Characterization of root traits for improvement of spring wheat in the Pacific Northwest

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.

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Genetic characterization of Flavobacterium columnare isolates from the Pacific Northwest, USA

Diseases of Aquatic Organisms ◽

10.3354/dao03588 ◽

2021 ◽

Author(s):

Fd Alexandre Sebastião ◽

K Shahin ◽

BR LaFrentz ◽

MJ Griffin ◽

TP Loch ◽

...

Keyword(s):

Pacific Northwest ◽

Genetic Characterization ◽

Flavobacterium Columnare ◽

The Pacific

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Spring Wheat Tolerance and Resistance to Heterodera avenae in the Pacific Northwest

Plant Disease ◽

10.1094/pdis-10-12-0906-re ◽

2013 ◽

Vol 97 (5) ◽

pp. 590-600 ◽

Cited By ~ 9

Author(s):

Richard W. Smiley ◽

Juliet M. Marshall ◽

Jennifer A. Gourlie ◽

Timothy C. Paulitz ◽

Shyam L. Kandel ◽

...

Keyword(s):

Pacific Northwest ◽

Spring Wheat ◽

Cyst Nematode ◽

Cereal Cyst Nematode ◽

Heterodera Avenae ◽

Breeding Lines ◽

The Pacific ◽

Potential Benefits ◽

Controlled Environments ◽

Systematic Field

The cereal cyst nematode Heterodera avenae reduces wheat yields in the Pacific Northwest. Previous evaluations of cultivar resistance had been in controlled environments. Cultivar tolerance had not been evaluated. Seven spring wheat trials were conducted in naturally infested fields in three states over 2 years. A split-plot design was used for all trials. Five trials evaluated both tolerance and resistance in 1.8-by-9-m plots treated or not treated with nematicides. Two trials evaluated resistance in 1-m head rows where each wheat entry was paired with an adjacent row of a susceptible cultivar. Cultivars with the Cre1 resistance gene (‘Ouyen’ and ‘Chara’) reduced the postharvest density of H. avenae under field conditions, confirming Cre1 parents as useful for germplasm development. Ouyen was resistant but it was also intolerant, producing significantly lower grain yield in controls than in plots treated with nematicides. Susceptible cultivars varied in tolerance. Undefined resistance was identified in one commercial cultivar (‘WB-Rockland) and four breeding lines (UC1711, SO900163, SY-B041418, and SY-97621-05). This research was the first systematic field demonstration of potential benefits to be derived through development and deployment of cultivars with resistance plus tolerance to cereal cyst nematode in North America.

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Nitrogen Fertility and Weed Management Critical for Continuous No-Till Wheat in the Pacific Northwest

Weed Technology ◽

10.1614/wt-05-133r.1 ◽

2006 ◽

Vol 20 (3) ◽

pp. 658-669 ◽

Cited By ~ 3

Author(s):

Frank L. Young ◽

Mark E. Thorne ◽

Douglas L. Young

Keyword(s):

Winter Wheat ◽

Pacific Northwest ◽

Crop Yield ◽

Spring Wheat ◽

Weed Management ◽

Weed Density ◽

N Level ◽

No Till ◽

The Pacific ◽

Density And Biomass

No-till cropping is an option for growers needing to reduce soil erosion in the Palouse annual-cropped region of the Pacific Northwest, which is well suited for wheat production. A 6-yr field study was conducted to determine optimum levels of fertilizer and herbicide inputs in a no-till continuous wheat crop production system. Three levels of nitrogen (N) and two weed management levels (WML) were compared in a spring wheat (SW)–winter wheat (WW)–WW rotation through two rotation cycles. The high WML reduced weed densities about 50% compared with the low WML. In general, herbicide treatments were more effective on broadleaf weeds and may have facilitated a shift toward grass weeds. The high WML reduced grass weed biomass only at the reduced N levels, whereas the high WML reduced broadleaf weed density at all N levels. Variable environmental conditions affected wheat yield; however, yield tended to be highest where winter wheat immediately followed spring wheat. Nitrogen had little effect on weed density but increased crop yield about 13% with each increased N level. Crop yield was greater at the high versus low WML at each N level, even though weed density and biomass were reduced least between WMLs at the highest N level. The highest crop yield and net returns were obtained with the highest N and WML; however, none of the N and WML combinations were profitable.

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Characterization of a Spring Wheat Association Mapping Panel for Root Traits

Agronomy Journal ◽

10.2134/agronj14.0015 ◽

2014 ◽

Vol 106 (5) ◽

pp. 1593-1604 ◽

Cited By ~ 14

Author(s):

Sruthi Narayanan ◽

P. V. Vara Prasad

Keyword(s):

Association Mapping ◽

Spring Wheat ◽

Root Traits ◽

Mapping Panel

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Geocenamus brevidens Associated with Reduced Yield of No-Till Annual Spring Wheat in Oregon

Plant Disease ◽

10.1094/pd-90-0885 ◽

2006 ◽

Vol 90 (7) ◽

pp. 885-890 ◽

Cited By ~ 11

Author(s):

Richard W. Smiley ◽

Ruth G. Whittaker ◽

Jennifer A. Gourlie ◽

Sandra A. Easley

Keyword(s):

