Fungi Associated with the Seeds of Commercial Lentils from the U.S. Pacific Northwest. Walter J. Kaiser, Research Plant Pathologist, Agricultural Research Service, U.S. Department of Agriculture, Western Regional Plant Introduction Station, Washington State University, Pullman 99164-6402. . Plant Dis. 76:605-610. Accepted for publication 13 December 1991. 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, 1992. DOI: 10.1094/PD-76-0605.

Seeds of commercial lentils (Lens culinaris) from the Palouse region of eastern Washington and northern Idaho were sampled for pathogenic seedborne fungi during 1982–1985. Ascochyta fabae f. sp. lentis, Botrytis cinerea, Fusarium acuminatum, F. avenaceum, Macrophomina phaseolina, Phoma medicaginis var. pinodella, Rhizoctonia solani, and Sclerotinia sclerotiorum were isolated. B. cinerea and P. m. pinodella were isolated most frequently. B. cinerea was isolated from 55 and 90% of the samples and 2.2 and 8.3% of the seeds within samples in 1982 and 1983, respectively. The incidence of pathogenic and nonpathogenic fungi in commercial lentil seed from the Palouse region varied greatly from year to year. The highest incidence occurred in 1983, when the quality of some lentil seed was reduced because of discoloration of the seeds. Several pathogenic fungi, particularly B. cinerea, were frequently isolated from the discolored seeds. Saprophytic fungi isolated most frequently from lentil seed were species of Alternaria and Cladosporium. The amount of rainfall during July, when the crop was nearing maturity or about to be harvested, appeared to markedly affect the incidence, prevalence, and severity of seedborne pathogenic fungi. In 1983, when 4.3 cm of rain fell during July, seed samples were most heavily infected by seven of the eight pathogenic fungi. A. f. lentis was isolated from commercial lentil seeds originating in the Palouse region, Montana, and North Dakota. When lentil samples from Montana and North Dakota were available, A. f. lentis was isolated from all samples from North Dakota and from 25 and 35% of the samples from Montana in 1982 and 1983, respectively. A. f. lentis was isolated only from 3 and 7% of the samples from the Palouse region in 1982 and 1983, respectively, and from none of the samples in 1984 or 1985.