Staff profile

John  Cullum

John Cullum


Lecturer in Horticultural Crop Production and Crop Science to undergraduate and postgraduate students. Also Admissions Tutor for the MSc and BSc Horticulture courses.


My teaching area is mostly plant sciences to horticulture students. I also undertake research in plant pathology, seed germination and plant breeding.

I was one of the original staff members responsible for the development of the BSc Horticulture which is now the largest in the country, and which still attracts well-qualified students from across the UK and overseas. I was then course manager for the MSc Horticulture for a number of years. I enjoy working with students from many different countries.

Horticulture continues to offer good career prospects and it is very rewarding to see former students occupying important positions within this industry.


BSc(Hons) in Botany
MSc in Plant Pathology
Certificate of Education

Subject Areas

My main subject areas are crop protection (plant pests and diseases), plant breeding and other areas of plant science – including plant micropropagtion.


One of my main areas of research is the dormancy of woody seeds, particularly rose. Over the course of 15 years we have developed a new technique using microbial decay to overcome the deep dormancy that these seeds possess. We have published more than 10 papers and articles on this novel technique. I am also interested in seed pathology and have written 7 papers and articles on this topic.

I have also worked on the germination and establishment of a rare plant, Bupleurum falcatum, which occurs in only one site in the UK - a roadside not far from Writtle College.

I am keen to involve students in my areas of research, particularly if the work is linked to external organisations. In recent years students have undertaken dissertations with a famous plant breeding company and a major fresh produce company.


Journal papers

M. U. Kahraman and F. J. Cullum (2020) Asymbiotic Germination and Seedling Development of Terrestrial Orchid Bletilla striata using in vitro and ex vitro cultures. Horticulture Studies 38 (1) 1-14.

Miao Yu, Lumbani Donton Mwafulirwa, John Cullum and Joanne Bayley. (2010) Establishment of an Efficient Protocol for Rapid Propagation of Chinese Foxglove Rehmannia angulata. Medicinal Plants 2 (2) 85-92.

S P San, J Cullum and T Thomidis. (2009) An assessment of the resistance of three hawthorn species to three strains of Erwinia amylovora using three different inoculation methods. Published online 4 August 2009 Phytoparasitica 37 (4) 371-373.

Conference proceedings

S O Tshwenyane, F J Cullum. C F H Bishop and A F H Gash. (2012) Effects of carbon dioxide enriched atmospheres on the postharvest control of botrytis rot of ‘Duett’ cut roses. IHC Conference, Lisbon. Acta Horticulturae 934 441-447.

Sara Potton and John Cullum (2012) Development of a Practical Method to Evaluate the Efficacy of Potassium Sorbate as a Germination Inhibitor of Penicillium digitatum Conidia for Potential Use in the Citrus Supply Chain. IHC Conference, Lisbon. Acta Horticulturae 934 327-333.