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2010 Plant Management Network. Published 26 May 2010.

The 8th I. E. Melhus Graduate Student Symposium: Forty-Five Years After Van der Plank, New Visions for the Future of Plant Disease Epidemiology

Forrest W. Nutter, Jr., Professor, Department of Plant Pathology, Iowa State University, Ames, IA 50011

Corresponding author: Forrest W. Nutter, Jr..

Nutter, F. W., Jr. 2010. The 8th I. E. Melhus graduate student symposium: Forty-five years after Van der Plank, new visions for the future of plant disease epidemiology. Online. Plant Health Progress doi:10.1094/PHP-2010-0526-01-SY.

The 8th I. E. Melhus Graduate Symposium


One of the most prestigious events held during each Annual Meeting of the American Phytopathological Society (APS) is the Irving E. Melhus Graduate Student Symposium. This symposium features graduate students who are chosen, on a competitive basis, to present their thesis research results. Each year, one of the APS Subject Matter Committees is appointed by the APS Scientific Program Board to organize and co-sponsor (with the APS Foundation) the next I. E. Melhus Graduate Student Symposium. Selection criteria are established by the sponsoring APS Subject Matter Committee. Selection criteria (established by the APS Epidemiology Subject Matter Committee) for the 8th I. E. Melhus symposium included: (i) submission of a 5-page synopsis of the student’s graduate research project (excluding tables and figures); (ii) a panel evaluation of the significance of each nominee’s research contribution towards improving our understanding of plant disease epidemics; (iii) the evaluation of each nominee’s communication skills; (iv) two letters of nomination from the nominee’s institution; and (v) active membership in APS.

History of the I. E. Melhus Graduate Student Symposium

Every three years (since 1984), the APS Epidemiology Committee has sponsored a Graduate Student Symposium to highlight the innovative, science-based epidemiological research that is conducted by APS graduate student members. The APS Foundation approached the Epidemiology Committee in 1999 with a proposal to organize the First I. E. Melhus Graduate Student Symposium. The APS Foundation wished to make this an annual event and pledged to provide partial travel awards for the four to six graduate students who were chosen each year. It was established that the APS Epidemiology Committee would continue its tradition of co-sponsoring the I. E. Melhus Symposium on a 3-year cycle, with other APS Subject Matter Committees submitting proposals to co-sponsor this symposium in the two intervening years.

Irving E. Melhus: The Early Years

It is highly appropriate that the APS Epidemiology Committee was invited to organize the First I. E. Melhus Graduate Student Symposium, as Irving E. Melhus was an early pioneer in plant disease epidemiology and had a major influence on the research and graduate training activities of students. Dr. Irving E. Melhus, a student of L. R. Jones, was the first person to receive a doctorate in plant pathology from the University of Wisconsin. Dr. Melhus came to Iowa State College (later Iowa State University) in 1916 as the first full-time plant pathologist, where he effectuated the college’s first intensive experimental research program in plant pathology. Dr. Melhus’ early work on late blight of potato led to a disease forecasting service that proved to be of tremendous value to potato growers. Melhus was the first to report that the pathogen responsible for late blight of potato (Phytopthora infestans) could overwinter in potato tubers. In addition, Melhus also conducted the early research on root and stalk rots of corn.

I. E. Melhus: Pioneer in Research, Teaching, and International Agriculture

Dr. Melhus was appointed Chief of Plant Pathology in the Iowa State Experiment Station in 1922, making him the first officially-recognized member of the faculty in a discipline separate from botany. In addition to being an outstanding plant disease epidemiologist, Dr. Melhus was also an inspiring mentor, with an engaging personality and a keen sense of humor. Over a period of thirty years, Dr. Melhus attracted many outstanding students, including L. W. Durrell, who, in 1923, earned the first doctorate in plant pathology from Iowa State College.

Melhus was named Head of the Department of Botany in 1930. A dedicated researcher and administrator, Melhus established Iowa’s network of college field research stations that, to this day, continue to serve the research, teaching, and extension Land Grant missions of the College and the Nation.

Often overlooked is the pioneering legacy that I. E. Melhus left behind concerning Iowa State’s involvement in international agriculture. For example, in 1946, Dr. Melhus founded the Iowa State College-Guatemala Tropical Research Center for the study of corn improvement. This was the first overseas experimental station operated by a U.S. university. Dr. Melhus led this program from 1946-1953.

Service to APS

Melhus served as President of APS in 1926 and was elected a Fellow of APS in 1965, the first year this prestigious recognition was given by the Society.

The I. E. Melhus Student Symposium Fund

I. E. Melhus, a recognized leader in plant pathology, was described as a man of infinite dignity who was highly regarded by his peers. The I. E. Melhus Graduate Student Symposium Fund was established in Melhus’ honor through generous donations provided by Dr. and Mrs. William Paddock, Mr. and Mrs. Walter Goeppinger, and Dr. and Mrs. Jack R. Wallin. The Melhus Fund was established with the goal of enhancing graduate student professionalism, as well as to memorialize this influential plant pathologist (epidemiologist).

