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Disease Note.

First Report of Lentil Anthracnose (Colletotrichum truncatum) in the United States. J. R. Venette, Department of Plant Pathology, North Dakota State University, Fargo 58105-5012. H. A. Lamey, and R. L. Lamppa. Department of Plant Pathology, North Dakota State University, Fargo 58105-5012. Plant Dis. 78:1216. Accepted for publication 16 September 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1216D.

In 1992 and 1993, Colletotrichum truncatum (Schwein.) Andrus & W. D. Moore was isolated from infected stems of lentil (Lens culinaris Medik.) collected from North Dakota fields within 220 km of Manitoba where the disease was previously described (1). The cultivar in each field was often unknown, but cvs. Crimson red and Brewer Chilean were most common in the area. Both are susceptible to anthracnose. In 9 of 15 fields inspected for anthracnose, severity was light to moderate. In four fields, the disease was judged very severe, and in two fields, it was undetected. Lesions occurred on small branches and petioles but not on leaves. Lesions were shallow, bleached, and characteristically held many black, small sclerotia especially on lower stems where lesions were confluent. Acervuli in lesions had unbranched, mono- or nonseptate dark setae and straight to slightly curved conidia that averaged 19.5 plus or minus 1.9SD x 3.75 plus or minus 0.5SD μ m. From axenic cultures, aqueous spore suspensions were prepared and spray-inoculated onto 30-day-old cvs. Eston and Laird. Wet plants were incubated 3 days in controlled environments (90+% RH, 22 C, 12 h dark/fluorescent light), then transferred to a greenhouse at 255 C where lesions appeared in 7-10 days. Acervuli and conidia were produced on lesions that were similar to those on infected field plants. The pathogen was reisolated from inoculated plants. In 1993, nearly 4,000 ha lentil were grown in North Dakota, mostly in the northwestern to central part of the state. Lentil is an important alternative crop in an area where small grain production is predominant.

Reference: (I) R. A. A. Morrall. Can. Plant Dis. Surv. 69:66, 1989.