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Director

Wye Research and Education Center and the Harry Hughes Center for Agro-Ecology 124 Wye Narrows Drive P.O. Box 169 Queenstown, Maryland 21658

Expertise

  • Vegetable Plant Pathology

RESEARCH FOCUS

  • Sclerotinia sclerotiorum diversity and management of white mold on lima bean (Phaseolus lunatus) in Maryland and Delaware
  • Downy mildew (Pseudoperonospora cubensis), detection and management
  • Interactions between Salmonella enterica Newport and Fusarium spp. on melon fruit
  • Sustainable management of foliar and soil borne disease of vegetable crops

Biography

Biography: 

I conduct research on the epidemiology and management of vegetable diseases that are economically important in the mid-Atlantic region. This translational research supports my extension responsibilities in the states of Maryland and Delaware. Currently my lab focuses on the soilborne diseases Fusarium wilt (Fusarium oxysporum f. sp. niveum) on watermelon, and white mold (Sclerotinia sclerotiorum) on lima bean (Phaseolus lunatus); Fusarium fruit rot on melon, and the foliar diseases cucurbit downy mildew (Pseudoperonospora cubensis) and powdery mildew (Podosphaera xanthii).  By increasing our knowledge of the epidemiology of these diseases, we aim to reduce disease losses and improve the sustainability of the crop.

Sustainable soilborne disease management relies on practices such as cover cropping and biological soil amendments to reduce the conduciveness of the soil environment to disease development. We have examined the mechanisms of suppression resulting from incorporation of a green manure of Vicia villosa or Trifolium incarnatum on Fusarium wilt. My extension program develops and delivers location-specific disease forecasting information such as MelCast for gummy stem blight, the Cornell DSS for late blight on tomato, and early warning for downy mildew of cucurbits. Practices resulting from the vegetable pathology lab research have improved management of vegetable diseases, and reduced fungicide use throughout the region.

Education: 

Ph.D., Michigan State University, East Lansing, MI, Plant Pathology
M.S., Colorado State University, Fort Collins, CO, Plant Pathology
B.S., Colorado State University, Fort Collins, CO, Plant Pathology (with Distinction)

Awards and Honors: 

Career Distinguished Service Award, Fruit & Vegetable Growers Association of Delaware 2018

College ADVANCE Leadership Fellow, 2016-2017

ADVANCE Professor, College of Agriculture and Natural Resources, University of Maryland, 2014-2016

Distinguished Service Award, Potomac Division American Phytopathology Society, 2011

Professional Work

Professional Positions Held: 

2008-Present Professor, Department of Plant Science and Landscape Architecture, University of Maryland, College Park
2002-2008 Associate Professor and Extension Plant Pathologist, University of Maryland and University of Delaware
1996-2002 Assistant Professor and Extension Plant Pathologist, University of Maryland and the University of Delaware
1995-1996 Research Associate, Vegetable Pathology, University of Delaware, Georgetown, DE
1992-1995 Manager, Cereal Pathology, Busch Agricultural Resources, Inc. Fort Collins, CO
1989-1991 Post-doctoral Research Associate, USDA-Agricultural Research Service, North Carolina State University, Raleigh, NC
1984-1988 Graduate Research Assistant, Michigan State University, East Lansing, MI
1982-1984 Graduate Research Assistant, Colorado State University, Fort Collins, CO

Professional Service: 

Senior Editor
Phytopathology, American Phytopathological Society. St. Paul, MN. 2012 – 2014.

Editor
Plant Disease Management Reports. American Phytopathological Society. St. Paul, MN. Vegetable Crops Section. 2007

Fungicide and Nematicide Tests.  American Phytopathological Society, St. Paul, MN-Vegetable Crops Section.  2003-2006.

