July 15, 1908–February 15, 2001

BY DONALD J. ARMSTRONG AND ELDON H. NEWCOMB

FOLKE KARL SKOOG WILL be remembered as one of the twentieth century’s major figures in plant biology. He was the last surviving member of the small group of investigators who began plant hormone research in this country, and his death in Madison, Wisconsin, at the age of 92 marked the end of an era. His personal contributions to the field of plant hormone research were monumental. Few single discoveries have had such a major impact on a field of plant science as did the isolation and identification of kinetin by Skoog and associates at the University of Wisconsin-Madison in 1955. This discovery was the founding event in the recognition of a major new class of plant hormones, the cytokinins, and it shaped and conditioned research in plant growth regulation for decades. Earlier Skoog had made several pioneering discoveries that helped to establish the general importance of auxin in plant growth regulation. During his multifaceted career he also investigated aspects of plant nutrition, advanced the science and art of plant tissue culture, and addressed a number of important questions in plant morphogenesis. His contributions to our understanding of the regulation of plant growth and development constitute a legacy that is rivaled by few others in the