FUNGI ASSOCIATED WITH HOT SPOTS IN FARM STORED GRAIN

Abstract

The temperature, moisture, germination and fungal relationships of normal and heated wheat and oats collected from grain bulks in 13 granaries in Manitoba and Saskatchewan were determined during the falls and winters of 1957–60. Eight bulks were studied in detail. It was found that hot spots could develop anywhere in a bin. Temperatures up to 53 °C. (in winter) were obtained and were usually highest at the base of the bulk. Heating grain was relatively dry (less than 11 per cent) except along the surface. The highest water contents (27 per cent) in the bulks always occurred in the gram along the surface layers. Loss of germinability could occur anywhere in the bulk. Field fungi, such as Alternaria, were common in viable seed, but negligible in heated grain. The seeds in hot spots were predominantly infected by storage fungi, among which Penicillium spp. were the most abundant, even in relatively dry grain at the 6-foot depth. Other fungi commonly found were Aspergillus spp., especially A. flavus Link, A. fumigatus Fresenius, A. versicolor (Vuillemin) Tiraboschi and Absidia spp. Actinomycetes (Streptomyces) were common in some heating grain bulks.