scholarly journals Rapid Quantitative Assessment of Rhizoctonia Resistance in Roots of Selected Wheat and Barley Genotypes

Plant Disease ◽  
2016 ◽  
Vol 100 (3) ◽  
pp. 640-644
Author(s):  
Patricia A. Okubara ◽  
Natalie Leston ◽  
Ute Micknass ◽  
Karl-Heinz Kogel ◽  
Jafargholi Imani
Keyword(s):  
Pacific Northwest ◽  
Management Practices ◽  
Production Systems ◽  
Low Cost ◽  
Genetic Resistance ◽  
Bare Patch ◽  
Rhizoctonia Root Rot ◽  
The Pacific ◽  
Wide Range ◽  
Barley Genotypes

Rhizoctonia solani AG8, causal agent of Rhizoctonia root rot and bare patch in dryland cereal production systems of the Pacific Northwest United States and Australia, reduces yields in a wide range of crops. Disease is not consistently controlled by available management practices, so genetic resistance would be a desirable resource for growers. In this report, we describe three rapid and low-cost assays for R. solani AG8 resistance in wheat and barley, with the view of facilitating screens for genetic resistance in these hosts. The first assay uses 50-ml conical centrifuge tubes containing soil infested with R. solani AG8 on a substrate of ground oats. The second assay uses roots of 3-day-old seedlings directly coated with infested ground oats, followed by incubation in plastic dishes. The third assay, suitable for barley, uses whole infested oat kernels in 50-ml tubes. Symptoms are quantified on the bases of root fresh weight and total root length at 7 and 3 days for the tube and coating assays, respectively. Each of the assays show the same disease differential between susceptible and partially resistant wheat genotypes. The assays can be conducted in the laboratory, growth chamber, or greenhouse.

scholarly journals Characterizing and Mapping Resistance in Synthetic-Derived Wheat to Rhizoctonia Root Rot in a Green Bridge Environment

2016 ◽  
Vol 106 (10) ◽  
pp. 1170-1176 ◽  
Author(s):  
A. K. Mahoney ◽  
E. M. Babiker ◽  
T. C. Paulitz ◽  
D. See ◽  
P. A. Okubara ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Root Rot ◽  
Recombinant Inbred Lines ◽  
Genetic Resistance ◽  
Genotyping By Sequencing ◽  
Interval Mapping ◽  
Environmentally Sustainable ◽  
Soilborne Disease ◽  
Rhizoctonia Root Rot ◽  
Green Bridge

Root rot caused by Rhizoctonia spp. is an economically important soilborne disease of spring-planted wheat in growing regions of the Pacific Northwest (PNW). The main method of controlling the disease currently is through tillage, which deters farmers from adopting the benefits of minimal tillage. Genetic resistance to this disease would provide an economic and environmentally sustainable resource for farmers. In this study, a collection of synthetic-derived genotypes was screened in high-inoculum and low-inoculum field environments. Six genotypes were found to have varying levels of resistance and tolerance to Rhizoctonia root rot. One of the lines, SPBC-3104 (‘Vorobey’), exhibited good tolerance in the field and was crossed to susceptible PNW-adapted ‘Louise’ to examine the inheritance of the trait. A population of 190 BC1-derived recombinant inbred lines was assessed in two field green bridge environments and in soils artificially infested with Rhizoctonia solani AG8. Genotyping by sequencing and composite interval mapping identified three quantitative trait loci (QTL) controlling tolerance. Beneficial alleles of all three QTL were contributed by the synthetic-derived genotype SPCB-3104.

Blueprints for Tropical Dairy Farming

2017 ◽  
Author(s):  
John Moran ◽  
Philip Chamberlain
Keyword(s):  
Developing Countries ◽  
Best Management Practices ◽  
Large Scale ◽  
Management Practices ◽  
Production Systems ◽  
Dairy Farming ◽  
Dairy Herds ◽  
Dairy Production ◽  
Wide Range ◽  
The Tropics

