VIEW ARTICLE

Etiology

Phytophthora capsici, Corrected Name for the Cause of Phytophthora Blight of Macadamia Racemes. R. K. Kunimoto, Research Associate, Department of Plant Pathology, University of Hawaii, Beaumont Agricultural Research Center, Hilo 96720; M. Aragaki(2), J. E. Hunter(3), and W. H. Ko(4). (2)Plant Pathologist, Department of Plant Pathology, University of Hawaii, Honolulu 96822; (3)(4)Associate Professors, respectively, Department of Plant Pathology, University of Hawaii, Beaumont Agricultural Research Center, Hilo 96720, (3)Present address: Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456. Phytopathology 66:546-548. Accepted for publication 10 November 1975. DOI: 10.1094/Phyto-66-546.

One of the causal organisms of Phytophthora blight of macadamia racemes, originally identified as most closely resembling Phytophthora nicotianae var. parasitica, is herein referred to P. capsici. Unlike P. nicotianae var. parasitica, the fungus did not produce chlamydospores after mycelial mats were submerged in water at 16 C for 3 weeks. It produced abundant ellipsoidal sporangia with a length-to-width ratio of approximately 2.0. The sporangia were readily detachable; substantial portions of the sporangiophore remain attached and resulted in conspicuous pedicels which average 144 µm in length.