Field experiments with medium red and mammoth red clover at Ames, conducted over a period of years, showed that the stage of maturity of the plants at the time the first crop was cut had a marked influence on total yield of forage, the actual and potential seed yields and the quality of forage.

Dry matter production in the first crop of medium red clover increased until maturity was reached, while in mammoth red clover, the highest yield was obtained at the full bloom stage. Leaf loss, as the plants of mammoth red clover approached maturity, apparently accounted for an actual decrease in the yield of dry matter.

The highest yield of forage of medium red clover, for the whole season, was obtained by cutting the first crop at the late bloom stage and the second crop at the full bloom stage. With mammoth red clover, the highest yield was obtained by cutting the first crop at the early bloom stage and the second crop at the full bloom stage. Data on actual and potential seed yields of medium red clover indicated that seed production was favored by cutting the first crop for hay at the early bloom stage.