VIEW ARTICLE

Chlorotic Mottle: A Newly Recognized Disease of Chrysanthemum. A. W. Dimock, Department of Plant Pathology, Cornell University, Ithaca, New York 14850; C. M. Geissinger(2), and R. K. Horst(3). (2)(3)Department of Plant Pathology, Cornell University, Ithaca, New York 14850. Phytopathology 61:415-419. Accepted for publication 13 November 1970. DOI: 10.1094/Phyto-61-415.

A chlorotic mottle of chrysanthemum (Chrysanthemum morifolium Ramat.) first noted in the cultivar Yellow Delaware proved to be graft-transmissible to a large number of chrysanthemum cultivars. Scions of some cultivars, although infected, remained symptomless, whereas others initially exhibited marked yellow-green mottling, but eventually developed pronounced general chlorosis and were somewhat dwarfed. Scions of some cultivars exhibited marked initial reaction, but later became symptomless though still carrying active incitant. The relative brevity of the early phase of striking variegation was an outstanding characteristic of the syndrome. No pathogenic bacterium or fungus was found associated with the diseased plants. The probability of virus etiology was indicated by successful inoculation of healthy chrysanthemums by standard sap inoculation techniques. Negative results of sap inoculations of standard indicator plants suggested that it was not caused by the viruses of chrysanthemum stunt, chrysanthemum mosaic, chrysanthemum aspermy, chrysanthemum dwarf-mottle, Noordam’s chrysanthemum virus B, tobacco mosaic virus, or cucumber mosaic virus. We propose that the disease be designated by the term “chlorotic mottle”.