Dr. Bill McCloskey is a University of Arizona Cooperative Extension Weed Specialist in the School of Plant Sciences in the College of Agriculture and Life Sciences. His Extension programs and supporting research over more than two decades have focused on economically managing weeds in Arizona’s irrigated crops using ecological principles and a variety of tactics. Tactics have included using precision guidance technology (GPS), optical and electronic sensor technology, computerized application technology and mechanical cultivation in addition to chemical tools (herbicides) in Arizona crops including alfalfa, barley, citrus (lemons and oranges), chile peppers, corn, cotton, wheat, and tree nuts (pecans and pistachios). Dr. McCloskey has also developed management tactics for the weeds associated with new crops such as guayule and has worked on managing invasive species such as buffelgrass, Russian knapweed and saltcedar in rangeland and natural landscapes. Bill presents numerous lectures and workshops on weed management to audiences involved in Southwestern crop production and weed management in urban, range and wild landscapes in support of Cooperative Extension educational programs.