My main research focus is the epidemiology, diagnosis and control of soil- and seed-borne diseases of potatoes. Diseases currently being investigated in my research programme include powdery scab (Spongospora subterranea f. sp. subterranea), black scurf and stem canker (Rhizoctonia solani), and blackleg and soft rot (Pectobacterium and Dickeya spp.). Soil-borne diseases are one of the most limiting factors in the production of potatoes and thus the main focus of the Potato Pathology Programme @ UP is understanding these pathogens and epidemiology of the diseases in order to improve management in the field. In order to do this, various techniques are combined to better understand disease spread and development in the field, interaction of host and pathogen, and ultimately use this information to provide growers with a risk assessment for the disease under consideration. I am also currently supervising students investigating the role of crop rotation on soil health and the effect thereof on pathogen inoculum in the soil, using a metagenomics approach. Other students in my programme are working on Macrophomina phaseolina, the causal agent of charcoal rot, which affects numerous agricultural crops including maize, soybean and sunflower. The focus of this project is to determine the etiology and population structure of the pathogen in South Africa.
I have strong collaborations with researchers in Scotland, The Netherlands, Israel, Poland and Zimbabwe and also work closely with numerous South African colleagues at UP and the Agricultural Research Council.
The Potato Pathology Programme @ UP not only conducts research into potato diseases, but also houses a diagnostic clinic for plant diseases, specifically potato diseases.