scholarly journals A Soil Bioassay for Predicting the Risk of Spinach Fusarium wilt

Plant Disease ◽  
2015 ◽  
Vol 99 (4) ◽  
pp. 512-526 ◽  
Author(s):  
Emily W. Gatch ◽  
Lindsey J. du Toit
Keyword(s):  
Soil Properties ◽  
Fusarium Wilt ◽  
Inbred Line ◽  
The United States ◽  
Inbred Lines ◽  
Soil Samples ◽  
Soil Bioassay ◽  
Inbred Parent ◽  
Wide Range ◽  
Seed Crops

The maritime Pacific Northwest is the only region of the United States suitable for production of spinach seed, a cool-season, daylength-sensitive crop. However, the acidic soils of this region are highly conducive to spinach Fusarium wilt, caused by Fusarium oxysporum f. sp. spinaciae. Rotations of at least 10 to 15 years between spinach seed crops are necessary to reduce the high risk of losses to this disease. The objectives of this study were to develop a greenhouse soil bioassay to assess the relative risk of Fusarium wilt in fields intended for spinach seed production, and to identify soil chemical and physical properties associated with conduciveness to this disease. Preliminary bioassays established a protocol for growing spinach plants in a greenhouse environment and inducing Fusarium wilt symptoms so that the bioassay can be completed in <2 months. Test soils with a range of Fusarium wilt inoculum potentials, and three spinach inbred parent lines (highly susceptible, moderately susceptible, and moderately resistant to Fusarium wilt) were used to evaluate sensitivity of the bioassay to different levels of risk of Fusarium wilt. Then, from 2010 to 2013, spinach seed growers and stakeholders submitted soil samples from 147 fields for evaluation with the bioassay. The fields were each under consideration for planting a spinach seed crop, yet the bioassay revealed a wide range in Fusarium wilt inoculum potential among soil samples. Differences in susceptibility to Fusarium wilt of the three inbred lines were key to detecting differences in wilt risk among soils. Visits to spinach seed crops planted in fields evaluated in the bioassay, as well as test plots of the three inbred lines planted in growers’ seed crops, confirmed the predictive value of the bioassay for Fusarium wilt risk. Correlation analyses for 23 soil properties revealed significant relationships of 15 soil properties with the Fusarium wilt potential of a soil, but the correlations were influenced significantly by susceptibility of the inbred line to Fusarium wilt (13, 10, and 8 soil properties correlated significantly with Fusarium wilt risk for the susceptible, moderate, and partially resistant inbreds, respectively). Multiple regression analyses identified different statistical models for prediction of Fusarium wilt risk depending on the spinach inbred line, but the best fitting model explained <34% of the variability in Fusarium wilt risk among 121 fields evaluated in the soil bioassay. Thus, no model was robust enough to replace the bioassay for the purpose of predicting Fusarium wilt risk.

Deep Learning-based Soil Property Prediction for Remediation of Radioactive Contamination in Agriculture

2021 ◽  
Author(s):  
Franck Albinet ◽  
Gerd Dercon ◽  
Tetsuya Eguchi
Keyword(s):  
Deep Learning ◽  
Soil Properties ◽  
Radioactive Contamination ◽  
The United States ◽  
Soil Survey ◽  
United States Department ◽  
Least Squares Regression ◽  
Transfer Factors ◽  
Wide Range ◽  
Plant Transfer

