Effects of green chopping on grain yield of naked and malting barleys in Cheju

The effects of seeding and clipping termination dates, and seeding and fertilizer rates on forage and grain yields were evaluated in 1989 harvest year for dual production of forage and grain of naked and malting barleys in Cheju province. In the experiment I, 'Saessalbori'(naked barley) and 'Doosan 22' (malting barley) were seeded on Sept. 21, Oct. 12 and Nov. 2, respectively. An unclipped (grain-only) treatment that was planted on Nov. 2 was included for check. In the experiment II, the two above cultivars were planted at seed rate of 14, 20 and 26 and Kg/10a. Fertilizer rates were 9-6-12, 17-13-8 abd 22-16-11 (N-P2O5-K2O) Kg/10a. Seeding dates were Oct. 13 and Nov. 7 for clipped treatments and grain-only treatment (seeding rate : 14Kg/10a, N-P2O5-K2O=9-6-12 Kg/10a), respectively. All treatments in both experiments were harvested for grain yield. In Saessalbori, survival following forage removal was 100 % regardless of seeding and clipping termination dates, and seeding and fertilizer rates. In Doosan 22, survival percentage decreased with increasing seeding and fertilizer rates when plants were clipped in January to Febuary. Forage yield of two cultivars increased with early planting and delays in clipping termination and tended to increase as seeding and fertilizer rates were increased. Crude ash and fat were not affected by seeding and fertilizer rates, and clipping date. N free extract tended to increase with delaying clipping date and decreased with increasing fertilizer rate. Earlier planting resulted in earlier heading and maturity. Clipping slightly delayed 3 to 5 days by increased fertilization. Clipping shortened culm length more severely in Doosan 22 than in Saessalbori. The later the clipping termination, the shorter the culm length. The number of spikes per m** (2) and the number of kernels per spike were not affected by clipping in Saessalbori while those of Doosan 22 were decreased with delays in clipping termination. Delaying forage harvest resulted in a reduction in grain yield