Research

Areas of Interest: 

  • Fusarium oxysporum f. sp. niveum

  • Sclerotinia sclerotiorum

  • Sustainable management of soilborne diseases

  • Vegetable disease forecasting for reducing fungicide use

  • Epidemiology of vegetable diseases

Current Research: 

Watermelon Plant with Fusarium Wilt

Sustainable Management of Soilborne Disease

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum (FON) is a re-emerging pathogen in the mid-Atlantic region. In Maryland and Delaware, the inoculum density of FON is high as a result of a long history of watermelon production. Sclerotinia sclerotiorum (white mold) is another severe soilborne pathogen of vegetable crops in the region. My program objectives are to develop sustainable management strategies for Fusarium wilt and white mold that are biologically-based and are compatible with soil health management practices, and to assist growers in learning and adopting these strategies. Outputs of this project include expanded knowledge on the biology and management of Fusarium wilt and white mold. A new management tactic developed by us is the production of watermelon following a fall planted Vicia villosa cover crop that is killed in the spring and amended into the soil as a green manure. We determined that V. villosa could reduce wilt by up to 69%. In addition, we showed that the cover crop Trifolium incarnatum also suppressed Fusarium wilt. Likewise we have determined the benefit of use of a biological control for white mold, and improved fungicide timing guidelines for growers. Extension of our knowledge discovery to growers is conducted through talks, newsletters, and electronic media.

Current Graduate Students:

Habtamu Demisse  “Monitoring and managing white mold disease on lima bean in the mid-Atlantic region of the United States.”

Habtamu Demisse  “Monitoring and managing white mold disease on lima bean in the mid-Atlantic region of the United States.”

watermelon plant

Robert C. Korir     “Microbial quality of melon fruits:  Interaction between Salmonella enterica Newport and plant pathogenic Fusarium spp.”

Foliar diseases of vegetable crops cause losses in yield, quality and add economic costs to management. In addition, excessive fungicide use to manage these diseases is associated with negative environmental outcomes, including new concerns about chlorothalonil exposure to honey bees (Apis mellifera). For example, one study found that bees that consume pollen containing the fungicides chlorothalonil and pyraclostrobin (which is also used in cucurbit production) were two or more times as likely to become infected with Nosema after exposure when compared to bees that were fed pollen not containing these products. Given the current extensive, season-long use of chlorothalonil in cucurbit production there is a need to evaluate and demonstrate that alternative fungicide programs can reduce reliance on chlorothalonil while maintaining crop productivity.

Current Graduate Student:

Jake Jones “Alternative disease management programs for Pseudoperonospora cubensis to reduce pollinator exposure to key fungicides.”

Teaching

Courses Taught: 

PLSC399 SPECIAL PROBLEMS PLSC Spring 2015, Spring 2016, Summer 2016

Extension

Achievements in Extension: 

 

 

Extension talk at Western Maryland REC Twilight meeting.

The overarching objective of my extension program is to assist growers in maintaining or improving yield, while reducing fungicide use on their crops. This is accomplished through providing tools for fungicide scheduling, information on regional epidemic spread, and resistance management to growers, extension educators, scouts, and consultants. We conduct translational research in the lab and field.

Undergraduate, graduate students and technicians in Vegetable Pathology Program Summer 2017 (from L to R - Kia Powell, Yacintha Johnson, Lori Lutz, Habtamu Demissie, Robert Korir, Jake Jones and Anthony LaBarck).

