Effects of Seeding Date and Rate on Growth and Yield of Barley Cultivar 'Duwonchapssalbori' in Southern Region

In order to develop an appropriate cultural practice for a newly bred 2-rowed, waxy, naked barley cultivar 'Duwonchapssalbori' in the southern region, 2 varieties, 3 seeding dates, 4 seeding rates were designed with 2 replications. The heading and maturity dates of 'Duwonchapssalbori' were' earlier than 'Saessalbori by 2-5 and 4 days, respectively. Culm length of 'Duwonchapssalbori' was 60 to 66cm with lodging resistance. Grain yields of both varieties were 4.28-4.33 ton/ha in the plot of Oct. 20 seeding, 4.11-4.18 ton in the plot of Oct. 28 seeding, and 3.7-13.89 ton/ha in the Nov. 5 seeding. Grain yield with different seeding rates highly significantly fitted with secondary polynomial equations in the plots of Oct. 20 and Oct. 28 seedings ($R^2$=0.84-0.85), showing the greatest yield with seeding rate of 140kg per ha. However, the grain yield with various seeding rates in the plot of Nov. 5 seeding showed simple linear regression ($R^2$=0.71), showing the seeding rate over 160kg in the case of later seeding to be optimal. Number of spikes per $m^2$ significantly contributed to grain yield, and fitted to simple linear regression ($R^2$=0.881-0.891), suggesting that plenty of early stands should be established at early seedling stage for high grain yield. Young spikes of 'Duwonchapssalbori' in the plot of Oct. 20 seeding elongated with linear increments since Feb. 10 (6.7mm), and showed rapid increment since March 7 (15.1mm). However, elongation of young spikes of 'Saessalbori' began from March 15 with slow increments. From these studies, the optimum seeding date and seeding rate in 'Duwonchapssalbori' were Oct. 20-28 and 140kg per ha for high grain yield in the southern regions.