Progress 09/01/10 to 08/31/15
Outputs
Target Audience:Nursery growers and greenhouse producers Garden centers, retailers, and landscapers Agricultural industry scientists and consultants Extension specialists and agents Plant disease diagnosticians, regulatory personnel Undergraduate and graduate students, postdoctoral associates Educators, horticulturists, mycologists, and researchers Conservation biologists Policy makers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Agricultural and Applied Economics, Virginia Tech Xiang Cao is completing his Ph.D. He is currently finishing a paper analyzing the potential for consumer premiums to compensate growers who produce plants with recycled water. Alyssa Cultice completed her M.S. with project support. Her M.S. thesis addressed producers' willingness to adopt water recirculation technology. Nicole D'Alessio completed her M.S. with project support. Her M.S. thesis addressed market segmentation by consumer environmental preferences. Nathaniel Ferraro completed his M.S. with project support. His M.S. thesis dealt with costs of water recycling on ornamental horticulture operations. David Hartter completed his M.S. with project support including his M.S. thesis on consumer wiliness-to-pay for ornamental plants with disease-free or water conservation labels. Gwen Rees was employed on the project for part of her M.S. program. Her research contributed to publications dealing with horticultural producers' irrigation and disease management strategies. Weibin Xu was employed on the project for part of his Ph.D. program. His research contributed to publications dealing with consumer willingness-to-pay for ornamental plants with disease-free or water conservation labels. Hampton Roads AREC, Virginia Tech Lauren Achtemeier, an undergraduate student from Christopher Newport University in Newport News, VA, completed her summer internship in 2011, learning the research process from literature review to project planning, execution, data analysis and interpretation, and writing for publication. Her studies were published along with those of Pistininzi in the Journal of Phytopathology in 2013. Ailing Ben completed her 6-month visiting scholarship on biological control of Phytophthora pathogens. Giovanni Cafa completed his 18-month postdoctoral fellowship project. Nicole Calderone, an undergraduate student from Christopher Newport University in Newport News, VA, completed her summer internship in 2011, learning the research process from literature review to project planning, execution, data analysis and interpretation, and writing for publication. Venkataramana Chapara, a visiting postdoctoral scientist from University of Illinois, completed a 4-week Oomycete Genomics Fellowship from the National Science Foundation via Oomycete Molecular Genetics Network. Wei Hao earned her Ph.D. and completed an 8-month postdoctoral fellowship. She attended annual meeting of the American Phytopathological Society every year. Kevin Hu, a high school junior from an International Baccalaureate Program at Princess Anne High was trained in microbiology and a statistical analysis package - R (2012 and 2013) Mrina Nikrad attended the Mothur Workshop on microbial diversity in Detroit, MI, March 2014 during her 12-month postdoctoral fellowship working on ammonium-oxidizing archaea and bacterial in recycling irrigation reservoirs. Michael Pistininzi, an undergraduate student from Christopher Newport University in Newport News, VA, completed his summer intern project in three consecutive years of 2011-2013, learning the research process from literature review to project planning, execution, data analysis and interpretation, and writing for publication. He presented his results at the annual project meetings. His studies were published in the Journal of Phytopathology (2013) Andrew Rotzin, an undergraduate student from Christopher Newport University in Newport News, VA, completed his summer internship in 2012, learning the research process from literature review to project planning, execution, data analysis and interpretation, and writing for publication. Xiao Yang earned his Ph.D., followed by a 6-month postdoctoral fellowship. He attended the annual meetings of the American Phytopathological Society and participated in several professional development workshops with Analysis of Population Genetic Data in R and Introduction to Bayesian Analysis in Plant Pathology in Minneapolis, MN (2014) and Ornamental Pathology Tour in Pasadena, CA (2015). In addition, he attended Oomycete Boinformatics Training and Phytophthora parasitica Genome Annotation Jamboree in Blacksburg, VA (2012) and a Mothur workshop on microbial diversity in Detroit, MI (2015). Haibo Zhang participated in the AWRA Annual Water Resources Conference in Tysons Corner, VA (2014) during her 21-month postdoctoral fellowship. Pennsylvania State University Maria L. Burgos-Garay earned her Ph. D., participated at the Oomycete Molecular Genetics Network meetings and the Fungal Genetics Conference (Asilomar Conference Center in Pacific Grove, CA), and completed an 18-month postdoctoral project. Carla E. Lanze earned her M. S., participated at the Oomycete Molecular Genetics Network meetings and the Fungal Genetics Conference (Asilomar Conference Center in Pacific Grove, CA), participated in the Oomycete Bioinformatics Workshop at Virginia Tech, and trained in genotyping-by-sequencing. Laura del Sol Bautista-Jalón (Ph. D. candidate) trained in genotyping-by-sequencing. How have the results been disseminated to communities of interest?Both conventional methods and multimedia were used in the dissemination of project results for the broadest reach to communities of interest. Specifically, the webinar series was added to the project for expedited delivery to end users. International outreach was accomplished by coordinating and editing one book, organizing two symposia, and presenting project results at international congresses and workshops. Outreach Website: Irrigation Pathogens and Water Quality (http://www.irrigation-pathogens.ppws.vt.edu/index.php) This website was first established in 2011 and updated regularly to communicate with the green industry and the public on our vision, mission and approaches, and highlight the project activities and major accomplishments. It also served as an effective instrument for announcing and promoting a 14-session webinar series on irrigation pathogens and water quality, and now for permanent housing of the webinar recordings. To help the industry manage boxwood blight, an emerging disease of national significance, a new tab was added to the site with the latest research and extension materials. In addition, this site provides links to other major resources on irrigation water availability and quality issues. According to the Google analytics, this outreach website has been visited by numerous viewers in the US and from over 60 foreign countries. Annual Project Meetings and Web Conferences Project-wide meetings were held annually in Virginia Beach, VA, along with regular web conferences, to keep the advisory panel and collaborating growers posted of project progress and solicit their input on project data analysis, interpretation and application. Panel members and collaborating growers are early adopters of new knowledge and technology. Many collaborating growers already have used the pathogen aquatic biology research data to modify their existing water recycling systems. These modifications included: (i) re-routing runoff water flow path, (ii) expanding the area and depth of runoff containment reservoirs, (iii) adding new reservoirs, all for the same purposes, extending the runoff water turnover time and settling pathogens out along the water path. They also used the same concept and results to build pathogen mitigation features into water recycling systems at new production facilities. In addition, they used recycled water quality research data to determine at which depth of the water column to place pump inlet and when to irrigate crops for the best performance of chlorination, a widely-used water treatment that is prone to alkaline water pH degradation. These early adoptions have set and will continue to serve as powerful examples for fellow growers to follow for improved crop health, water and environmental sustainability. Extension and Outreach Presentations In addition to communicating with the panel members and collaborating growers, we presented the project results at over twenty extension and outreach venues. These covered a variety of crops from ornamentals to vegetables, fruit, etc. at state (e.g., Chesapeake Green Conference, VNLA Field Days), national (Beach Summit), and international levels (Flowers Canada Conference, International Plant Propagators' Society Annual meetings). Webinar Series: Irrigation Pathogens and Water Quality A 14-session webinar series was added to the project for expedited tech delivery to the end users. This webinar series exemplified the partnership between the project team and its collaborating growers and institutions. Growers actively involved in the development and delivery of the webinar materials and participated in the discussion after each presentation. AmericanHort, the Society of American Florists, network of ornamental pathologists and entomologists, and other collaborating institutions helped promote the webinar series and individual sessions through their memberships. These webinars were delivered via Adobe Connect at https://connect.extension.iastate.edu/irrigation-water/. They were well attended with participants from coast to coast and from Canada to Florida. All webinar sessions including discussion were recorded and the recordings are archived at http://www.irrigation-pathogens.ppws.vt.edu/webinar/index.php. Additional webinars were conducted on Pythium and Phytopythium: isolation, handling and culture identification, and on pathogen management through sensor-driven irrigation. One-on-One Consultations with Growers Numerous consultations were conducted through on-site visit, email exchange and via phone conversation to advise on irrigation pathogens and recycled water quality. Disease diagnoses were completed on samples submitted by growers, retailers, landscapers as well as extension agents concerned about plant pathogens in irrigation water. Online Knowledge Center: Irrigation Water Management for Ornamental Horticulture (www.extension.org) An online knowledge center on irrigation water management for ornamental horticulture was recently released to the public. This knowledge center consists of thirteen learning modules, a number of factsheets and best management practices (BMPs) protocols, as well as links to other major online resources on irrigation water availability and quality issues. It also includes an Excel-based assessment tool on its home page for learners to evaluate their production cases and determine which module(s) to begin with. This online knowledge center will serve the horticultural industries well in the years to come. Scientific Publications The project results were disseminated to researchers, educators, postdoctoral associates, graduate and undergraduate students, extension specialists and agents, professional consultants via eight theses and dissertations, over forty refereed journal articles, one book, seventeen book chapters, and twenty-four abstracts. Lectures and Presentations Research results were also disseminated to the science communities and educators via over 25 invited lectures in institutions here (e.g., Cornell University, Ithaca, NY) and overseas (University of Hertfordshire, Hatfield, UK), and presentations at regional (APS Divisional meetings), national (Land Grant and Sea Grant National Water conference), and international meetings (International Crop Protection Congress) as well as voluntary contributions. International Symposia In addition to presenting the project results at professional meetings, two symposia were organized on irrigation pathogen management, in conjunction with the 7th International IPM Symposium in Memphis, TN, March 27 to 29, 2012, and the 18th International Plant Protection Congress in Berlin, Germany, August 24 to 27, 2015, respectively. These symposia not only provided effective outreach platforms for this project but also fostered future collaborations on this issue of growing global significance. The Book: Biology, Detection and Management of Plant Pathogens in Irrigation Water This book was a product of collaboration with 49 world leading plant pathologists, horticulturists, and agricultural engineers contributing chapter contents. It consists of 30 chapters in five Parts with thefirst four Parts reviewing and summarizing the existing literature on irrigation pathogens andthe fifth Part highlighting the new approaches and latest research data from this project. The book chapters were written for both science communities and growers of different horticultural crops including ornamentals, vegetables, tree fruits and nuts. This comprehensive resource published by the American Phytopathological Society was released in July 2014 and immediately became one of its best sellers of the year. An e-book is currently being prepared by the Society to further extend its reach, applications and impacts. What do you plan to do during the next reporting period to accomplish the goals?Project completed.
Impacts
What was accomplished under these goals?
