BIO: Dr. Johnson is a Professor of Weed Science in the Department of Botany and Plant Pathology at Purdue University. He has statewide responsibilities for weed science extension and research in agronomic crops. Dr. Johnson has extensive experience in the biology and management of weeds common to no-till systems and herbicide-resistant weeds and crops. Dr. Johnson is a past President of the North Central Weed Science Society (NCWSS) and an active member of the Weed Science Society of America (WSSA) and the American Society of Agronomy (ASA).