VIEW ARTICLE

Disease Detection and Losses

Effect of Potato Virus Y on Cultivars and Hybrids of Burley Tobacco. R. C. Sievert, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Tobacco Experiment Station, Greeneville, TN 37743, Present address: Tobacco Research Laboratory, Route 2, Box 16G, Oxford, NC 27565; Phytopathology 68:974-978. Accepted for publication 10 February 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-974.

Eleven burley tobacco cultivars and hybrids infected with potato virus Y had lower yields, grade and crop indices, and market values. Tolerance to the virus was exhibited by some cultivars because its effect ranged from mild to severe. The value per hectare of tobacco from infected plants was reduced by 11 to 83%. The most tolerant cultivars were Kentucky (Ky) 10, Ky 12, and Ky 14; the least tolerant were hybrids involving L8 parentage. Cured leaf from diseased plants generally had significantly higher levels of total nitrogen, acid-insoluble nitrogen, and nitrate nitrogen, and produced a solution with a higher pH. Soluble nitrogen, total alkaloids, phenols, and water-soluble acids were generally significantly lower in infected material. Infected plants generally were shorter, and had fewer and smaller leaves than healthy plants.