This wheat yield study in northeastern Colorado revealed that with a 50% reduction in nitrogen, yields were still excellent when Vitazyme was applied. However, it was essential that Vitazyme be applied to the seeds at planting to achieve the highest yield potential. The two hard red winter wheat varieties — Wesley and Wahoo — having similar yield potential, yielded from 57.2 to 65.1 bu/acre, while the Antelope hard white wheat, having inherently a greater yield potential than the red wheats, produced only 42.6 bu/acre. Because the Antelope white wheat did not receive a fall at-planting Vitazyme application while both red wheat varieties did, all other fer- tilizer and spring Vitazyme applications being equal across all areas, it is deduced that a fall at-planting Vitazyme application of 13 oz/acre is very important to achieve optimum dryland wheat yields.