Abstract
Studies were conducted in Potter Co., Pennsylvania to investigate the effect of powdery scab (Spongospora subterranea) on five potato cultivars (Norchip, Rosa, Kennebec, Katahdin, and Monona) at two planting dates. Soil temperature was within the range of 15–18 C and soil moisture was within 15–19% based on dry weight throughout the season. The effect of planting date was significant at each disease assessment, except for the severity on the fourth assessment. By the end of the season, incidence of scab was 66% or more for all cultivars. Rosa, Kennebec and Katahdin had a greater scab incidence over both planting dates and a greater severity at the first planting date than Monona and Norchip.
Compendio
Se realizaron estudios en el Condado de Potter, Pennsylvania con el objeto de investigar el efecto de la roña (Spongospora subterranea) sobre cinco cultivares de papa (Norchip, Rosa, Kennebec, Katahdin y Monona) a dos fechas de siembra. La temperatura del suelo se mantuvo en un intervalo de 15–18 C y la humedad basada en el peso seco durante el cultivo estuvo entre 15–19%. El efecto de la fecha de siembra fué significativo para cada avaluación con excepción de la severidad hacia la cuarta evaluación. Hacia el final del cultivo, la incidencia de roña fue de 60% o mayor para todos los cultivares. Rosa, Kennebeck y Katahdin tuvieron una mayor incidencia de roña para ambas fechas de siembra y una mayor severidad que Monona y Norchip para la primera fecha de siembra.
Similar content being viewed by others
Literature Cited
James, W.C. 1971. An illustrated series of assessment keys for plant diseases, their preparation and usage. Can Plant Dis Surv 51:39–65.
Manzer, F.E., R.V. Akeley and D. Merriam. 1964. Resistance to powdery scab inSolanum tuberosum L. Am Potato J 41:374–376.
Ramsey, G.B. 1918. Influence of moisture and temperature upon infection bySpongospora subterranea. Phytopathology 8:29–31.
Roer, Lars. 1983. Testing potato cultivars for resistance to powdery scab (Spongospora subterranea). Potato Res 26:398.
Tooley, P.W. and C.R. Grau. 1984. Field characterization of rate-reducing resistance toPhytophthora megasperma f. sp.glycinea in soybean. Phytopathology 74:1201–1208.
Van Arsdel, E.P. 1963. A simple weather instrument shelter for plant disease investigations. US For Serv Res Note LS-18.
Author information
Authors and Affiliations
Additional information
Contribution No. 1647, Department of Plant Pathology, the Pennsylvania Agricultural Experiment Station. Authorized for publication June 24, 1987 as Journal Series Paper No. 7715.
Rights and permissions
About this article
Cite this article
Christ, B.J., Weidner, R.J. Incidence and severity of powdery scab on potatoes in Pennsylvania. American Potato Journal 65, 583–588 (1988). https://doi.org/10.1007/BF02908339
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02908339