VIEW ARTICLE

Postharvest Pathology and Mycotoxins

Fungal Populations in U.S. Farm-Stored Grain and Their Relationship to Moisture, Storage Time, Regions, and Insect Infestation. D. B. Sauer, Research plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, U.S. Grain Marketing Research Laboratory, Manhattan, KS 66502; C. L. Storey(2), and D. E. Walker(3). (2)(3)Research entomologist, and electrical engineer, respectively, U.S. Department of Agriculture, Agricultural Research Service, U.S. Grain Marketing Research Laboratory, Manhattan, KS 66502. Phytopathology 74:1050-1053. Accepted for publication 14 May 1984. 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, 1984. DOI: 10.1094/Phyto-74-1050.

One hundred surface-disinfected kernels were plated from each of 2,557 samples taken from farm bins in 27 states in 1980. Aspergillus glaucus was found in 84% of the corn, 70% of the oat, and 37% of the wheat samples. Corn, oat, and wheat samples with A. glaucus had averages of 26, 20, and 14% of the kernels invaded, respectively. Fungal contamination varied little in corn from four crop years. Wheat from the most recent (1979) crop year was low in storage fungi and high in field fungi compared with earlier crop years. Storage fungi averaged higher in samples with higher as-received moisture contents, even though most moisture contents were too low to permit mold growth. A. glaucus was also higher in northern compared with southern states in the central plains. Other storage fungi found included A. restrictus and other species of Aspergillus and Penicillium. A. flavus was found in an average of 1.2% of all corn kernels and in less than 0.1% of the oats and wheat. Samples heavily invaded by storage fungi were more likely to also contain insects than were lightly invaded or uninvaded samples. This report provides the first extensive documentation of the incidence and extent of fungal invasion in farm-stored grain in the United States.