• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.196-207
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• 2016

In monsoon climates, persistent shade is a troublesome weather condition with an impact on the growth and yield of corn (Zea mays L.). We imposed 7, 14, 21, and 28 days of consecutive shade (CS) on Gwangpyeongok and P3394 corn hybrids at the beginning of the kernel filling stages. Shade had little impact on leaf area and dry matter accumulation in the stem and leaves. However, dry matter accumulation in the ear was severely reduced by approximately 28% and 53% after 14 and 28 days of CS, respectively. For the components of grain yield, 7 and 14 days of shade did irreparable damage to the number of filled kernels, the kernel number per ear row, and the percent of filled kernels, but did little damage or reversible damage after removal of the shade to the 100-grain weight and the row number per ear. Shade significantly reduced the relative growth rate (RGR) due to a decrease in the net assimilation rate (NAR). These results suggest that source activity limitation by shade during the kernel filling stages leads to the inhibition of sink activity and size. The yield of biomass, ear, and grain logistically declined as the length of CS increased. Probit analysis revealed that the number of days of CS needed to cause 25% and 50% reductions in grain yield were 3.7 and 23.1, respectively. These results suggest that the plant yield loss induced by shade at the beginning of the kernel filling stages is mainly achieved within the first 7 days of consecutive shade.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.29-34
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• 2012

This study was carried out to identify the characteristics of 37 corn hybrids, which composed with 18 yellow colored kernel, 9 purple colored kernel, 8 white colored kernel. Days to silking of three colored waxy corn hybrids ranged from 61 to 73 days after sowing as midium-late ecotype. Ear length of hybrids ranged from 10.3 to 22.7 cm, and among them a total 22 waxy corn hybrids including CNU038 showed over 20 cm in ear length. The fresh weight per ear ranged from 58 to 289 g as the 32.9% of large coefficient of variance. In there results, we found yellow colored waxy corn hybrids showed relatively longer in ear length and heavier in fresh weight per ear compare to other colored waxy corn hybrids. In correlation relationships, plant height, ear height, stem diameter, ear length and ear weight showed positive correlation between themselves, while tip filling ratio did negative correlation with silking stage, plant height, ear length, ear weight and kernel thickness. Also, 100 kernel weight did positive correlation between traits related to ear and kernel.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.73-82
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• 2014

This study was conducted to investigate the ear and kernel characteristics of waxy corn during ripening by double cropping, and to understand the pattern of starch accumulation in endosperm of waxy corn kernels. Chalok4 and Ilmichal were sown at April 20 (first cropping) and July 20 (second cropping) in 2011~2012. The accumulated temperature from silking to harvesting was about $590{\sim}630^{\circ}C$. It takes 23~24 days when Chalok4 and Ilmichal were sown in April 20, but July 20 sowing takes 32~35 days. Ear length and kernel set length were significantly shorter in second cropping (p<0.05). Kernel length, kernel width, 100-kernel weight, and starch content of waxy corn were increased as ears matured (p<0.05). Growth temperature was getting decreased during the ripening stage of second cropping, the rate of ear and kernel development had slowed. Starch granules started to accumulate in the cells around the pericarp, then developed in the cells around the embryo. In the second cropping, starch granules in the kernel of waxy corn were less compact than the first cropping, harvesting time of waxy corns can be extended. These results will be helpful to farmers for double cropping of waxy corn cultivation and management.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.4
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• pp.71-82
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• 1979

Transparent vinyl-mulching cultivation plots heavy-fertilized (6-14-20 kg $10a^{-1}\; of\; N-P_2O_5-K_2O)$ in growing peanuts produced 315-344Kg $10a^{-1}$ of quality kernels through improvement of the low temperature conditions of underground environment during the early growing stage and kernel-filling stage. The yields of which were 82-99 percent higher than that of conventional cultivation plot. The vinyl-mulching cultivation techniques accelerated emergence, young seedling growth, flowering, pod bearing and kernel filling of peanuts in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.445-456
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• 2014

This study was conducted to investigate the kernel characteristics of sweet corn during ripening with different sowing date. Godangok and Guseulok were sown at April 10, July 10, July 20, and July 30 in 2013. Irrespective of sowing date, fresh and dry weight of 100 kernel, starch content, crude fat content, and hardness of sweet corn kernels were significantly increased according to maturation (p<0.05). But moisture content, total sugar content, crude protein content and crude ash content of sweet corn kernels were significantly decreased according to maturation (p<0.05). The changing rates of 100 kernel weight and starch content on kernels were faster at early sowing date than at late sowing date. The moisture content of sweet corn kernels was 68~69% at optimum for harvesting. The degree of sweetness on Godangok was about 1.8 and 1.4 times higher in sowing at July 20 and July 30 than in sowing at April 10. On the other hand, the degree of sweetness was similar regardless of sowing time on Guseulok. These results will be helpful to farmers for fall-harvest sweet corn cultivation and management.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.73-78
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• 1994

This experiment was carried out to investigate the major characteristics associated with the flavor rate and their changes according to days after silking of super sweet corn(Cocktail 86) for vegetable and waxy corn(Chalok 1). Ear elongation finished around 22∼24 days after silking. In kernel development, elongation was much more prominant in super sweet corn than that in waxy corn but thickness was vice versa. Pericarp thickness and kernel hardness of super sweet corn were slightly increased but those of waxy corn were increased rapidly as the ears matured. Moisture and sucrose content of super sweet corn remained high but the waxy corn was not. The reducing sugars(glucose, fructose) were relatively high at the early maturity stage but they were decreased as the ears matured and negatively correlated with sucrose and flavor rate. Soluble solids (Brix %) were positively correlated with sucrose and total sugar(sucrose+ glucose+fructose) content in waxy corn but not in super sweet corn and was considered as inappropriate criate criterion to envaluate the sugar content and flavor rate. Pericarp thickness and sucrose content were positively correlated with the flavor rate in both hybrids but total sugar content, and kernel hardness were positively correlated with flavor rate in super sweet corn and waxy corn respectively.