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  • School of Integrative Plant Science
  • Soil and Crop Sciences Section
  • Organic

Charles “Chuck” Leon Mohler (73), senior research associate in the Section of Soil and Crop Sciences, School of Integrative Plant Science, at Cornell’s College of Agriculture and Life Sciences, died April 1, 2021.

Dr. Mohler was born in Salem, Oregon, graduated from the University of Oregon in 1971 with a BA in biology, and obtained a PhD in Ecology and Evolutionary Biology from Cornell University in 1979. His dissertation research involved an aspect of theoretical community ecology (the predictability of species interactions) which he tested through careful field work in natural communities. Subsequently, as his primary interests shifted from basic plant ecology to more applied aspects, Dr. Mohler became a close colleague and 20-year member of Professor Antonio DiTommaso’s Weed Ecology and Management Laboratory at Cornell. His research there produced new and innovative approaches to integrated weed management. He brought strong plant ecological knowledge, scientific rigor, and elegant experimental design to weed biology and management studies. His studies of the ecology of agricultural weeds and ecological methods of weed management made him a key innovator in this area of weed science. He examined the effects of tillage, cultivation, and crop residue on weed control, testing his methods to make them hypothesis-driven and yet still practical. He wanted growers to be able to use them, and they did. And he used some of these same approaches in the management of weeds in his extensive vegetable garden at home.

He was instrumental in moving the field in this new direction. Over time, younger researchers followed and improved on what he had done and the standards he had set. These young students are themselves now some of the top weed ecologists, and they were all influenced by Dr. Mohler’s work. He co-authored four books, including the highly acclaimed Ecological Management of Agricultural Weeds (2001) with co-authors Matt Liebman and Charles Staver. He also produced dozens of refereed scientific articles as well as a number of media presentations. He mentored numerous graduate and undergraduate students and visiting scholars. He often visited with and listened closely to the concerns of growers.

His ability to focus was critical to his success. He was able to get down to work in the field as efficiently as he did in the office. He evaluated information dispassionately, trying never to let his emotions or his preferences shade the evidence. He grasped the minutiae of weed ecology research without ever losing sight of the big picture—how does a given weed management practice influence the environment and human health?

Dr. Mohler had little interest in professional recognition (and he might have chafed at the use of “Dr. Mohler” here). Regardless, his significant contributions to the field of weed science were recognized when he received the Outstanding Researcher Award from the Northeastern Weed Science Society in 2014.

His unfailing generosity was an inspiration to his colleagues. He was always ready to help them think through the design of an experiment. Status and reputation were not meaningful distinctions for him. A request for proposal advice received out of the blue from an unknown graduate student in Iran was answered with meticulous care, a gesture that the younger researcher never forgot. Later in Dr. Mohler’s career, as his sight began to fail and he could no longer read thesis chapters or manuscript drafts students brought him, he invited them to come to his office and read them aloud. He spent hours going through their work with them this way, sentence by sentence. His loss is keenly felt by many within the weed science community as well as by his many friends in the local community.

He was predeceased by his parents, his sister Mardi (Martha Keltner), and his second wife, Carol. He is survived by a sister, Ann Wederspahn (Gary), his partner Linda Heyne, and his children, Loden and Ariel. A Memorial Meeting for Worship will be held by Ithaca Monthly Meeting (Quakers). Further information is available from the meeting. In place of flowers, the family asks that friends consider a donation in Chuck’s memory to the Northeast Organic Farming Association of New York, to Indigenous Climate Action, or to the Ovarian Cancer Research Alliance.

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