Browsing by Author "Rideout, Steven L."

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    2014 Commercial Vegetable Production Recommendations
    Reiter, Mark S.; Rideout, Steven L.; Kuhar, Thomas P.; Wilson, Henry P.; Parkhurst, James A.; Straw, Allen; Samtani, Jayesh B.; Gu, Ganyu; Mullins, Chris; Hines, Thomas E.; Waldenmaier, Christine M.; Doughty, Hélène; Mason, John E.; Freeman, Josh H. (Virginia Cooperative Extension, 2014-02-19)
    New varieties and strains of vegetables are constantly being developed throughout the world and it is impossible to list and describe all of them, only those that are available and are adapted to the mid-Atlantic region are listed in this publication. The ultimate value of a variety for a particular purpose is determined by the grower: performance under his or her management adaptation to specific environmental conditions, and having desired horticultural characteristics.
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    2020 Virginia Tech Eastern Shore AREC Virtual Research Field Day
    Reiter, Mark S.; Deitch, Ursula; Pittman, Theresa; Flessner, Michael; Rideout, Steven L.; Zhang, Bo; Vallotton, Amber; Thomason, Wade E.; Wolters, Bethany; Templeton, Jenny; Lawrence, Cris; Strawn, Laura K.; Neill, Clinton L.; Sutton, Kemper; Britt, Kadie; Boyle, Sean; Pagini, Mika; Kuhar, Thomas P. (Virginia Cooperative Extension, 2020-08-18)
    Eastern Shore Agricultural Research and Extension Center Virtual Research Field day includes various presentations and publications of the authors’ above, which are each linked in the body of the publication
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    2021 Home Grounds and Animals PMG - Author Contact List
    Askew, Shawn D.; Wycoff, Stephanie B.; Bergh, J. Christopher; Bush, Elizabeth A.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F.; Frank, Daniel L.; Hansen, Mary Ann; Hong, Chuan X.; Laub, Curtis A.; McCall, David S.; Miller, Dini M.; Nita, Mizuho; Parkhurst, James A.; Paulson, Sally L.; Pfeiffer, Douglas G.; Rideout, Steven L.; Wilson, James; Yoder, Keith S. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Home Grounds and Animals PMG - Home Vegetables
    Day, Eric R.; Del-Pozo, Alejandro; Bush, Elizabeth A.; Rideout, Steven L.; Derr, Jeffrey F. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Home Grounds PMG - Index
    Askew, Shawn D.; Wycoff, Stephanie B.; Bush, Elizabeth A.; Day, Eric R.; Del-Pozo, Alejandro; Derr, Jeffrey F.; Frank, Daniel L.; Hansen, Mary Ann; Laub, Curtis A.; McCall, David S.; Miller, Dini M.; Nita, Mizuho; Parkhurst, James A.; Paulson, Sally L.; Pfeiffer, Douglas G.; Rideout, Steven L.; Wilson, James; Yoder, Keith S.; Hong, Chuan X. (Virginia Cooperative Extension, 2021-02-12)
    This is a chapter of the 2021 Home Grounds and Animals PMG. This 2021 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. This publication contains information about prevention and nonchemical control as alternatives to chemical control or as part of an integrated pest management approach. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.
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    2021 Southeastern U.S. Vegetable Crop Handbook
    Kuhar, Thomas P.; Rideout, Steven L.; Reiter, Mark S. (Virginia Cooperative Extension, 2021-01-07)
    This handbook represents a joint effort among Extension specialists and researchers from 12 land-grant universities in the U.S. who work in the area of vegetable production. These specialists and researchers represent a wide array of disciplines: agricultural engineering, entomology, olericulture (vegetable production), plant pathology, postharvest physiology, soil science, and weed science.
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    2021 Virtual Eastern Shore Agricultural Conference and Trade Show
    Pittman, Theresa; Deitch, Ursula T.; Reiter, Mark S.; Singh, Vijay; Mason, John; Duerksen, Keren; Haymaker, Joseph; Doughty, Helene; Holshouser, David Lee, 1963-; Langston, David B.; Flessner, Michael; Rideout, Steven L.; Thomason, Wade E.; McCullough, Chris T.; Sutton, Kemper L.; Bekelja, Kyle; Kuhar, Thomas P.; Richardson, Bruce; Harper, Robert; Richardson, Brett; Shockley, Bill (Virginia Cooperative Extension, 2021-03-12)
    Join us for the 2021 virtual Eastern Shore Agricultural Conference and Trade Show! Hear updates and continuing education presentations that are pertinent to Eastern Shore of Virginia growers.
