FUNGAL AND MYCOTOXIN CONTAMINATION OF PEARL-MILLET GRAIN IN RESPONSE TO ENVIRONMENTAL-CONDITIONS IN GEORGIA

Pearl millet hybrid Tift 90DAE X Tift 8677 was planted at Tifton, Georgia, on five dates in both 1990 and 1991. Grain was harvested about 33 days after anthesis. Seedborne fungi were determined from 300 seeds from each seed lot. The most frequently isolated fungi were Fusarium semitectum (26% of seed), Alternaria spp. (19%), and Curvularia spp. (13%). Total Fusarium isolations, including F. semitectum, averaged 46%. Isolation frequencies of several fungi were related to weather conditions 2-4 wk prior to harvest. Aflatoxins were detected from grain planted in both years, and concentrations averaged 0.3 ng/g. Deoxynivalenol, nivalenol, zearalenone, and 15-acetylscirpentriol were detected only in the 1991 samples, and levels averaged 0.3, 1.2, 0.3, and 0.4 mug/g, respectively, Isolation of F. chlamydosporum was positively correlated (r greater-than-or-equal-to 0.66) with concentrations of trichothecenes and zearalenone. Although pearl millet grown in Georgia does not appear to be prone to infection by Aspergillus flavus and aflatoxin contamination, a potential for problems from infection by toxigenic Fusarium species does exist.