This east central Iowa corn study showed that Vitazyme alone produced the greatest yield increase among the five treatments evaluated, a highly significant 18% increase (25.8 bu/acre); this yield increase produced $77.40/acre more gross income at $3.00/bu corn. Actinovate and glucose, alone or in combination, produced significant yield increases of from 9 to 15%. Grain moisture at harvest was reduced by all treatments except Vitazyme + glucose; Vitazyme + Actinovate produced a major 1.38 percentage points grain moisture reduction. Grain per plant was increased by all treatments, the greatest increase being with Actinovate alone (15%) and Actinovate + Vitazyme + glucose (14%).