EFFECTS OF PREVIOUS STORAGE HISTORY, HYBRID, AND DRYING METHOD ON THESTORABILITY OF MAIZE GRAIN (CORN)

Maize grain (corn) from three harvest years (1986, 1991, and 1992) was harvested, dried, and stored in small bins. Samples taken at harvest and samples taken after various periods of bin storage (up to 77 month s) were subjected to accelerated storage tests for measurement of carb on dioxide (CO2) evolution. The initial (t < 72 h) slopes (SLOPE72) of CO2 evolution rate curves were related to storability (r = 0.82), as measured by cumulative CO2 evolution at 200 h. SLOPE72 (a faster test method than cumulative evolution) was subsequently used to evaluate th e effects of the following factors on storability: (1) hybrid, (2) dry ing method, and (3) previous storage history. Differences in storabili ty, attributable to hybrid, were significant both at harvest and after periods of bin storage. One extremely unusual growing year (severe dr ought stress) affected the otherwise consistent storability ranking am ong hybrids. Maize grain dried by high-temperature (95 degrees C) batc h crossflow drying had significantly lower storability (i.e. greater S LOPE72) than did the same hybrids dried by low-temperature (ambient ai r) drying. Previous storage history (moisture content and duration) af fected subsequent storability. Storage for longer periods, given the s ame moisture content, resulted in lower subsequent storability, and st orage at higher moisture content, given the same time period, also res ulted in lower subsequent storability.