VIEW ARTICLE

Residual Effect of Soil Fumigation with Vine Burning on Control of Verticillium Wilt of Potato. G. D. Easton, Associate Plant Pathologist, Experimental Aide II, Department of Plant Pathology, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser, WA 99350; M. E. Nagle(2), and D. L. Bailey(3). (2)(3)Experimental Aide II, and Technical Farm Laborer, respectively, Department of Plant Pathology, Washington State University, Irrigated Agriculture Research and Extension Center, Prosser, WA 99350. Phytopathology 65:1419-1422. Accepted for publication 3 July 1975. DOI: 10.1094/Phyto-65-1419.

Soil fumigation in a potato field left a residual effect for a year which increased tuber yields even though it did not measurably reduce Verticillium albo-atrum in soil or potato stems. Current-season fumigation, however, reduced populations of the pathogen and increased tuber yields more than the 1-year-old residual effect of fumigation. The residual effect of fumigation with yearly vine burning increased potato yields as much as current-season fumigation. By the second year after fumigation, with or without continued vine burning, no residual effect of fumigation was detected on either pathogen propagules or potato yields. Beneficial effects from repeated current-season fumigations were not cumulative since a single current-year fumigation gave tuber yields equal to repeated annual fumigations.