FUNGAL COLONISTS OF MAIZE GRAIN CONDITIONED AT CONSTANT TEMPERATURES AND HUMIDITIES

Fungal colonization of shelled maize (Pioneer 3320) harvested from a f ield near Furman, South Carolina, in 1992 was determined after 348 and 751 days of continuous storage at each of seven temperatures (10, 15, 20, 25, 30, 35, or 40 degrees C) and four constant relative humiditie s, giving equilibrium grain moisture contents ranging from 9.4% to 17. 5% m.c. in 28 grain conditioning environments. Twenty fungal species i nfected surface sterilized seeds and were recorded from these conditio ned grain treatments, including species commonly found in preharvest m aize [e.g. Acremonium zeae, Aspergillus flavus, Fusarium moniliforme ( syn. F. verticillioides), Pennicillium pinophilum (syn. P. funiculosum ), etc.]. Eupenicillium cinnomopurpureum and Monascus ruber were recor ded only from conditioned grain treatments, Eurotium chevalieri coloni zed 50-96% of the kernels from grain conditioning treatments with the highest moisture content for each incubation temperature. Grain sample s with >33% E. chevalieri infection had a decreased occurrence of F. m oniliforme, and A. zeae, and no kernels from these samples germinated. No fungi colonized more than 50% of the kernels conditioned at 30-40 degrees C and 9.4-14.2% m.c. The results of this study indicate that i ndividual patterns of fungal colonization during grain conditioning we re a function of the survival rates for preharvest fungal colonists an d their potential replacement by E. chevalieri. Published by Elsevier Science Ltd.