This project has greatly advanced the science and technology in a wide range of disciplines from pathogen aquatic biology to applied microbial ecology, hydrology, and socio-economics of recycling irrigation water. These advancements support the hypothesis that pathogen risk associated with recycling irrigation can be mitigated by increasing runoff water turnover time. They already haveenabled early adoptersto build pathogen mitigation features into water recycling systems and implement best irrigation practices for improved horticultural profitability and sustainability whilereducing theirenvironmental footprint. The advancement in pathogen aquatic biology is highlighted by three major discoveries. First, eleven new taxa of Phytophthora were identified, characterized and described from recycling irrigation reservoirs (RIRs) in VA, MS, and MD, with only P. hydropathica having been found to attack ornamental crops so far. Second, great diversity of Phytophthora, Pythium, and Phytopythium species are present in individual RIRs or water tanks with the majority being not aggressive plant pathogens. This discovery highlights the importance of identifying these cultures to species level when determining whether an irrigation water sample is contaminated. Third, the majority of the major Phytophthora and Pythium pathogens are not well adapted to agricultural water environments as perceived over the past 70 years. As demonstrated in the lab assays, their zoospores, the principal infective and dispersal propagules via water are short-lived, in particular under stressful water pH, dissolved oxygen and carbon dioxide environments. An additional product in this line of research is a comprehensive phylogeny for the genus Phytophthora constructed mostly on the sequences of type and authentic cultures. This new phylogeny along with the description of the eleven new species has spurred discoveries of the same species in other regions and countries. They also have reduced and will continue to reduce misidentifications of high-impact species such as P. ramorum in the years to come. Studies of applied microbial ecology have uncovered a distinct bacterial community in RIRs in comparison with natural freshwater lakes and rivers. These studies also have yielded in thousands of bacterial cultures. Few of these individuals alone have been found to effectively affect diseases caused by Phytophthora nicotianae, Pythium aphanidermatum, Py. irregulare, or Py. cryptoirregulare, destructive pathogens of numerous ornamental plants. How they may act together on disease development in the real world is not known at this point. Nevertheless, these resultant bacterial cultures are a significant bio-resource for future studies and development with some cultures already showing biological control activities against the boxwood blight pathogen, an emerging invasive species of national significance. Similarly, tremendous algal diversity was identified from the same reservoirs and their interactions with Phytophthora species is yet to be elucidated. Continuous monitoring of water quality in a dozen RIRs across the Mid-Atlantic and Gulf Coast regions has confirmed that dramatic seasonal and diurnal water quality fluctuation is common in this emerging aquatic system of global significance. Such fluctuations are stressful for pathogens in the system, thus, pathogen decline along water path from runoff entrance to outlet/pump inlet should be expected. These monitoring data also provided a framework for assessing the recycled water quality impact on performance of agricultural chemicals including chlorine and pesticides that are pH sensitive. The ideal pH for most pesticides is 5 to 6, and pesticides degrade with increasing pH through a hydrolysis process, which can be rapid in the pH range of 8 and 9. Pest control could be greatly diminished or lost completely at the basic pH observed in water from RIRs. Checking pH and acidifying as needed before recycled water is used in a spray solution could easily realize 5 to 20% of the pesticide potential that otherwise would have been lost. In the United States, approximately 500 million kilograms of more than 600 different pesticides are estimated to be applied annually at a direct cost of $10 billion plus an indirect cost of over $10 billion (Pimentel, 2005). This improved practice alone could save $1 to 4 billion per year in the United States. These new data on water quality and the discoveries about pathogen aquatic biology are foundational for recycled water science. It also was discovered for the first time that thermal stratification occurs in relatively small and shallow RIRs; and this stratification contributes to recycled water quality dynamics. However, within individual reservoirs water quality variations are relatively minor. Both consumer and grower surveys have provided important insights into the socio-economics. First, consumers are willing to pay a price premium for horticultural products with disease-free and/or water conservation labels. Second, irrigation water shortages do not stimulate nursery operators to adopt water recycling. Third, adoption of recycling is impeded by fear of increased disease outbreaks. It was estimated that a 6% net cost savings would be required to break even with the increased disease risk of water recycling (=$6,000 for grower with production costs of $100,000). Cost of adopting recycling technology depends on a grower's location and access to alternative water sources. Analysis of recycling costs revealed that 6 of the 8 case study growers who currently recycle are saving money by recycling compared to obtaining water from wells or municipal systems. Major changes that have been made by early adopters to their existing recycling irrigation system design included: (i) re-routing runoff water flow path on production facilities, (ii) expanding the area and depth of runoff sedimentation reservoirs, (iii) adding new reservoirs to existing water recycling systems, all for the same purposes, extending the runoff water turnover time and settling pathogen out along the water path. The same concept and results also have been used to build pathogen mitigation features into new water recycling systems. Examples of irrigation practice change included (1) placement of the pump inlet immediately below the thermocline of the water column, and (2) irrigating crops in early morning for the best performance of chlorination, a widely-used water treatment that is especially sensitive to alkaline water pH. These changes in irrigation system design and practice have put early adopters on track tosustainability. Extending these changes to other production facilities and horticultural crops will have enormous impacts on the nation's agriculture and consumers by producing more and better quality produces at reduced cost and environmental footprint. This project will continue to promote thehorticutlure industry's long-term sustainability byhavingeducatednext generation leaders who will be scientists and educators in water reuse, (ii)expanded our team's research and extention capacityand industry partnerships concerned with water use and healthy plant production, and (iii) fostered a broader international network of scientists working on water related plant pathogen issues.For example,our industry partnership is stronger than ever as evidenced by the total in-kind contributions during the first 4 years ($915,111) already well exceeding that ($752,990) planned for the entire 5-year project period. More importantly, the advisory panel and collaborating growers contributed much to the project quality and productivity by actively taking part in every step from proposal development to research planning, field study execution, data interpretation as well as technology delivery and implementation.
Publications
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ivors, K. L., and Moorman, G. W. 2014. Oomycete plant pathogens in irrigation water. Pages 57-64 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Lea-Cox, J. D. 2014. Water quality dynamics and influences on pathogen mitigation in irrigation reservoirs. Pages 333-346 In Biology, Detection, and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Lea-Cox, J. D., and Ross, D. S. 2014. Water management to minimize pathogen movement in containerized production systems. Pages 377-388 In Biology, Detection, and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Moorman, G. W., Gevens, A. J., Granke, L. L., Hausbeck, M. K., Hendricks, K., Roberts, P. D., and Pettitt, T. R. 2014. Sources and distribution systems of irrigation water and their potential risks for crop health. Pages 3-11 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Moorman, G. W. 2014. Irrigation water and the health of greenhouse crops. Pages 23-29 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ristvey, A. G. and Moorman, G. W. 2014. An integrated approach to minimizing plant pathogens in runoff water from containerized production systems. Pages 365-375 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ross, D. S. 2014. Water resources and designs of recycling irrigation system for healthy crops. Pages 321-332 In Biology, Detection, and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Burgos-Garay, M., Hong, C. X., and Moorman, G. W. 2014. Complex heterotrophic bacterial interactions with plant pathogenic Pythium in recycled irrigation water. HortScience 49:961-967
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Copes, W. E., Yang, X., and Hong, C. X. 2015. Phytophthora species recovered from irrigation reservoirs in Mississippi and Alabama nurseries and pathogenicity of three new species. Plant Disease 99: dx.doi.org/10.1094/PDIS-11-14-1197-RE
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Garz�n, C. D., Molineros, J. E., Y�nez, J. M., Flores, F. J., Jim�nez-Gasco, M. M., and Moorman, G. W. 2011. Sublethal doses of mefenoxam enhance Pythium damping-off of geraniums. Plant Disease 95: 1233-1238
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Ghimire, S. R., Richardson, P. A., Kong, P., Hu, J. H., Lea-Cox, J. D., Ross, D. R., Moorman, G. W., and Hong, C. X. 2011. Distribution and diversity of Phytophthora species in nursery irrigation reservoir adopting water recycling system during winter months. Journal of Phytopathology 159:713-719
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Hao, W., Ahonsi, M. O., Vinatzer, B. A., and Hong, C. X. 2012. Inactivation of Phytophthora and bacterial species in water by a potential energy-saving heat treatment. European Journal of Plant Pathology 134:357-365 (online at doi: 10.1007/s10658-012-9994-4)
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Hao, W., and Hong, C. X. 2014. Heat treatment induced bacterial changes in irrigation water and their implications for plant disease management. World Journal of Microbiology and Biotechnology 30:1591-1601 (online version at doi: 10.1007/s11274-013-1583-y)
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Hao, W., Richardson, P. A., and Hong, C. X. 2010. First report of foliar blight of Catharanthus roseus caused by Phytophthora tropicalis in Virginia. Plant Disease 94:274
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Hong, C. X., Gallegly, M. E., Richardson, P. A., and Kong, P. 2011. Phytophthora pini Leonian resurrected to distinct species status. Mycologia 103:351-360
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Kong, P., and Hong, C. X. 2010. Zoospore density-dependent behaviors of Phytophthora nicotianae are autoregulated by extracellular products. Phytopathology 100:632-637
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Hong, C. X. 2014. Oxygen stress reduces zoospore survival of Phytophthora species in a simulated aquatic system. BMC Microbiology http://www.biomedcentral.com/1471-2180/14/124
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Kong, P., Lea-Cox, J. D., and Hong, C. X. 2012. Effect of electrical conductivity on survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment. Plant Pathology 61:11791186
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Kong, P., Lea-Cox, J. D., Moorman, G. W., and Hong, C. X. 2012. Survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment at different levels of pH. FEMS Microbiology Letters 332:54-60
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Kong, P., Lee, B. W. K., Zhou, Z. S., Bhalla, R., and Hong, C. X. 2010. Zoosporic plant pathogens produce bacterial autoinducer-2 that affects Vibrio harveyi quorum sensing. FEMS Microbiology Letters 303:55-60
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Hong, C. X., Gallegly, M. E., Richardson, P. A., Kong, P., Moorman, G. W., Lea-Cox, J. D., and Ross, D. S. 2010. Phytophthora hydropathica, a new pathogen identified from irrigation water, Rhododendron catawbiense and Kalmia latifolia. Plant Pathology 59:913-921
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Hong, C. X., Richardson, P. A., Hao, W., Ghimire, S. R., Kong, P., Moorman, G. W., Lea-Cox, J. D., and Ross, D. S. 2012. Phytophthora aquimorbida sp. nov. and Phytophthora taxon aquatilis recovered from irrigation reservoirs and a stream in Virginia, USA. Mycologia. 104:1097-1108
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Kong, P. 2012. Carbon dioxide as a potential water disinfectant for Phytophthora disease risk mitigation. Plant Disease http://dx.doi.org/10.1094/PDIS-09-12-0844-RE
- Type:
Journal Articles
Status:
Published
Year Published:
2010
Citation:
Kong, P., Tyler, B. M., Richardson, P. A., Lee, B. W. K., Zhou, S. H., and Hong, C. X. 2010. Zoospore interspecific signaling promotes plant infection by Phytophthora species. BMC Microbiology http://www.biomedcentral.com/1471-2180/10/313
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
Lanze, C. E., Burgos-Garay, M., Hong, C. X., and Moorman, G. W. 201X. The community of Pythium and Phytopythium species that inhabit two commercial Pennsylvania recycled irrigation water greenhouse tanks. Plant Disease (accepted)
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Man in 't Veld, W. A., Rosendahl, K. C. H. M., and Hong, C. X. 2012. Phytophthora Xserendipita sp. nov., a new species generated by natural hybridization. Mycologia 104:1390-1396 (Online at doi:10.3852/11-272)
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Pistininzi, M., Weiss, E., Achtemeier, L., and Hong, C. X. 2013. Zoospore production biology of pythiaceous plant pathogens. Journal of Phytopathology 162:69-80 (Online at doi: 10.1111/jph.12154)
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
Yang, X., Balci, Y., Brazee, N. J., Lyod, A. L., and Hong, C. X. 2015. Phytophthora intercalaris sp. nov., a new species recovered from stream and irrigation water in eastern United States. International Journal of Systematic and Evolutionary Microbiology
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Copes, W. E., and Hong, C. X. 2013. Phytophthora mississippiae sp. nov., a new species recovered from irrigation reservoirs at a plant nursery in Mississippi. Journal of Plant Pathology and Microbiology http://dx.doi.org/10.4172/2157-7471.1000180
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Copes, W. E., and Hong, C. X. 2014. Two novel species representing a new clade and cluster of Phytophthora species. Fungal Biology 118:72-82
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Gallegly, M. E., and Hong, C. X. 2014. A new high-temperature tolerant species in the clade 9 of the genus Phytophthora: P. hydrogena sp. nov. Mycologia 106:57-65 (online version at doi:10.3852/13-043)
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., and Hong, C. X. 2013. Phytophthora virginiana sp. nov., a high-temperature tolerant species from irrigation water in Virginia. Mycotaxon 126:167-176 (online version at http://dx.doi.org/10.5248/126.167)
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Richardson, P. A., and Hong, C. X. 2014. Phytophthora�stagnum nothosp. nov., a new hybrid from irrigation reservoirs at ornamental plant nurseries in Virginia. PLoS One at http://dx.plos.org/10.1371/journal.pone.0103450
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., Kong, P., and Hong, C. X. 2013. Fungicidal control of Phytophthora aerial blight on annual vinca in Virginia, 2012. Plant Disease Management Reports 7:OT005
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., Olson, H. A., and Hong, C. X. 2013. Root and stem rot of begonia caused by Phytopythium helicoides in Virginia. Plant Disease 97:1385
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Zhang, H., Richardson, P. A., Belayneh, B. E., Ristvey, A. G., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. 2015. Characterization of water quality in stratified nursery recycling irrigation reservoirs. Agricultural Water Management 160:76-83
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., and Hong, C. X. 2014. Halophytophthora fluviatilis sp. nov. from freshwater in Virginia. FEMS Microbiology Letters 352:230-237 (online version at doi: 10.1111/1574- 6968.12391)
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Kong, P., and Hong, C. X. 2013. Evaluation of fungicide drenches for control of Phytophthora root rot of petunia, 2012. Plant Disease Management Reports 7:OT002
