Link to home

Finger Imprint of Poncirus trifoliata: A Specific Interaction of a Viroid, a Host, and Irrigation

July 2004 , Volume 88 , Number  7
Pages  709 - 713

G. Vidalakis , D. J. Gumpf , J. A. Bash , and J. S. Semancik , Department of Plant Pathology, University of California, Riverside 92521

Go to article:
Accepted for publication 26 February 2004.

The unusual symptom, “finger imprint”, described exclusively on Poncirus trifoliata, has been reported in only a single field trial investigating the effects of citrus viroids on crop performance. With this, the question has persisted whether the observed growth abnormality was a disease symptom induced by Citrus viroid IIIb (CVd-IIIb) or a consequence of mechanical damage caused by the handling of young trees during propagation or cultural practices in the field. The recurrence of finger imprint symptoms on trees after 5 years in the field in which no abnormal growth features were previously noted now supports the proposition of a viroid-induced disease. The symptom expression results from an unusual etiology of a complex relationship of the specific viroid CVd-IIIb on the specific rootstock P. trifoliata only when supplemental water is applied by sprinkler irrigation.

Additional keywords: citrus disease, citrus dwarfing

© 2004 The American Phytopathological Society