UCHIDA, J. Y., and M. ARAGAKI. 1979. Etiology of necrotic flecks on Dendrobium blossoms. Phytopathology 69:1115-1117. Dark necrotic flecks are common on field-cultivated Dendrobium inoculation. A. alternata was the most frequently isolated organism. The flowers in Hawaii and are a significant factor in quality reduction. recovery rate of A. alternata from flecks was 40.5% 3 days and 4.1% 6 days Microscopic examinations revealed one or more amerospores, after laboratory inoculation. The low isolation rate of fungi from fielddictyospores, or phragmospores near the center of 41.7% of the flecks. collected flecks and the rapid loss of viability of A. alternata after artificial Among the many fungi isolated from the flecks, only Botrytis cinerea, inoculation are consistent with the proposition that flecks are Alternaria alternata, Bipolaris setariae, B. urochloae, B. sorokiniana, predominantly aborted infections. Exserohilum rostratum, and Stemphylium sp. incited flecks by artificial Blossom blights and rots caused by Botrytis cinerea Pers. ex Fr. had a minimum of five open flowers and one bud. One isolate of (1,8), Botrytis spp. (1,7,8), A lternaria spp., and Gloeosporium spp. each of the following fungi from Dendrobium blossom flecks was (7) create serious problems in orchid production. Numerous used: Alternaria alternata (Fr.) Keissler, Bipolaris setariae (Saw.) restricted necrotic lesions or flecks (less than 0.5 mm in diameter) Shoemaker, B. urochloae (Putterill) Shoemaker, B. sorokiniana also occur on Dendrobium flowers. In a previous study (8), (Sacc. ex Sorok.) Shoemaker, B. hawaiiensis (Bugnicourt ex M. B. isolations from field-collected flecks did not yield Botrytis or reveal Ellis) Uchida & Aragaki comb. nov., Exserohilum rostratum any consistent fungal associations. Artificial inoculation with B. (Drechsl.) Leonard & Suggs, Curvularia sp., Stemphylium sp., cinerea and Botrytis spp., however, induced flecks on Dendrobium Phyllostictina sp., Nigrospora sp., and Pestalotia sp. [Bipolaris blossoms. hawaiiensis is transferred from Drechslera because its conidial The persistent occurrence of flecks on Dendrobium blossoms, morphology and bipolar germination are consistent with particularly in outdoor cultivation and often without Botrytis Shoemaker's (11) description of Bipolaris. Thus: outbreaks, suggests there are other fleck incitants. Even though Bipolaris hawaiiensis (Bugnicourt ex M. B. Ellis) Uchida & functional damage to the flowers is insignificant, flecking reduces Aragaki comb. nov. market acceptability and causes considerable economic losses. The = Drechslera hawaiiensis (Bugnicourt) Subramanian & Jain ex present study was undertaken to resolve the etiology of flecks on M. B. Ellis, 1971, Dematiaceous Hyphomycetes, Commonw. Dendrobium blossoms.