Entyloma gaillardianum in North America

Plant Health Progress ◽

10.1094/php-2010-0428-01-br ◽

2010 ◽

Vol 11 (1) ◽

pp. 51 ◽

Cited By ~ 3

Author(s):

Dean A. Glawe ◽

Tess Barlow ◽

Steven T. Koike

Keyword(s):

North America ◽

Leaf Spot ◽

Its Region ◽

Morphological Features ◽

Causal Agent ◽

Leaf Spot Disease ◽

First Report ◽

Spot Disease ◽

Leaf Smut

In the summer of 2009, a leaf spot disease occurred on 100% of Gaillardia × grandiflora cv. Goblin in a commercial nursery in coastal Monterey Co., CA. Nearly all of the affected plants were unsalable. The causal agent was determined to be Entyloma gaillardianum based on morphological features, host, and ITS region. This species has not been reported previously from this host in North America. Accepted for publication 16 March 2010. Published 28 April 2010.

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First Report of Powdery Mildew of Mahonia aquifolium Caused by Microsphaera berberidis (Erysiphe berberidis) in North America

Plant Health Progress ◽

10.1094/php-2003-0206-01-hn ◽

2003 ◽

Vol 4 (1) ◽

pp. 41

Author(s):

Dean A. Glawe

Keyword(s):

North America ◽

Powdery Mildew ◽

Pacific Northwest ◽

First Report ◽

Mahonia Aquifolium ◽

First Time ◽

Grown Plant

Mahonia aquifolium is a widely-grown plant in the coastal Pacific Northwest. This report documents for the first time a powdery mildew on M. aquifolium in North America caused by a fungus fitting the description of Microsphaera berberidis. Accepted for publication 14 January 2003. Published 6 February 2003.

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