Irrigated Hunter River lucerne (Medicago sativa), grown at Milang, South Australia, was harvested at three, four, five, and six-week frequencies during the summers of 1964-65 and 1965-66. During the second season, dry matter yields were measured and representative subsamples analyzed for crude protein, digestibility, and crude fibre. Plant density was estimated at the end of the experiment. Maximum dry matter yield was obtained when the six-week cutting frequency was used, but lucerne quality was significantly reduced below that obtained from the five-week cutting frequency. Yield and plant density were significantly reduced by the three-week cutting regime, and substantial weed invasion was recorded.