Triticum Aestivum ◽

Pacific Northwest ◽

Spring Wheat ◽

Cropping Systems ◽

Wheat Yield ◽

Economic Damage ◽

Nematode Density ◽

No Till ◽

Single Location ◽

The Pacific

Associations between stunt nematodes and yield of no-till annual spring wheat (Triticum aestivum) were examined at two eastern Oregon locations. Geocenamus brevidens was the only species detected at one location and was mixed with Tylenchorhynchus clarus at another location. Six cultivars were planted with or without application of aldicarb during 2001. Inverse correlations between yield and stunt nematode density were significant at the G. brevidens-only site (P = 0.04) but not the G. brevidens + T. clarus site (P = 0.44). Yields were inversely correlated (P < 0.01) with stunt nematode populations at both sites during 2002. Aldicarb improved grain yields at both locations during 2001 (17 and 24%, P < 0.01) but not at the single location treated with aldicarb during 2002 (10%, P = 0.06). A lack of association between yield and T. clarus in 19 previously unreported experiments is discussed. Reduced wheat yield in response to stunt nematodes in Oregon is likely due to parasitism by G. brevidens and not T. clarus. This is the first report associating G. brevidens with suppression of wheat yield in the Pacific Northwest. Further studies are needed to define cropping systems and locations where G. brevidens may cause economic damage.

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Adapting the nitrogen replacement approach to dryland spring wheat in the Pacific Northwest

Crops & Soils ◽

10.2134/cs2017.50.0503 ◽

2017 ◽

Vol 50 (5) ◽

pp. 34-37

Author(s):

Dan Long ◽

John McCallum ◽

Catherine Reardon ◽

Richard Engel

Keyword(s):

Pacific Northwest ◽

Spring Wheat ◽

The Pacific

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Resistance and Tolerance of Landrace Wheat in Fields Infested with Pratylenchus neglectus and P. thornei

Plant Disease ◽

10.1094/pdis-10-13-1069-re ◽

2014 ◽

Vol 98 (6) ◽

pp. 797-805 ◽

Cited By ~ 11

Author(s):

Richard W. Smiley ◽

Jennifer A. Gourlie ◽

Guiping Yan ◽

Karl E. L. Rhinhart

Keyword(s):

Pacific Northwest ◽

Spring Wheat ◽

Economic Loss ◽

The United States ◽

Economic Benefits ◽

Field Resistance ◽

Pratylenchus Neglectus ◽

Species Dominance ◽

The Pacific ◽

Controlled Environments

Pratylenchus neglectus and P. thornei reduce wheat yields in the Pacific Northwest of the United States. Resistant landrace cultivars have been identified using controlled environments. Field resistance and tolerance characteristics were compared over 3 years and two locations for four spring wheat cultivars: the susceptible ‘Alpowa’ and ‘Louise’ and the resistant landraces AUS28451 and Persia 20. Proportions and densities of P. neglectus and P. thornei differed across seasons and locations. Resistance was evaluated by comparing preplant and postharvest densities of nematodes in soil. Tolerance was evaluated by comparing grain yield and grain quality in plots treated or untreated by the nematicide aldicarb. Alpowa was susceptible and intolerant, Louise was susceptible and moderately tolerant, AUS28451 was resistant and intolerant, and Persia 20 was moderately susceptible and moderately intolerant. The species dominance shifted from P. neglectus to P. thornei in one field over a period of 3 years in apparent response to cultivars and crops planted. Estimates of economic loss caused by Pratylenchus spp. ranged from $8 to $20/ha. Economic benefits appear to be achievable by developing a spring wheat genotype with tolerance plus resistance, such as with a cross between AUS28451 and Louise.

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Characterization of Environmental Sources of the Human and Animal Pathogen Cryptococcus gattii in British Columbia, Canada, and the Pacific Northwest of the United States

Applied and Environmental Microbiology ◽

10.1128/aem.01330-06 ◽

2006 ◽

Vol 73 (5) ◽

pp. 1433-1443 ◽

Cited By ~ 156

Author(s):

Sarah E. Kidd ◽

Yat Chow ◽

Sunny Mak ◽

Paxton J. Bach ◽

Huiming Chen ◽

...

Keyword(s):

British Columbia ◽

Pacific Northwest ◽

Sampling Site ◽

The United States ◽

Cryptococcus Gattii ◽

Environmental Distribution ◽

The Pacific ◽

Genetic Subtype ◽

The Central Nervous System

ABSTRACT Cryptococcus gattii has recently emerged as a primary pathogen of humans and wild and domesticated animals in British Columbia, particularly on Vancouver Island. C. gattii infections are typically infections of the pulmonary and/or the central nervous system, and the incidence of infection in British Columbia is currently the highest reported globally. Prior to this emergence, the environmental distribution of and the extent of colonization by C. gattii in British Columbia were unknown. We characterized the environmental sources and potential determinants of colonization in British Columbia. C. gattii was isolated from tree surfaces, soil, air, freshwater, and seawater, and no seasonal prevalence was observed. The C. gattii concentrations in air samples were significantly higher during the warm, dry summer months, although potentially infectious propagules (<3.3 μm in diameter) were present throughout the year. Positive samples were obtained from many different areas of British Columbia, and some locations were colonization “hot spots.” C. gattii was generally isolated from acidic soil, and geographic differences in soil pH may influence the extent of colonization. C. gattii soil colonization also was associated with low moisture and low organic carbon contents. Most of the C. gattii isolates recovered belonged to the VGIIa genetic subtype; however, sympatric colonization by the VGIIb strain was observed at most locations. At one sampling site, VGIIa, VGIIb, VGI, and the Cryptococcus neoformans serotype AD hybrid all were coisolated. Our findings indicate extensive colonization by C. gattii within British Columbia and highlight an expansion of the ecological niche of this pathogen.

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