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    Agricultural Practices Attitudes and Perceived Risk Study
    Harrison, Lauren V.; Rideout, Steven L.; Strawn, Laura K.; Cox, Heather (Virginia Tech, 2023-12-11)
    Though the existing literature does not provide evidence to suggest that genetically modified foods are worse for humans and the environment than organically grown foods, a general tone exists from the public expressing primarily distrust and negativity towards genetically modified organisms (GMOs), pesticides, and growth hormones. This can result in fear/distrust around food, damage to the agriculture industry, and misinformed nutrition advice, leading to further negative outcomes. The purpose of this project was to formally understand the consumer’s attitudes and perceived risk in relation to their knowledge about common agricultural practices, specifically genetic engineering of food. Additionally, the project aimed to identify if there is a correlation between the occurrence of disordered eating/dieting and knowledge, attitudes, and perceived risk of genetically modified organisms. One hundred thirty participants volunteered to take a survey which gathered basic demographic information, prevalence of dieting/disordered eating and eating disorder diagnosis, general knowledge of GMOs and their attitudes and perceived risk in relation to human health, nutrition, and environmental impact. The results provide trends of high self-confidence in knowledge about GMOs, moderate-to-low actual knowledge, neutral-to-negative overall attitudes, and moderate-to-high overall perceived risk. The trends suggest that increasing levels of inaccurate knowledge on the topic of GMOs correlate with increasing negative attitudes towards GMOs. Those diagnosed with an eating disorder reported the highest prevalence of fear of GMOS, followed by those who engaged in dieting or disordered eating. The evidence gives way to the idea that individuals who have a higher involvement in following diets or engaging in disordered eating behaviors are more likely to feel fearful of agriculture- and food-related practices. Based on the findings of this study, a call for improved education dissemination strategies is indicated.
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    Agricultural Practices Influence Salmonella Contamination and Survival in Pre-harvest Tomato Production
    Gu, Ganyu; Strawn, Laura K.; Oryang, David O.; Zheng, Jie; Reed, Elizabeth A.; Ottesen, Andrea R.; Bell, Rebecca L.; Chen, Yuhuan; Duret, Steven; Ingram, David T.; Reiter, Mark S.; Pfuntner, Rachel; Brown, Eric W.; Rideout, Steven L. (Frontiers, 2018-10-16)
    Between 2000 and 2010 the Eastern Shore of Virginia was implicated in four Salmonella outbreaks associated with tomato. Therefore, a multi-year study (2012-2015) was performed to investigate presumptive factors associated with the contamination of Salmonella within tomato fields at Virginia Tech's Eastern Shore Agricultural Research and Extension Center. Factors including irrigation water sources (pond and well), type of soil amendment: fresh poultry litter (PL), PL ash, and a conventional fertilizer (triple superphosphate - TSP), and production practices: staked with plastic mulch (SP), staked without plastic mulch (SW), and non-staked without plastic mulch (NW), were evaluated by split-plot or complete-block design. All field experiments relied on naturally occurring Salmonella contamination, except one follow up experiment (worst-case scenario) which examined the potential for contamination in tomato fruits when Salmonella was applied through drip irrigation. Samples were collected from pond and well water; PL, PL ash, and TSP; and the rhizosphere, leaves, and fruits of tomato plants. Salmonella was quantified using a most probable number method and contamination ratios were calculated for each treatment. Salmonella serovar was determined by molecular serotyping. Salmonella populations varied significantly by year; however, similar trends were evident each year. Findings showed use of untreated pond water and raw PL amendment increased the likelihood of Salmonella detection in tomato plots. Salmonella Newport and Typhimurium were the most frequently detected serovars in pond water and PL amendment samples, respectively. Interestingly, while these factors increased the likelihood of Salmonella detection in tomato plots (rhizosphere and leaves), all tomato fruits sampled (n = 4800) from these plots were Salmonella negative. Contamination of tomato fruits was extremely low (< 1%) even when tomato plots were artificially inoculated with an attenuated Salmonella Newport strain (10(4) CFU/mL). Furthermore, Salmonella was not detected in tomato plots irrigated using well water and amended with PL ash or TSP. Production practices also influenced the likelihood of Salmonella detection in tomato plots. Salmonella detection was higher in tomato leaf samples for NW plots, compared to SP and SW plots. This study provides evidence that attention to agricultural inputs and production practices may help reduce the likelihood of Salmonella contamination in tomato fields.
