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United States Department of Agriculture

Agricultural Research Service

Title: Fungal Colonists of Maize Grain Conditioned at Constant Temperatures and Humidities

Authors
item Wicklow, Donald
item Weaver, David
item Throne, James

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 1998
Publication Date: N/A

Interpretive Summary: Improper storage of shelled corn can lead to mold growth resulting in significant losses in grain quality which can lead to reduced acceptability by the end user. Our only examples of mold colonization of stored grain are "hot spots" associated with damp pockets from leaks in the storage structure and storage of high-moisture corn. There is a need to examine mold colonization of undamaged grain under long-term "safe" storage conditions. Different patterns of mold colonization of shelled corn are reported for a range of constant temperatures and moistures for a period of 751 days' continuous storage. These data will be used by scientists in evaluations of the practical use of selected environmental controls to maintain grain quality.

Technical Abstract: Fungal colonization of shelled corn (Pioneer 3320) was determined after 348 and 751 d of continuous storage at each of seven temperatures (10, 15, 20, 25, 30, 35, or 40 C) and four constant relative humidities, giving equilibrium grain moisture contents in the range of 9.4%-17.5% m.c. Twenty fungal species were recorded from these conditioned grain treatments, including commonly occurring species from preharvest corn [e.g. Acremonium zeae, Aspergillus flavus, Fusarium moniliforme (syn. F. verticillioides), Penicillium pinophilum (syn. P. funiculosum), etc.]. Eupenicillium cinnamopurpureum and Monascus ruber were recorded only from conditioned grain. Eurotium chevalieri colonized 50%-96% of the kernels from grain conditioning treatments giving the highest moisture content for each incubation temperature. Grain samples with >33% E. chevalieri infection showed a decreased occurrence of F. moniliforme and A. zeae, with no germinated kernels. No fungal colonists were recorded from 50-100% of the kernels condition at 30-40 C and 14.2-9.4% m.c. Individual patterns of fungal colonization during grain conditioning were a function of the survival rates for pre-harvest fungal colonists and their potential replacement by E. chevalieri, E. cinnamopurpureum or M. ruber.

Last Modified: 11/23/2014