Many trials comparing the yielding ability of some of the sudan hybrids with Piper sudangrass have failed to show any significant differences in pasture production when based upon dry matter produced. Greenchop operators in California utilize these summer annuals in every stage of growth from near 20 inches in height to near maturity. The height at which these crops are harvested as greenchop depends upon how often the stand must be recut to keep material moving to the feeding operations. The data presented here suggests that if greenchop operators harvest their crop at about 5 to 6 ft or less in height, there is little or no advantage in using hybrids. If, however, green-chopping is confined to plant material, 7, 8, or 9 ft in height, there is a definite yield advantage from using the excellent sudan hybrids.