The Symposium Participants

In honor of the leadership and professionalism that Dr. Melhus exhibited throughout his distinguished career, it is with great respect and pleasure that the following graduate students are recognized for their participation in the 8th I. E. Melhus Graduate Student Symposium that was held during the 100th Meeting of the American Phytopathological Society in Minneapolis, MN, in 2008.


Emmanuel Byamukama, a native of Uganda, received his B.Sc. Degree in Agriculture and M.Sc. Degree in Crop Science from Makerere University, Kampala, Uganda. Working with Forrest W. Nutter, Jr. and Alison Robertson during his doctoral program, Emmanuel was the first to quantify the rate of Bean pod mottle virus (BPMV) spread in soybeans over the course of two full growing seasons and documented that BPMV incidence can double as fast as every 4.1 days. He is also the first to report that the spatial pattern of BPMV infected quadrats was highly aggregated throughout the growing season, which indicates that systematic sampling designs should be employed to quantify BPMV incidence. Emmanuel also found there is significant spatial dependence for BPMV incidence among Iowa counties. Emmanuel is currently a Postdoctoral Research Associate at Iowa State University and is investigating the biotic and abiotic risk factors that influence BPMV prevalence and incidence. Emmanuel received first place in the 2006 Norman Borlaug Lecture Poster Competition for Graduate and Undergraduate students that was held in Des Moines, IA. Emmanuel would like to devote his career to investigating virus-vector interactions and how these interactions affect the spatial and temporal dynamics of plant virus epidemics.


Felix Cervantes received his M.S. Degree in Ecology of Desert Ecosystems from the prestigious Ben Gurion University in Negev, Israel, where he studied the survival and epidemiology of the flea (vector)/fat sand rat (Psamomys obesus)/human pathogen (Yersinia spp.) pathosystem. This background in vector/host/pathogen relationships led to his joining Dr. Juan Manuel Alverez’s research program at the University of Idaho to study the epidemiology of insect vector/plant virus/alternative weed host interactions in the Potato virus Y-potato pathosystem. Felix’s research, "The Role of Hairy Nightshade (Solanum sarrachoides) in the transmission of Potato virus Y", involved laboratory and field experiments to elucidate the epidemiological relationships and roles that virus vectors (aphids) and alternative weed hosts (hairy nightshade) play in the initial infection and spread of Potato virus Y in potato crops. Felix’s career goals are to pursue post-doctoral training and a career in academia. He wishes to continue investigating insect vector-plant interactions in order to solve pest and disease problems in an environmentally-sound and cost-effective manner, and is interested in conducting research at micro and macro scales in cropping systems.


Alex Mello, native of Brazil, received his B.Sc. and M.Sc. degrees in Agronomy, with a major in Plant Pathology, from the University of Sao Paulo, Brazil. Alex studied the epidemiology of Spiroplasma citri, a significant threat to California citrus production that is not well understood. His research group optimized pathogen-detection protocols and found fruit columella and receptacle tissues best suited for bacterial isolation. Comparisons of S. citri strains isolates collected 20 years ago with those collected in recent years by RAPD analyses revealed the presence of significant genetic diversity. Alex’s findings also showed that disease incidence in commercial groves can be very high, and the impact on yield and fruit quality is significant. Alex is currently the lead Plant Pathologist for Monsanto Corporation in Uberlandsa, Brazil and is responsible for the development of maize resistance to plant pathogens.


Michelle Moyer received her B.Sc. degree from the University of Wisconsin. Michelle was awarded an educational fellowship from the New York Wine and Grape Foundation in 2006 and 2007 to begin her Ph.D. research at the Cornell Agricultural Experiment Station in Geneva, NY, working with Dr. Robert Seem and Dr. David Gadoury. In 2007 she also received a scholarship from the American Society of Enology and Viticulture. Michelle’s Ph.D. research is focused on the development of a forecasting system for grapevine powdery mildew (Erysiphe necator) in the northeastern United States. Biological and ecological studies are the foundation of this work. She is investigating: (i) how disease develops and progresses during the early part of the growing season, from budbreak to bloom; (ii) the overwinter survival of the pathogen and the distribution and timing of primary infection; and (iii) the correlation of environmental factors with severe disease on fruit. Her studies use a combination of field and laboratory-based experiments, along with the analysis of historical disease and weather data. Michelle plans to complete requirements for her Ph.D. in the summer of 2010. Upon completion of her graduate studies, Moyer would like to develop a career in applied research, extension, and teaching, with a focus in viticulture, perennial fruit crops, or ornamentals.


As the organizer of the 8th I. E. Melhus Graduate Students Symposium and on behalf of the APS Foundation and APS, I would like to acknowledge and thank the following individuals who served on the ad hoc Evaluation Committee that selected the four students chosen to participate in the 8th I. E. Melhus Graduate Student Symposium. They were:

• Dr. Ann Chase, 2008 Chair, APS Foundation

• Dr. Megan Kennelly, Assistant Professor, Kansas State University and former I. E. Melhus Awardee

• Dr. Linda Kinkle, Professor, University of Minnesota

• Dr. Norm Lalancette, Professor, Rutgers University

• Dr. James Marois, Professor, University of Florida