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    Association of Salmonella enterica serotype Newport with Tomato Plants through Irrigation Water, Grown under Controlled Environmental Conditions
    Hintz, Leslie Diane (Virginia Tech, 2008-11-21)
    Tomato fruit have been associated with numerous outbreaks of salmonellosis in recent years. Trace back suggests tomato fruit may become contaminated during pre-harvest, however exact routes are unclear. The objective of this study was to determine the potential for Salmonella enterica serotype Newport to be associated with the roots, leaves, stems, and ultimately fruit of red round tomato plants through contaminated irrigation water, at various stages of plant development, when grown under controlled environmental conditions. Tomato plants were individually root irrigated with 250 or 350 ml (depending on growth stage) of 7 log CFU/ml S. Newport contaminated irrigation water every seven days. Presence of the pathogen in plant tissue was evaluated at five growth stages; 14 days post transplant, early fruit, mid fruit, full fruit, and terminal stages. At each stage, roots, stems, leaves, and two tomato fruit, if present, from four S. Newport and four water irrigated (negative control) tomato plants were sampled for S. Newport contamination. Association of S. Newport was detected in tomato roots and stems using both conventional plating and molecular techniques. Twenty-four samples were confirmed positive for S. enterica using PCR. Sixty-five percent of the roots, 40% of the stems, 5% of the leaves and 5% of the fruit sampled were confirmed to contain S. enterica. Overall, there was significant difference in the presence of S. Newport according to tissue sampled (roots > stems > leaves and fruit) (P > 0.05). There was no correlation between growth stage and presence of S. Newport in tissues (P > 0.05). Ultimately, irrigation with S. Newport has a low probability of contaminating tomato fruit.
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    Avoiding Protoporphyrinogen Oxidase Inhibiting Herbicide Selection Pressure on Common Ragweed and Palmer amaranth in Soybean
    Blake, Hunter B. (Virginia Tech, 2019-01-31)
    Palmer amaranth (Amaranthus palmeri) and common ragweed (Ambrosia artemisiifolia) can cause detrimental soybean yield loss. Due to widespread resistance to glyphosate and ALS-inhibiting herbicides, growers rely on protoporphyrinogen oxidase inhibiting herbicides (PPO) such as flumioxazin applied preemergence (PRE) and fomesafen postemergence (POST) to control both weeds. Experiments were conducted with the overarching goal of reducing PPO selection pressure for Palmer amaranth and common ragweed. Flumioxazin alone PRE controlled Palmer amaranth near 100%. However, sulfentrazone combined with pyroxasulfone or pendimethalin provided similar control to flumioxazin. Acetochlor and linuron controlled common ragweed <74%, yet controlled Palmer amaranth >96%. Glufosinate applied POST controlled Palmer amaranth and common ragweed 74-100%, regardless of PRE treatment. Flumioxazin PRE followed by fomesafen POST controlled common ragweed well; however, several non-PPO herbicide treatments or programs with only 1 PPO-inhibiting herbicide provided similar common ragweed control as the 2 PPO system (flumioxazin followed by fomesafen). Treatments consisting of a PRE and POST herbicide controlled Palmer amaranth at least 80% and common ragweed 95%. To reduce PPO selection pressure, soybean producers growing glufosinate-resistant soybean may use flumioxazin PRE followed by glufosinate POST whereas non-glufosinate-resistant soybean growers should reduce PPO herbicide use by using a non-PPO herbicide PRE. Alternatively, these producers can effectively reduce PPO selection pressure by implementing residual combinations of a PPO-inhibiting herbicide + non-PPO with spectrums of weed control that overlap at either Palmer amaranth or common ragweed.