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Yang, X., Richardson, P. A., Ghimire, S. R., Kong, P., and Hong, C. X. 2012. Phytophthora hedraiandra detected from irrigation water at a perennial plant nursery in Virginia. Plant Disease 96:915
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., and Hong, C. X. 2013. Evaluation of nonregistered fungicide for control of rose downy mildew, 2012. Plant Disease Management Reports 7:OT001
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Zhang, H., Richardson, P. A., Belayneh, B. E., Ristvey, A. G., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. 2015. Comparative analysis of water quality between the runoff entrance and middle of recycling irrigation reservoirs. Water 7:3861-3877
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
Zhang, H., Richardson, P. A., Belayneh, B. E., Ristvey, A. G., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. 2015. Recycling irrigation reservoir stratification and implications for crop health and production. Journal of the American Water Resources Association
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Caf�, G., and Hong, C. X. 2015. Distinct bacterial community composition in an emerging ecosystem of agricultural runoff water containment basins. Applied and Environmental Microbiology
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Kong, P., and Hong, C. X. 2015. Environmental bacteria promote infection of host and nonhost plants by Phytophthora species. ISME Journal
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Yang, X., and Hong, C. X. 2015. Comparative analysis of Phytophthora, Phytopythium and Pythium diversity among different depths of sediments in an agricultural runoff sedimentation reservoir. Plant Pathology
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Kong, P., and Hong, C. X. 2015. Genetic diversity and abundance of cyanobacteria and associated microbes in agricultural runoff containment reservoirs. Journal of Environmental Management
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Kong, P., and Hong, C. X. 2015. Seasonal dynamics of cyanobacterial and associated microbial communities in a multi-reservoir recycling irrigation system. Applied and Environmental Microbiology
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Nikrad, M., and Hong, C. X. 2015. Diversity and abundance of ammonia-oxidizing archaea and bacteria in recycled irrigation waters in eastern and central Virginia. Applied and Environmental Microbiology
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Zhang, H., Richardson, P. A., Belayneh, B. E., Ristvey, A. G., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. 2015. Dominance and crop production implications of alkaline pH in recycling irrigation reservoirs. Irrigation Science
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Hao, W., and Hong, C. X. 2013. Biological control of Phytophthora nicotianae by heat-tolerant bacteria in irrigation water (Abstr.) Phytopathology 103:S2.56
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Burgos-Garay, M. L., and Moorman, G. W. 2011. Influence of Pythium aphanidermatum, P. irregulare, and P. cryptoirregulare on the bacterial community in recycled irrigation water (Abstr.) Phytopathology 102:S23
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Hao, W., Vinatzer, B. A., and Hong, C. X. 2011. Effect of temperature on survival of Phytophthora and bacterial species in irrigation water (Abstr.) Phytopathology 101:S69
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Hong, C. X. 2013. Diversity and significance of waterborne pathogens to plant biosecurity under a changing climate (Abstr.) Chinese Journal of Plant Pathology 43:S163
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Burgos-Garay, M. L., Edson, J., and Moorman, G. W. 2012. Influence of Pythium aphanidermatum, P. irregulare, and P. cryptoirregulare on the bacterial community in recycled irrigation water (Abstr.) Phytopathology 102:S1.2
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Burgos-Garay, M. L., and Moorman, G. W. 2011. Effect of microbial communities in recycled irrigation water on the development of three Pythium species (Abstr.) Phytopathology 101:S258
- Type:
Other
Status:
Accepted
Year Published:
2015
Citation:
Copes, W. E., Yang, X., and Hong, C. X. 2015. Phytophthora species recovered from irrigation reservoirs in Mississippi and Alabama nurseries and pathogenicity of three new species (Abstr.) Phytopathology 105
- Type:
Other
Status:
Published
Year Published:
2010
Citation:
Gallegly, M. E., Hong, C. X., Richardson, P. A., and Kong, P. 2010. Phytophthora pini, a valid distinct species (Abstr.) Phytopathology 100:S207
- Type:
Other
Status:
Published
Year Published:
2010
Citation:
Hao, W., and Hong, C. X. 2010. Effect of temperature on survival of chlamydospores and oospores of Phytophthora species in irrigation water (Abstr.) Phytopathology 100:S47
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Hong, C. X., and Richardson, P. A. 2012. Validation of water quality fluctuation patterns in runoff water containment basins of eastern and central Virginia (Abstr.) Phytopathology 102:S4.55
- Type:
Other
Status:
Published
Year Published:
2010
Citation:
Hong, C. X., Richardson, P. A., Ghimire, S. R., Hao, W., Kong, P., Moorman, G. W., Lea-Cox, J. L., and Ross, D. S. 2010. Two new homothallic species of Phytophthora from irrigation reservoirs and natural waterways in Virginia (Abstr.) Phytopathology 100:S51
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Hong, C. X., Richardson, P. A., Ghimire, S. R., Kong, P., Hu, J. H., Moorman, G. W., Lea-Cox, J. D., and Ross, D. S. 2011. Diversity of Phytophthora species identified in a nursery irrigation runoff water containment basin of eastern Virginia (Abstr.) Phytopathology 101:S74
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Hong, C. X., Richardson, Kong, P., Edgerton, T., Asaro, C., and Oak, S. W. 2011. Phytophthora species identified from streams in Virginia (Abstr.) Phytopathology 101:S74
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Kong, P., and Hong, C. X. 2013. Aquatic ecology of pythiaceous plant pathogens (Abstr.) Chinese Journal of Plant Pathology 43:S520 (International Congress of Plant Pathology, Beijing, China, August 25-31, 2013)
- Type:
Other
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Hong, C. X. 2014. Effects of water quality on survival of zoosporic oomycetes and implications (Abstr.) HortScience 49(9):S195
- Type:
Other
Status:
Published
Year Published:
2011
Citation:
Kong, P., Lea-Cox, J. D., Moorman, G. W., and Hong, C. X. 2011. Survival of three quarantine pathogens in a simulated aquatic system at different levels of pH (Abstr.) Phytopathology 101:S93
- Type:
Other
Status:
Published
Year Published:
2014
Citation:
Lanze, C., and Moorman, G. W. 2014. Characterization of Pythium spp. frequently found in recycled irrigation water (Abstr.) Phytopathology 104:S3.66
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Lea-Cox, J. D., and Belayneh, B. E. 2012. Environmental sensors for measuring weather and intra-canopy conditions (Abstr.) In Symposium: The Use, Application and Analysis of Experimental and Field Sensor Data for Horticultural Applications. 109th Annual American Society for Horticultural Science Conference. Miami, FL. HortScience 47(9): S80
- Type:
Other
Status:
Other
Year Published:
2010
Citation:
Hong, C. X. 2010. Fishing for Phytophthoras a journey of surprises, Invited Lecture for the Plant Physiology Seminar Series. Virginia Tech (Department of Plant Pathology, Physiology and Weed Science), Blacksburg, VA
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Boyle, K., Hartter, D., Pease, J., Bosch, D., and Xu, W. B. 2014. Consumer preferences for ornamental plants grown with water conservation practices. Invited Presentation at the Annual Meeting of Agricultural and Applied Economics Association, Minneapolis, MN
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2010
Citation:
Hong, C. X. 2010. Water recycling and its implications for crop health management. Invited Presentation for the Symposium of Water Issues in the Production of Ornamental Crops in the United States. The Land Grant and Sea Grant National Water Conference, Hilton Head, SC
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Lea-Cox, J. D., Belayneh, B. E., and Ristvey, A. G. 2013. Daily and seasonal changes in the water quality of irrigation containment ponds (Abstr.) American Society for Horticultural Science Annual Conference: The Challenges of Using Alternative and Recycled Water Sources for Horticultural Use Workshop. HortScience 48:S106
- Type:
Other
Status:
Published
Year Published:
2014
Citation:
Ristvey, A. G., Belayneh, B. E., Zazanis, J. P., Beaulieu, J., Balci, Y., and Lea-Cox, J. D. 2014. Investigating alternative pathogen management through sensor-driven irrigation (Abstr.) 111th Annual American Society for Horticultural Science Conference. Orlando, FL. HortScience 49(9): S226-227
- Type:
Other
Status:
Accepted
Year Published:
2015
Citation:
Yang, X., Brazee, N. J., Loyd, A., and Hong, C. X. 2015. Phytophthora intercalaris, a novel species from streams and irrigation water in eastern United States (Abstr.) Phytopathology 105
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Yang, X., Copes, W. E., and Hong, C. X. 2013. Three novel Phytophthora species from irrigation water in Mississippi (Abstr.) Phytopathology 103:S2.164
- Type:
Other
Status:
Published
Year Published:
2012
Citation:
Yang, X., and Hong, C. X. 2012. Isolation of Phytophthora and Pythium species from different depths of sediments in a runoff water sedimentation pond of eastern Virginia (Abstr.) Phytopathology 102:S4.140
- Type:
Other
Status:
Published
Year Published:
2014
Citation:
Yang, X., Tyler, B. M., and Hong, C. X. 2014. Constructing a new phylogeny for the genus Phytophthora. Phytopathology 104:S3.133
- Type:
Other
Status:
Other
Year Published:
2010
Citation:
Hong, C. X. 2010. Fishing for Phytophthoras a journey of surprises, Invited Lecture for Zhejiang University, Hangzhou, China
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2010
Citation:
Hong, C. X. 2010. Ecology of Phytophthora species in ornamental irrigation water. Invited Presentation at the 17th Ornamental Workshop Diseases and Insects, Hendersonville, NC
- Type:
Other
Status:
Other
Year Published:
2011
Citation:
Hong, C. X. 2011. Commodity health and quality: advancing postharvest science and technology in a changing world. Invited Lecture for the USDA ARS San Joaquin Valley Agricultural Sciences Center, Parlier, CA
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2011
Citation:
Hong, C. X. 2011. Irrigation pathogen mitigation without water treatment. Invited Presentation at the 36th Annual Conference of the International Plant Propagators Society - Southern Region of North America, Valdosta, GA, October 23 to 26, 2011
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
Hong, C. X. 2012. Water dispersal of plant pathogens in a thirsty world. Invited Lecture for the University of Hertfordshire, Hatfield, UK, April 27, 2012
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
Hong, C. X. 2012. Challenges and opportunities for integrated pest management, Invited Lecture for the University of California, Davis, CA, September 24, 2012
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2012
Citation:
Hong, C. X. 2012. Fungicide resistance in Phytophthora species attacking ornamentals. Invited Presentation at the 18th Ornamental Workshop Diseases and Insects, Hendersonville, NC, September 24 to 28, 2012
- Type:
Other
Status:
Other
Year Published:
2013
Citation:
Hong, C. X. 2013. Plant health management in a thirsty world. Invited Lecture for the Christopher Newport University, Newport News, VA, February 22, 2013
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Hong, C. X. 2013. Treasure hunt in agricultural runoff water containment basins. Invited Presentation at the American Phytopathological Society Potomac Division Annual Meeting/Recent Advancements in Biological Control symposium. Shepherdstown, WV, April 4, 2013
- Type:
Other
Status:
Other
Year Published:
2013
Citation:
Hong, C. X. 2013. Recycled water quality dynamics and implications for ornamental horticultural crop production and health. Invited Lecture for the Virginia Tech (Department of Horticulture), Blacksburg, VA, May 6, 2013
- Type:
Other
Status:
Other
Year Published:
2013
Citation:
Hong, C. X. 2013. Water dispersal of plant pathogens. Invited Lecture for Cornell University (Department of Plant Pathology and Plant-Microbe Biology), Ithaca, NY, June 26, 2013
- Type:
Other
Status:
Other
Year Published:
2015
Citation:
Hong, C. X. 2015. Integrated pest management in the 21st century. Invited Lecture for the University of California, Davis, CA, July 21, 2015
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Hong, C. X. 2013. Recycling irrigation system, a focal point of agricultural water security and plant biosecurity in the 21st century. Invited Presentation at the First Emerging Information Technology Association (EITA) Conference on Agricultural Sciences and Engineering, Biosystems Engineering (the theme of Precision Agriculture Challenges and Future Directions), Ithaca, NY, June 27, 2013
- Type:
Other
Status:
Other
Year Published:
2015
Citation:
Hong, C. X. 2015. Specialty crop science and technology in the 21st century. Invited Lecture for the Office of National Programs, USDA Agricultural Research Service, Beltsville, MD, May 22, 2015
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Kong, P., Richardson, P. A., Yang, X., Zhang, H. B., Ghimire, S. R., Copes, W. E., Moorman, G. W., Lea-Cox, J. D., and Hong, C. X. 2014. Biology of Phytophthora species in aquatic ecosystems. Invited Presentation at the 7th IUFRO Working Party 7.02.09 on Phytophthora in Forests and Natural Ecosystems. Esquel, Chubut, Argentina, November 10 to 14, 2014
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Kong, P., Richardson, P. A., Yang, X, Zhang, H. B., Ghimire, S. R., Moorman, G. W., Lea-Cox, J. D., Copes, W. E., Ross, D. R., Ristvey, A. G., Boyle, K. J., Bosch, D., Pease, J., and Hong, C. X. 2015. Building crop health into water recycling systems. Invited Presentation at the 18th International Plant Protection Congress, Berlin, Germany, August 24 to 27, 2015
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
Lea-Cox, J. D. 2012. Some observations on interdisciplinary project planning and management. In: Collaborative Research Projects Highlight the Economic Benefits of Agricultural Research. Webinar organized by the Tri-Societies (ASA/CSSA/SSSA) and Council on Food, Agriculture and Resource Economics (C-FARE) for USDA-NIFA Program Leaders. Washington, DC, October 15, 2012
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2012
Citation:
Lea-Cox, J. D. 2012. Pathogen risk mitigation with good system design and best management practices. Invited Presentation at the 7th International IPM Symposium, Memphis, TN. March 27 to 29, 2012. http://www.ipmcenters.org/ipmsymposium12/27-2_LeaCox.pdf
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2011
Citation:
Moorman, G. W. 2011. Oomycetes in irrigation water: Challenges and opportunities. Invited Presentation at the Northeastern Division-American Phytopathological Society annual meeting symposium. New Brunswick, NJ, October 13, 2011
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2012
Citation:
Moorman, G. W. 2012. Plant pathogens in irrigation water. Invited Presentation at the 7th International IPM Symposium. Memphis, TN, March 27, 2012
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Yang, X., Copes, W. E., and Hong, C. X. 2014. Phytophthora species found in irrigation systems and their risk assessments. Invited Presentation at the 19th Ornamental Workshop on Diseases and Insects, Hendersonville, NC, September 29 to October 3, 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Yang, X., Tyler, B. M., and Hong, C. X. 2014. A multi-locus phylogeny for the genus Phytophthora. Invited Presentation at the 7th IUFRO Working Party 7.02.09 on Phytophthora in Forests and Natural Ecosystems. Esquel, Chubut, Patagonia Argentina, November 10 to 14, 2014
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Cultice, A., Bosch, D., Pease, J., and Boyle, K. 2013. Horticultural producers' willingness to adopt water recirculation technology. Agricultural and Applied Economics Association and Canadian Agricultural Economics Society Joint Annual Meeting, Washington, DC, August 4 to 6, 2013
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Hong, C. X., and Moorman, G. W. 2013. Diversity and significance of plant pathogens as agricultural water contaminants. 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25 to 27, 2013
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Hong, C. X., Richardson, P. A., Kong, P., and Caf�, G. 2013. Tracking water quality dynamics in a multi-basin agricultural water recycling system, 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25 to 27, 2013
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2013
Citation:
