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Roger C. Pearson Student Travel Grant

Colleagues and friends established this grant in honor and memory of Dr. Roger C. Pearson (1946-1993) for the contributions he made to plant pathology.


Roger C. Pearson

Roger C. Pearson was born in California in 1946. He received his B.S. degree in biological sciences and M.S. and Ph.D. degrees in plant pathology from the University of California-Davis in 1968, 1969, and 1973, respectively. After working as a research associate for two years at Cornell University’s Hudson Valley Tree Fruit Research Lab, he was appointed assistant professor of plant pathology in 1975. In 1977, Dr. Pearson moved from the Hudson Valley Lab to the New York State Agricultural Experiment Station at Geneva and changed the emphasis of his research program from diseases of tree fruits to diseases of grapes. He was promoted to associate professor in 1981 and to professor in 1990.

In the short time that he was at the Hudson Valley Lab, Dr. Pearson made significant contributions to our knowledge of cedar apple rust. Basic studies saw immediate application in the development of predictive models to identify cedar apple rust infection periods, and tables developed from these models now enable growers to efficiently and effectively use post-infection fungicide applications to control cedar apple rust.

At Geneva, an initial major focus of Dr. Pearson’s research was the ecology of Uncinula necator and the epidemiology of grape powdery mildew. His research on powdery mildew served as a model for similar studies in California, Germany, France, and Australia. Collectively, these studies demonstrated that cleistothecia, which were formerly regarded as degenerate structures, were important sources of primary inoculum worldwide. This ended over a century of speculation and uncertainty regarding the role of ascocarps in the epidemiology of grape powdery mildew. Dr. Pearson’s findings resulted in a number of new approaches to controlling grape powdery mildew, including eradication of cleistothecia on the bark of the vine and the use of post-infection fungicide applications targeted against the rain-released ascospores. Furthermore, the many innovations of these ecological and epidemiological studies provided useful models for other researchers in investigations of powdery mildews of other deciduous perennial hosts.

Dr. Pearson’s research and extension program consistently addressed relevant problems and produced results of great value to plant pathologists, viticultural scientists, and especially to growers. His timely identification of resistance to benomyl in U. necator, the first such report in the United States, prevented catastrophic losses due to fungicide resistance in the following season. His studies on the epidemiology and control of Eutypa armeniacae demonstrated that ascospore release of this unusual wound pathogen was triggered by snow-melt in New York, thus releasing inoculum at the time of pruning. He and his coworkers identified a new fungal disease of grapevines (Angular leaf scorch), identified and taxonomically classified the causal agent (Pseudopezicula tetraspora), and developed fungicidal control programs for the disease. Dr. Pearson and coworkers discovered a yellows disease of grapevine in the United States and conducted the first comparative studies of this disease and similar yellows diseases reported from Europe. He developed an innovative method of deploying vapor-action fungicides and the biological control agent Ampelomyces quisqualis on wicks suspended in the grapevine trellis. In addition, Dr. Pearson and coworkers determined that infection of grape berries by Phomopsis viticola occurred during bloom and that only fungicides applied at this critical time would substantially reduce fruit rot. They also determined that a major contributing factor in the recent increase of this disease was an increase in dead canes in vines as manual pruning was abandoned in favor of mechanical hedging.

Dr. Pearson’s authoritative knowledge of grape diseases, kindness, fairness, integrity, and the superior quality of his work were appreciated and highly respected within his department at Geneva, Cornell University, and throughout the world-wide scientific community. He was named a research Fellow of the Alexander von Humboldt Foundation; awarded the Lee M. Hutchins Award from APS in 1991 and the Award of Merit of the APS Northeastern Division in 1994; and was invited to spend sabbatical leave at the Biologische Bundesanstalt Institut für Pflanzenschutz im Weinbau, Bernkastel-Kucs, Germany, the INRA Station de Pathologie Vegetale, Bordeaux, France, and the Eidgenössische Forschunganstalt für Obst-, Wein-, und Gartenbau, Wädenswil, Switzerland.

Dr. Pearson’s daily activities and long-term goals reflected a genuine and abiding concern for the needs of grape growers with respect to controlling destructive diseases. His basic research was always closely followed by an application of the results to improve disease management programs. He traveled extensively throughout New York vineyards during the growing season to talk to growers. Dr. Pearson was a productive and effective researcher and writer. He coedited the APS Compendium of Grape Diseases, published 41 refereed journal papers, 12 reviews and book chapters, and 82 technical and extension articles. He was awarded U.S. patents for his novel deployment of the biocontrol agent Ampelomyces quisqualis and for his discovery of the biocontrol activity of Fusarium proliferatum against a broad range of downy mildews.

At the time of his death in April 1993 at the age of 46, Roger Pearson was perhaps the most widely known and respected authority on grapevine diseases in the world. His record of accomplishment in research, the impact of that research on the science of plant pathology, and the benefits derived from his efforts to extend his results to commercial agriculture will be appreciated for many decades. Dr. Pearson’s family include his wife Karen and children Heather, Adam, and Alicia, who reside in Geneva, NY.