Phytophthora Fruit and Heart Rots of Coconut in Hawaii. J. Y. Uchida, Department of Plant Pathology, University of Hawaii, Honolulu 96822. M. Aragaki, J. J. Ooka, and N. M. Nagata. Department of Plant Pathology, University of Hawaii, Honolulu 96822; Kauai Branch Station, University of Hawaii, Kapaa 96746; and Maui Branch Station, University of Hawaii, Kula 96790. Plant Dis. 76:925-927. Accepted for publication 10 April 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0925.

Serious fruit and heart rots of coconut have been found on the major Hawaiian islands of Kauai, Oahu, Hawaii, and Maui. Early symptoms are dark fruit rots and premature loss of young nuts. A Phytophthora species is consistently associated with fruit rots. There is a high association of fruit rots and subsequent heart rot followed by tree death. Fruit and heart rots were reproduced by inoculations. The causal organism resembles Phytophthora katsurae, but its identification remains undetermined.

Keyword(s): oogonial protuberance, Phytophthora castaneae, P. heveae.