THE PRODUCTIVITY OF INTERMEDIATE WHEATGRASS AS AFFECTED BY INITIAL HARVEST DATES AND RECOVERY PERIODS

Abstract

The productivity of Agropyron intermedium (Host.) Beauv., as influenced by variation in the date of initial harvest and length of recovery period between cuttings, was studied on irrigated land over a 2-year period. Ten initial cutting dates, each spaced 3 days apart, and two recovery periods of 21 days and 42 days, were used. Delaying the initial harvest date resulted in progressively greater dry-matter yields at the first cutting and progressively lower yields at the second cutting. Earlier and later initial cuttings gave higher yields than at the shotblade stage when this species seems to be in a critical phase of development. Grass given a 42-day recovery period between cuttings produced an average dry-matter yield of 3.63 tons per acre over the 2-year period, and 1.71 tons of root material per acre in the first crop year. Comparable yields in tons per acre for grass given a 21-day recovery period were 2.29 for dry matter and 1.31 for root material. Likewise, grass given a 21-day recovery period showed a rapid stand deterioration, whereas that given a 42-day recovery period did not show a reduction. Intermediate wheatgrass is high-yielding if managed properly and not abused by intensive cutting or grazing. It appears to be more suitable for hay production than for pasture.