Fungal Colonists of Maize Grain Conditioned at Constant Temperatures and Humidities

Authors

• Donald T. Wicklow, USDA-ARS
• David K. Weaver, USDA-ARS
• James E. Throne, USDA-ARS, Manhattan, KSFollow

Document Type

Article

Date of this Version

1998

Citation

J. stored Prod. Res. Vol. 34, No. 4, pp. 355-361, 1998

Comments

Published by Elsevier Science Ltd

This document is a U.S. government work and is not subject to copyright in the United States.

Abstract

Fungal colonization of shelled maize (Pioneer 3320) harvested from a field 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°C) and four constant relative humidities, giving equilibrium grain moisture contents ranging from 9.4% to 17.5% m.c. in 28 grain conditioning environments. Twenty fungal species infected surface sterilized seeds and were recorded from these conditioned grain treatments, including species commonly found in preharvest maize [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 treatments. Eurotium chevalieri colonized 50-96% of the kernels from grain conditioning treatments with the highest moisture content for each incubation temperature. Grain samples with >33% E. chevalieri infection had a decreased occurrence of F. moniliforme and A. zeae, and no kernels from these samples germinated. No fungi colonized more than 50% of the kernels conditioned at 30-40°C and 9.4-14.2% m.c. The results of this study indicate that individual patterns of fungal colonization during grain conditioning were a function of the survival rates for preharvest fungal colonists and their potential replacement by E. chevalieri.