Relationships Among Aphids, Virus Yellows, and Sugarbeet Yields in the Pacific Northwest

Production of sugar from sugarbeets inoculated with beet western yellows virus (BWYV) and beet yellows virus (BYV) was reduced 27 and 17% in 1975 and 1976, respectively. Production was reduced as much as 15% when beets were inoculated with BWYV alone in 1976. Root samples from 41 commercial fields showed that the mean weight of diseased beets was significantly less than that of healthy beets. Moreover, percentage of sugar in diseased beets also was reduced. A significant correlation existed between the percentage of plants infested with green peach aphids, Myzus persicae (Sulzer), percentage infected plants, root yield, and sugar production.