Blueprints for Tropical Dairy Farming provides insight into the logistics, infrastructure and management required for the development of small and large dairy farms in tropical developing countries. Farmers will learn how to improve the welfare, milk quality and productivity of their dairy herds. This book complements author John Moran’s five previous books on the principles of tropical dairy farming. The manual covers a wide range of topics related to ensuring the sustainability of dairy production systems in tropical developing countries, such as South and East Asia, Africa and Central America. It also provides guidelines for the best management practices of large-scale, more intensive dairy systems. While smallholder farms are the major suppliers of milk in the tropics, many larger farms are becoming established throughout the tropics to satisfy the increasing demands for fresh milk. Blueprints for Tropical Dairy Farming will be a valuable resource for farmers and stockpeople who want to improve the productive performance of their dairy herds, farm advisers who can assist farmers to achieve this aim, educators who develop training programs for farmers or who train dairy advisers in the basics of dairy production technology, and other stakeholders in tropical dairy production, such as local agribusiness, policy makers and research scientists. National and international agencies will learn new insights into the required long-term logistics for regional dairy development, while potential investors will acquire knowledge into intensive tropical dairy farming.

scholarly journals Clinical laboratory test menu changes in the Pacific Northwest: 1994 to 1996

1998 ◽  
Vol 44 (4) ◽  
pp. 833-838 ◽  
Author(s):  
Kathleen M LaBeau ◽  
Marianne Simon ◽  
Steven J Steindel
Keyword(s):  
Managed Care ◽  
Laboratory Test ◽  
Pacific Northwest ◽  
Medical Practice ◽  
Clinical Laboratory ◽  
Site Testing ◽  
Physician Office ◽  
Clinical Laboratory Test ◽  
The Pacific ◽  
Wide Range

Abstract Laboratory testing services are presently undergoing dynamic changes in response to a wide range of external factors. Government regulations, reimbursement, and managed care are only a few of the influences affecting the availability of testing services and on-site testing capabilities in hospital, independent, and physician office laboratories. Medical practice changes, marketplace influences, test technologies, and costs also play a role in determining where testing is being performed. To better understand the factors influencing clinical laboratory test volumes and menus and to identify on-site testing deemed essential in physician office laboratories, we gathered information from a network of clinical laboratories in the Pacific Northwest. Questionnaires were sent to 257 Laboratory Medicine Sentinel Monitoring Network participants in March 1996. In the past 2 years, changes in on-site test volumes and test menus have been primarily due to medical practice changes and marketplace influences. When laboratories had a decrease in test volumes or test menu choices, the size of the patient workload and the volumes of test orders have had the greatest impact. Laboratory regulations and managed care contracts have played a role in shifting on-site testing to outside sources; however, these factors did not appear to be primary influences. Only 5% of physician office laboratories identified tests that they believed were essential for optimal patient care but did not perform on-site.

scholarly journals The Effects of Forestry Site Preparation on Mountain Beaver Demographics and Associated Damage to Tree Seedlings

2010 ◽  
Vol 25 (3) ◽  
pp. 127-135
Author(s):  
Wendy Arjo
Keyword(s):  
Pacific Northwest ◽  
Management Practices ◽  
Site Preparation ◽  
Home Ranges ◽  
Tree Seedlings ◽  
Animal Damage ◽  
The Pacific ◽  
Mountain Beaver ◽  
Aplodontia Rufa ◽  
Species Specific

Abstract Timber resources are a vital part of the economy in the Pacific Northwest, yet reforestation efforts are often hampered by animal damage. Understanding the factors that influence seedling damage can assist managers in implementing appropriate techniques to reduce species-specific damage. I radio-collared and monitored mountain beavers (Aplodontia rufa) from preharvest to seedling planting to determine the impacts of forest management practices on demographics. In addition, I monitored Douglas-fir (Pseudotsuga menziesii) seedlings on 28 plots on two harvest units (Vesta and Schoolhouse) to determine the effects of chemical site preparation on mountain beaver foraging and subsequent seedling damage. Mountain beaver densities differed between silvicultural treatments (F3,39 = 3.58, P < 0.02), although reproductive success did not (χ2 = 0.14, df = 1, P = 0.70). Larger mountain beaver home ranges were documented in the mature timber compared with those following harvest. Home ranges were also larger in the chemical site preparation portion of the unit (mean = 3.37 ± 0.9 ha) than in the nontreated portion of the unit (mean = 0.82 ± 0.17 ha) on Vesta. Herbicide treatment did not promote seedling damage on either unit. Vegetation does not appear to be the only factor influencing mountain beaver movements and seedling damage. Availability of water is very important for mountain beavers and may also influence their foraging choice, as well as contributing to their increased movements in mature timber (reduced groundwater) versus clearcut areas. Understanding the effects of vegetation on population demographics and subsequent seedling damage may allow for initiating a nonlethal management method using alternative forage.

