VIEW ARTICLE

Ecology and Epidemiology

Splash Dispersal of Phytophthora cactorum from Infected Strawberry Fruit. G. G. Grove, Former graduate research associate, The Ohio State University and Ohio Agricultural Research and Development Center, 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, The Ohio State University and Ohio Agricultural Research and Development Center, Wooster, 44691. Phytopathology 75:611-615. Accepted for publication 2 January 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/Phyto-75-611.

Strawberry fruits (cultivar Tristar) infected with Phytophthora cactorum were used to demonstrate and quantify the effects of splashing water on dispersal and distribution of inoculum. Water drops, averaging 0.026 or 0.41 cm in diameter, were dropped from various heights on infected fruits adjacent to petri plates containing selective media and positioned up to 1.2 m away. Sporangia, zoospores, and mycelia were readily dispersed; as a result of water-splash from the 0.41- and 0.026-cm-diameter drops, colonies formed up to 120 and 50 cm, respectively, from the inoculum source. Numbers of colonies that developed in the plates were negatively correlated with distance from the inoculum source. A multiple regression model was used to describe number of colonies as a function of distance and water drop velocity at impact. Splash dispersal of inoculum from infected fruit to healthy, attached fruit was demonstrated with potted plants.