Our program outputs are site specific weather-based fungicide application guidelines in-season with three disease models, data contributions to web-based disease monitoring systems (http://extension.umd.edu/mdvegetables/vegetable-plant-diseases/disease-f... ), and information disseminated through regional talks, newsletters and electronic media such as Twitter (Vegetable Pathology @KathryneEverts). Specific program outputs are: 1) Melcast, which is a weather based fungicide forecasting system for anthracnose and gummy stem blight on watermelon; 2) Late Blight Decision Support System (DSS) for potato and tomato, which is a fungicide forecasting program; 3) IPM Pipe for Cucurbit Downy Mildew www.cdm.ipmpipe.org (we maintain sentinel plots in Maryland and monitor and report the initial onset of downy mildew on six cucurbit species); 4) Isolates of Phytophthora infestans for lineage testing are collected for analysis (provided through a collaborative arrangement by Cornell). Additional outputs of this program are 1) The Commercial Vegetable Recommendation Guide (Maryland Extension Bulletin 236; lead author on five commodity sections and one pest management section); 2) yearly reports published in Plant Disease Management Reports; 3) one-on-one interactions with agribusiness personnel and Delaware and Maryland Cooperative Extension educators in training on recognition of vegetable disease symptoms; 4) newsletters such as the Weekly Crop Update http://extension.udel.edu/weeklycropupdate , a University of Delaware Cooperative Extension vegetable and agronomic crops newsletter; the University of Maryland’s Fruit and Vegetable Newsletter, and Pennsylvania Vegetable Growers Association Newsletter; and 5) meetings that include plant clinics, field days, and county and regional vegetable growers meetings, statewide meetings such as Delaware Ag Week, hands-on diagnostic field days, and twilight tours. One impact of this program is that over 1500 acres of watermelons are currently managed in part with MelCast (26% of commercial production). The average participant reports two fewer fungicide sprays (~25% reduction) using Melcast, which can translate into an annual reduction of more than 2500 kg of fungicide active ingredient applied. Additionally, advice disseminated through direct interactions, talks, newsletters, and twitter quickly teaches the latest applied research on foliar disease management, information on resistance management, non-chemical alternatives and recent fungicide registrations. There has been a significant reduction in misapplication of ineffective fungicides and fungicides applied for the incorrect disease.

Publications

Recent Articles in Refereed Journals:

Everts, K.L. 2017 Cercospora leaf spot in Compendium of Cucurbit Diseases and Pests, Second Edition Edited by A. P. Keinath, W. M. Wintermantel, and T. A. Zitter. (This is a short section with the description of the disease and importance).

Wyenandt, C.A., McGrath, M.T., Everts, K.L., Rideout, S.L., Gugino, B.K., and Kleczewski, N. Fungicide resistance management guidelines for cucurbit downy and powdery mildew control in the mid-Atlantic and Northeast regions of the United States in 2018. Plant Health Progress. (Accepted Dec. 14, 2017).

Hansen, Z.R., Everts, K.L., Fry, W.E., Gevens, A.J., Grünwald, N.J., Gugino, B.K., Johnson, D.A., Johnson, S.B., Judelson, H.S., Knaus, B.J., McGrath, M.T., Myers, K.L., Ristaino, J.B., Roberts, P.D., Secor, G.A., and Smart, C.D. 2016. Genetic Variation within Clonal Lineages of Phytophthora infestans Revealed through Genotyping-By-Sequencing, and Implications for Late Blight Epidemiology. PLoS ONE 11(11): e0165690. doi:10.1371/journal.pone.0165690 http://dx.doi.org/10.1371/journal.pone.0165690

Marine, S.C., Newark, M.J., Korir, R.C., and Everts, K.L. 2016. Evaluation of rotational biopesticide programs for disease management in organic cucurbit production. Plant Dis. 100:2226-2233.

Himmelstein, J.C., Maul, J.E., Balci, Y., Everts, K.L. 2016. Factors associated with leguminous green manure incorporation and Fusarium wilt suppression in watermelon. Plant Dis. 100:1910-1920. http://dx.doi.org/10.1094/PDIS-08-15-0956-RE

Kness, A.A., Johnson, G., Everts, K.L. Evans, T.A., Donofrio, N.M., Earnest, E.G. 2016. Managing pod rot of lima bean caused by Phytophthora capsici with fungicides in the mid-Atlantic region. Plant Health Progress. 17:130-132.

Meyer, S.L.F., Everts, K.L., McSpadden Gardener, B., Masler, E.P., Abdelnabby, H.M.E., Skantar, A.M. 2016. Assessment of DAPG-producing Pseudomonas fluorescens for Management of Meloidogyne incognita and Fusarium oxysporum on Watermelon. Journal of Nematology 48(1):43–53.