scholarly journals What drives the evolution of hunter–gatherer subsistence technology? A reanalysis of the risk hypothesis with data from the Pacific Northwest

2011 ◽  
Vol 366 (1567) ◽  
pp. 1129-1138 ◽  
Author(s):  
Mark Collard ◽  
Briggs Buchanan ◽  
Jesse Morin ◽  
Andre Costopoulos
Keyword(s):  
Pacific Northwest ◽  
Northwest Coast ◽  
Contact Period ◽  
Hunter Gatherers ◽  
The Pacific ◽  
Wide Range ◽  
Relevant Variables ◽  
The Impact ◽  
The Relationship

Recent studies have suggested that the decisions that hunter–gatherers make about the diversity and complexity of their subsistence toolkits are strongly affected by risk of resource failure. However, the risk proxies and samples employed in these studies are potentially problematic. With this in mind, we retested the risk hypothesis with data from hunter–gatherer populations who lived in the northwest coast and plateau regions of the Pacific Northwest during the early contact period. We focused on these populations partly because the northwest coast and plateau differ in ways that can be expected to lead to differences in risk, and partly because of the availability of data for a wide range of risk-relevant variables. Our analyses suggest that the plateau was a more risky environment than the northwest coast. However, the predicted differences in the number and complexity of the populations' subsistence tools were not observed. The discrepancy between our results and those of previous tests of the risk hypothesis is not due to methodological differences. Rather, it seems to reflect an important but hitherto unappreciated feature of the relationship between risk and toolkit structure, namely that the impact of risk is dependent on the scale of the risk differences among populations.

scholarly journals Susceptibility of Weedy Hosts from Pacific Northwest Potato Production Systems to Crop-Aggressive Isolates of Verticillium dahliae

Plant Disease ◽  
2017 ◽  
Vol 101 (8) ◽  
pp. 1500-1506 ◽  
Author(s):  
Z. A. Frederick ◽  
T. F. Cummings ◽  
D. A. Johnson
Keyword(s):  
Pacific Northwest ◽  
Verticillium Dahliae ◽  
Production Systems ◽  
Potato Crop ◽  
Potato Production ◽  
Plant Host ◽  
Term Survival ◽  
Wide Range ◽  
Potato Isolate ◽  
Dahliae Isolate

Verticillium wilt, caused by Verticillium dahliae, is a disease of dicotyledonous crops such as potato and has a wide host range and persistent, long-term survival structures called microsclerotia that can persist in soil for up to 14 years. Some V. dahliae isolates are particularly aggressive on a specific plant host while retaining the ability to infect a wide range of other hosts. Weeds can serve as hosts for V. dahliae but whether they serve as sources of inoculum for aggressive isolates of V. dahliae to crop hosts is unknown. The goal of this research was to quantify V. dahliae microsclerotia obtained from 16 weeds which were grown in the greenhouse. Potting medium was infested with one of eight V. dahliae isolates from potato, mint, sugar beet, sunflower, tomato, and watermelon. The isolates from mint and potato were aggressive on the host from which they were originally isolated. All 16 weeds were infected by at least one V. dahliae isolate, although the number of microsclerotia produced from some infections was relatively low (≤5 microsclerotia/g of dry plant). Black nightshade yielded greater numbers of microsclerotia of the V. dahliae potato isolate than any other isolate in three of four trials in the greenhouse (second trial false discovery rate, adjusted P ≤ 0.0158; third trial, P ≤ 0.0264; and fourth trial, P ≤ 0.0193). Litchi tomato yielded greater numbers of microsclerotia of the V. dahliae potato isolate than any other isolate in one of four trials (first trial, P ≤ 0.0149). A V. dahliae isolate from tomato yielded greater numbers of microsclerotia in large crabgrass and wild oat in a second trial (P ≤ 0.0158). Weeds, depending on the species, grown during and between potato crop rotations may increase the number of microsclerotia of the potato-aggressive isolates of V. dahliae.

