RELATIONSHIP BETWEEN EQUILIBRIUM RELATIVE-HUMIDITY AND DETERIORATION OF SHELLED CORN

The effects of hybrid and mechanical damage on equilibrium relative hu midity (ERH) and allowable storage time (AST), as determined by CO2 pr oduction and dry matter loss caused by fungi, were measured for shelle d corn. The results were used to study the relationship between ERH an d AST. Corn with 16% mechanical damage had lower ERH than corn with 2% mechanical damage, but corn with greater mechanical damage had shorte r AST. Normally, fungi grow more slowly (meaning AST is longer) at low er ERH. Apparently, the seed pericarp breakage associated with mechani cal damage allowed faster fungal growth even though mechanical damage reduced ERH. Pioneer hybrid P3377 had higher ERH and shorter AST than hybrids FRB73xMo17 and FR35xFR20. Differences in ERH helped explain th e differences in storability of the hybrids. For 13 to 22% moisture co rn, chemical composition could be used to predict the ERH of each hybr id within two percentage points, and thus composition could be used to predict the relative storability of each hybrid.