Management optimization of dual-purpose barley (Hordeum spontaneum C. Koch) for forage and seed yield

Abstract

Dual-purpose barley (Hordeum spontaneum C. Koch.) is a winter annual native to Southern Mediterranean regions. It is used to establish permanent pasture because it has a brittle rachis. Crude protein, crude fiber contents, and responses of dual-purpose barley to time of defoliation were investigated in the northern mountains of Jordan. Field trials were conducted in the 1999-2000 and 2000-2001 growing seasons in Samta (32 degrees 23′N, 35 degrees50′E) at an elevation of 1043 m. The highest protein contents (P ≤ 0.05) of 25% were recorded in February 2001. Protein content declined gradually and reached the lowest values (2.5%) at maturity. Clipping produced shorter plants, but did not impact tillering. Clipping individual plants on 28 February (14.3 and 10.2 g plant-1, respectively in 2000 and 2001) and 15 March (10.3 and 9.2 g plant-1, respectively in 2000 and 2001) did not reduce the plant shoot weight. Forage production from plants clipped on 28 February (2902 and 1274 kg ha-1, respective years), 15 March (1793 and 1394 kg ha-1, respectively in 2000 and 2001) and 15 April (1554 and 994 kg h-1, respectively in 2000 and 2001) were similar to forage production from unclipped plants. Clipping on 15 April inhibited seed production. Defoliation during early growth stages optimized seed yield and forage quantity and quality.