Korean Journal of Agricultural Science ISSN:2466-2402(Print) 2466-2410(Online) 농업과학연구

This study was done to determine the optimum sowing time for spring sowing wheat in the southern region of the entire Korean peninsula. Jokyoung and Keumkangmil were sown four times at one-week intervals starting from Feb. 14, 2013. The thousand grain weights of the two wheat varieties were the highest on February 14 with the seed weights ranging from 36.6 to 40 g and significantly decreasing as the seeding time was delayed. The unmatured grain percentage increased sharply when both cultivars were sown starting on March 7. The grain yields were the highest for Keumkangmil with 3.07 MT/ha when sowed on February 21 and 3.37 MT/ha for Jokyoung when sowed on February 14. In both cultivars, the grain yield decreased drastically when they were sown on March 7. Ash content did increase when the sowing date was delayed. The flour gluten index was the highest at 96.2 in Keumkangmil with a February 28 sowing, and the sodium dodecyl sulphate (SDS) segmentation was the lowest ranging from 63.8 to 65.3 mL with the February 28 sowing. The falling number tended to increase with the delay of the sowing period. The flour milling rate was gradually decreased with the delay of sowing, and the bran gradually decreased. When both cultivars were sown after February 28, the grain and flour yields sharply decreased. In the southern region, the optimum time for the spring sowing of wheat is from February 14 to February 21.