VIEW ARTICLE

Dispersal of Beet Yellows and Beet Mosaic Viruses in the Inland Valleys of California. R. J. Shepherd, Department of Plant Pathology, University of California, Davis 95616; F. J. Hills, Department of Agronomy, University of California, Davis 95616. Phytopathology 60:798-804. Accepted for publication 4 December 1969. DOI: 10.1094/Phyto-60-798.

Surveys of sugarbeet fields in inland-valley areas of California following intensive spring flights of the green peach aphid indicate that beet mosaic and beet yellows may be markedly reduced by isolating beet fields by 12-15 and 15-20 miles, respectively, from a large area source of infected beets. Early-season mosaic decreased as a parabolic function of distance, whereas early-season yellows decreased linearly with distance from inoculum source. The probable source of infection with both viruses appeared to be infected beets.