Peter Davies has a prime appointment in teaching plant physiology to students of agriculture and horticulture, though he has taught plant growth and development and plant hormones, as well as biology to non-majors, for many years. His area of expertise is plant growth and development, with special reference to the role of hormones in growth and development, and the regulation of the senescence of whole plants. Most of his research has involved the utilization of defined genotypes. He has published over 100 papers in these areas, as well as written several books. The revised third edition of his book on plant hormones, Plant Hormones: Biosynthesis, Signal Transduction, Action!, which he produced and edited, was published in 2010 and is the standard authority in the field of plant hormones. He is also the editor covering plant physiology for the McGraw-Hill Encyclopedia of Science and Technology. Davies has spent sabbatical leaves at the Universities of Cambridge (UK), Wales (UK), Minnesota, Tasmania (Australia) and Bologna (Italy). While in Tasmania he was a part of the team that isolated and characterized Mendel`s genes regulating tallness. He has also been a distinguished visiting lecturer at the University of Bologna in Italy. Currently he is revising his plant physiology text The Life of the Green Plant. In 2011-2012 Davies was a Jefferson Fellow with the United States Department of State in Washington DC as a senior science advisor on biotech crops (GMOs) in the Bureau of Economics and Business, and made several trips abroad as a lecturer and educator in this field. He continues as a Jefferson Fellow in a consultancy role. He is now also involved as a faculty member in International Agriculture and Rural Development at Cornell.