Control of Pineapple Disease of Sugarcane with Propiconazole. J. C. Comstock, Associate Plant Pathologists, Crop Science Department, Experiment Station, Hawaiian Sugar Planters’ Association, Aiea 96701. S. A. Ferreira, Associate Plant Pathologists, S. A. Ching, Associate Chemist, and H. W. Hilton, Head, Crop Science Department, Experiment Station, Hawaiian Sugar Planters’ Association, Aiea 96701. Plant Dis. 68:1072-1075. Accepted for publication 18 May 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1072.

In culture, propiconazole inhibited the growth of Ceratocystis paradoxa, the major pathogen that rots vegetative cuttings of sugarcane (Saccharum spp.) in Hawaii. Percent germination of the lateral buds of propiconazole-treated vegetative cuttings was greater than that of vegetative cuttings treated with benomyl and thiophanate-methyl, the two fungicides registered for use in Hawaii, and considerably greater than for untreated controls. Propiconazole is water-soluble at the recommended concentrations, and hence compatible with a 20-min immersion in water at 52 C, which is used in Hawaii to stimulate lateral bud germination of vegetative cuttings. At 8 or 12 wk, whole plants that developed from treated vegetative cuttings had residues less than 0.01 ppm based on the use of radiolabeled fungicide. Once registered, propiconazole will be useful in controlling an important sugarcane disease.