The appearances of growth and yield according to the cultivation types were investigated in chalok 1. The days to harvest under double vinyl house, open mulching and open cultivation were 87.7, 95.8, and 101.8 days, respectively and significantly different in each cultivation types. The branched ears of open mulching, double vinyl house and open cultivation were started at 7,8, and 13 days after silking, respectively. The frequency of branched ear per total plants to double vinyl house, open cultivation and open mulching were 10%, 13%, and 19%, respectively. The ear weight of open mulching and open cultivation was superior to branched ear weight. The yields (kg/10a) of double vinyl house, open mulching and open cultivation were 755.7kg, 740.7kg, and 530.0kg, respectively. The yields(kg/10a) of double vinyl house and open mulching were significantly different to that of open cultivation and LSD(5%) was 133.42. Thus, early cultivations in double vinyl house were more beneficial than other cultivation types because of the highest yield and the lowest branched ear.

Chalok 1/Cooktail 51' corns, supersweet corn gene controlled by either brittle-l (bt l) or shrunken-2(sh2) gene introduced into waxy corn, showed agronomic characteristics between supersweet corn and waxy corn. The ears were harvested at different development stages from 15 to 35 days after silking (DAS). Ear diameter of Cocktail 51 and 'Cocktail 51'/Chalok 1 increased from 15 DAS to 30 DAS and little increased thereafter, but that of Chalok 1/Cocktail 51 and 'Chalok l' increased until 35 DAS. Diameter of ear extension increased more in Cocktail 51 and Chalok 1/Cocktail 51 corn than Chalok 1. Ear fresh weight of Cocktail 51 decreased later 30 DAS but those of the other hybrids were vice versa. Rate of super-sweet kernels per ear of Chalok 1/Cocktail 51 corns was about 38 %. Development, and elongation of kernel were much more prominent in supersweet kernel than in waxy kernel, but fresh weight increased higher in waxy kernel than supersweet kernel. Moisture content in kernel decreased from 15 DAS to 35 DAS. Total sugar content of the kernel increased until 25 DAS, and that of Cocktail 51 kernel showed the highest among of them. After cooked by steam, flavor and mastication feeling rate cooked by steam of Cocktail 51 and Chalok 1/Cocktail 51 were increased from 15 DAS to 25 DAS and markedly decreased thereafter. But those of Chalok l/Cocktail 51 and, Chalok 1 were decreased after 30 DAS. These results suggested that the optimum harvest date for fresh supersweet corn (Cocktail 51), Cocktail 51/Chalok 1 seems to be about 20 DAS and Chalok 1/Cocktail 51 and waxy com (Chalok 1) was about 25 DAS.