Everts, K.L., Korir, R.C., and Newark, M.J. 2016. Re-evaluation of MelCast for fungicide scheduling in mid-Atlantic watermelon. Plant Health Progress. 17:51-52. doi:10.1094/PHP-BR-15-0041

Callahan, M.T., Marine, S.C., Everts, K.L., Micallef, S.A. 2016. Drip line flushing with chlorine may not be effective in reducing bacterial loads in irrigation water distribution systems. Journal of Food Protection. 79:1021-1025.

Reed-Jones, N.L., Marine, S.C., Everts, K.L., Micallef, S.A. 2016. Effects of cover crop species and season on population dynamics of Escherichia coli and Listeria innocua in soil. Appl. Environ. Microbiol 82:1767-1777. doi:10.1128/AEM.03712-15.

Pagadala, S., Marine, S.C., Micallef, S.A., Wang, F., Pahl, D.M., Melendez, M.V., Kline, W.L., Oni, R.A., Walsh, C.S., Everts, K.L., Buchanan, R.L. 2015. Assessment of region, farming system, irrigation source and sampling time as food safety risk factors for tomatoes. International Journal of Food Microbiology 196:98–108. ( http://dx.doi.org/10.1016/j.ijfoodmicro.2014.12.005)

Meyer, S.L.F., Zasada, I.A., Rupprecht, S.M., VanGessel, M.J., Hooks, C.R.R., Morra, M.J. Everts, K.L. 2015. Mustard Seed Meal for Management of Root-Knot Nematode and Weeds in Tomato Production. HortTechnology 25:192-202                                    

Marine, S.C., Pagadala, S., Wang, F., Pahl, D.M., Melendez, M.V., Kline, W.L., Oni, R.A., Walsh, C.S., Everts, K.L., Buchanan, R.L. and Micallef, S.A. 2015. Growing season, but not farming system, a food safety risk determinant for leafy greens in the mid-Atlantic region. Applied and Environmental Microbiology. doi: 10.1128/AEM.00051-15

Fry, W.E., Birch, P.R.J., Judelson, H.S., Grunwald, N.J., Danies, G.,  Everts, K.L., Gevens, A.J., Gugino, B.K., Johnson, D.A.,  Johnson, S.B.,  McGrath, M.T., Myers, K.L., Ristaino, J.B.,  Roberts, P.D., Secor, G. and Smart, C.D.  2015. Five reasons to consider Phytophthora infestans a re-emerging pathogen. Phytopathology 105: 966-981.

Marine, S.C., Martin, D.A., Adalja, A., Mathew, S., and Everts, K.L. 2015. Effect of market channel, farm scale, and years in production on mid-Atlantic vegetable producers’ knowledge and implementation of Good Agricultural Practices. Food Control 59:128-138.

Everts, K.L. and Himmelstein, J.C. 2015. Fusarium wilt of watermelon: towards sustainable management of a re-emerging plant disease. Crop Prot. 73:93-99. (Invited Review)

Summers, C.F., Park, S., Dunn, A.R., Rong, X., Everts, K.L., Meyer, S.L.F., Rupprecht, S.M., Kleinhenz, M.D., McSpadden Gardener, B., and Smart, C.D. 2014. Single season effects of mixed-species cover crops on tomato health (cultivar Celebrity) in multi-state field trials. Applied Soil Ecology 77:51-58.

Summers, C.F., Park, S., Dunn, A.R., Rong, X., Everts, K.L., Kleinhenz, M.D., McSpadden Gardener, B., and Smart, C.D. 2014. Fungal and oomycete pathogen detection in the rhizosphere of organic tomatoes grown in cover crop-treated soils. Applied Soil Ecology 80:44–50.

Himmelstein, J. C., Maul, J., and Everts, K. L., 2014. Impact of Five Cover Crop Green Manures and Actinovate on Fusarium Wilt of Watermelon. Plant Disease, 98:965-972. (doi: http://dx.doi.org/10.1094/PDIS-06-13-0585-RE).

Everts, K.L., Egel, D.S., Langston, D. and Zhou, X.G. 2014. Chemical management of Fusarium wilt of watermelon. Crop Protection 66:114-119.

