VIEW ARTICLE

Disease Detection and Losses

Influence of Recent and Chronic Virus Infections on Strawberry Growth and Yield. L. W. Martin, Superintendent, North Willamette Experiment Station, Oregon State University, Aurora, OR 97002; R. H. Converse, Plant Pathologist, Western Region, Agricultural Research Service, United States Department of Agriculture, Corvallis, OR 97331. Phytopathology 67:573-575. Accepted for publication 15 November 1976. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-573.

The spread of viruses into strawberry (Fragaria × ananassa ‘Hood’), and the effects of these viruses on growth and yield were measured under field conditions in the Willamette Valley, Oregon, over a 37-mo period. Strawberry mottle, mild yellow-edge, and crinkle viruses were the most common of those detected and usually occurred together. The percentage of infected plants increased yearly, reaching 91% in the 3rd yr. Recent virus infections (those that occurred within 1 yr prior to the sampling date) did not significantly reduce the number or weight of fruit per plant compared to that of healthy plants in 1973 and 1974. In contrast, during the same period, fruit number, weight of fruit per plant, and weight of plant tops after harvest were significantly reduced (16, 19, and 17%, respectively) by chronic virus infections (those occurring more than 1 yr before sampling) when compared to recently infected plus healthy plants.