Hong, C. X., Richardson, P. A., Kong, P., Caf�, G., Lea-Cox, J. D., Belayneh, B. E., and Ristvey, A. G. 2013. Dramatic fluctuations of water quality in agricultural runoff containment basins. 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25 to 27, 2013
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Kong, P., and Hong, C. X. 2015. Genetic diversity and abundance of cyanobacteria and associated microbial communities in agricultural runoff containment reservoirs. Phytobiomes 2015: Designing a New Paradigm for Crop Improvement, Washington, DC, June 29 to July 2, 2015
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Ferraro, N., Bosch, B., and Pease, J. 2015. Economic analysis of recapturing and recycling irrigation on container horticultural nurseries. Southern Nursery Growers Association. Atlanta, Georgia, July 21, 2015
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Kong, P., and Hong, C. X. 2015. Zoospore exudates suppress plant defense gene expression in Arabidopsis thaliana. The 18th International Plant Protection Congress, Berlin, Germany, August 24 to 27, 2015
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Yang, X., and Hong, C. X. 2015. Comparative analysis of oomycete diversity between water and sediment in a runoff water sedimentation reservoir in Virginia. Phytobiomes 2015: Designing a New Paradigm for Crop Improvement, Washington, DC, June 29 to July 2, 2015
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
DAlessio, N. 2015. Segmentation of the market for labeled ornamental plants by environmental preferences: A latent class analysis. M.S. Thesis. Virginia Tech, Blacksburg, VA
- Type:
Websites
Status:
Published
Year Published:
2011
Citation:
Irrigation pathogens and water quality at www.irrigation-pathogens.info or http://www.irrigation-pathogens.ppws.vt.edu/. This site was released to the public in 2011 and thereafter updated regularly.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Burgos-Garay, M. L. 2013. Effect of heterotrophic bacterial communities on Pythium spp. in recycled irrigation water. Ph.D. dissertation. The Pennsylvania State University, University Park, PA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Cultice, A. 2013. Horticultural producers' willingness to adopt water recirculation technology in the Mid-Atlantic region. M.S. Thesis. Virginia Tech, Blacksburg, VA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
Ferraro, N. 2015. Economic analysis of recapturing and recycling irrigation techniques on horticulture nurseries. M.S. Thesis. Virginia Tech, Blacksburg, VA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2012
Citation:
Hartter, D. 2012. Understanding consumers ornamental plant preferences for disease-free and water conservation labels. M.S. Thesis. Virginia Tech, Blacksburg, VA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
Lanze, C. E. 2015. Characterization of Pythium and Phytopythium species frequently found in irrigation water. M. S. thesis. The Pennsylvania State University, University Park, PA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Copes, W. E., Barbeau, B., and Chastagner, G. A. 2014. Chlorine dioxide for irrigation water treatment. Pages 251-266 In Biology, Detection, and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2014
Citation:
Yang, X. 2014. New species and phylogeny of the genus Phytophthora. Ph.D. Dissertation. Virginia Tech, Blacksburg, VA
- Type:
Books
Status:
Published
Year Published:
2014
Citation:
Hong, C. X., Moorman, G. W., Wohanka, W., and B�ttner, C. (eds.) 2014. Biology, Detection, and Management of Plant Pathogens in Irrigation Water. American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
B�ttner, C., Hong, C. X., Moorman, G. W., and Wohanka, W. 2014. Preface. In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Elmer, W. H., Buck, J., Ahonsi, M. O., and Copes, W. E. 2014. Emerging technologies for irrigation water treatment. Pages 289-302 In Biology, Detection, and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2012
Citation:
Hao, W. 2012. A potential energy-efficient heat treatment and its biological mechanisms. Ph.D. Dissertation, Virginia Tech, Blacksburg, VA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hao, W., Vinatzer, B. A., and Hong, C. X. 2014. Pasteurization for irrigation water treatment. Pages 187-195 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. 2014. Management of plant pathogens in irrigation water. Pages 74-75 In Compendium of Rhododendron and Azalea Diseases. R. Linderman, and D. M. Benson (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. 2014. Developing a facility and production plan for management of plant pathogens in irrigation water. Page 75 In Compendium of Rhododendron and Azalea Diseases. R. Linderman, and D. M. Benson (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. 2014. Selecting a water treatment technology for control of plant pathogens in irrigation water. Pages 75-76 In Compendium of Rhododendron and Azalea Diseases. R. Linderman, and D. M. Benson (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. 2014. Component analysis of irrigation water in plant disease epidemiology. Pages 111-121 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. 2014. Economic threshold of plant pathogen in irrigation water. Pages 175-183 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.) American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X., B�ttner, C., Moorman, G. W., and Wohanka, W. 2014. A partial list of plant pathogens found in water to date. Pages 389-411 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.), American Phytopathological Society, St. Paul, MN, USA
|
Progress 09/01/13 to 08/31/14
Outputs
Target Audience: Nursery growers and greenhouse producers Garden centers, retailers, and landscapers Agricultural industry scientists and consultants Extension specialists and agents Plant disease diagnosticians, regulatory personnel Undergraduate and graduate students, postdoctoral associates Educators, horticulturists, mycologists, and researchers Conservation biologists Government policy makers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Eight graduate research assistantships: Cao, Dart, D’Alessio, Ferraro, Lanze, Ree, Xu, Yang Four postdoctoral research fellowships: Avenot, Burgos-Garay, Nikrad, Zhang These graduate students and postdoctoral fellows were sent to workshops for professional development whilelearning required skills for performing their parts of the project. They also were sent toprofessional meetings to present their research data and network with peers. For example, Mrina Nikrad attended the Mothur Workshop in Detroit, MI (March 2014), Carla E. Lanze participated in the Ooomycete Bioinformatics Workshop at Virginia Tech in Blacksburg, VA (June 2014), and Xiao Yang participated in two workshops (Analysis of Population Genetic Data in R and Introduction to Bayesian Analysis in Plant Pathology) in Minneapolis, MN (August 2014). Herve Avenot, Norm Dart, and Xiao Yang attended the 2nd International Boxwood Summit in Beltsville, MD (May 2014). Carla E. Lanze and Xiao Yang presented their results at the Annual Meeting of American Phytopathological Society in Minneapolis, MN (August 2014). Xiao Yang also participated and presented his research and moderated a session at the 19th Ornamental Workshop on Diseases and Insects in Hendersonville, NC (September 2014). Haibo Zhang participated in the AWRA Annual Water Resources Conference in Tysons Corner, VA (November 2014). All graduate students and postdoctoral fellows were mentored as they prepared data for publication. Fourteen webinar sessions: irrigation pathogens and water quality, for the industry and other stakeholders How have the results been disseminated to communities of interest? Webinar series: Irrigation Pathogens and Water Quality A 14-session webinar series was advertised throughout the U. S. and delivered via Adobe Connect at https://connect.extension.iastate.edu/irrigation-water/. It was well attended and participants included growers, extension agents and specialists and other stakeholders from coast to coast and from Canada to Florida. All webinar sessions including discussion were recorded and archived at http://www.irrigation-pathogens.ppws.vt.edu/webinar/index.php. 1. Project Team. 2013. A path to plant biosecurity, water and environmental sustainability – SCRI Project overview. Held on October 8, 2013 and recording posted at https://connect.extension.iastate.edu/p8c8irvmphw/ 2. Pease, J. 2013. Disease management and irrigation practices of Mid-Atlantic ornamental nurseries. Held on November 6, 2013 and recording posted at https://connect.extension.iastate.edu/p7vxio4amkj/ 3. Moorman, G. W. 2014. What plant pathogens could be in irrigation water? Held on December 3, 2013 and recording posted at https://connect.extension.iastate.edu/p3u8rvp77kf/ 4. Moorman, G. W. 2014. How do plant pathogens get into and move in irrigation water? Held on January 7, 2014 and recording posted https://connect.extension.iastate.edu/p5k9xrwl0vb/ 5. Moorman, G. W. 2014. How do we determine irrigation water is clean or contaminated? Held on February 4, 2014 and recording posted at https://connect.extension.iastate.edu/p6g6f7h6dj2/ 6. Hong, C. X. 2014. Chlorination of recycled water in ornamental horticultural production. Held on March 4, 2014 and recording posted at https://connect.extension.iastate.edu/p56g9fijkmi/ 7. Copes, W. E. 2014. Alternative disinfectant treatments. Held on April 8, 2014 and recording posted at https://connect.extension.iastate.edu/p1pbnh37awv/ 8. Ristvey, A. 2014. Substrate management practices vital for pathogen risk mitigation. Held on May 6, 2014 and recording posted at https://connect.extension.iastate.edu/p8a3yfye8s2/ 9. Lea-Cox, J. D. 2014. Pathogen recycling risk mitigation through system design and best management practices. Held on June 3, 2014 and recording posted https://connect.extension.iastate.edu/p514ujen4de/ 10. Hong, C. X. 2014. Locating a new production facility for crop health and sustainability. Held on July 1, 2014 and recording posted at https://connect.extension.iastate.edu/p7uv8isuow4/ 11. Hong, C. X. 2014. Building pathogen risk mitigation into water recycling systems. Held on August 5, 2014 and recording posted at https://connect.extension.iastate.edu/p7j64j891gy/ 12. Hong, C. X. 2014. Recycled water quality dynamics and implications for crop health and production. Held on September 2, 2014 and recording posted at https://connect.extension.iastate.edu/p7csfg98et9/ 13. Hong, C. X. 2014. Water pH management for improved horticultural productivity and profit margin. Held on October 7, 2014 and recording posted at https://connect.extension.iastate.edu/p1ec2ajsn5v/ 14. Hartter, D., Boyle, K., Pease, J., Bosch, D., D’Alessio. 2014. Understanding consumer preferences for ornamental plants with disease-free and water conservation labels. Held on November 4, 2014 and recording posted at https://connect.extension.iastate.edu/p4wiyfsyslr/ Newsletter articles 1. Hong, C. X. 2014. Three reasons to irrigate plants in the early to mid-morning. Virginia Nursery and Landscape Association (VNLA) Newsletter 84(1):66-68 2. Hong, C. X. 2013. Water pH dictates chlorine performance. VNLA Newsletter 83 (4):58-60 Related extension publications 1. Avenot, H., Baudoin, A., Bordas, A., Bush, E., Dart, N., Hansen, M. A., Hong, C. X., Likins, T. M., Martin, D, and Nichols, L. 2014. Virginia boxwood blight task force. Virginia Cooperative Extension Publication No.: PPWS-30NP at http://pubs.ext.vt.edu/PPWS/PPWS-30/PPWS-30.html 2. Bush, A., Hansen, M. A., Dart, N., Hong, C. X., Bordas, A., and Likins, T. M. 2014. Best management practices for boxwood blight in the Virginia home landscape. Virginia Cooperative Extension Publication No.: PPWS-29NP at http://pubs.ext.vt.edu/PPWS/PPWS-29/PPWS-29.html 3. Dart, N., Hong, C. X., Bordas, A., Bush, A., Hansen, M. A., and Likins, T. M. 2014. Best management practices for boxwood blight in Virginia production nurseries WITHOUT boxwood blight. Virginia Cooperative Extension Publication No.: PPWS-33NP at http://pubs.ext.vt.edu/PPWS/PPWS-33/PPWS-33.html 4. Dart, N., Hong, C. X., Bordas, A., Bush, A., Hansen, M. A., and Likins, T. M. 2014. Best management practices for boxwood blight in Virginia retail nurseries WITH boxwood blight. Virginia Cooperative Extension Publication No.: PPWS-34NP at http://pubs.ext.vt.edu/PPWS/PPWS-34/PPWS-34.html 5. Dart, N., Hong, C. X., Bordas, A., Bush, A., Hansen, M. A., and Likins, T. M. 2014. Best management practices for boxwood blight in Virginia retail nurseries WITHOUT boxwood blight. Virginia Cooperative Extension Publication No.: PPWS-35NP at http://pubs.ext.vt.edu/PPWS/PPWS-35/PPWS-35.html 6. Hansen, M. A., Bush, A., Bordas, A., Dart, N., Hong, C. X., and Likins, T. M. 2014. Best Management Practices for Boxwood Blight for Greenery Producers. Virginia Cooperative Extension Publication No.: PPWS-39NP at http://pubs.ext.vt.edu/PPWS/PPWS-39/PPWS-39-pdf.pdf Related extension presentations Hong, C. X. 2014. Boxwood blight: avoidance and control. “Kick-off the Season” Specialist Day, Painter, VA, March 11, 2014 Presentations to the External Reviewers of Virginia Tech’s Hampton Roads AREC 1. Kong, P., Richardson, P. A., Yang, X, Zhang, H. B., Ghimire, S. R., Copes, W. E., Moorman, G. W., Lea-cox, J. D., and Hong, C. X. 2014. Biology of Phytophthora species in aquatic ecosystems 2. Zhang, H. B., Richardson, P. A., Belayeh, B. E., Ristvey, A., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. Recycling irrigation reservoirs: thermal stratification and water quality variation One-on-one consultations with growers Numerous consultation were conducted through on-site visit, email exchange and via phone conversation to advise on irrigation pathogens and irrigation water quality. Disease diagnoses were completed on samples submitted by growers, retailers, landscapers as well as extension agents concerned about plant pathogens in irrigation water. What do you plan to do during the next reporting period to accomplish the goals? In addition to the activities outlined in the proposal for the final year of this project, we will endeavor to explore some new research horizons of fundamental importance to the national and global plant biosecurity. Specifically, we will: 1. Construct a new phylogeny for the genus Phytophthora by integrating the new clades and recently described species as a result of this project. This work will be foundational for developing and implementing sustainable risk mitigation plan for pathogens in irrigation systems and beyond at national and global scales. 2. Expand the hunt in runoff containment basins for naturally occurring biological control agents. This work has begun with investigations into the diversity of algae in recycling irrigation reservoirs and their interactions with selected Phytophthora species. 3. Explore the differences in the genetic makeup between aquatic and terrestrial species of Phytophthora and Pythium and their association with genes regulating pathogenicity. 4. Model the seasonal and diurnal water quality fluctuations in runoff containment basins. This research integrates the initial four years of environmental and water quality data for better understanding the water quality dynamics. It aims to provide a tool for water quality manipulation in order to suppress pathogens, improve crop productivity and quality as well as a tool for assessing water resource conservation and protection benefits of capturing and recycling runoff water. 5. Develop a better understanding of the interactions between the isolates of Pythium very frequently found in recirculating irrigation water but not associated with crop losses and those species of Pythium that are known to cause significant crop losses in commercial greenhouses. This research is being conducted by a graduate student as part of her Master of Science degree research project at Penn State University. 6. Morphological and physiological characteristics of species of Pythium (known and new-to-science species) will be determined. Their plant pathogenicity on geranium seedlings and cardinal temperatures in culture will be determined. Two students, Carla Lanze and Laura del Sol Bautista-Jalon, will participate at the Oomycete Molecular Genetics Network meeting and the Fungal Genetics Conference (Asilomar Conference Center in Pacific Grove, CA) in 2015. These students will receive two weeks of training in genotyping-by-sequencing analysis at Cornell University's Institute of Biotechnology. Both will apply this training to the analysis of Pythium isolate DNA, submit manuscipts to scientific journals, and present research results at the August 2015 American Phytopatholgical Society meeting in Pasadena, CA. Carla Lanze will complete her M. S. degree requirements. BMPs for Pythium management in greenhouses will be completed and added to the Knowledge Center. A risk assessment guide for use by Knowledge Center visitors will be completed and made available. 7. Conduct case studies of growers in Virginia, Maryland, and Pennsylvania to estimate costs of recycling. 8. Estimate relationship between premiums consumers are willing to pay for plants grown using water conserving methods and growers’ costs of implementing such methods.
