Sclerotinia Rot of Carrots

Sclerotinia rot of carrot (SRC), caused by Sclerotinia sclerotiorum, is one of the most economically important diseases of carrots. Losses to this disease can occur from pre-harvest epidemics, originating in the field, or from post-harvest outbreaks caused by infected carrots entering storage. Post-harvest outbreaks are particularly devastating, with storage losses of some commercial growers reported as high as 50% in Canada.

“Typically, in Prince Edward Island (PEI), where about 300 ha of carrots are grown, losses in storage due to SRC occur in most years. In 2006, losses due to SRC cost carrot growers in PEI approximately $500,000. In 2007, losses in storage of approximately 25% (valued at $350,000) occurred, and yet, 2007 was not considered a year with high disease pressure. After witnessing the serious disease pressure and crop losses occurring at the local vegetable co-op first hand, our research teams initiated a program to examine potential post-harvest control options for SRC in storage.

Based on the results of our studies, fludioxonil (Scholar) was found to be an excellent tool for managing SRC in storage. …In 2008 and again in 2009, Scholar 50WP (a product currently registered in Canada for post-harvest control of some fruit diseases) received emergency registration in Canada for post-harvest use by carrot growers for control of SRC in storage. Feedback from growers in PEI indicated that the post-harvest use of fludioxonil in 2008 prevented the type of losses due to SRC experienced in previous years.”

Peters, R. D., et al.
Affiliation: Agriculture and Agri-Food Canada.
Title: Post-harvest Application of Fludioxonil for Control of Sclerotinia Rot (Sclerotinia sclerotiorum) of Carrots in Storage.
Source: Carrot Country. Winter 2009. Pgs. 12-15.