Experimental Transmission of Citrus Blight. D. P. H. Tucker, Professor, University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, Lake Alfred 33850. R. F. Lee, Associate Professor, L. W. Timmer, Professor, L. G. Albrigo, Professor, and R. H. Brlansky, Assistant Professor, University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, Lake Alfred 33850. Plant Dis. 68:979-980. Accepted for publication 1 May 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-979.

Eight mature, blight-affected Pineapple sweet orange (Citrus sinensis) trees on rough lemon (C. jambhiri) rootstock were transplanted to an area of low blight incidence. Healthy trees of bearing age and of the same cultivar were transplanted next to each blight-affected donor tree and several roots each of the healthy, receptor trees and the blighted donors were splice-grafted together. An equal number of control trees was transplanted to an adjacent row. After 3 yr, receptor trees had significantly higher concentrations of zinc in trunk phloem than the controls. After 4 yr, seven of eight receptor trees had typical visual symptoms of blight, significantly higher concentrations of zinc in trunk wood, lower water uptake, and amorphous plugs in the vessels of the trunk. Only one of eight control trees developed these typical blight symptoms. This is the first report of experimental transmission of citrus blight.