Impacts
What was accomplished under these goals?
Research data translation and dissemination to end users has emerged as a central theme of our project activities this past year. The most significant accomplishments included: (i) a well-attended 14-session webinar series on irrigation pathogens and water quality, and (ii) publication of a comprehensive reference resource on irrigation pathogens. The webinar series was added to the project for an expedited dissemination of resultant knowledge and technology and for the broadest reach to end users possible. Each session was advertised nationally via AmericanHort and the Society of American Florists as well as other local and national networks of growers, diagnosticians and extension professionals. The webinar series was launched in October of 2013 and delivered monthly via Adobe Connect at https://connect.extension.iastate.edu/irrigation-water/. Several sessions were conducted in collaboration with leading growers in water decontamination technologies. The webinar series has attracted attendance from coast to coast and from Canada to Florida. All sessions were archived at http://www.irrigation-pathogens.ppws.vt.edu/webinar/index.php for future viewing. The reference book project was undertaken to maximize the reach and impact of this project by raising the awareness of the growing global water shortage and associated pathogen recycling risk. The content was developed in order to educate specialists and larger growers, and to encourage young scientists to enter this field of research. As indicated in the book title, this reference resource summarizes the current knowledge about the biology, detection and management of plant pathogens in irrigation water. This book, published by the American Phytopathological Society, includes five sections: (i) linkage between crop disease and irrigation water, (ii) diversity and biology of plant pathogens in irrigation water, (iii) detection technology and economic threshold for plant pathogens in irrigation water, (iv) pathogen management through water treatment, and (v) pathogen management through effective system design and best practices. This book was a result of an international collaboration involving 49 leading agricultural engineers, horticulturists, irrigation specialists, microbiologists and plant pathologists from three continents (Africa, America, and Europe). It is regarded as "an ideal textbook and highly recommended for Agricultural Department curriculums and Academic Library reference collections." (http://www.apsnet.org/apsstore/shopapspress/Pages/44266.aspx). In addition, we continued research to further develop our understanding of water quality dynamics, pathogen aquatic biology, and economics of water recycling. To date, a total of nine new species and one new taxon of Phytophthora have been characterized and described from nursery irrigation systems in Virginia and Mississippi.Among themP. stricta represents a new clade in the genus while majority of the other news species form a high temperature cluster within clade 9. None of these new species and taxon has caused severe disease or damage to ornamental crops at local nurseries, nor have they survived well in soilless potting mixes. These results, however, do not necessarily mean thatthey pose no or low risk to crops under different conditions and/or elsewhere. These studies have already facilitated worldwide identification of the above species and diseases they cause as indicated by P. hydropathica. They also have raised some fundamental questions regarding the origin, ecological function and horticultural implications of these novel species while challenging the current phylogeny of the genus Phytophthora. Continuous monitoring at two commercial greenhouses in Pennsylvania has demonstrated that irrigation water holding tanks harbor numerous Pythium species, especially those characterized by filamentous, non-inflated sporangia (Group F of Plaats-Niterink). In addition, one greenhouse harbors Pythium helicoides, P. middletonii, P. rostratifigens and two species that are new to science. The second greenhouse harbors Pythium chamaehyphon and one species that is new to science. Resultant cultures were tested to determine their cardinal temperatures of growth and sensitivity to a widely used fungicide, mefenoxam. Analyses of DNA sequences on these isolates were intensified in order to determine identity and to characterize new species. In greenhouse experiments where these isolates were used to inoculate geraniums each separately and in combination with the highly pathogenic Pythium aphanidermatum, P. irregulare, and P. cryptoirregulare, there did not appear to be disease inhibitory or enhancement effects between Pythium species. Analyses of water quality and weather data collected from multiple locations in Virginia and Maryland over the past 4 years have identified for the first time that thermal stratification occurs in shallow recycling irrigation reservoirs. These data revealed water quality variations at different depths of the water column and along water path within reservoirs from the entrance to the outflow point. These new findings document the dramatic diurnal and seasonal fluctuations of water quality in these reservoirs and have direct applications in irrigation pathogen and water quality management. In addition to water pH and electrical conductivity, dissolved oxygen (DO) was determined to be a major factor limiting zoospore survival in recycling irrigation reservoirs. Zoospores survived the best at a DO level of 5 to 6 mg/L, equivalent to that of tap water. Zoospore survival decreased with DO reduction down to 0 mg/L or elevation up to 20 mg/L and above in lab assays simulating its fluctuation ranges documented for recycling irrigation reservoirs. In-depth analyses of grower survey data regarding irrigation and disease management practices and attitudes toward recycling irrigation and rainfall runoff have resulted in a number of new findings with policy implications. First, among the198 respondent growers were 50adopters and 148 non-adopters. The adopterswould recycle in response to at least one of the two choice questions whilethe non-adopters would not recycle in response to both questions. Compared to non-adopters, adopters had a lower proportion of respondents fromretailsand a higher proportionfrom container, field nursery, and hoop house production. Adopters and non-adopters were similar in terms of years of experience. Compared to non-adopters, adopters were less likely to be the owners of their businesses, more likely to be a head grower, and more likely to have a four-year college degree. Adopters had higher total firm costs and nursery costs compared to non-adopters. Second, cost and disease are deterrents to recycling while water scarcity is not a consideration for the decision to recycle. Growers would need to be compensated 7% their nursery production cost to accept the risk of increased disease associated with recycling. Wide spread adoption of water recycling technologies is unlikely to occur in the Mid-Atlantic region without regulation. Financial assistance (tax credits, cost share, subsidies, loans) could encourage growers to invest in infrastructure to capture and recycle water. Research and outreach can demonstrate ways to recycle without increased disease risk, thereby increasing grower acceptance of recycling. Additionally, the project team effectively addressed the immediate need for recommendations concerning the containment of boxwood blight, an emerging disease, through collaborations with regulatory personnel and extension ornamental pathologists. These collaborations have produced six best management practices (BMPs) protocols each targeting a specificclientele group. These BMPs provide the most up-to-date information regarding boxwood blight management and are available at http://www.ext.vt.edu/topics/agriculture/commercial-horticulture/boxwood-blight/index.html.
Publications
- Type:
Books
Status:
Published
Year Published:
2014
Citation:
Hong, C. X., Moorman, G. W., Wohanka, W., and B�ttner, C. (eds). Biology, Detection and Management of Plant Pathogens in Irrigation Water. APS Press, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
B�ttner, C., Hong, C. X., Moorman, G. W., and Wohanka, W. Preface. In Biology, Detection and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Copes, W. E., Barbeau, B. and Chastagner, G. A. Chlorine dioxide for irrigation water treatment. Pages 251-266 In Biology, Detection and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society. St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Elmer, W. H., Buck, J., Ahonsi, M. O., and Copes, W. E. Emerging technologies for irrigation water treatment. Pages 289-302 In Biology, Detection and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society. St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hao, W., Vinatzer, B. A., and Hong, C. X. Pasteurization for irrigation water treatment. Pages 187-195 In Biology, Detection and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). APS Press, St Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. Management of plant pathogens in irrigation water. Pages 74-75 In Compendium of Rhododendron and Azalea Diseases. R. Linderman and D. M. Benson (eds.). American Phytopathological Society, St. Paul. MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. Developing a facility and production plan for management of plant pathogens in irrigation water. Page 75 In Compendium of Rhododendron and Azalea Diseases. R. Linderman and D. M. Benson (eds.). American Phytopathological Society, St. Paul. MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. Selecting a water treatment technology for control of plant pathogens in irrigation water. Pages 75-76 In Compendium of Rhododendron and Azalea Diseases. R. Linderman and D. M. Benson (eds.). American Phytopathological Society, St. Paul. MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Lea-Cox, J. D., and Ross, D. S. Water management to minimize pathogen movement in containerized production systems. Pages 377-388 In Biology, Detection and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Moorman, G. W., A. J. Gevens, L. L. Granke, M. K. Hausbeck, K. Hendricks, P. D. Roberts, and T. R. Pettitt. Sources and Distribution Systems of Irrigation Water and Their Potential Risks for Crop Health. Pages 3-11 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Moorman, G. W. Irrigation Water and the Health of Greenhouse Crops. Pages 23-29 In: Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. Component analysis of irrigation water in plant disease epidemiology. Pages 111-121 In Biology, Detection and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X. Economic threshold of plant pathogen in irrigation water. Pages 175-183 In Biology, Detection and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ristvey, A. G. and G. W. Moorman. An Integrated Approach to Minimizing Plant Pathogens in Runoff Water from Containerized Production Systems. Pages 365-375 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Hong, C. X., B�ttner, C., Moorman, G. W., and Wohanka, W. A partial list of plant pathogens found in water to date. Pages 389-411 In Biology, Detection and Management of Plant Pathogens in Irrigation Water, C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.), American Phytopathological Society, St Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ivors, K. L. and G. W. Moorman. Oomycete Plant Pathogens in Irrigation Water. Pages 57-64 In Biology, Detection, and Management of Plant Pathogens in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Lea-Cox, J. D. Water quality dynamics and influences on pathogen mitigation in irrigation reservoirs. Pages 333-346 In Biology, Detection and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Book Chapters
Status:
Published
Year Published:
2014
Citation:
Ross, D. S. Water resources and designs of recycling irrigation system for healthy crops. Pages 321-332 In Biology, Detection and Management of Plant Pathology in Irrigation Water. C. X. Hong, G. W. Moorman, W. Wohanka, and C. B�ttner (eds.). American Phytopathological Society, St. Paul, MN, USA
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Burgos, M., Hong, C. X., and Moorman, G. W. Complex heterotrophic bacterial interactions with plant pathogenic Pythium in recycled irrigation water. HortScience 49:961-967.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Dart, N., Hong, C. X., and Bradley, W. T. An improved leaf disc bioassay for detecting microsclerotia of Calonectria pseudonaviculata in soil and potting media. Plant Disease 98:1626-1631
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Hao, W., and Hong, C. X. Heat treatment induced bacterial changes in irrigation water and their implications for plant disease management. World Journal of Microbiology and Biotechnology 30:1591-1601 (online version at doi: 10.1007/s11274-013-1583-y)
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Hong, C. X. Oxygen stress reduces zoospore survival of Phytophthora species in a simulated aquatic system. BMC Microbiology http://www.biomedcentral.com/1471-2180/14/124
- Type:
Journal Articles
Status:
Submitted
Year Published:
2014
Citation:
Zhang, H. B., Richardson, P. A., Belayeh, B. E., Ristvey, A., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. Recycling irrigation reservoirs: thermal stratification and its implications for crop health and production. Irrigation Science
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Copes, W. E., and Hong, C. X. Two novel species representing a new clade and cluster of Phytophthora species. Fungal Biology 118:72-82
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Richardson, P. A., and Hong, C. X. Phytophthora�stagnum nothosp. nov., a new hybrid from irrigation reservoirs at ornamental plant nurseries in Virginia. PLoS One at http://dx.plos.org/10.1371/journal.pone.0103450
- Type:
Journal Articles
Status:
Submitted
Year Published:
2014
Citation:
Copes, W., Yang, X., and Hong, C. X. Phytophthora species recovered from irrigation reservoirs in Mississippi and Alabama nurseries and pathogenicity of three new species. Plant Disease
- Type:
Journal Articles
Status:
Submitted
Year Published:
2014
Citation:
Zhang, H. B., Richardson, P. A., Belayeh, B. E., Ristvey, A., Lea-Cox, J. D., Copes, W. E., Moorman, G. W., and Hong, C. X. 2014. Characterization of water quality in stratified recycling irrigation reservoirs. Agricultural Water Management
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Douglas, S. M., Benson, D. M., Crouch, J. A., Dart, N., Daughtrey, M., Hong, C. X., Ivors, K. L., LaMondia, J. A., Marra, R. E., Palmer, C. L., and Shishkoff, N. Boxwood blight and the dawn of a research collaboration. Phytopathology 104:S3.147
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Lanze, C., and Moorman, G. W. Characterization of Pythium spp. frequently found in recycled irrigation water. Phytopathology 104:S3.66
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Yang, X., Tyler, B. M., and Hong, C. X. Constructing a new phylogeny for the genus Phytophthora. Phytopathology 104:S3.133
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., Gallegly, M. E., and Hong, C. X. A new high-temperature tolerant species in the clade 9 of the genus Phytophthora: P. hydrogena sp. nov. Mycologia 106:57-65 (online version at doi:10.3852/13-043)
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., and Hong, C. X. Phytophthora virginiana sp. nov., a high-temperature tolerant species from irrigation water in Virginia. Mycotaxon 126:167-176 (online version at http://dx.doi.org/10.5248/126.167)
