Effect of Mosaic Viruses on Infection of Horseradish by Spiroplasma citri. Jacqueline Fletcher, Department of Plant Pathology, University of Illinois, Urbana 61801. Gerald A. Schultz and Catherine E. Eastman, Illinois Natural History Survey, Champaign 61820. Plant Dis. 68:565-567. Accepted for publication 1 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-565.

Horseradish (Armoracia rusticana) crops in Illinois may be severely damaged by brittle root disease, caused by Spiroplasma citri. Horseradish, a vegetatively propagated crop, is virtually 100% infected with turnip mosaic virus, and cauliflower mosaic virus has also been found. Studies to determine the effect of these viruses on brittle root disease in horseradish showed that prior infection with mosaic viruses is neither a requirement nor a preventive for subsequent infection with S. citri or for development of brittle root symptoms.

Keyword(s): Circulifer tenellus.