Fry, W.E., McGrath, M.T, Seaman, A., Zitter, T.A, McLeod, A., Danies, G., Small, I.M., Myers, K., Everts, K.L., Gevens, A.J., Gugino, B.K., Johnson, S.B., Judelson, H., Ristaino, J., Roberts, P., Secor, G., Seebold, K., Snover-Clift, K., Wyenandt, A., Grunwald, N.J., and Smart, C. D., 2013. The 2009 Late Blight Pandemic in Eastern USA – causes and results Plant Disease. Plant Disease 97(3): 296-306.

Fry, W.E., McGrath, M.T., Seaman, A., Zitter, T.A., McLeod, A., Danies, G., Small, I., Myers, K., Everts, K., Gevens, A., Gugino, B.K., Johnson, S., Judelson, H., Ristaino, J., Roberts, P., Secor, G., Seebold, K., Snover-Clift, K., Wyenandt, A., Grunwald, N.J., and Smart, C.D. 2012. The 2009 late blight pandemic in eastern USA". Invited and peer-reviewed feature article. APS Features, 2012. doi:10.1094/APSFeature-2012-08.

Zhou, X.G., and Everts, K.L. 2012. Anthracnose and gummy stem blight are reduced on watermelon grown on a no-till hairy vetch cover crop. Plant Disease. 96:431-436 (http://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS-07-110608).

Everts, K.L., Osborne, L., Gevens A.J., Vasquez, S.J., Gugino, B.K., Ivors, K., and Harmon, C. 2012. Extension plant pathology: Strengthening resources to continue serving the public interest. Phytopathology 102:652-655.

Ojiambo, P.S., Holmes, G.J., Britton, W., Keever, T., Adams, M.L., Babadoost, M., Bost, S.C., Boyles, R., Brooks, M., Damicone, J., Draper, M.A., Egel, D.S., Everts, K.L., Ferrin, D.M., Gevens, A.J., Gugino, B.K., Hausbeck, M.K., Ingram, D.M., Isakeit, T., Keinath, A.P., Koike, S.T., Langston, D., McGrath, M.T., Miller, S.A., Mulrooney, R., Rideout, S., Roddy, E., Seebold, K.W., Sikora, E.J., Thornton, A., Wick, R.L., Wyenandt, C.A., and Zhang, S. 2011. Cucurbit downy mildew ipmPIPE: A next generation web-based interactive tool for disease management and extension outreach. Online. Plant Health Progress doi: 10.1094/PHP-2011-0411-01-RV.

Zhou, X.G., Everts, K.L., and Bruton, B.D. 2010. Race 3, a new and highly virulent race of Fusarium oxysporum f.sp. niveum causing Fusarium wilt in watermelon. Plant Dis. 94:92-98.

Keinath, A.P., Hassell, R.L., Everts, K.L. and Zhou, X.G. 2010. Cover crops of hybrid common vetch reduce Fusarium wilt of seedless watermelon in the eastern United States. Online. Plant Health Progress. doi: 10.1094/PHP-2010-0914-01-RS.

Extension Publications – Fact Sheets:

Everts, K.L. 2016 Soil Biology: Cover Crops and Disease Suppression. Southern over Crops 2016 Conference Fact Sheet. http://www.southernsare.org/Events/Southern-Cover-Crop-Conference/Southern-Cover-Crop-Conference-Fact-Sheets#disease

Kness, A.A., Kleczewski, N., Everts, K.L. 2015. Downy mildew of lima bean, University of Delaware Fact Sheet, http://cdn.extension.udel.edu/wp-content/uploads/2015/10/15090633/Downy-mildew-of-lima-bean-3.pdf

Kness, A.A., Kleczewski, N., Everts, K.L. 2015. Pod rot of lima bean, University of Delaware Fact Sheet, http://cdn.extension.udel.edu/wp-content/uploads/2015/10/15092237/Pod-Rot-of-Lima-Bean-fact-sheet-3.pdf

Marine, S.C., Everts, K.L. 2015. Cantaloupe (Muskmelon) in Maryland. University of Maryland Fact Sheet.

