What is Heart Rot pg.2
This coconut Phytophthora is new to Hawaii and is unique in that it has not been found on any other host in the Islands. Pure cultures of the new Phytophthora were taken from diseased coconut collected on the islands of Kauai, Oahu, Maui, and Hawaii. These cultures were tested on healthy coconut fruits and young plants, and pathogenicity was confirmed on fruits (Figs. 1O, 11, 12, 13, and 14) and young plants.
The coconut Phytophthora resembles P. katsurae, a pathogen causing a serious disease on chestnut in Japan. Among all species of Phytophthora described by 1970, P. katsurae was the best match for identification of the coconut Phytophthora. The coconut pathogen was tentatively named P. katsurae. In Africa, a similar coconut disease reportedly has been caused by a pathogen assigned to P. heveae. Based on oogonial characteristics, this coconut pathogen from Africa appears similar to the coconut pathogen discovered in Hawaii and resembles P. katsurae more than P. heveae.
Fig.1 Coconut fruits infected with Phytophthora. A, B. Diseased areas are mottled, brown, and black.Irregular expansion of tha disease produces green islands surrounded by darkened diseased tissue.