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    Baseline survey of the anatomical microbial ecology of an important food plant: Solanum lycopersicum (tomato)
    Ottesen, Andrea R.; González Peña, Antonio; White, James R.; Pettengill, James B.; Li, Cong; Allard, Sarah; Rideout, Steven L.; Allard, Marc W.; Hill, Thomas; Evans, Peter; Strain, Errol; Musser, Steven; Knight, Rob; Brown, Eric (2013-05-24)
    Background Research to understand and control microbiological risks associated with the consumption of fresh fruits and vegetables has examined many environments in the farm to fork continuum. An important data gap however, that remains poorly studied is the baseline description of microflora that may be associated with plant anatomy either endemically or in response to environmental pressures. Specific anatomical niches of plants may contribute to persistence of human pathogens in agricultural environments in ways we have yet to describe. Tomatoes have been implicated in outbreaks of Salmonella at least 17 times during the years spanning 1990 to 2010. Our research seeks to provide a baseline description of the tomato microbiome and possibly identify whether or not there is something distinctive about tomatoes or their growing ecology that contributes to persistence of Salmonella in this important food crop. Results DNA was recovered from washes of epiphytic surfaces of tomato anatomical organs; leaves, stems, roots, flowers and fruits of Solanum lycopersicum (BHN602), grown at a site in close proximity to commercial farms previously implicated in tomato-Salmonella outbreaks. DNA was amplified for targeted 16S and 18S rRNA genes and sheared for shotgun metagenomic sequencing. Amplicons and metagenomes were used to describe “native” bacterial microflora for diverse anatomical parts of Virginia-grown tomatoes. Conclusions Distinct groupings of microbial communities were associated with different tomato plant organs and a gradient of compositional similarity could be correlated to the distance of a given plant part from the soil. Unique bacterial phylotypes (at 95% identity) were associated with fruits and flowers of tomato plants. These include Microvirga, Pseudomonas, Sphingomonas, Brachybacterium, Rhizobiales, Paracocccus, Chryseomonas and Microbacterium. The most frequently observed bacterial taxa across aerial plant regions were Pseudomonas and Xanthomonas. Dominant fungal taxa that could be identified to genus with 18S amplicons included Hypocrea, Aureobasidium and Cryptococcus. No definitive presence of Salmonella could be confirmed in any of the plant samples, although 16S sequences suggested that closely related genera were present on leaves, fruits and roots.
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    Biology and Control of Eastern Black Nightshade, Palmer Amaranth, and Common Pokeweed, in No-Till Systems on the Eastern Shore Regions of Virginia and Maryland
    Vollmer, Kurt Matthew (Virginia Tech, 2014-12-05)
    Eastern black nightshade, Palmer amaranth, and common pokeweed are three hard to control weed species on the Eastern Shore regions of Virginia and Maryland. Herbicide resistance and lack of herbicide efficacy further complicate the job of controlling these weeds. Studies were conducted on each of these weeds in order to determine herbicide efficacy and potential herbicide resistance. In addition, the translocation and metabolism of 14C-glyphosate was studied in common pokeweed. This research identified a population of eastern black nightshade that was differentially sensitive to families of ALS-inhibiting herbicides, with tolerance to members of the sulfonylurea family, but controlled with herbicides of the imidazolinone family. A population of Palmer amaranth was found to be glyphosate-resistant, but herbicide programs were identified that could control this biotype in soybean and corn systems. Experiments on the fate of glyphosate in common pokeweed indicated that glyphosate does not readily translocate from treated foliage to other plant parts, which may contribute to shoot regeneration from taproots following glyphosate treatment. Taken together, this research highlights the important weed control issues, including resistant and perennial weeds in agronomic crops that have arisen in Eastern Shore agriculture. This work will help growers to better assess their particular control issues, and take appropriate steps to mitigate any problems.
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    Characterization, development of a field inoculation method, and fungicide sensitivity screening of the Pythium blight pathogen of snap bean (Phaseolus vulgaris L.)