Plant Disease Management Reports:

Everts, K.L. and Johnson, G.C. 2017. Evaluation of fungicide programs for management of downy mildew of cucumbers – Trial 3, 2016. Plant Dis. Manag. Rep. 11:V021.

Everts, K.L. and Korir, R.C. 2017. Evaluation of fungicides for management of foliar diseases on watermelon, 2016. Plant Dis. Manag. Rep. 11:V022.

Everts, K.L. and Johnson, G.C. 2017. Evaluation of fungicide programs for management of downy mildew of cucumbers – Trial 2, 2016. Plant Dis. Manag. Rep. 11:V107.

Everts, K.L., Korir, R., and Marine, S.C. 2016. Evaluation of fungicides for management of foliar diseases on watermelon, 2015. Plant Dis. Manag. Rep. 10:V068.

Everts, K.L., Korir, R., and Marine, S.C. 2016. Evaluation of fungicides for management of powdery mildew on squash, 2015. Plant Dis. Manag. Rep. 10: V094.

Everts, K.L. and Korir, R. 2016. Evaluation of Proline and Topsin fungicides for management of Fusarium wilt on watermelon, 2015. Plant Dis. Manag. Rep. 10: V046.

Marine, S.C., Korir, R. and Everts, K.L. 2016. Field evaluation of muskmelon cultivars for susceptibility to anthracnose, powdery mildew and downy mildew when grown in organic no-till and plastic-mulch production systems in Maryland, 2015. Plant Dis. Manag. Rep. 10: V090.

Marine, S.C. and Everts, K.L. 2016. Field evaluation of rescue treatments for manganese toxicity in muskmelon production in Maryland, 2015. Plant Dis. Manag. Rep. 10:V097.

Everts, K.L., Korir, R., Armentrout, D.A. 2015. Evaluation of fungicides for suppression of root rot disease on snap bean, 2014, Plant Dis. Manag. Rep., 9:V048. Online publication. doi:10.1094/PDMR09

Everts, K.L., Korir, R. 2015. Evaluation of fungicides and Melcast forecasting program for watermelon disease management, 2014, Plant Dis. Manag. Rep. 9:V047., Online publication. doi: 10.1094/PDMR09.

Everts, K.L., Korir, R.C. 2015. Field evaluation of pollenizers for resistance to Fusarium wilt of watermelon in Maryland, 2014. Plant Dis. Manag. Rep. 9:V046., Online publication. doi: 10.1094/PDMR09.

Everts, K.L., Korir, R.C. 2015. Evaluation of fungicides for management of foliar diseases on watermelon, 2014, Plant Dis. Manag. Rep. 9:V045. Online publication. doi: 10.1094/PDMR09.

Everts, K.L., Korir, R.C. 2015. Field evaluation of triploid cultivars for resistance to Fusarium wilt of watermelon in Maryland, Plant Dis. Manag. Rep. 9:V006. Online publication. doi: 10.1094/PDMR09.

Everts, K.L. and Newark, M.J. 2014. Evaluation of fungicide programs for management of downy mildew of cucumbers, 2013, Plant Dis. Mang. Rep., 8:V196. Online publication. doi: 10.1094/PDMR08

Everts, K.L. and Newark, M.J. 2014. Evaluation of fungicides for management of mildew diseases in organic squash and pumpkin, 2013, Plant Dis. Mang. Rep., 8:V211. Online publication. doi: 10.1094/PDMR08

Everts, K.L. and Newark, M.J. 2014. Evaluation of fungicides for management of mildew diseases of cucurbits, 2013, Plant Dis. Mang. Rep., 8:V210. Online publication. doi: 10.1094/PDMR08

Everts, K.L. and Newark, M.J. 2014. Evaluation of fungicides for management of foliar diseases on watermelon, 2013, Plant Dis. Mang. Rep, 8:V209. Online publication. doi: 10.1094/PDMR08

Everts, K.L. and Newark, M.J. 2014. Evaluation of triploid cultivars for resistance to Fusarium wilt of watermelon in Maryland, 2013, Plant Dis. Mang. Rep., 8:V258. Online publication. doi: 10.1094/PDMR08