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Yang, X., and Hong, C. X. Halophytophthora fluviatilis sp. nov. from freshwater in Virginia. FEMS Microbiology Letters 352:230-237 (online version at doi: 10.1111/1574- 6968.12391)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Kong, P., and Hong, C. X. Effects of water quality on survival of zoosporic oomycetes and implications. Annual Meeting of American Society of Horticultural Science, Orlando, FL, July 27 to August 1, 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Kong, P., Richardson, P. A., Yang, X, Zhang, H. B., Ghimire, S. R., Copes, W. E., Moorman, G. W., Lea-cox, J. D., and Hong, C. X. Biology of Phytophthora species in aquatic ecosystems. The 7th IUFRO Working Party 7.02.09 on Phytophthora in Forests and Natural Ecosystems. Esquel, Chubut, Argentina, November 10 to 14, 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Yang, X., Cope, W. E., and Hong, C. X. Phytophthora species found in irrigation systems and their risk assessments. The 19th Ornamental Workshop on Diseases and Insects, Hendersonville, NC, September 29 to October 3, 2014
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Yang, X., Tyler, B. M., and Hong, C. X. A multi-locus phylogeny for the genus Phytophthora. The 7th IUFRO Working Party 7.02.09 on Phytophthora in Forests and Natural Ecosystems. Esquel, Chubut, Patagonia Argentina, November 10 to 14, 2014
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Progress 09/01/12 to 08/31/13
Outputs
Target Audience: Nursery growers and greenhouse producers Garden centers, retailers, and landscapers Agricultural industry scientists and consultants Extension specialists and agents Plant disease diagnosticians, regulatory personnel Undergraduate and graduate students, postdoctoral associates Educators, horticulturists, mycologists, and researchers Conservation biologists Government policy makers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Nine Graduate Research Assistantships (GRAs): four at doctoral level (Burgos-Garay, Dart, Hao, Yang) and five at masters level (Cultice, D’Alession, Lanze, Ree, Xu) Four Postdoctoral Research Fellowships (Burgos-Garay, Cafà, Hao, Nikrad) One visiting scientist scholarship (Ben) Two internships (Hu, Pistininzi), and One nationwide webinar series: Irrigation Pathogens and Water Quality, for the industry How have the results been disseminated to communities of interest? Grower Meetings Dart, N., and Hong, C. X. 2013. Microsclerotia formation and soil biology of the box blight pathogen, Calonectria pseudonaviculata, Boxwood Blight Webinar (Organized by the American Nursery and Landscape Association). 2/25/2013 Hong, C. X. 2013. Making the most out of the agricultural chemical dollars. Eastern Shore Agricultural Conference, Belle Haven, VA. 1/4/2013 Hong, C. X. 2013. Getting down to the basics with Phytophthora. Beech Summit, Longwood Garden, Kennett Square, PA. 4/5/2013 Hong, C. X., 2013. Water treatment updates. VNLA Field Day, Gloucester, VA. 8/8/2013 Kong, P., Cafa, G., Hao, W., Yang, X., Ghimire, S., Richardson, P. A., and Hong, C. X. 2013. Irrigation systems for crop health, water security and environmental sustainability. VNLA Field Day, Gloucester, VA. 8/8/2013 Moorman, G. W. Plant pathogens in irrigation water. Northwestern Pennsylvania Greenhouse Seminar. Erie, PA. 2/21/13 Newsletter Articles Yang, X., Richardson, P. A., Kong, P., Olson, H. A., and Hong, C. X. 2013. New pathogens causing root and stem rot of Begonia. Virginia Nursery and Landscape Association (VNLA) Newsletter 83(2):46-48. Hong, C. X. 2013. SCRI Project Update Series I – Recycled Water Quality: Recycled water quality and management implications. VNLA Newsletter 83(3):55-56 Project Meetings & Field Visits Research results were shared with collaborating growers and advisory panel members via regular web conferences and annual project meeting in Virginia Beach, VA. They also were disseminated to other growers via field visits, etc. Lab Tours at Virginia Tech’s Hampton Roads AREC Shared the project results with two groups: Fifteen members of the Dean’s Council in the College of Agriculture and life Science (CALS) of Virginia Tech visited the Hong lab on May 2, 2013 Fourteen people including new CALS faculty members and two international visiting scholars visited the lab on May 29, 2013 Invited Lectures and Presentations Hong, C. X. 2013. Plant health management in a thirsty world. Department of Molecular Biology and Chemistry, Christopher Newport University, Newport News, VA. 2/22/2013 Hong, C. X. 2013. Recycled water quality dynamics and implications for ornamental horticultural crop health and production. Horticulture Department, Virginia Tech, Blacksburg, VA. 5/6/2013 Hong, C. X. 2013. Treasure hunt in agricultural runoff water containment basins, Recent Advancements in Biological Control session of APS Potomac Division Meeting, Shepherdstown, WV. 4/4/2013 Hong, C. X. 2013. Water dispersal of Phytophthora species. Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY. 6/26/2013 Hong, C. X. 2013. Recycling irrigation system – a focal point of plant biosecurity and agricultural water sustainability in the 21st century. EITC: Precision Agriculture – Future Challenges and Directions. Ithaca, NY, 6/27/2013 What do you plan to do during the next reporting period to accomplish the goals? In addition to planned activities, we are striving to expand the research horizon and expedite the technology delivery. New research horizons Understanding the interactions between the isolates of Pythium very frequently found in recirculating irrigation water but not associated with crop losses and those species of Pythium that are known to cause significant crop losses in commercial greenhouses. This research is being conducted by a graduate student as part of her Master of Science degree research project at Penn State University. Expanding the hunt in runoff containment basins for naturally occurring biological control agents. This work has begun with investigations into the ammonium-oxidizing bacteria and archaea in this aquatic ecosystem. Modelling the seasonal and diurnal water quality fluctuations in runoff containment basins. This research integrates the initial three years of environmental and water quality data for better understanding the water quality dynamics. It aims to provide a tool for water quality manipulation in order to suppress pathogens, improve crop productivity and quality as well as a tool for assessing water resource conservation and protection benefits of capturing and recycling runoff water. Expedited technology delivery We have launched a monthly webinar series on plant pathogens found in irrigation water and irrigation water quality. These webinars aim to expedite the delivery of new knowledge and technologies resulting from this project and put our research data into practice as quickly as possible. Information gathered to date on pathogen diversity in irrigation water, their aquatic biology and recycled water quality will be summarized and made available in the online Knowledge Center. A user-friendly interactive form allowing Knowledge Center users to assess the threat of plant pathogens in irrigation water in their production facility will be developed and tested in the Knowledge Center. We have initiated a field demonstration plot at one of the collaborating nurseries in Virginia in 2013 and will expand this effort in 2014 to demonstrate (i) how locating the pump house away from the runoff entrance will mitigate pathogen risk in a single-basin water recycling system, and (ii) how a multi-basin water recycling system with a stepwise water flow will further reduce pathogen dissemination via irrigation water.
Impacts
What was accomplished under these goals?
Seven phylogenetically distinct groups of nursery water isolates that do not belong to any known species of Phytophthora were named following detailed morphological examination, physiological and molecular analyses. Three groups isolated from Mississippi in 2011 and 2012 were named Phytophthora mississippiae, P. stricta, and P. macilentosa. The other four groups were from Virginia with two formally described as P. hydrogena, and P. virginiae, and the rest provisionally named P. stagnum and Halophytophthora fluviatilis. To assess the potential pathogenicity of these new species, isolates of P. mississippiae, P. stricta and P. macilentosa were inoculated on wounded roots, non-wounded roots, and wounded collars of six plant hosts: Rhododendron 'Scintallation' x white form of R. hyperythrum Southgate™ 'Brandi™', Pieris japonica, Hydrangea quercifolia 'Snowflake', Ilex ‘Liberty’, Gardenia jasminoides ‘August Beauty’, and Catharanthus roseus. The experiment is being repeated, but to date results indicate none of the three new Mississippi species is pathogenic on any of these six plants under the test conditions in the Gulf Coast region. Descriptions of these new species will help diagnosticians, regulatory personnel and researchers in correctly identifying Phytophthora pathogens, and avoid the risk of misidentifying high-impact species such as P. ramorum, P. kernoviae, and P. alni. This information along with those in the literature are being developed into fact sheets to help farmers better understand, assess and manage crop health risks posed by Phytophthora species in irrigation systems. Several new Pythium species were isolated from greenhouse water in Pennsylvania and their crop health risk is being assessed. DNA sequences from the internal transcribed spacer region (ITS) of isolates of Pythium very frequently obtained by continuously baiting recycling irrigation water tanks indicates that these isolates may be species new to science. They can be put into groups that are similar to but not identical to known isolates as follows. Group 1 (similar to P. dissotocum, P. diclinum, P. lutarium, P. coloratum), group 2 (similar to P. adhaerens, P. chondricola, P. porphyrae), group 3 (similar to P. flevoense, P. capillosum, P. pectinolyticum) and group 4 (similar to P. apleroticum, P. aquatile, P. pachycaule, P. oopapillum). The cox II region is being sequenced to further characterize these isolates. Three known species frequently found in the water are Pythium helicoides, P. chamaehypon, and P. middletoni. Some of the new species are pathogenic on geranium seedlings. None of these species is associated with significant crop losses in commercial greenhouses. Co-inoculations of geranium seedlings indicate that the new species do not inhibit the pathogenic activity of P. aphanidermatum, a highly pathogenic species often associated with crop losses. The effect of three selected bacteria isolated from recycled irrigation water on Pythium root rot of geranium (Pelargonium cv. 'White Orbit') in greenhouse ebb and flow experiments was tested. Individual bacteria that inhibited or enhanced Pythium sporangium and zoospore development in culture did not inhibit P. aphanidermatum or P. cryptoirregulare on geraniums in the greenhouse. Studies using q-PCR to quantify changes in bacterial populations when P. aphanidermatum, P. cryptoirregulare, and P irregulare were added to recycled irrigation water samples indicate that ?-proteobacteria populations increase in the presence of all three Pythium species. To better understand the pathogen dynamics along water path in single-basin irrigation recycling systems and at every step in multi-basin systems, pathogen aquatic studies have been expanded from zoospores to include chlamydospores and oospores in the lab and microbial characterization to multiple basins at three production facilities in Virginia. Specifically, chlamydospores produced by six isolates of P. nicotianae, P. palmivora and P. tropicalis and oospores by three isolates of P. hedraiandra and P. pini were assessed against five water pH levels from 3.0 to 11.0. Both chlamydospores and oospores survived much longer in this range of water pH than zoospores. These new data are an integral part of the pathogen aquatic biology. Bacterial diversity was surveyed in six basins at two production nurseries each with a unique runoff water recycling system. At least eighteen phyla of bacteria were identified from these basins with proteobacteria, bacterioidetes, actinobacteria, verrucomicrobia and firmicutes being most abundant. These studies offer numerous clues to revealing naturally-occurring pathogen-suppressing agents in irrigation runoff containment basins. A small subset of over 2000 bacterial strains was evaluated individually and in combinations of two, three and four against zoospores of P. nicotianae in vitro and in vivo. These studies indicate that some bacterial strains suppressed zoospore survival and disease development on lupine seedlings while others promoted both. These new data are foundational for developing guidelines on water recycling system designs for pathogen mitigation and, consequently, the profitability and sustainability of the ornamental horticulture industry. Nine nursery ponds (six in Virginia, two in Maryland, and one in Mississippi) have been monitored continuously for surface water temperature, electrical conductivity (EC), pH, dissolved oxygen (DO), oxidation-reduction potential (ORP), and chlorophyll a. Results of this expanded monitoring in Mid-Atlantic and Gulf Coast regions supports the hypotheses that dramatic seasonal and diurnal fluctuations of water quality are common in runoff containment basins and that these fluctuations are tied to the photosynthetic activities which, in turn, are affected by physical and environmental factors including light, temperature and nutrient load into the basins. Other water quality parameters, pathogen survival, crop health, productivity and horticultural product quality data are being collected and analyzed. Water samples were taken from selected nurseries in three states for N, P, and micronutrient analyses and the results will be used to better understand water quality dynamics. Microclimatic weather data also are being continuously monitored at each of the selected Maryland and Virginia nurseries. The impacts of seasonal and diurnal water pH fluctuations on the performance of fungicides, insecticides, herbicides, and plant growth regulators, as well as on chlorine treatment used in the horticultural industry have been assessed. Recommendations to help farmers maximize their agricultural chemical performance have been developed and disseminated through invited lectures at universities, newsletters and presentations at various extension venues. Information and the recommendations developed through this project are being delivered via a monthly webinar series launched in October 2013 (www.irrigation-pathogens.info) and incorporated into an online knowledge center. A producer survey was developed and distributed to approximately 2,000 growers in Pennsylvania, Maryland, and Virginia. It was found that (i) a majority of the respondents considered any threat to water resources is important but they are unaware of growing global water scarcity; (ii) 60-70% of small and medium nurseries and 20% of large facilities do not capture runoff because of cost and disease concerns; (iii) Both Phytophthora and Pythium diseases are considered as major limiting factors in large production facilities, and (iv) chlorination is the most widely used water treatment for pathogen risk mitigation. Some of these data have been delivered to the industry via the webinar on November 6, 2013.
