VIEW ARTICLE

Ecology and Epidemiology

Influence of Temperature and Wetness Duration on Sporulation of Phytophthora cactorum on Infected Strawberry Fruit. G. G. Grove, Former graduate research associate, Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center (OARDC), Wooster 44691, Present address: Department of Plant Pathology, University of California, Davis 95616; L. V. Madden(2), and M. A. Ellis(3). (2)(3)Assistant professor, and associate professor, respectively, Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center (OARDC), Wooster 44691. Phytopathology 75:700-703. Accepted for publication 18 January 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/Phyto-75-700.

Strawberry fruits (cultivar Tristar) infected with P. cactorum were used to determine the effects of temperature and wetness duration on sporangial production. Sporangial production increased with increased wetness duration (3?24 hr) between 12.5 and 27.5 C. For each wetness duration, sporangia production increased up to the optimum temperature (about 20 C) and then declined. Sporangia were present after 3 hr of wetness between 15 and 25 C; 100 or more sporangia were produced at these temperatures with ??16 hr of wetness. A multiple regression model was developed to describe sporangial production as a function of temperature and wetness duration.