Removal of Systematic Model Bias on a Model Grid

2008 ◽  
Vol 23 (3) ◽  
pp. 438-459 ◽  
Author(s):  
Clifford F. Mass ◽  
Jeffrey Baars ◽  
Garrett Wedam ◽  
Eric Grimit ◽  
Richard Steed
Keyword(s):  
Pacific Northwest ◽  
Bias Reduction ◽  
Systematic Bias ◽  
Regime Changes ◽  
Dewpoint Temperature ◽  
The Pacific ◽  
Short Period ◽  
Wide Range ◽  
Forecast Models ◽  
Grid Points

Abstract Virtually all numerical forecast models possess systematic biases. Although attempts to reduce such biases at individual stations using simple statistical corrections have met with some success, there is an acute need for bias reduction on the entire model grid. Such a method should be viable in complex terrain, for locations where gridded high-resolution analyses are not available, and where long climatological records or long-term model forecast grid archives do not exist. This paper describes a systematic bias removal scheme for forecast grids at the surface that is applicable to a wide range of regions and parameters. Using observational data and model forecasts over the Pacific Northwest, a method was developed to reduce the biases in gridded 2-m temperature, 2-m dewpoint temperature, and 12-h precipitation forecasts. The method first estimates bias at observing locations using errors from forecasts that are similar to the current forecast. These observed biases are then used to estimate bias on the model grid by pairing model grid points with stations that have similar elevation and/or land-use characteristics. Results show that this approach reduces bias substantially, particularly for periods when biases are large. Adaptations to weather regime changes are made within a short period, and the method essentially “shuts off” when model biases are small. With modest modifications, this approach can be extended to additional variables.

Responding to an Introduced Pathogen: Podosphaera macularis (Hop Powdery Mildew) in the Pacific Northwest

2003 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Walter F. Mahaffee ◽  
Carla S. Thomas ◽  
William W. Turechek ◽  
Cynthia M. Ocamb ◽  
Mark E. Nelson ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Management Practices ◽  
Risk Index ◽  
Lessons Learned ◽  
Infection Model ◽  
The Pacific ◽  
Sphaerotheca Macularis ◽  
The Cost ◽  
Podosphaera Macularis

Powdery mildew of hop (Humulus lupus L.), which is caused by Podosphaera macularis (formerly Sphaerotheca macularis) was found in the Yakima Valley, WA in 1996 and subsequently spread to the growing regions in Oregon and northern and southern Idaho. To rapidly assist growers in reducing the cost associated with the preventive fungicide program, the Gubler/Thomas grape powdery mildew risk infection model was adapted for hops. In addition, field surveys were utilized to identify other management practices that impacted disease development. Weather networks were established and utilized to deliver daily regional maps indicating the risk index. These maps were posted to the web for daily access. Lessons learned from this experience will be useful in addressing future pathogen introductions. Accepted for publication 28 March 2003. Published 13 November 2003.

scholarly journals Species-Specific PCR Assays for Differentiating Heterodera filipjevi and H. avenae

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1611-1619 ◽  
Author(s):  
Guiping Yan ◽  
Richard W. Smiley ◽  
Patricia A. Okubara ◽  
Andrea M. Skantar
Keyword(s):  
Pacific Northwest ◽  
Management Practices ◽  
Pcr Amplification ◽  
Nematode Species ◽  
Heterodera Avenae ◽  
Cyst Nematodes ◽  
Specific Pcr ◽  
The Pacific ◽  
Pcr Assays ◽  
Species Specific

Heterodera avenae and H. filipjevi are economically important cyst nematodes that restrict production of cereal crops in the Pacific Northwest United States and elsewhere in the world. Identification of these two species is critical for recommending and implementing effective management practices. Primers were designed from the internal transcribed spacer (ITS) regions of H. avenae and H. filipjevi ribosomal DNA. The primers were highly specific when examined on target isolates but did not amplify DNA from nontarget Heterodera, Globodera, Meloidogyne, Pratylenchus, and other nematode species tested. Polymerase chain reaction (PCR) and amplification conditions were established, and H. avenae and H. filipjevi were clearly distinguished by PCR fragments of 242 and 170 bp, respectively. Robust PCR amplification was achieved with DNA extracted from a single egg or second-stage juvenile (J2) using a laboratory-made worm lysis buffer, and DNA from 0.5 egg or J2 using a commercial kit. The PCR assays were successfully employed for differentiation of H. filipjevi and H. avenae populations collected from eight locations in three Pacific Northwest states. This is the first report of a species-specific ITS PCR assay to detect and identify H. filipjevi. The assays for both species will enhance diagnosis of cereal cyst nematode species in infested fields.

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