Peter Davies

Peter Davies


255 Plant Science Building
(607) 255-8237

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.

Research Focus

Davies recent research has been on the role of plant hormones in stem growth, whole-plant senescence, tomato ripening and potato tuberization. More recently he has been undertaking metabolomic analyses of grapes and apples in relation to disease resistance and metabolic disorders. However he is now on phased retirement and no longer accepting research students.

Outreach and Extension Focus

Davies spent one year (2011-2012) as a Jefferson Fellow in residence at the Department of State in Washington DC, serving as a senior science adviser to the office of Agriculture, Biotechnology and Textile Trade Affairs in the Bureau of Economics and Business. He was particularly involved as an adviser on biotech (GMO) crops within the office, including involvement in a Foreign Service Institute course on biotech crops for foreign service personnel. In addition he visited nine countries and delivered 26 lectures or presentations on biotech crops at universities, institutes, academies, farmers groups and schools, as well as to government officials in these countries. During his overseas trips he conducted several interviews with journalists and on TV resulting in extensive reports on biotech crops on local newspapers. In November he was recalled to the Philippines as an expert witness in a court hearing on Bt eggplant trials. On returning to Cornell Davies has become involved in International Agriculture in International Programs. The Fellow position continues with Davies in the role of consultant.

Teaching Focus

Professor Davies was appointed at Cornell with the expressed purpose of teaching Plant Physiology to students in agriculture and horticulture because of his agronomy background and research experience in basic plant physiology. He has taught Plant Function and Growth since 1970, keeping it up to date but at an appropriate level for undergraduate students. After three years teaching introductory biology to non majors his current emphasis is encouraging students to learn how advances in biology affect their lives with a course Issues in Social Biology, Diet to Disease, DNA to Deforestation, subtitled Biology in the News, where the emphasis is self-discovery via articles in the media rather than rote learning of biological facts. He is also involved in teaching in International Agriculture including Agriculture in Developing Nations and The GMO Debate.

Awards and Honors

  • International Professor of Plant Biology (2013)
  • Jefferson Fellow (2017) United States Department of State
  • OECD (Trade & Agriculture) Research Fellow (2010) Università di Bologna, Italy
  • Senior Fellow (2010) Institute of Advanced Studies, Università di Bologna, Italy
  • Named Most Influential Faculty Member (2008) Merill Scholar Graham Dow

Selected Publications

Journal Publications

  • Yang, X., Brown, S. K., & Davies, P. J. (2013). The content and in vivo metabolism of gibberellin in apple vegetative tissues. Journal of American Society of Horticultural Science. 138:1-11.
  • Davies, P. J., & Gan, S. (2012). Towards an integrated view of monocarpic plant senescence. Russian Journal of Plant Physiology. 59:476-478.
  • Lee, J., Rudell, D. R., Davies, P. J., & Watkins, C. B. (2012). Metabolic changes in 1-methylcyclopropene (1-MCP)-treated ‘Empire’ apple fruit during storage. Metabolomics. 8:742-753.
  • Sklensky, D. E., & Davies, P. J. (2011). Resource partitioning to male and female flowers of Spinacia oleracea L. in relation to whole-plant monocarpic senescence. Journal of Experimental Botany. 62:4323–4336.
  • Silva, T. M., & Davies, P. J. (2007). Elongation rates and endogenous indoleacetic acid levels in roots of pea mutants differing in internode length. Physiologia Plantarum. 129:804-812.
  • Silva, T. M., & Davies, P. J. (2007). Hormone growth responses of roots of shoot height mutants of pea. Physiologia Plantarum. 129:813-821.
  • Tassoni, A., Watkins, C. B., & Davies, P. J. (2006). Inhibition of the ethylene response by 1-MCP in tomato suggests that polyamines are not involved in delaying ripening, but may moderate the rate of ripening or over-ripening. Journal of Experimental Botany. 57:3313–3325.
  • Hannapel, D. J., Chen, H., Rosin, F. M., Banerjee, A. K., & Davies, P. J. (2004). Molecular controls of tuberization. American Journal of Potato Research. 81:5-16.
  • Ewing, E. E., Simko, I., Omer, E. A., & Davies, P. J. (2004). Polygene mapping as a tool to study the physiology of potato tuberization and dormancy. American Journal of Potato Research. 81:33-41.
  • Rosin, F. M., Hart, J. K., Horner, H. T., Davies, P. J., & Hannapel, D. J. (2003). Overexpression of a knotted like homeobox gene of potato alters vegetative development by decreasing gibberellin accumulation. Plant Physiology. 132:106-117.
  • Mapes, C. C., & Davies, P. J. (2001). Cytokinins in the ball gall of Solidago altissima and in the gall forming larvae of Eurosta . New Phytologist. 151:203-212.
  • Mapes, C. C., & Davies, P. J. (2001). Indole-3-acetic acid and ball gall development on Solidago altissima. New Phytologist. 151:195-202.
  • Davies, P. J., Šimko, I., Mueller, S. M., Yencho, C., Lewis, C., McMurry, S., Taylor, M. A., & Ewing, E. E. (1999). Quantitative trait loci for polyamine content in an RFLP-mapped potato population and their relationship to tuberization. Physiologia Plantarum. 106:210-218.
  • Lester , D. R., Ross, J. J., Davies, P. J., & Reid, J. B. (1997). Mendel's stem length gene (Le) encodes a gibberellin 3-hydroxylase. Plant Cell. 9:1435-1443.


  • Davies, P. J. (2010). Plant Hormones: Biosynthesis, Signal Transduction, Action! . p. 801pp Springer, Dordrecht, The Netherlands