Scientists have recently identified the first specimens of the fungus Sclerotinia subarctica in the UK. The fungus has not previously been found this far south and may pose a risk to UK agriculture. The findings were made by scientists at the Warwick Crop Centre at the University of Warwick.
During the research, S. subarctica was found in carrots and meadow buttercups in Perthshire and as far south as Herefordshire. This is surprising as before now it has been restricted to the much colder climates of Alaska and Norway.
The fungus infects the foliage and travels down the leaves of the plants where symptoms emerge. There are no long-term implications for buttercups as only the flowers are affected and their underground rhizomes generally remain untouched. However, carrots are more severely affected, with the fungus travelling into the crown of the carrot and potentially causing them to rot whilst still in the ground or whilst being stored.
The fungus is closely related to Sclerotinia sclerotiorum, which is more of a threat to UK agriculture. S. sclerotiorum has a global presence (see the Plantwise Distribution map) and is already found in the UK. DEFRA surveys have shown it to be a serious disease of oilseed rape, affecting 2-4% of winter oilseed rape that has translated into a 1-2% yield loss in England.
The findings were made during research, funded by DEFRA, into S. sclerotiorum by Dr Clarkson at the Warwick Crop Centre. The Horticultural Development Company is also funding a new PhD to investigate S. subarctica in more depth.
Dr John Clarkson, one of the research scientists involved in this project, said: “By studying Sclerotinia subarctica on meadow buttercups and crop plants we have a great opportunity to find out more about its epidemiology as further research needs to be done on understanding this disease and the potential threat it poses to agriculture in the UK.”