Managing Sclerotinia rot of carrots with canopy trimming

K.R. Sanderson and R.D. Peters

Abstract
Recent research in Prince Edward Island (PEI), Canada has indicated that clipping the carrot canopy at row closure has been shown to reduce disease levels dramatically and promote conditions detrimental to the development of Sclerotinia rot of carrots (SRC), caused by Sclerotinia sclerotiorum.

In 2006 at the Harrington Research Farm in PEI, a prototype carrot foliage trimmer (CFT) was designed and manufactured. The CFT mows the lateral foliage of adjacent carrot rows which opens the carrot canopy to allow sunlight to penetrate, foliage to dry and also removes older senescing foliage, thus eliminating conditions conducive to SRC development.

Field evaluation has shown that trimming has no effect on carrot yield or quality.

In 2006, trimming at row closure significantly reduced the incidence of SRC on foliage by 82% and in carrot roots in storage by 75%, compared to the untrimmed control plots.

In 2007, two nine-row commercial units were built by the carrot industry in North America, one in Nova Scotia, Canada and one in Wisconsin, USA. In the Annapolis Valley, Nova Scotia, commercial trimming in 2007 reduced the number of diseased petioles in selected grower fields by 72%, 54% and 37% for the varieties Sugarsnax, Topcut and Uppercut, respectively.

Mechanical canopy trimming is rapidly becoming an effective tool in the management of carrot disease.


Source
Presented at Guelph Organic Conference 2008


Author Locations and Affiliations
Agriculture and Agri-Food Canada, 440 University Ave., Charlottetown, PE C1A 4N6. Tel: 902-566-6881; Fax: 902-566-6821; E-mail: sandersonk@agr.gc.ca


en français


Posted January 2008