First Report of Cristulariella moricola on Kenaf in Louisiana. G. E. Holcomb, Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. H. P. Viator II, and L. P. Brown. Iberia Research Station, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. Plant Dis. 76:642. Accepted for publication 28 January 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0642A.
Kenaf (Hibiscus cannabinus L.) is grown on about 240 ha in Louisiana
for use as an absorbent in oil field and animal production operations.
A severe leaf spot that resulted in 50% defoliation of all plants
was observed on cultivars Cuban 108 and Everglade 71 in a 0.5-ha
experimental planting in July 1991. Cristulariella moricola (Hino)
Redhead (syn. C. pyramidalis A. M. Waterman & R. P. Marshall)
was identified on the basis of conidial morphology from necrotic zonate
leaf spots that were up to 15 mm in diameter. The fungus, originally
isolated from leaf spots on 2% water agar, produced microconidia
and sclerotia, but no macroconidia, on potato-dextrose agar (PDA).
Typical zonate leaf spots developed on 4-wk-old seedlings 5-7 days
after they were inoculated with mycelial disks from PDA and held
in a dew chamber for 48 hr at 27 C. C. moricola was reisolated from
leaf lesions that developed on nine of 12 inoculated plants. The fungus,
previously reported from kenaf (1), is now recognized as having a
fairly large host range in the United States (2).