Effect of Ribavirin on Green Ring Mottle Causal Agent and Necrotic Ringspot Virus in Prunus Species. A. J. Hansen, Research Scientist, Agriculture Canada, Research Station, Summerland, BC, Canada V0H 1Z0. Plant Dis. 68:216-218. Accepted for publication 29 August 1983. Copyright 1984 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-68-216.

Ribavirin, a guanosine analogue, was applied as a foliar spray to seven 2-yr-old Prunus serrulata ‘Kwanzan’ trees infected with the non-sap-transmissible viruslike agent (VLA) of green ring mottle (GRM). Weekly applications of 500 ppm ribavirin prevented symptom development on newly developing Kwanzan foliage and gradually eliminated the infective principle from the previously infected older wood. Back-indexing confirmed that new shoots were free of GRM and demonstrated that the VLA in older wood gradually disappeared. One year after ribavirin treatments were stopped, no symptoms or VLA could be detected in shoots or limbs. Two P. persica ‘Veteran’ trees infected with necrotic ringspot virus (NRSV) and treated with weekly foliar applications of ribavirin continued to display virus symptoms throughout the growing season. Back-indexing in the fall indicated that NRSV was still present.

Keyword(s): chemotherapy.