Host Range and Virulence of Colletotrichum truncatum, a Potential Mycoherbicide for Hemp Sesbania (Sesbania exaltata). C. D. Boyette, Research Plant Pathologist, Southern Weed Science Laboratory, Agricultural Research Service, U. S. Department of Agriculture, Stoneville, MS 38776. Plant Dis. 75:62-64. Accepted for publication 25 June 1990. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1991. DOI: 10.1094/PD-75-0062.

A previously unreported anthracnose disease incited by Colletotrichum truncatum was discovered on hemp sesbania seedlings in Washington County, Mississippi, in 1987. Hemp sesbania inoculated with 2 × 10⁷ spores per milliliter in the greenhouse were killed within 7 days. Soybean cvs. Bragg, Bedford, and Hill developed small, necrotic leaf spots, but no further symptoms occurred after 3 wk. Several cultivars of cotton, rice, and 23 other plant species representing eight plant families were immune to disease, as measured by visual assessment. Results of these tests indicate that this fungus has potential as a mycoherbicide to control hemp sesbania.

Keyword(s): bioherbicide.