&lt;p&gt;The Joint IAEA/FAO Division of Nuclear Techniques in Food and Agriculture, through its Soil and Water Management &amp; Crop Nutrition Laboratory (SWMCNL), launched in October 2019, a new Coordinated Research Project (D15019) called &amp;#8220;Monitoring and Predicting Radionuclide Uptake and Dynamics for Optimizing Remediation of Radioactive Contamination in Agriculture''. Within this context, the high-throughput characterization of soil properties in general and the estimation of soil-to-plant transfer factors of radionuclides are of critical importance.&lt;/p&gt;&lt;p&gt;For several decades, soil researchers have been successfully using near and mid-infrared spectroscopy (MIRS) techniques to estimate a wide range of soil physical, chemical and biological properties such as carbon (C), Cation Exchange Capacities (CEC), among others. However, models developed were often limited in scope as only small and region-specific MIR spectra libraries of soils were accessible.&lt;/p&gt;&lt;p&gt;This situation of data scarcity is changing radically today with the availability of large and growing library of MIR-scanned soil samples maintained by the National Soil Survey Center (NSSC) Kellogg Soil Survey Laboratory (KSSL) from the United States Department of Agriculture (USDA-NRCS) and the Global Soil Laboratory Network (GLOSOLAN) initiative of the Food Agency Organization (FAO). As a result, the unprecedented volume of data now available allows soil science researchers to increasingly shift their focus from traditional modeling techniques such as PLSR (Partial Least Squares Regression) to classes of modeling approaches, such as Ensemble Learning or Deep Learning, that have proven to outperform PLSR on most soil properties prediction in a large data regime.&lt;/p&gt;&lt;p&gt;As part of our research, the opportunity to train higher capacity models on the KSSL large dataset (all soil taxonomic orders included ~ 50K samples) makes it possible to reach a quality of prediction for exchangeable potassium so far unsurpassed with a Residual Prediction Deviation (RPD) around 3. Potassium is known for its difficulty of being predicted but remains extremely important in the context of remediation of radioactive contamination after a nuclear accident. Potassium can help reduce the uptake of radiocaesium by crops, as it competes with radiocaesium in soil-to-plant transfer.&lt;/p&gt;&lt;p&gt;To ensure informed decision making, we also guarantee that (i) individual predictions uncertainty is estimated (using Monte Carlo Dropout) and (ii) individual predictions can be interpreted (i.e. how much specific MIRS wavenumber regions contribute to the prediction) using methods such as Shapley Additive exPlanations (SHAP) values.&lt;/p&gt;&lt;p&gt;SWMCNL is now a member of the GLOSOLAN network, which helps enhance the usability of MIRS for soil monitoring worldwide. SWMCNL is further developing training packages on the use of traditional and advanced mathematical techniques to process MIRS data for predicting soil properties. This training package has been tested in October 2020 with thirteen staff members of the FAO/IAEA Laboratories in Seibersdorf, Austria.&lt;/p&gt;

scholarly journals Transfer of the Long-lived Postharvest Keeping Characteristic from a long-lived Inbred line of Antirrhinum majus (L.) to a Short-lived Line through the Inbred Backcross Method

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 812A-812
Author(s):  
Kenneth R. Schroeder ◽  
Dennis P. Stimart
Keyword(s):  
Inbred Line ◽  
Inbred Lines ◽  
Antirrhinum Majus ◽  
Vase Life ◽  
Cut Flowers ◽  
Single Seed Descent ◽  
Life Evaluation ◽  
Inbred Parent ◽  
Chemical Usage ◽  
Inbred Backcross

In an effort to reduce chemical usage to prolong postharvest keeping time of cut flowers, a cross was made between a long-lived (vase life, 10.9 days) inbred line of Antirrhinum majus and a short-lived (vase life, 5.0 days) inbred line. The F1 hybrid was backcrossed to the short-lived parent. Sixty plants of the BC1 generation were carried on through three generations of selfing by single-seed descent. Eight replications each of 60 BC1S3 families, the parents, and the F1 hybrid were grown in the greenhouse, harvested with 40-cm stems when five florets opened, and placed in distilled water for vase life evaluation. Stems were discarded when 50% of the florets on a spike wilted, browned, or dried. Three families proved not significantly different from the long-lived inbred parent. Results indicate that inbred backcross breeding shows potential to increase the postharvest keeping time of short-lived Antirrhinum majus inbred lines.