    Harrison, Leigh Ann (Virginia Tech, 2011-03-08)
    New Jersey, Georgia, and the Eastern Shore of Virginia (ESV) are important snap bean (Phaseolus vulgaris L.) growing regions, but profitability is threatened by Pythium blight. Causal agents of Pythium blight on snap bean were identified using morphological characterization and sequence analysis of the rDNA-internal transcribed spacer (ITS) regions of 100 isolates. Most isolates were Pythium aphanidermatum (Edson) Fitzp. (53%), and also included Pythium deliense Meurs (31%; all from Georgia), Pythium ultimum Trow (12%), Pythium myriotylum Drechsler (2%), Pythium catenulatum Matthews (1%), and unknown Pythium sp. (1%). To our knowledge, this is the first report of P. deliense in Georgia and on common bean and squash (Cucurbita pepo L.); as well as the first report of P. catenulatum on lima bean (Phaseolus lunatus L.) and in New Jersey. Fungicide labeling and cultivar selection for Pythium blight management is hindered by difficulties associated with conducting successful trials, because the disease occurs sporadically and clustered in the field. Three P. aphanidermatum-infested inoculum substrates were evaluated at three concentrations. The vermiculite/V8 juice (5:3 weight to volume) inoculum (10,000 ppg/0.3 m) consistently caused at least 50% disease in 3 field trials. Sensitivity of the Pythium blight pathogens was determined in vitro against five fungicides. Twenty-two Pythium isolates representing P. aphanidermatum, P. deliense, P. ultimum, and P. myriotylum were inoculated to media amended with each active ingredient at 0, 100μg/ml, the concentration equivalent to the field labeled rate if applied on succulent beans at 187 L/ha, and the equivalent if applied at 374 L/ha. All isolates were completely sensitive (100% growth reduction, or GR) to all active ingredients at the labeled rates, except azoxystrobin. At 100μg/ml azoxystrobin, one P. deliense isolate had 8.9% GR. All isolates had 100% GR to copper hydroxide at 100μg/ml, and the lowest GR on mefenoxam-amended medium was 91.9%. At 100μg/ml cyazofamid, all P. deliense isolates were completely sensitive and variation was observed in P. aphanidermatum isolates. At 100μg/ml potassium phosphite, significant GR similarities were recorded within isolates of the same species, and less than 50% GR was observed in all P. deliense isolates.
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    Chemical Compositions of Edamame Genotypes Grown in Different Locations in the US
    Yu, Dajun; Lin, Tiantian; Sutton, Kemper L.; Lord, Nick; Carneiro, Renata C. V.; Jin, Qing; Zhang, Bo; Kuhar, Thomas P.; Rideout, Steven L.; Ross, W. Jeremy; Duncan, Susan E.; Yin, Yun; Wang, Hengjian; Huang, Haibo (2021-02-12)
    The consumption of edamame [Glycine max (L.) Merr.] in the US has rapidly increased due to its nutritional value and potential health benefits. In this study, 10 edamame genotypes were planted in duplicates in three different locations in the US-Whitethorne, Virginia (VA), Little Rock, Arkansas (AR), and Painter, VA. Edamame samples were harvested at the R6 stage of the bean development when beans filled 80-90% of the pod cavity. Afterward, comprehensive chemical composition analysis, including sugars, alanine, protein, oil, neutral detergent fiber (NDF), starch, ash, and moisture contents, were conducted on powdered samples using standard methods and the total sweetness was calculated based on the measured sugars and alanine contents. Significant effects of the location were observed on all chemical constituents of edamame (p < 0.05). The average performance of the genotypes was higher in Whitethorne for the contents of free sucrose (59.29 mg/g), fructose (11.42 mg/g), glucose (5.38 mg/g), raffinose (5.32 mg/g), stachyose (2.34 mg/g), total sweetness (78.63 mg/g), and starch (15.14%) when compared to Little Rock and Painter. The highest soluble alanine (2.67 mg/g), NDF (9.00%), ash (5.60%), and moisture (70.36%) contents were found on edamame planted in Little Rock while edamame planted in Painter had the highest crude protein (43.11%) and oil (20.33%) contents. Significant effects of genotype were observed on most of the chemical constituents (p < 0.05) except NDF and raffinose. Among the 10 genotypes, R13-5029 consistently had high sucrose content and total sweetness across the three locations, meanwhile it had relatively high protein and fiber contents. Overall, the results indicate that to breed better edamame genotypes in the US, both genotype and planting location should be taken into considerations.
