Cylindrocladium Root Rot of Kiwifruit. J. P. Krausz, Associate Professor, Department of Plant Pathology and Physiology, Clemson University Pee Dee Research and Education Center, Florence, SC 29501. J. D. Caldwell, Assistant Professor, Department of Horticulture, Clemson University, Clemson, SC 29634. Plant Dis. 71:374-375. Accepted for publication 19 November 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0374.

A new disease of kiwifruit (Actinidia chinensis) has been confirmed in South Carolina. Symptoms appear as a rapid wilting of the foliage and subsequent death of plants in newly established vineyards. Extensive reddish brown to black root rot is common, and a brown discoloration of stem tissue below the bark may extend 2–6 cm above the soil line. Reddish orange perithecia occasionally develop on the lower stems of severely affected plants. A species of Cylindrocladium was consistently isolated from infected stem and root tissues of kiwifruit plants from two widely separated vineyards in the state, and proof of pathogenicity was demonstrated in greenhouse tests. Morphological observations tentatively indicate the pathogen is Cylindrocladium crotalaria (perfect stage Calonectria crotalaria). In a greenhouse test, a North Carolina isolate of C. crotalaria from peanut caused root rot symptoms on kiwifruit plants similar to those caused by an isolate of the fungus from kiwifruit.