John studied Applied Biology at Leeds University and then went on to a co-operative award PhD at Rothamsted Experimental Station (now Rothamsted Research) and Leeds University in Plant Pathology. During his PhD studies, John was awarded the Best Student Paper Award, from the Society of Nematologists at their meeting in Salt Lake City. This was followed by a Potato Marketing Board postdoctoral fellowship at Rothamsted. John joined HRI in 1983 and is currently group leader for the Plant Virus Interactions group. This group has a broad range of research projects from Applied, through Strategic to Fundamental, funded from a wide variety of sources. The underlying aim is to provide environmentally friendly sustainable disease control measures whilst at the same time reducing inputs.
John has served his field as a member of the Association of Applied Biologists, Virology Group Committee, secretary to the International Society for Horticultural Science, Vegetable Virus Working Group, SGM Virology Division Committee and NERC Peer Review College. He is also an editor for the Annals of Applied Biology and the European Journal of Plant Pathology. John is President Elect of the International Working Group for Legume and Vegetable Viruses.
John's group have had a number of products commercialised including germplasm possessing resistance genes to plant viruses and diagnostic reagents for detection of plant viruses and protists.