OCCURRENCE OF FUNGI AND MYCOTOXINS ASSOCIATED WITH FIELD MOLD DAMAGEDSOYBEANS IN THE MIDWEST

Abnormally warm, humid weather from 18 September to 7 October 1986 res ulted in a delayed soybean harvest throughout the northern half of Ill inois and portions of Iowa, Michigan, Minnesota, Missouri and Wisconsi n. Twenty-four soybean samples from Illinois, Iowa, and Michigan from soybean seed either refused or heavily discounted by grain elevators w ere analyzed for percent damage, fungal infection and germination, and oil and protein content; free fatty acid content in oil; and mycotoxi ns including diacetoxyscirpenol (DAS), deoxynivalenol (DON), HT-2 toxi n, ochratoxin, T-2 toxin, zearalenone, zearalenol, and aflatoxins B-1, B-2, G(1), and G(2). The percent damage ranged from 4.7 to 25.8%, and germination ranged from 7.5 to 39.0%. Seeds were heavily infected wit h Alternaria alternata (6.3-63.0%), Fusarium graminearum (13.0-51.3%), and Phomopsis spp. (12.5-49.0%). Other fungi, including Cercospora ki kuchii and Aspergillus spp., were identified in 2.0-15.5% of the seeds . Protein, oil, and free fatty acid content were in expected ranges. Z earalenone was detected in whole soybeans, hulls, meal, and oil. Zeara lenol was detectable in hulls and meal. DON was detected in whole soyb eans, hulls, meal, and oil. DAS was detected in whole soybeans, hulls, and meal. T-2 (primarily HT-2) was detected in whole soybeans, hulls, meal, and oil. Ochratoxin was not detected and aflatoxin B-1 was foun d in hulls of only three of 24 samples, with the greatest amount detec ted being 5.8 eta g/g.