Fungicide Control of Albinism in Citrus Seedlings Caused by Alternaria tenuis. C. R. Barmore, Associate Professor, Institute of Food and Agricultural Sciences, 700 Experiment Station Road, Lake Alfred 33850. G. E. Brown, Research Scientist III, Florida Department of Citrus, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850, and C. O. Youtsey, Chief, Citrus Budwood Registration, Division of Plant Industry, Winter Haven, FL 33880. Plant Dis. 68:43-44. Accepted for publication 20 July 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-43.

Alternaria tenuis was isolated from albino but not from healthy citrus seedlings. Seed coats of ungerminated seeds from commercial seed lots that produced a large percentage of albino seedlings were also infected with A. tenuis. Surface-inoculation of freshly extracted, air-dried seeds with Alternaria isolates obtained from albino seedlings resulted in a high incidence of albinism after storage for 4 days at 4.5 C. Infected seeds stored for 64 days at 4.5 C showed extensive decay caused by A. tenuis and reduced germination. Application of the fungicide thiram, but not chlorothalonil, immediately after inoculation of seeds effectively controlled A. tenuis and prevented albinism.