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Professor John Clarkson



Phone: 024 765 75148

Office (W): PPB 1.28

Office (GH): B 1.25A

Twitter: @plant_disease

Research Clusters

Plant & Agricultural Biosciences

Warwick Centres and GRPs

Warwick Crop Centre

Vacancies and Opportunities

For PhD and postdoctoral opportunities, and interest in potential collaborations, please contact me at the above email address.

Research Interests

Research in my team is focussed on plant diseases that have a major impact on the supply and quality of fresh produce while also threatening the livelihoods of farmers. In particular, we investigate fungal plant pathogens resident in the soil that can sometimes survive for decades and are therefore a major challenge to control.

Through our research we aim to better understand, identify, quantify and control these pathogens with an emphasis on key vegetable crops such as onion, lettuce, carrot and brassicas as well as more specialist produce such as peas, parsnips, herbs, asparagus and cut flowers.

We work collaboratively with other researchers, plant breeders, crop protection companies, agronomists and growers to develop sustainable ways of combating these important diseases through plant resistance, diagnostics and biological / cultural control and other approaches.

Research: Technical Summary

My team investigates important soil-borne plant pathogens with a focus on fungi such as Fusarium, Sclerotinia and Pythium spp. in fundamental and applied research projects funded by government, research councils and industry.

General areas of interest and expertise include plant pathogen biology, epidemiology, ecology, evolution and diversity with translational work encompassing plant resistance, molecular diagnostics, and integrated disease management approaches such as biological control.

Fusarium oxysporum which causes wilts and root rots in many important crop plants is a focus for much of our current research in these areas and provides a fascinating example of host specialisation through the evolution of more than 120 formae speciales each of which is uniquely adapted to different host plants. In collaborative projects with NIAB, we have employed genome sequencing and effector discovery pipelines to identify some of the pathogenicity genes associated with host specificity for f.spp. associated with onion, lettuce, Narcissus and pea which we have also used as targets for new molecular diagnostics. We are also addressing the challenge of new races which overcome plant resistance following the emergence in the UK of F. oxysporum f.sp lactucae race 4 in lettuce.

  • 2022-present: Professor, School of Life Sciences, University of Warwick
  • 2017-2021: Reader, School of Life Sciences, University of Warwick
  • 2004-2017: Research Fellow, School of Life Sciences, University of Warwick
  • 1993-2004: Horticulture Research International
  • 1993 PhD: 'Biological control of cereal eyespot disease', Life Science Dept, Nottingham University.
  • 1988 BSc (Hons) First Class in Agricultural Science (Crops), Leeds University.