The society grants this honor to a current APS member in recognition of distinguished contributions to plant pathology or to The American Phytopathological Society. Fellow recognition is based on significant contributions in one or more of the following areas: original research, teaching, administration, professional and public service, and/or extension and outreach.
Dr. Timothy L. Widmer was raised in Albany, Oregon and earned his B.A. in chemistry from Goshen College. After researching diagnostic enzyme production for five years in industry, he completed his Ph.D. in plant pathology in 1996 at the University of Florida under the supervision of Drs. Dave Mitchell and Jim Graham. By researching the use of composted municipal waste as a soil amendment to reduce the impact of Phytophthora root rot of citrus, he determined the mechanism of pathogen suppression on citrus seedlings. Later, he conducted post-doctoral research at Cornell University with Dr. George Abawi, investigating the use of green manure to suppress root knot nematodes. There he began his lifelong involvement in international issues, participating in the Cornell Rice-Wheat Consortium’s work on rice and wheat declines in Southeast Asia. In 2000, he began his career with USDA-ARS as a Research Plant Pathologist at the European Biological Control Laboratory near Montpellier, France, where he identified European plant pathogens on problematic U.S. invasive weeds and screened them for efficacy and safety for biocontrol. In 2006, he joined the Foreign Disease-Weed Science Research Laboratory in Fort Detrick, MD, where he studied exotic Phytophthora spp., seeking approaches to mitigate P. ramorum in nursery settings, and discovered and patented a biological control agent that reduces P. ramorum propagules to undetectable limits in the soil.
From 2018 until his retirement in 2024, Dr. Widmer was the Plant Disease National Program Leader for USDA-ARS. In this role, he set the vision for plant disease research across the agency through the USDA-ARS strategic plan for National Program 303, which includes 43 congressionally-appropriated projects in 23 different locations across the U.S., involving 131 full-time permanent scientists and a budget of $74.8 million. He coordinated national and international research activities and established collaborations between USDA-ARS scientists and researchers from universities, industry, other government agencies, and non-profit organizations. He led monthly calls on citrus greening and cotton leafroll dwarf virus that brought together USDA, university, industry scientists, and commodity board members to facilitate sharing of ideas and increase collaborations. He also oversaw the congressionally-mandated National Plant Disease Recovery System (NPDRS), prioritizing emerging plant diseases for the preparation of Recovery Plans, identifying lead authors for each plan, and facilitating publication in Plant Health Progress. Furthermore, he reviewed and allocated NPDRS funding for high priority proposals from USDA-ARS researchers who collaborated with university and industry partners. Through NPDRS funding, he supported significant projects leading to the discovery of peanut resistance to peanut smut, significant advances in mitigating the threat of Ug99 stem rust, development of new diagnostics for exotic plant viruses, and genomic resources for downy mildews.
In his position, Dr. Widmer was sought for consultation by other federal entities including Department of Homeland Security (DHS), Environmental Protection Agency (EPA), Food and Drug Administration (FDA), National Institute of Health (NIH), and Centers for Disease Control and Prevention (CDC) on issues related to plant diseases, agricultural biosecurity and food security. He advocated for and ensured the inclusion of Plant Health in the 2022 National Biodefense Strategy Plan and was a member of the team that received the 2022 USDA Assistant Secretary for Administration Award for this effort. He was also part of interagency committees and working groups to draft Plant Health-related language on recommended guidelines for handling sequences of concern, oversight of dual-use research of concern, and initiatives of interest to the G7/G20, such as antimicrobial resistance. In most cases, he was the lone plant disease representative among human and animal health interests. He was co-lead for the Plant Sector on the White House National Science and Technology Council One Health Realtime Research Response Plan, mandated in the 2022 National Biosecurity Strategy. In 2023, he drafted a tabletop exercise on Annual Ryegrass Toxicity caused by Rathayibacter toxicus to test the Response Plan, which is required to guide development of a research plan within 14 days of a bioincident, using a One Health framework.
Dr. Widmer’s dedicated work across federal agencies has provided and enhanced the critical recognition that Plant Health is important. His ability to work across agencies has provided new visibility to APS and our discipline, which will have an impact for years. Dr. Widmer’s recognition as a leader in Plant Health extends internationally. He co-led a research collaboration effort with Taiwan, overseeing plant disease projects. He chaired the PROCINORTE Plant Health Task, an agricultural research and technology program designed to facilitate cooperative research interests of Canada, Mexico and the U.S. In this capacity, he organized and led annual plant health-related workshops relevant to the three countries and regions that were attended by international registrants.
Dr. Widmer routinely consulted with international research centers and government agencies to address plant diseases of global concern. He has ensured USDA-ARS scientist involvement in critical research projects around the world, including establishing global Ug99 sentinel plots, funding field trials to test wheat germplasm for resistance to wheat blast, and finding solutions for Fusarium head blight in Africa. Dr. Widmer was also the U.S. representative on the United Nations Methyl Bromide Technical Options Committee, which monitors, leads the discovery of alternatives, and makes recommendations for critical use exemptions of methyl bromide fumigations around the world.
Dr. Widmer’s scientific excellence is documented in 54 peer-reviewed papers, a patent, three book chapters, and numerous proceedings from national and international scientific conferences. He has delivered multiple invited presentations as a subject matter expert at numerous national and international conferences and meetings.
As National Program Leader of USDA-ARS, Dr. Widmer provided unprecedented support for APS beyond agricultural circles, which has given APS new visibility with other Federal Agencies including DHS, CDC, NIH, FDA and EPA.
Dr. Widmer’s many professional accomplishments and contributions, his career-long leadership and dedication to the field of plant pathology, and multi-pronged efforts to assure food security in a global context merit him to be named an APS Fellow.