Soil Properties Influence Saflufenacil Phytotoxicity

Weed Science ◽  
2014 ◽  
Vol 62 (4) ◽  
pp. 657-663 ◽  
Author(s):  
Travis W. Gannon ◽  
Adam C. Hixson ◽  
Kyle E. Keller ◽  
Jerome B. Weber ◽  
Stevan Z. Knezevic ◽  
...  
Keyword(s):  
Organic Matter ◽  
Regression Analysis ◽  
Soil Properties ◽  
Texture Classification ◽  
Organic Matter Content ◽  
The United States ◽  
Exchange Capacity ◽  
Matter Content ◽  
Crop Tolerance ◽  
Wide Range

Saflufenacil, a pyrimidinedione herbicide, is used for contact and residual broadleaf weed control in various crops. Bioactivity of saflufenacil in soil was tested in greenhouse and laboratory studies on 29 soils representing a wide range of soil properties and geographic areas across the United States. A greenhouse bioassay method was developed using various concentrations of saflufenacil applied PPI to each soil. Whole canola plants were harvested 14 d after treatment, and fresh and dry weights were recorded. Nonlinear regression analysis was used to determine the effective saflufenacil doses for 50% (ED50,), 80% (ED80), and 90% (ED90) inhibition of total plant fresh weight. Bioactivity of saflufenacil in soil was strongly correlated to soil organic (R= 0.85) and humic matter (R= 0.81), and less correlated to cation exchange capacity (R= 0.49) and sand content (R= −0.32). Stepwise regression analysis indicated that organic matter was the major soil constituent controlling bioactivity in soil and could be used to predict the bioactivity of saflufenacil. Saflufenacil phytotoxicity was found to be dependent on soil property; therefore, efficacy and crop tolerance from PRE and PPI applications may vary based on soil organic matter content and texture classification.

scholarly journals Pathogenicity, Virulence, and Vegetative Compatibility Grouping of Verticillium Isolates from Spinach Seed

Plant Disease ◽  
2013 ◽  
Vol 97 (11) ◽  
pp. 1457-1469 ◽  
Author(s):  
Angela M. Iglesias-Garcia ◽  
Maria I. Villarroel-Zeballos ◽  
Chunda Feng ◽  
Lindsey J. du Toit ◽  
James C. Correll
Keyword(s):  
United States ◽  
New Zealand ◽  
The Netherlands ◽  
Pacific Northwest ◽  
Its Region ◽  
The United States ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Groups ◽  
Wide Range ◽  
Seed Crops

In 2005, Verticillium dahliae was first reported to be pathogenic to spinach seed crops in the Pacific Northwest, with symptoms only developing after initiation of the reproductive stage of plant growth, and to be prevalent on commercial spinach seed lots produced in Denmark, The Netherlands, and the United States. In this study, the genetic diversity, pathogenicity, and virulence were examined for a collection of isolates of Verticillium spp. from spinach as well as other hosts (alfalfa, cotton, lettuce, mint, peppermint, potato, radish, and tomato) from various countries and from different vegetative compatibility groups (VCGs). Of a total of 210 isolates of V. dahliae obtained from spinach seed produced in Denmark, the Netherlands, New Zealand, or the United States, 128 were assigned to VCG 4B (89% of 91 U.S. isolates, 86% of 42 isolates from the Netherlands, 19% of 43 Denmark isolates, and 8% of 13 New Zealand isolates), 65 to VCG 2B (92% of the New Zealand isolates, 79% of the Denmark isolates, 14% of the Netherlands isolates, and 9% of the U.S. isolates), and 3 to VCG 2A (2% of each of the Denmark and U.S. isolates, and 0% of the Netherlands and New Zealand isolates); 14 isolates could not be assigned to a VCG. Although little variation in the sequence of the internal transcribed spacer (ITS) region of ribosomal DNA was observed among isolates within each Verticillium sp., the ITS region readily differentiated isolates of the species V. dahliae, V. tricorpus, and Gibellulopsis nigrescens (formerly V. nigrescens) obtained from spinach seed. Greenhouse pathogenicity assays on spinach, cotton, lettuce, and tomato plants using isolates of V. dahliae (n = 29 to 34 isolates), V. tricorpus (n = 3), G. nigrescens (n = 2), and V. albo-atrum (n = 1) originally obtained from these hosts as well as from alfalfa, mint, peppermint, potato, and radish, revealed a wide range in virulence among the isolates. Isolates of V. tricorpus and G. nigrescens recovered from spinach seed and an isolate of V. albo-atrum from alfalfa were not pathogenic on spinach. In addition, isolates of V. dahliae from mint and peppermint were not pathogenic or only weakly virulent on the hosts evaluated. Although there was a wide range in virulence among the isolates of V. dahliae tested, all of the V. dahliae isolates caused Verticillium wilt symptoms on spinach, lettuce, tomato, and cotton. None of the isolates of V. dahliae showed host specificity. These results indicate that Verticillium and related species associated with spinach seed display substantial variability in virulence and pathogenicity to spinach and other plants but the V. dahliae isolates were restricted to three VCGs.

