White Rot of Garlic and Onion (Causal Agent, Sclerotium cepivorum): A Status Report from the Pacific Northwest

2013 ◽  
Vol 14 (1) ◽  
pp. 33
Author(s):  
Shari L. Lupien ◽  
Barbara C. Hellier ◽  
Frank M. Dugan ◽  
Linnea G. Skoglund ◽  
Karen F. Ward
Keyword(s):  
Pacific Northwest ◽  
Commercial Production ◽  
Causal Agent ◽  
White Rot ◽  
Status Report ◽  
Department Of Agriculture ◽  
Sclerotium Cepivorum ◽  
The Pacific ◽  
National Plant Germplasm System ◽  
First Time

There is evidence from literature, state department of agriculture documents, and recent diagnoses that Sclerotium cepivorum, causal agent of white rot of garlic and onion, is spreading and/or becoming more established in the Pacific Northwest. Previously documented distributions are summarized and the fungus is reported for the first time from Latah Co., ID; Pend Oreille Co., WA; and Lake, Sanders, and Missoula counties, MT. Although known from a tightly quarantined prior occurrence in the Idaho portion of Treasure Valley (southwest Idaho), the pathogen has not been formally reported from that state nor from the state of Montana. Latah Co. has commercial production of seed garlic and borders adjacent Whitman Co., WA, where the National Plant Germplasm System (NPGS) maintains North America's largest non-commercial collection of garlic and wild/ornamental onion. Strict phytosanitary protocols have been implemented on the NPGS farm. Various areas within the Pacific Northwest have long been important for commercial Allium production, and a list of state departments of agriculture regulations addressing white rot is presented for Idaho, Oregon, and Washington. Accepted for publication 18 February 2013. Published 19 June 2013.

Identification of Resistance to Powdery Mildew in Publicly Available Male Hop Germplasm

2018 ◽  
Vol 19 (3) ◽  
pp. 258-264
Author(s):  
David H. Gent ◽  
Briana J. Claassen ◽  
Megan C. Twomey ◽  
Sierra N. Wolfenbarger
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Pacific Northwest ◽  
Western United States ◽  
R Genes ◽  
Sources Of Resistance ◽  
Department Of Agriculture ◽  
Breeding Programs ◽  
The Pacific ◽  
The U.S

Powdery mildew (caused by Podosphaera macularis) is one of the most important diseases of hop in the western United States. Strains of the fungus virulent on cultivars possessing the resistance factor termed R6 and the cultivar Cascade have become widespread in the Pacific Northwestern United States, the primary hop producing region in the country, rendering most cultivars grown susceptible to the disease at some level. In an effort to identify potential sources of resistance in extant germplasm, 136 male accessions of hop contained in the U.S. Department of Agriculture collection were screened under controlled conditions. Iterative inoculations with three isolates of P. macularis with varying race identified 23 (16.9%) accessions with apparent resistance to all known races of the pathogen present in the Pacific Northwest. Of the 23 accessions, 12 were resistant when inoculated with three additional isolates obtained from Europe that possess novel virulences. The nature of resistance in these individuals is unclear but does not appear to be based on known R genes. Identification of possible novel sources of resistance to powdery mildew will be useful to hop breeding programs in the western United States and elsewhere.

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

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.

scholarly journals Progress of White Rot on Garlic Cultivars Planted at Different Times

Plant Disease ◽  
1998 ◽  
Vol 82 (10) ◽  
pp. 1142-1146 ◽  
Author(s):  
Cleide M. F. Pinto ◽  
Luiz A. Maffia ◽  
Richard D. Berger ◽  
Eduardo S. G. Mizubuti ◽  
Vicente W. D. Casali
Keyword(s):  
Management Strategy ◽  
Allium Sativum ◽  
Average Duration ◽  
Minas Gerais ◽  
Causal Agent ◽  
White Rot ◽  
Sclerotium Cepivorum ◽  
Early Planting ◽  
Minas Gerais State ◽  
Epidemiological Parameters

In the region of Amarantina, Minas Gerais state, Brazil, four annual experiments with garlic (Allium sativum) were established in fields infested with Sclerotium cepivorum, causal agent of garlic white rot, to investigate the effect of time of planting on the day when disease was first noticed (tonset), incidence at harvest (yf), duration of epidemics (tf — tonset), and the response of five cultivars to white rot. Most epidemiological parameters were similar among cultivars. In 1986 to 1988, no white rot was observed on garlic planted during the warm temperatures in January. The average onset of white rot occurred at different times dependent on the day of planting as average temperatures decreased from January to May. That is, for February plantings, onset occurred after 93 to 140 days (between 1 June and 5 July); for March plantings, about 90 days (15 to 28 June); for mid-April plantings, about 77 days (1 July); and mid-May plantings, about 66 days (20 July). Because of these different times of onset, the average duration of epidemics was shorter for crops planted in February (30 days) compared to crops planted in March (48 days) or April to May (54 to 69 days). In general, most disease (highest incidence and longest duration) occurred on crops planted in March to May. Therefore, severe losses to white rot would be expected when garlic is planted at the traditional times (March and April) in areas infested with sclerotia of S. cepivorum. The early planting of garlic is recommended as an important management strategy to avoid white rot in areas with these infested soils.

