Carrots: Understanding the ecology and epidemiology of Pythium violae to enable disease management (PhD Studentship)

Cavity spot is a major disease of carrots in the UK which is caused mainly by the soilborne oomycete pathogen Pythium violae. Despite being soilborne, control of cavity spot relies on the application of foliar fungicides but levels of control can vary and enhanced degradation may also occur in some soils. Long rotations between carrot crops are recommended (but not always possible) although some experiments have suggested there was no build-up of disease over four years of continuous carrot cropping.

Although P. violae has been studied extensively at times in the past, progress has always been hampered by the lack of effective procedures for detection and quantification of the pathogen in soil. However, a quantitative PCR assay for P. violae has been developed recently (FV353) enabling a preliminary understanding of pathogen dynamics in soil and the effect of some abiotic and biotic factors. However, there are still fundamental gaps in our knowledge concerning the epidemiology of P. violae and how it interacts with its environment and hosts. Effective tools and methodologies for P. violae research are also still lacking including further optimisation / development of the qPCR to make it more robust.