scholarly journals Limestone-Mediated Suppression of Fusarium Wilt in Spinach Seed Crops

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Emily W. Gatch ◽  
Lindsey J. du Toit
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Seed Production ◽  
Fusarium Wilt ◽  
Seed Yield ◽  
Acid Soils ◽  
The United States ◽  
Suppressive Effect ◽  
Female Line ◽  
Seed Crops

Fusarium wilt of spinach is caused by the soilborne fungus Fusarium oxysporum f. sp. spinaciae and occurs in most regions of spinach production. The disease is favored by acid soils and warm temperatures, and the fungus can survive extended periods as chlamydospores or by asymptomatic colonization of the roots of nonhost plant species. The 10- to 15-year rotation required to minimize losses to Fusarium wilt is the primary constraint on spinach seed production in the maritime Pacific Northwest, the only region of the United States suitable for this cool-season, daylength-sensitive crop. Raising soil pH with agricultural limestone (97% CaCO3) results in a transitory, partially suppressive effect on spinach Fusarium wilt. A field trial was completed from 2009 to 2012 to assess the potential for annual applications of agricultural limestone at 0, 2.24, and 4.48 tons/ha for 3 years prior to a spinach seed crop to improve Fusarium wilt suppression compared with the level of suppression attained from a single limestone amendment at 4.48 tons/ha. Three proprietary female spinach lines were planted that ranged from highly susceptible to partially resistant to Fusarium wilt. Three successive annual applications of limestone at 4.48 tons/ha reduced midseason wilt incidence by an average of 20%, increased spinach biomass by 33%, and increased marketable spinach seed yield by 45% compared with plots amended once with the same rate of limestone in the spring of planting. The suppressive effect increased with increasing rate of limestone amendment, with the greatest difference observed when limestone was applied at between 0 and 2.24 tons/ha annually for 3 years. The effects on seed yield were greatest for the partially resistant female line, followed by the moderately susceptible and highly susceptible female lines. Overall, the results demonstrate that annual applications of agricultural limestone on acid soils of the maritime Pacific Northwest of the United States can enhance suppression of spinach Fusarium wilt, potentially reducing the required rotation interval by as much as 50%, thereby doubling the capacity for spinach seed production in the United States.

Music after the Fall

2017 ◽  
Author(s):  
Tim Rutherford-Johnson
Keyword(s):  
New Media ◽  
Contemporary Music ◽  
The United States ◽  
Art Music ◽  
Sound Art ◽  
Musical Composition ◽  
Western Art ◽  
Wide Range ◽  
Definition Of ◽  
The Cold War