Publications
- Type:
Books
Status:
Accepted
Year Published:
2014
Citation:
Hong, C. X., Moorman, G. W., Wohanka, W., and B�ttner, C. Biology, Detection and Management of Plant Pathogens in Irrigation Water. American Pathological Society, St. Paul, MN (in press)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Hong, C. X., and Moorman, G. W. Diversity and significance of plant pathogens as agricultural water contaminants. 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25-27, 2013
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Kong, P., and Hong, C. X. 2013. Aquatic biology of oomycete plant pathogens. 10th International Congress of Plant Pathology, Beijing, China, August 25-31, 2013
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Lea-Cox, J. D., Belayneh, B. E., and Ristvey, A.G. Daily and seasonal changes in the water quality of irrigation containment ponds. In: Workshop - The challenges of using alternative and recycled water sources for horticultural use. American Society for Horticultural Science Annual Meeting, 24 July, 2013, Palm Desert, CA. HortScience 48:S106.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Richardson, P. A., Kong, P., Caf�, G., and Hong, C. X. Tracking water quality dynamics in a multi-basin agricultural water recycling system, 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25-27, 2013
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Richardson, P. A., Kong, P., Caf�, G., Lea-Cox, J. D., Belayneh, B. E., Ristvey, A. G., and Hong, C. X. Dramatic fluctuations of water quality in agricultural runoff containment basins. 2013 AWRA Spring Specialty Conference on Agricultural Hydrology and Water Quality II, St. Louis, MO, March 25-27, 2013
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Dart, N., and Hong, C. X. Significance of soil inoculum in the epidemiology of boxwood blight caused by Calonectria pseudonaviculata. Phytopathology 103:S2.33
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Hao, W., and Hong, C. X. Biological control of Phytophthora nicotianae by heat-tolerant bacteria in irrigation water. Phytopathology 103:S2.56
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Hong, C. X. Diversity and significance of waterborne pathogens to plant biosecurity under a changing climate. 10th International Congress of Plant Pathology, Beijing, China, August 25-31, 2013
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Yang, X., Copes, W. E., and Hong, C. X. Three novel Phytophthora species from irrigation water in Mississippi. Phytopathology 103:S2.164
- Type:
Journal Articles
Status:
Accepted
Year Published:
2014
Citation:
Burgos-Garay, M. L., Hong, C. X., and Moorman, G. W. Effects of heterotrophic bacteria from recycled irrigation water on Pythium in vitro and in vivo. Plant Disease
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Majsztrik, J.C., and Lea-Cox, J.D. Water quality regulations in the Chesapeake Bay: Working to more precisely estimate nutrient loading rates and incentivize best management practices in the nursery and greenhouse industry. HortScience 48: 1097-1102
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Pistininzi, M., Weiss, E., Achtemeier, L., and Hong, C. X. Zoospore production biology of pythiaceous plant pathogens. Journal of Phytopathology doi: 10.1111/jph.12154
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Copes, W. E., and Hong, C. X. Phytophthora mississippiae sp. nov., a new species recovered from irrigation reservoirs at a plant nursery in Mississippi. Journal of Plant Pathology and Microbiology http://dx.doi.org/10.4172/2157-7471.1000180
- Type:
Journal Articles
Status:
Accepted
Year Published:
2014
Citation:
Yang, X., Copes, W. E., and Hong, C. X. Two novel species representing a new clade and cluster of Phytophthora. Fungal Biology
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Gallegly, M. E., and Hong, C. X. A new species in the subclade 9a of the genus Phytophthora: P. hydrogena sp. nov. Mycologia
- Type:
Journal Articles
Status:
Accepted
Year Published:
2014
Citation:
Yang, X., and Hong, C. X. Phytophthora virginiae sp. nov., a high-temperature tolerant species from irrigation water in Virginia. Mycotaxon
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Kong, P., and Hong, C. X. Evaluation of fungicide drenches for control of Phytophthora root rot of petunia, 2012. Plant Disease Management Reports 7:OT002
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., and Hong, C. X. Evaluation of nonregistered fungicide for control of rose downy mildew, 2012. Plant Disease Management Reports 7:OT001
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., Kong, P., and Hong, C. X. Fungicidal control of Phytophthora aerial blight on annual vinca in Virginia, 2012. Plant Disease Management Reports 7:OT005
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Yang, X., Richardson, P. A., Olson, H. A., and Hong, C. X. Root and stem rot of begonia caused by Phytopythium helicoides in Virginia. Plant Disease 97:1385
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Burgos-Garay, Maria L. Effect of heterotrophic bacterial communities on Pythium spp. in recycled irrigation water. Ph. D. Dissertation. The Pennsylvania State University, University Park, PA
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Cultice, Alyssa. Horticultural producers' willingness to adopt water recirculation technology in the Mid-Atlantic region. M.S. Thesis, Virginia Tech, Blacksburg, VA
- Type:
Theses/Dissertations
Status:
Submitted
Year Published:
2012
Citation:
Hao, Wei. An energy-saving heat treatment for re-circulated irrigation water and the potential biological mechanisms. Ph. D. Dissertation. Virginia Tech, Blacksburg, VA
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: This project had an exciting and productive second year. 1) Continued water sampling in AL, MS and PA has resulted in discovery of several new Phytophthora and Pythium species. 2) Two new species Phytophthora aquimorbida and Phytophthora taxon "aquatilis" were formally named and they were also evaluated for pathogenicity to rhododendron. 3) The hypotheses that we put forward in 2009 on water quality dynamics in agricultural irrigation reservoirs were tested with the new data from five nurseries across the mid-Atlantic region. Water quality relations to nutrient influx into the reservoirs and surrounding weather conditions were also investigated. 4) Among three high-impact pathogens assessed for zoosporic responses to water pH and electrical conductivity, P. ramorum is most adapted to agricultural water environment compared with P. alni and P. kernoviae. This research has been expanded to include other pathogens and water quality parameters. 5) Through an internship, the "wet-plate" method for mass zoospore production was improved and defined of its applications. 6) Diverse bacterial species were identified from both greenhouse and nursery irrigation water; selected species and strains are being evaluated for their biocontrol potential. 7) Some of the new Pythium species found repeatedly in recycling greenhouse irrigation water are non-plant pathogenic but may inhibit the survival and activity of highly pathogenic species of Pythium. 8) Current heat treatment protocol was re-examined consequently a new treatment temperature and time combination has been proposed for greenhouse applications to improve the economics and reduce the environmental footprint. 9) After consultation with collaborating growers and advisory panel members as well as other industry professionals, a survey was developed on consumer preference for ornamental plants with disease-free and water conservation labels. This survey was administered by qSample to 14,175 individuals with gardening interest in MD, PA, VA and GA. The resultant 1,596 usable surveys were analyzed and written in a thesis. 10) A producer survey is being developed on water recycling and disease control practices, and the associated economics. 11) To complement the proposed project activities, current knowledge on biology and management of plant pathogens in irrigation water was synthesized in a 30-chapter book in collaboration with 49 world leading scientists. As a result, our research consortium also has expanded to cover vegetables, tree fruit and nut crops, and to have a global focus. 12) The knowledge center has been established as part of eXtension and three learning modules have been developed. 13) Our research updates were disseminated through organization of a session at the 7th International IPM Symposium in Memphis, TN on March 27, 2012, and sixteen presentations at national and international extension and outreach venues. 14) Five graduate students, two summer interns from a medium-sized college in Newport News, VA, and one high school senior from an International Baccalaureate Program in Virginia Beach, VA were mentored. 15) Industry support increased in research grant and in-kind contribution. PARTICIPANTS: Gary Moorman (co-PI, Pennsylvania State University), John Lea-Cox (co-PI, University of Maryland), Kevin Boyle (co-PI, Virginia Tech), Ping Kong (co-PI, Virginia Tech), Darrell Bosch (co-PI, Virginia Tech), James Pease (co-PI, Virginia Tech), Warren Copes (co-PI, USDA-ARS), Belinda Carroll (co-PI, Virginia Tech), Edward Weiss (co-PI, Christopher Newport University), Andrew Ristvey (co-PI, University of Maryland), Boris Vinatzer (co-PI, Virginia Tech), Joshua Chambers (Web Design Specialist, Virginia Tech), Carl Estes (Instructional Technologist, Virginia Tech), Giovanni Cafa (Postdoctoral Research Associate, Virginia Tech), Patricia Richardson (Research Specialist, Virginia Tech), Marcia Stefani (Research Specialist, Virginia Tech), Thomas Wilchynski (Field Research Support Staff, Virginia Tech), Adam Sleeper (Field Research Support Staff, Virginia Tech), Peter Schultz (Professor, Virginia Tech), Bruk Belayneh (Research Associate, University of Maryland), Maria Burgos-Garay (Graduate Research Assistant, Pennsylvania State University), Alyssa Cultice (Graduate Research Assistant, Virginia Tech), Wei Hao (Graduate Research Assistant, Virginia Tech), David Hartter (Graduate Research Assistant, Virginia Tech), Xiao Yang (Graduate Research Assistant, Virginia Tech), Andrew Rotzin (Summer Intern, Christopher Newport University), Michael Pistininzi (Summer Intern, Christopher Newport University), Kevin Hu (High School Senior, Princess Anne High School in Virginia Beach), David Ross (co-PI, University of Maryland), Mike Stanghellini (co-PI, UC Riverside), Gladis Zinati (co-PI, Rutgers), All Advisory Panel members, All collaborating growers, Gary Chastagner (Washington State University), and Chuan Hong (PD, Virginia Tech) TARGET AUDIENCES: Growers, diagnosticians and field responders, extension specialists and agents, crop health care professionals, microbiologists, mycologists, bacteriologists, horticulturists and irrigation specialists, conservation biologists, and policy-makers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
As illustrated in two theses, eight refereed journal articles, two conference papers and six abstracts, this project has advanced the science and technology in a broad range of disciplines from biology to agricultural engineering and economics. Each of these advancements provides a basis for technology innovation and development of an integrated approach to zoosporic pathogens and irrigation water quality for more profitable and sustainable green industry. Some of these findings have already been incorporated into the practices at collaborating nurseries and greenhouses as well as a few early adapters, resulting positive impacts. This is exemplified by a change in heat pasteurization practice in a greenhouse that recycles 500 liter of water for irrigation per day under an ambient temperature at 20oC. The energy required to raise and maintain water temperature at 95oC for 30 seconds per the current heat treatment protocol is 148,500 British thermal units (Btu), neglecting the heat loss during treatment. Comparatively, per new protocol resulted from this project, only 55,000 Btu is needed to raise the water temperature to 48oC, and an additional 10,748 Btu to maintain at this temperature for 24 hours according to the minimum energy performance standard (MEPS and Labeling Requirements, 2005). Switching from the current heat treatment practice to the new protocol would cut the energy consumption by half (55%) in this greenhouse operation. The immediate benefits of such a switch are reduced production cost and environmental footprint, improving the profitability and promoting the "green" status of this green industry. This new protocol also has several other benefits which could further improve its economics and reduce the environmental impact. It enhances bacterial activities against plant pathogens, thus improves its compatibility with other disease control strategies in particular of biological control. It also opens the possibility to use solar, geothermal and possibly other alternative energy sources. The overall potential benefits of implementing the resultant findings and novel technologies from this project are enormous on a national scale. Particularly, the benefits of using better design for new recycling irrigation systems and modifying the existing systems to prolong irrigation runoff water turnover time will be everlasting and multifaceted. With these new technologies and practices, growers will be able to reduce crop losses consequently produce more and better quality horticultural products at reduced energy consumption, fungicide and water usage, improving their profit margin and public image. Disease-free ornamental plants produced with water conservation practices may be marketed and sold at greater prices while adding to the consumer satisfaction. These additional benefits, in turn, will put the horticulture industry on an even faster track to great profitability and sustainability.