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    Co-Enriching Microflora Associated with Culture Based Methods to Detect Salmonella from Tomato Phyllosphere
    Ottesen, Andrea R.; Gonzalez, Antonio; Bell, Rebecca L.; Arce, Caroline; Rideout, Steven L.; Allard, Marc W.; Evans, Peter; Strain, Errol; Musser, Steven; Knight, Rob; Brown, Eric; Pettengill, James B. (PLOS, 2013-09-09)
    The ability to detect a specific organism from a complex environment is vitally important to many fields of public health, including food safety. For example, tomatoes have been implicated numerous times as vehicles of foodborne outbreaks due to strains of Salmonella but few studies have ever recovered Salmonella from a tomato phyllosphere environment. Precision of culturing techniques that target agents associated with outbreaks depend on numerous factors. One important factor to better understand is which species co-enrich during enrichment procedures and how microbial dynamics may impede or enhance detection of target pathogens. We used a shotgun sequence approach to describe taxa associated with samples pre-enrichment and throughout the enrichment steps of the Bacteriological Analytical Manual's (BAM) protocol for detection of Salmonella from environmental tomato samples. Recent work has shown that during efforts to enrich Salmonella (Proteobacteria) from tomato field samples, Firmicute genera are also co-enriched and at least one co-enriching Firmicute genus (Paenibacillus sp.) can inhibit and even kills strains of Salmonella. Here we provide a baseline description of microflora that co-culture during detection efforts and the utility of a bioinformatic approach to detect specific taxa from metagenomic sequence data. We observed that uncultured samples clustered together with distinct taxonomic profiles relative to the three cultured treatments (Universal Pre-enrichment broth (UPB), Tetrathionate (TT), and Rappaport-Vassiliadis (RV)). There was little consistency among samples exposed to the same culturing medias, suggesting significant microbial differences in starting matrices or stochasticity associated with enrichment processes. Interestingly, Paenibacillus sp. (Salmonella inhibitor) was significantly enriched from uncultured to cultured (UPB) samples. Also of interest was the sequence based identification of a number of sequences as Salmonella despite indication by all media, that samples were culture negative for Salmonella. Our results substantiate the nascent utility of metagenomic methods to improve both biological and bioinformatic pathogen detection methods.
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    Combining Agronomic and Pest Studies to Identify Vegetable Soybean Genotypes Suitable for Commercial Edamame Production in the Mid-Atlantic U.S.
    Lord, Nick; Kuhar, Thomas P.; Rideout, Steven L.; Sutton, Kemper L.; Alford, Adam M.; Li, Xiaoying; Wu, Xingbo; Reiter, Mark S.; Doughty, Hélène; Zhang, Bo (Scientific Research Publishing, 2021)
    Currently, domestic production of vegetable soybean (aka “edamame”) lags well behind consumer demand, with approximately 70% of U.S.-consumed edamame imported each year. A major barrier for growth of the U.S. edamame industry is an overall lack of varieties with adequate consumer acceptability and adaption to the U.S. climate and environment. In this study, we evaluated eleven vegetable soybean genotypes (including one commercial check) for differences in yield, pod size, and resistance to local insect, bacterial, and fungal pressures in order to identify genotypes with the greatest potential for use in commercial edamame production. Although there were variations in average pod length (42.1 - 53.6 mm), width (10.9 - 12.7 mm), and thickness (6.29 - 7.34 mm) among the genotypes, only pod length showed statistical significance. In addition, genotype significantly affected fresh pod yield. The prevalence of specific insect pests varied by location and year and included soybean aphid, potato leafhopper, Mexican bean beetle, as well as a complex of stink bugs and lepidopteran larvae. For each of these insect pests, significant differences were observed. Some plant diseases observed on the edamame genotypes included: downy mildew, bacterial pustule, Fusarium pod rot, Cercospora blight and purple seed stain, and damping off. In 2018, in Whitethorne, VA, soybean downy mildew was quite prevalent and disease symptoms varied considerably. Overall, genotypes V16-0524 and R15-10280 showed particularly favorable yield, and resilience to native pests compared to the commercial check, UA-Kirksey. The genotypes V16-0524 and R15-10280 showed strong potential to increase the availability of varieties that can be used for commercial edamame production in the Mid-Atlantic region.