By the start of the 21st century many of the foundations of postwar culture had disappeared: Europe had been rebuilt and, as the EU, had become one of the world’s largest economies; the United States’ claim to global dominance was threatened; and the postwar social democratic consensus was being replaced by market-led neoliberalism. Most importantly of all, the Cold War was over, and the World Wide Web had been born. Music After The Fall considers contemporary musical composition against this changed backdrop, placing it in the context of globalization, digitization, and new media. Drawing on theories from the other arts, in particular art and architecture, it expands the definition of Western art music to include forms of composition, experimental music, sound art, and crossover work from across the spectrum, inside and beyond the concert hall. Each chapter considers a wide range of composers, performers, works, and institutions are considered critically to build up a broad and rich picture of the new music ecosystem, from North American string quartets to Lebanese improvisers, from South American electroacoustic studios to pianos in the Australian outback. A new approach to the study of contemporary music is developed that relies less on taxonomies of style and technique, and more on the comparison of different responses to common themes, among them permission, fluidity, excess, and loss.

Death in the City

2017 ◽  
Author(s):  
Kathryn A. Sloan
Keyword(s):  
Scientific Inquiry ◽  
The United States ◽  
Violent Death ◽  
Special Relationship ◽  
Intimate Friend ◽  
Counter Narrative ◽  
Wide Range ◽  
European Heritage ◽  
The City ◽  
The Temple

Popular culture has long conflated Mexico with the macabre. Some persuasive intellectuals argue that Mexicans have a special relationship with death, formed in the crucible of their hybrid Aztec-European heritage. Death is their intimate friend; death is mocked and accepted with irony and fatalistic abandon. The commonplace nature of death desensitizes Mexicans to suffering. Death, simply put, defines Mexico. There must have been historical actors who looked away from human misery, but to essentialize a diverse group of people as possessing a unique death cult delights those who want to see the exotic in Mexico or distinguish that society from its peers. Examining tragic and untimely death—namely self-annihilation—reveals a counter narrative. What could be more chilling than suicide, especially the violent death of the young? What desperation or madness pushed the victim to raise the gun to the temple or slip the noose around the neck? A close examination of a wide range of twentieth-century historical documents proves that Mexicans did not accept death with a cavalier chuckle nor develop a unique death cult, for that matter. Quite the reverse, Mexicans behaved just as their contemporaries did in Austria, France, England, and the United States. They devoted scientific inquiry to the malady and mourned the loss of each life to suicide.

The Politics of Precaution

2012 ◽  
Author(s):  
David Vogel
Keyword(s):  
United States ◽  
Animal Feed ◽  
The United States ◽  
Hazardous Substances ◽  
Risk Regulation ◽  
Scientific Certainty ◽  
European Public ◽  
Wide Range ◽  
Regulatory Controls ◽  
Milk Hormones

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.

The ffs Allele Conditions Flower Stem Fasciation in Red Beet

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 527f-528
Author(s):  
I.L. Goldman
Keyword(s):  
Genetic Control ◽  
Inbred Line ◽  
Goodness Of Fit ◽  
Female Parent ◽  
Inbred Lines ◽  
Chi Square ◽  
Recessive Character ◽  
Variable Expression ◽  
Red Beet ◽  
Flower Stem

A fasciated flower stem character arose spontaneously during development of the red beet (Beta vulgaris L.) inbred line W411. The fasciated character is manifest by a flattened flower stem with petioles coalesced into a twisted, ribbonlike appearance. No fasciation is present in the vegetative stem or petioles. An inheritance study was conducted to determine the genetic control of flower stem fasciation. The inbred line W411 was used both as a male and female parent in crosses with four red beet inbred lines. Segregating progenies in both the BC1 and F2 generations were developed and scored for the fasciated flower stem character. Variable expression of the fasciated flower stem phenotype was observed in these progenies; however, the presence of flattened flower stems at the stem/hypocotyl junction was unequivocal. Chi-square goodness-of-fit tests in both the BC1 and F2 generations did not deviate significantly from expected ratios for a monogenic recessive character for each genetic background. No reciprocal differences were detected for any cross in this group of four inbred lines, which suggests the lack of maternal effect for the fasciated character. The symbol ffs is proposed to describe the genetic control of the fasciated flower stem phenotype.

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