Publications
- 1. Burgos-Garay, M., Edson, J., and Moorman, G. W. 2012. Influence of Pythium aphanidermatum, P. irregulare, and P. cryptoirregulare on the bacterial community in recycled irrigated water. Phytopathology 102:S1.2
- 2. Garzon, C. D., Molineros, J. E., Yanez, J. M., Flores, F. J., Jimenez-Gasco, M. M., and Moorman, G. W. 2011. Sublethal doses of mefenoxam enhance Pythium damping-off of geraniums. Plant Disease 95:1233-1238
- 3. Hao, W. 2012. A potential energy efficient heat treatment and its biological mechanisms. PhD Dissertation. Department of Plant Pathology, Physiology and Weed Science, Virginia Tech
- 4. Hao, W., Ahonsi, M. O., Vinatzer, B. A., and Hong, C. X. 2012. Inactivation of Phytophthora and bacterial species in water by a potential energy-saving heat treatment. European Journal of Plant Pathology DOI 10.1007/s10658-012-9994-4
- 5. Hartter, D. 2012. Understanding consumers ornamental plant preferences for disease-free and water conservation labels. M.S. Thesis. Department of Agricultural and Applied Economics, Virginia Tech
- 6. Hong, C. X., and Richardson, P. A. 2012. Validation of water quality fluctuation patterns in runoff water containment basins of eastern and central Virginia. Phytopathology 102:S4.55
- 7. Hong, C. X., Richardson, P. A., Hao, W., Ghimire, S. R., Kong, P., Moorman, G. W., Lea-Cox, J. D., and Ross, D. S. 2012. Phytophthora aquimorbida sp. nov. and Phytophthora taxon aquatilis recovered from irrigation reservoirs and a stream in Virginia, USA. Mycologia doi:10.3852/11-055
- 8. Lea-Cox, J. D, Belayneh, B., Kim, J., and Majsztrik, J. C. 2012. The value of weather data for daily nursery management decisions. Proceedings of Southern Nursery Association Research Conference 57:87-93
- 9. Lea-Cox, J. D., and Majsztrik, J. C. 2011. Considering the value of real-time sensor information. 108th Annual American Society for Horticulture Science Conference. Waikoloa, HI. HortScience 46(9): S210
- 10. Kong, P. 2012. Carbon dioxide as a potential water disinfectant for Phytophthora disease risk mitigation. Plant Disease http://dx.doi.org/10.1094/PDIS-09-12-0844-RE
- 11. Kong, P., Lea-Cox, J. D., and Hong, C. X. 2012. Effect of electrical conductivity on survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment. Plant Pathology DOI: 10.1111/j.1365-3059.2012.02614.x
- 12. Kong, P., Lea-Cox, J. D., Moorman, G. W., and Hong, C. X. 2012. Survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment at different levels of pH. FEMS Microbiology Letters DOI: 10.1111/j.1574-6968.2012.02574.x
- 14. Majsztrik, J., Lea-Cox, J. D., Ross, D. S., and Ristvey, A. G. 2011. An in-depth analysis of water and nutrient management in the nursery and greenhouse industry in Maryland. 108th Annual American Society for Horticulture Science Conference. Waikoloa, HI. HortScience 46(9): S220-221
- 15. Majsztrik, J. C., Ristvey, A. G., and Lea-Cox, J. D. 2012. An in-depth look at fertilizer and irrigation practices in Marylands ornamental nursery industry. Proceedings of Southern Nursery Association Research Conference 57:35-42.
- 16. Man in 't Veld, W. A., Rosendahl, K. C. H. M., and Hong, C. X. 2012. Phytophthora Xserendipita sp. nov., a new species generated by natural hybridization. Mycologia doi:10.3852/11-272
- 17. Yang, X., and Hong, C. X. 2012. Isolation of Phytophthora and Pythium species from different depths of sediments in a runoff water sedimentation pond of eastern Virginia. Phytopathology 102:S4.140
- 13. Majsztrik, J., Lea-Cox, J. D., Ross, D. S., and Ristvey, A. G. 2011. Modeling nitrogen, phosphorus, and water dynamics in the nursery and greenhouse industry. 108th Annual American Society for Horticulture Science Conference. Waikoloa, HI. HortScience 46(9): S160-161
- 18. Yang, X., Richardson, P. A., Ghimire, S. R., Kong, P., and Hong, C. X. 2012. Phytophthora hedraiandra detected from irrigation water at a perennial plant nursery in Virginia. Plant Disease 96:915
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: During the first year, the following project outputs were achieved: 1) Instruments were installed to continuously monitor water quality in nine reservoirs and weather conditions at five nurseries in Maryland and Virginia. Water quality data from four ponds are transmitted real-time to an office computer through telemetry systems and satellites. Weather data are communicated through the Internet, allowing access by team members and collaborating growers. 2) Nineteen new and distinct subgroups of Phytophthora were identified from Virginia nursery irrigation water. From these subgroups, two new species were formally described and thirty representative isolates were assessed for their pathogenicity to rhododendron plants. Irrigation water was baited with rhododendron leaves for Phytophthora species at two nurseries in Alabama and Mississippi and with bentgrass for Pythium species in two greenhouses in Pennsylvania. 3) Water samples were taken for characterization of bacteria species by ARISA (automated ribosomal intergenic spacer analysis). Selected bacterial strains were evaluated in the lab and greenhouse for their potential as pathogen-suppressive microbes. 4) Laboratory systems were developed to assess the impacts of pH, electrical conductivity, and dissolved oxygen on zoospores from a variety of Phytophthora species including three quarantine pathogens (P. alni, P. kernoviae, P. ramorum). 5) A consumer survey has been drafted after visiting garden centers and meeting three consumer focus groups. This survey focuses on consumer awareness of plant disease and risk of plant loss and their willingness to pay for healthier plant products or those grown using water conservation practices. Irrigation systems, extent and causes of crop losses, control methods and water decontamination technologies used, and marketing techniques were documented by visiting production nurseries and meeting one focus group at the MANTS in Baltimore, MD. 6) The current knowledge on biology, detection, and management of plant pathogens in irrigation water was reviewed and assembled into a book to be published by APS Press. 7) A draft outline of knowledgebase contents was developed for an online learning center. The web host and general templates for individual learning modules were explored with a test module. 8) Four graduate students and three interns were mentored. To maximize the impacts of our activities, the team met with the Advisory Panel at Virginia Tech in October 2010 to chart detailed project plans and kept the panel members informed through two web conferences in February and June 2011and Project Newsletters. Panel feedback and grower collaborations from instrument installation and maintenance to pathogen baiting and data interpretation have been crucial to project progress. A collaboration web site (scholar.vt.edu) was developed to facilitate communications among the subject teams and between researchers and panel members. A second website (irrigation-pathogens.inf) was developed to promote outreach activities. Research updates were presented as invited speakers at three international and regional conferences, one refereed journal article and six abstracts. PARTICIPANTS: Gary Moorman (co-PI, Pennsylvania State University), John Lea-Cox (co-PI, University of Maryland), Kevin Boyle (co-PI, Virginia Tech), Ping Kong (co-PI, Virginia Tech), Darrell Bosch (co-PI, Virginia Tech), James Pease (co-PI, Virginia Tech), Warren Copes (co-PI, USDA-ARS), Belinda Carroll (co-PI, Virginia Tech), Edward Weiss (co-PI, Christopher Newport University), Andrew Ristvey (co-PI, University of Maryland), Boris Vinatzer (co-PI, Virginia Tech), Joshua Chambers (Web Design Specialist, Virginia Tech), Carl Estes (Instructional Technologist, Virginia Tech), Patricia Richardson (Research Specialist, Virginia Tech), Marcia Stefani (Research Specialist, Virginia Tech), Maria Burgos-Garay (Graduate Research Assistant, Pennsylvania State University), Wei Hao (Graduate Research Assistant, Virginia Tech), David Hartter (Graduate Research Assistant, Virginia Tech), Xiao Yang (Graduate Research Assistant, Virginia Tech), Lauren Achtemeier (Summer Intern, Christopher Newport University), Nicole Calderone (Summer Intern, Christopher Newport University), David Ross (co-PI, University of Maryland), Mike Stanghellini (co-PI, UC Riverside), Gladis Zinati (co-PI, Rutgers), and Chuan Hong (PD, Virginia Tech) TARGET AUDIENCES: Growers; Diagnosticians and field responders; Extension specialists and agents; Crop health care professionals; Microbiologists, mycologists, bacteriologists; Horticulturists and irrigation specialists; Conservation biologists; and Policy-makers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project has advanced the science in a wide range of disciplines from taxonomy to plant biosecurity, from microbial interactions to chemical communication, from water quality dynamics to pathogen aquatic biology, and from agricultural engineering to economics, as well as the environmental and social dimensions of waterborne pathogens and crop health management. Each of these findings provides the basis for development of novel pathogen and disease control technologies and better management practices that will lead to more sustainable agricultural industries while reducing their environmental footprints. For example, the collected water quality data has had multiple immediate uses. The water pH in runoff containment ponds was mostly basic and could go up to 10.8 depending on location and time of the year. This observation has tremendous ramifications. One immediate use of this data is to improve the efficacy of pesticide applications. The ideal pH for most pesticides is 5 to 6, and pesticides degrade with increasing pH through a hydrolysis process, which can be rapid in the pH range of 8 and 9. Pest control could be greatly diminished or lost completely at the basic pH observed in water from runoff containment ponds. Checking pH and acidifying as needed before pond water is used in a spray solution could easily realize 5 to 20% of the pesticide potential that otherwise would have been lost. In the United States, approximately 500 million kilograms of more than 600 different pesticides are estimated to be applied annually at a direct cost of $10 billion plus an indirect cost of over $10 billion (Pimentel, 2005). This improved practice alone could save $1 to 4 billion per year in the United States. Water pH is equally important in the performance of chlorination, the most widely-used water treatment in the green industry. There are three species of free chlorine (Cl2, HClO-, OCl-) in water and their equilibrium is pH dependent. The proportion of hypochlorous acid, the most potent chlorine species for pathogen kill, is the highest at pH 5 and 6. The proportion of hypochlorous acid and, subsequently, chlorination efficacy drops sharply with increasing pH and can be reduced by 80% at pH 8. Thus, measuring pH and acidifying water as needed is essential to maximize the pathogen control potential of every chlorine dollar; otherwise, not only is the chlorine expense wasted but entire crops could be at risk to pathogens. The water pH data also provides a framework for interpreting pathogen survival data from controlled conditions and understanding pathogen dynamics in recycled irrigation systems. In addition, the data will help time water sampling for assessing microbial diversity and identifying naturally-occurring pathogen-suppressive microbes in irrigation ponds, adding quality and productivity to this project. Finally, these data are essential to assessing the green industry contributions to global water resource conservation and protection by capturing runoff water in containment ponds and using it for irrigation. Pimentel, D. 2005. Environment, Development and Sustainability 7:229-252.
Publications
- Hong, C. X. 2011. Irrigation pathogen mitigation without water treatment. Proceedings of the 36th Annual Meeting of the International Plant Propagator Society - Southern Region of North America, Valdosta, GA, USA, October 23-26, 2011 (in press)
- Hong, C., X., Richardson, P. A., Ghimire, S. R., Kong, P., Hu, J. H., Moorman, G. W., Lea-Cox, J. D., Ross, D. S. 2011. Diversity of Phytophthora species identified in a nursery irrigation runoff water containment basin of eastern Virginia. Phytopathology 101:S74
- Hong, C. X., Richardson, P. A., Kong, P., Edgerton, T., Asaro, C., and Oak, S. 2011. Phytophthora species identified from streams in Virginia. Phytopathology 101:S74
- Kong, P., Lea-Cox, J. D., Moorman, G. W., and Hong, C. X. 2011. Survival of three quarantine pathogens in a simulated aquatic system at different levels of pH. Phytopathology 101:S93
- Kong, P., Tyler, B. M., Richardson, P. A., Lee, B. W. K., Zhou, Z. H., and Hong, C. X. 2010. Zoospore interspecific signaling promotes plant infection by Phytophthora. BMC Microbiology http:www.biomedcentral.com/1471-2180/10/313
- Burgos-Garay, M. L., and Moorman, G. W. 2011. Influence of Pythium aphanidermatum, P. irregulare, P. cryptoirregulare on the bacterial community in recycled irrigation water. Phytopathology 202:S23
- Burgos-Garay, M. L., and Moorman, G. W. 2011. Effect of microbial communities in recycled irrigation water on the development of three Pythium species. Phytopathology 101:S258
- Hao, W., Vinatzer, B. A., and Hong, C. X. 2011. Effect of temperature on survival of Phytophthora and bacterial species in irrigation water. Phytopathology 101:S69
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