Fungi Associated with Sorghum Seed in Kansas

Abstract

Summary Six sorghum varieties, Westland, Midland, Martin, Atlas, Ellis, and Sumac, used in these investigations were obtained from the Kansas State Seed Laboratory at Topeka. Seed samples represented the 4-year period, 1951 to 1954. A total of 355 sorghum samples was tested, 340 of which were infected. A total of 35,500 seeds was plated and 8,702 isolations were examined. Thirty-four different genera and 63 species were identified among the fungi isolated from seed. Among the fungi isolated, Alternaria was the most common genus. The other common genera, in order of prevalence, were Fusarium, Helminthosporium, Curvularia, Thielavia, and Aspergillus. Seed from the eastern and central thirds of the state was more frequently infected than that from the western third. The total number of fungi isolated in these 3 sections of the state was 2,563 (29%), 3,627 (26%), and 2,512 (20%7o), respectively. The fungi were isolated from viable and nonviable seed with 7,026 isolations (24%) from viable and 1,676 (28%) from nonviable seed. Grain sorghums had more infected seed than did forage sorghums. A total of 5,398 isolations was made in the first group compared with 3,304 isolations from the second group. The number of isolations made in the high weight class was 4,667 compared with 4,035 in the low weight class, or seed lots with large seed were infected slightly oftener. There was a definite relationship between the incidence of fungi and poor color of the seed. The percentage of fungi isolated from the poor color seed was 32 compared with 20 for the good color group.