Carrot crown rot has been identified as a major constraint to carrot production in Tasmania. The economic impacts are significant for growers, as affected carrots are either discarded or substantially downgraded in value.

The Australian vegetable industry has highlighted the need for improved knowledge on the causes of the disease complex.

A two-year strategic levy investment under the Hort Innovation Vegetable Fund, Improved knowledge of factors contributing to carrot rot (VG15066) examined the conditions conducive to the development of carrot crown rot disorders in Tasmanian production regions.

Diagnostic examinations identified five different types of carrot crown symptoms that may affect carrot marketability.

Four were carrot crown rots (ring crown rots, smooth crown rot, corky crown rot and soft watery crown rot) and one was a carrot blemish (black ring).

Carrots that have the crown rots are unmarketable. Carrots with black rings are still marketable, but most will be downgraded to low-grade carrots, drastically reducing returns to affected growers.

Read the final report here.