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    Common Diseases of Soybean in the Mid-Atlantic Region
    Phipps, P. M.; Koenning, Steve; Rideout, Steven L.; Stromberg, Erik L.; Bush, Elizabeth A. (Virginia Cooperative Extension, 2010)
    Describes some common diseases of soybean plants, symptoms and types of damage, and methods of control.
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    Correlation of Salmonella enterica and Listeria monocytogenes in Irrigation Water to Environmental Factors, Fecal Indicators, and Bacterial Communities
    Gu, Ganyu; Strawn, Laura K.; Ottesen, Andrea R.; Ramachandran, Padmini; Reed, Elizabeth A.; Zheng, Jie; Boyer, Renee R.; Rideout, Steven L. (2021-01-08)
    Outbreaks of foodborne illnesses linked to fresh fruits and vegetables have been key drivers behind a wide breadth of research aiming to fill data gaps in our understanding of the total ecology of agricultural water sources such as ponds and wells and the relationship of this ecology to foodborne pathogens such as Salmonella enterica and Listeria monocytogenes. Both S. enterica and L. monocytogenes can persist in irrigation water and have been linked to produce contamination events. Data describing the abundance of these organisms in specific agricultural water sources are valuable to guide water treatment measures. Here, we profiled the culture independent water microbiota of four farm ponds and wells correlated with microbiological recovery of S. enterica (prevalence: pond, 19.4%; well, 3.3%), L. monocytogenes (pond, 27.1%; well, 4.2%) and fecal indicator testing. Correlation between abiotic factors, including water parameters (temperature, pH, conductivity, dissolved oxygen percentage, oxidation reduction potential, and turbidity) and weather (temperature and rainfall), and foodborne pathogens were also evaluated. Although abiotic factors did not correlate with recovery of S. enterica or L. monocytogenes (p > 0.05), fecal indicators were positively correlated with incidence of S. enterica in well water. Bacterial taxa such as Sphingomonadaceae and Hymenobacter were positively correlated with the prevalence and population of S. enterica, and recovery of L. monocytogenes was positively correlated with the abundance of Rhizobacter and Comamonadaceae (p < 0.03). These data will support evolving mitigation strategies to reduce the risk of produce contamination by foodborne pathogens through irrigation.
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    Cucurbit Downy Mildew (Pseudoperonospora cubensis): Cucumber Resistance
    Cooper, Jessica G. (Virginia Tech, 2013-01-23)
    Pseudoperonospora cubensis (Bert. et Curt) Rost. is the causal agent of cucurbit downy mildew (CDM). It is the most damaging cucumber pathogen on the Eastern Shore of Virginia and eastern parts of the United States. Pseudoperonospora cubensis is an obligate oomycete pathogen, infecting crops within the Cucurbitaceae family. The disease is characterized by angular chlorotic lesions and a downy or felt-like appearance on the abaxial side of the leaf. Control of this pathogen includes use of resistant cucumber cultivars and costly fungicide programs. Continuous use has led to resistance to commonly used fungicides. This has become a major concern and in response, seed companies have developed cucumber cultivars which claim downy mildew resistance.  This study evaluates different cucumber cultivars and assesses their level of resistance to CDM. The results indicate that an integrated management approach of reduced fungicide application and the use of resistant cultivars can suppress levels of CDM and yield a cucumber crop. Additionally, a molecular study was conducted, comparing the relative expression of genes encoding a basic PR-1 protein, a cytosolic ascorbate peroxidase protein and three resistance (R) gene proteins, in nineteen cultivars. All of the selected genes were analyzed using real-time PCR. The relative expression levels of the R-genes varied between cultivars. The basic PR-1 protein decreased expression in the majority of the cultivars, suggesting no involvement in the first twenty-four hours. Cytosolic ascorbate peroxidase relative expression levels suggest an increase in susceptible cultivars and a decrease in tolerant cultivars.