Occurrence, Impact, and Fungicidal Control of Girdling Stem Cankers Caused by Cylindrocladium scoparium on Eucalyptus Seedlings in a South Florida Nursery. E. L. Barnard, Forest Pathologist, Divisions of Forestry and Plant Industry, Florida Department of Agriculture and Consumer Services, P.O. Box 1269, Gainesville 32602. Plant Dis. 68:471-473. Accepted for publication 21 December 1983. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-471.

Cylindrocladium scoparium caused extensive losses of eucalyptus seedlings in a south Florida tree nursery by inducing girdling cankers on the lower stems of Eucalyptus grandis and E. robusta. Infections apparently started in the leaves and progressed through the petioles to the stems. Disease was enhanced by ambient nursery conditions, including overhead irrigation, high temperatures and humidity, and reduced aeration resulting from close seedling spacing. Seedlings with incipient stem infections recovered after being removed from the nursery environment and outplanted in the field. Seedlings with advanced stem lesions, however, generally failed to recover, although some initially resprouted from below the cankers after outplanting. Fungicide trials and operational experience indicate that infections can be controlled with regular applications of benomyl, chlorothalonil, and possibly, copper hydroxide.