Fluid-sediment dynamics around a barb: an experimental case study of a hydraulic structure for the Pacific Northwest

2005 ◽  
Vol 32 (5) ◽  
pp. 853-867 ◽  
Author(s):  
James F Fox ◽  
Athanasios N Papanicolaou ◽  
Brandon Hobbs ◽  
Casey Kramer ◽  
Lisa Kjos
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Hydraulic Structure ◽  
Flow Characteristics ◽  
Experimental Tests ◽  
Flow Regimes ◽  
The Pacific ◽  
Bank Protection ◽  
Bank Stabilization ◽  
First Time

Three sets of experimental tests are administered in the vicinity of a model barb — a unique hydraulic structure used to provide bank protection for mild-sloped, gravel-bed streams in the Pacific Northwest — under modeled, bankfull conditions. First, experiments are performed using acoustic Doppler velocimetry to provide a description of the flow characteristics around the model barb, as this is the first time that this type of structure has been considered. These initial experiments provide quantitative flow regimes as a guide for scour and spacing tests. Second, scour around the structure is described because existing knowledge in the literature is limited to scour in sand bed streams. Lastly, the performance of the barbs as it relates to bank protection is evaluated using the large-scale particle-image velocimeter for the first time to the authors' knowledge. The results provide quantification of three distinct flow regimes around a barb, scour geometry, and dimensionless ratios for scour depth and spacing for the barbs when designed for bankfull discharge in the Pacific Northwest.Key words: streambank erosion, bank stabilization, barb, flow diversion, hydraulic structure, turbulent eddies.

PUGET SOUND FISHERIES AND OIL POLLUTION – A Status Report

1971 ◽  
Vol 1971 (1) ◽  
pp. 139-145
Author(s):  
Robert C. Clark ◽  
John S. Finley
Keyword(s):  
Pacific Northwest ◽  
State Government ◽  
Oil Pollution ◽  
Economic Value ◽  
Puget Sound ◽  
Petroleum Industry ◽  
Status Report ◽  
Research Activities ◽  
The Pacific ◽  
The Impact

ABSTRACT The Greater Puget Sound Basin is one of the largest oil handling areas on the West Coast of North America. Due to the increased local need for petroleum products and to the proposed influx of Alaskan North Slope crude oil in the near future, this area will undoubtedly experience even greater petroleum transportation and processing activities. In terms of living resources of economic value—fish, shellfish, waterfowl and aquatic animals—Puget Sound is one of the most productive estuaries on the Pacific Coast. There is increasing evidence that the extensive sport, commercial and aquacultural fisheries resources are threatened by pollution resulting from oil spilled in the transport, handling, and use of petroleum. This paper presents a stauts report of what is being done in the Pacific Northwest by the petroleum industry, state government and federal agencies to protect the environment prior to the anticipated expansion of the petroleum industry. Research activities which will provide additional information for minimizing the impact of oil pollution on an already pollution-stressed environment are also discussed.

A REVISION OF THE GENUS TACHYPORUS GRAVENHORST (COLEOPTERA: STAPHYLINIDAE) OF NORTH AND CENTRAL AMERICA

1979 ◽  
Vol 111 (S109) ◽  
pp. 1-95 ◽  
Author(s):  
J. M. Campbell
Keyword(s):  
United States ◽  
Central America ◽  
Pacific Northwest ◽  
The United States ◽  
Central American ◽  
The North ◽  
The Pacific ◽  
Species Groups ◽  
Diagnostic Key ◽  
First Time

AbstractThe 35 species of the genus Tachyporus Gravenhorst (Staphylindae: Tachyporinae) of North and Central America are revised. Eighteen new species are described: neomexicanus, fenyesi, and howdenorum from the southwestern United States; sharpi from Mexico and the western United States; blomae from Mexico; nigripennis from California; dimorphus, pacificus, and stacesmithi from the Pacific northwest; rulomoides and browni from southeastern Canada and the northeastern United States; and borealis, canadensis, nimbicola, inornatus, ornatus, lecontei, and flavipennis, which are transcontinental in the United States and Canada. Two European species are reported for the first time from North America: abdominalis (Fabricius) and transversalis Gravenhorst. The following new specific synonymy is proposed: tehamae Blackwelder (= californicus Horn); temacus Blackwelder, oregonus Blackwelder, and alleni Blackwelder (= mexicanus Sharp); and acaudus Say, maculipennis LeConte, and chrysomelinus var. infuscatus Bernhauer (= jocosus Say). The genus is divided into 2 subgenera of which Palporus (type species Staphylinus nitidulus Fabricius) is described as new. The subgenus Tachyporus is divided into 12 species groups. Each species is described and its distribution is mapped. The male aedeagus and the pattern of elytral chaetotaxy are illustrated for each species. Major generic characters are illustrated with the aid of scanning electron photomicrographs. Neotypes are designated for the Say species faber, jocosus, and acaudus and lectotypes are designated (when needed) for the North and Central American species described by Erichson, LeConte, Horn, Sharp, and Blatchley and for a variety described by Bernhauer. A diagnostic key for all the species is given.

First Report of Powdery Mildew of Onion (Allium cepa) Caused by Leveillula taurica in the Pacific Northwest

2004 ◽  
Vol 5 (1) ◽  
pp. 17 ◽  
Author(s):  
Lindsey J. du Toit ◽  
Dean A. Glawe ◽  
Gary Q. Pelter
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Allium Cepa ◽  
Washington State ◽  
Causal Agent ◽  
Columbia Basin ◽  
First Report ◽  
Leveillula Taurica ◽  
The Pacific ◽  
Published Report

A powdery mildew disease of onion has been observed infrequently in the Columbia Basin of Washington State since 1996, but this is the first published report of this disease in the Pacific Northwest. The causal agent was determined to be Leveillula taurica (Lév.) G. Arnaud. Accepted for publication 29 October 2004. Published 29 November 2004.

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