Cereal Chem 60:127 - 130. | VIEW
Preharvest Fungal Invasion of Sorghum Grain.
L. M. Seitz, H. E. Mohr, R. Burroughs, and J. A. Glueck. Copyright 1983 by the American Association of Cereal Chemists, Inc.
Sorghum grain from Kansas and Texas was analyzed for fungal invasion by ergosterol and whole seed plating assays. Five sorghum hybrids grown near Manhattan, KS, in 1977 were harvested at 12 weekly intervals. Fungal invasion began at or very soon after physiological maturity. Ergosterol content increased rapidly two to three weeks after physiological maturity and then relatively slowly the next seven or eight weeks as the grain weathered and discolored. The five hybrids differed little in susceptibility to fungal invasion. Species of Alternaria and Fusarium were found in all of the hybrids, with the former predominant. When Alternaria spp. began invading the grain, ergosterol contents began to increase. Eight sorghum lines, grown in 1976 at College Station, TX, were harvested on two dates 29 days apart. Due to wet weather, fungal invasion was already extensive at the first harvest and was considerably greater in all lines, especially in TAM428 and TX2536, at the second harvest. Although visual ratings of weathering and discoloration in the field correlated significantly and positively with ergosterol contents, the ratings did not adequately indicate extent of fungal invasion. Concentrations of ergosterol and another fungal metabolite, ergosta- 4,6,8(14),22-tetraen-3-one, in the College Station samples correlated. Grain from Dallas, TX, was not weathered or discolored, but differences in extent of fungal invasion were detectable by ergosterol and whole seed plating assays.