First Report of Dichotomophthora indica on Common Purslane in Virginia. A. B. A. M. Baudoin, Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg 24061. Plant Dis. 70:352. Accepted for publication 5 December 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-352a.
A stem blight of common purslane (Portulaca oleracea L.) was observed in Blacksburg and Winchester, Virginia, during the summer of 1985. A Dichotomophthora sp. sporulating profusely on the stems was identified as D. indica Rao on the basis of tall (230–530 μm, mean 396 μm), usually unbranched conidiophores in groups on the host tissue and relatively large (140–430 × 140–430 μm in culture) sclerotia. Koch’s postulates were completed. The fungus has been reported from India and Ontario, Canada, but not from the United States. A related species, D. portulacae Mehrlich & Fitzpatrick ex M. B. Ellis, has been reported from Hawaii and California and has been tested as a potential mycoherbicide. D. indica produces similar stem rot symptoms and may also have potential as a mycoherbicide.