Crop Science Research Group

Crops growing in arid soil

The Crop Science Research Group at ARU Writtle investigates the environmental and physiological aspects of crop plant productivity and pathology through the use of various field and controlled techniques, including elemental analysis, micropropagation and cryogenic storage.

Our current focuses are disease reduction in stored fruits and vegetables using non-chemical treatments, and the pre-harvest treatment of cut flowers to improve post-harvest longevity.

We regularly collaborate with other institutions. Our established partners include the universities of Abertay, Essex and East London, the Rubber Research Institute of Sri Lanka, and Egerton University, Kenya.

Through commercial consultancy work, we have also cultivated an excellent reputation in the fields of post-harvest and supply chain, particularly in relation to cold storage and international transport.

Comparing the effectiveness of a new basal medium for plant micropropagation

Principal Investigator: John Cullum
Start date: April 2009
Collaborative partner: Valcent Products EU Ltd and Phytoplant Research, Spain

Formula Beta is a new basal medium for plant micropropagation and trials on Chinese foxglove, a medicinal herb, showed that better results were obtained compared with using the standard basal medium. The results of these trials have now been published.

The comparative trials will next look at the effectiveness of Formula Beta as a basal medium in potato micropropagation.

Assessing the resistance of plant species to pathological diseases

Principal investigator: John Cullum
Start date: April 2008
Collaborative partner: Technological Educational Institute of Thessaloniki, Greece

The initial investigations examined the resistance of hawthorn species to isolates of the fireblight bacterium using laboratory and field methods developed at TEI. The results were subsequently published.

The next series of trials test whether these techniques are appropriate for assessing the resistance of elm to Dutch elm disease.

Methods for overcoming seed dormancy

Principal investigator: John Cullum
Start date: 1990
Collaborative partner: Italian Environment Protection Agency

This has been an ongoing area of investigation. The principal area of investigation has looked at the seeds of various rose species and marked improvements have been seen when a compost activator is added to the pre-treatment medium.

Currently, the College germination of Bupleurum falcatum seed is being investigated. This rare plant, the sickle-leaved hare's-ear, is found at only one site in the UK, not far from ARU Writtle.

Conservation staff are working to safeguard this plant population, and understanding more about its seed dormancy mechanism has enabled more plants to be produced and returned to the site.

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

Yu, M., Mwafulirwa, L. D., Cullum, J. and Bayley, J. (2010) 'Establishment of an Efficient Protocol for Rapid Propagation of Chinese Foxglove Rehmannia angulata', Medicinal Plants, 2(2), pp. 85-92.

San, S. P., Cullum, J. and Thomidis, T. (2009) 'An assessment of the resistance of three hawthorn species to three strains of Erwinia amylovora using three different inoculation methods', Phytoparasitica, 37(4), pp. 371-372.

O'Connell, M. N., Kethees Wararajah, V., Fieldsend, A. F. and Cullum, F. J. (2005) 'Sources of infection and methods of control of Septoria oenotheraw in Evening Primrose (Oenothera spp.)', Acta Agronomica Hungarica, 53(4), pp. 385-391.

Kalousis, N. K., Cullum, F. J. and Wainwright, H. (2005) 'Identifying Harvest Maturity Indices for Five Cultivars of Gooseberry (Ribes uva-crispa) Fruit', Small Fruits Review, 4, pp. 33-41.

Fieldsend, A. F. (2004) 'Interactive effects of light, temperature and cultivar on photosynthesis in evening primrose (Oenothera spp.) crops', Acta Agronomica Hungarica, 52(4), pp. 333-342.

Fieldsend, A. F. (2004) 'Low temperature effects on the growth of evening primrose (Oenothera spp.) rosettes', Acta Agronomica Hungarica, 52(1), pp. 19-28.

Belletti, P., Cullum, J., Gorian, F., Monteleone, I. and Piotto, B. (2003) 'The use of a compost activator to overcome seed dormancy in Rosa canina L.'. In: Ciccarese, L., Lucci, S. and Mattsson, A. (Eds) (2003) Proceedings of the conference “Nursery production and stand establishment of broadleaves to promote sustainable forest management', Rome, Italy, May 7-10, 2001. Rome: APAT.