• Proceedings of the Korean Society of Grassland Science Conference
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• 1999.06a
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• pp.79.1-79
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• 1999

사일리지용 옥수수 정부 장려품종의 상대숙도(MNRM)를 한국의 기후조건하에서 비교하기 위하여 장려품종 중 1998년 현재 낙농가가 재배하고 있던 12종을 수원지역에서 4월 10일에 파종하고 출사기(50% 출사)와 8월 15일 수확시에 알곡과 전체 사초중의 수분 함량을 조사하였다. 얻어진 결과를 가지고 출사기와 곡실중의 수분 함량, 출사기와 전채 사초중의 수분함량 및 곡실과 전체 사초중의 수분함량 간의 상관관계를 계산하였다.(중략)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.70-73
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• 1988

The changes of kernel size, contents of moisture and total sugar, and rates of flavor and stickiness of a waxy corn (cv. Hongcheon native) were observed from 15 days after silking (DAS) to 40 DAS at Suwon and Cheongju in 1984, nespectively. Fresh kernel length and width greatly increased from 15 DAS to 30 DAS and slightly increased thereafter. Fresh 100-kernel weight was markedly increased during 15 DAS to 30 DAS, and slightly and continuously increased thereafter while dry 100-kernel weight almost linearly increased with maturity. Total sugar content of fresh kernel was the highest at 20 DAS and then continuously decreased with maturity. Flavor and stickiness rates of boiled waxy corn were significantly increased during 15 DAS to 30 DAS and flavor rate decreased thereafter. However, stickiness rate maintained the level until 35 DAS and then decreased slightly. The optimum harvest date for fresh waxy corn seems to be about 30 DAS considering kernel size, and flavor and stickiness rates of boiled corn.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.79-84
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• 1994

Sweet corn hybrid GCB 70 and super sweet corn hybrid NES were cultivated at vinyl tunnel in 1991 to determine the physiologically optimum harvest time for higher eating quality and sugar contnent of kernel by eat parts after silking and stored in refrigerator of 4$^{\circ}C$ and in the air. The development of ear increased continuously from silking to 30th day after silking, and sugar content was the hightest on 15th day after silking. The physiologically optimum harvest time for GCB 70 and NES was about 15~20th day and 20~25th day after silking, respectively. The sugar content of kernel by ear parts for two hybrids were high in order of basal, middle and top parts of the ear and showed significant differences among the parts of the ear. Changes of total sugar content during the storing period at 4$^{\circ}C$ for NES was almost the same by 9th day, but for GCB 70 rapidly decreased from 3rd day. The content of sucrose, glucose and fructose in super sweet corn NES were much higher than those of sweet corn GCB 70, but the maltose content of NES was lower than that of GCB 70.

• Proceedings of the Korean Society of Grassland Science Conference
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• 1999.06a
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• pp.81.2-82
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• 1999

본 연구는 사일리지용 옥수수의 정확한 수확시기를 결정하기 위하여 생육일수(출사 후 일수), 유효적산은도(GDD), 유선(milk line) 및 건물률을 비교하였다. 출사 후 수확시기(황숙초기)까지의 일수는 35-42일이 소요되었으며 파종시기가 지연될수록 단축되었다. 한편 유효적산온도는 출사 후 일수와는 반대로 높았다. 옥수수의 사초 수량과 사료가치를 함께 고려한 적정 수확시기를 건물률은 30∼36%이었으며, 이 시기 내에서 농가의 사정에 따라 적정 수화시기를 결정하는 것이 좋을 것으로 여겨진다.(중략)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.334-339
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• 1995

Removal of apical ear after silking is a method to increase seed production in corn inbreds. Due to the phenomenon of apical dominance, the subapical ear would develope and produce seeds following the removal of the apical ear. This experiment was conducted to investigate the varietal difference in subapical ear development and seed production. Days to silking of subapical ears were delayed by about 4 days compared to normal apical ears. Cob length and filled ear length of subapical ears across seven inbreds tested were reduced by 21% and 36%, respectively. Those of inbred INV302 decreased less and subapical ear of inbred NC246 were barren, which incicated the varietal defferences. Number of kernel rows, kernels per row, and total kernels per ear also decreased. The mean reduction rates for those characters were 28%, 37%, and 47%, respectively. Weights of ears and kernels were reduced and showed different response among inbred lines. Coefficients of variations for cob and filled ear lengths, number of kernel rows and kernels were greater in subapical ears than in apical ears. Seed production of subapical ears was 40 ~ 80% of apical ears, depending on inbred lines when the apical ear is removed immediately after silking.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.86-91
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• 1987

Changes in the contents of sugars and soluble solids and flavor rate of cooked kernels of three sweet com hybrids (Great Bell, Danok 1, and Golden Cross Bantam) and a super sweet corn hybrid (Crisp Super Sweet 720) were observed from 15 days after silking (DAS) to 27 or 33 DAS in 1985 and 1986 to determine the optimum harvest time. Sucrose content in all hybrids and fructose and glucose contents of Crisp Super Sweet 720 increased from 15 DAS to 21 or 24 DAS and then decreased. However, in the three sweet corn hybrids both fructose and glucose contents were highest at 15 DAS and then continuously decreased with maturity. At harvest time the major sugar component was sucrose and the highest total sugar content of Crisp Super Sweet 720 was 2-3 times higher than that of three sweet corn hybrids. Soluble solids were continuously increased with maturity in three sweet com varieties, but that of Crisp Super Sweet 720 increased up to 24 DAS, maintained the level through 30 DAS and then decreased. At harvest time soluble solids of three sweet com varieties were much higher than that of Crisp Super Sweet 720. The optimum harvest time seems to be about 27 DAS considering flavor rate and marketing conditions although the total sugar content was lower than those of earlier harvests. Soluble solids but not total sugars were positively correlated with the flavor of cooke6 com harvested at different growth stages in the same variety. Total sugars were not correlated with soluble solids or negatively correlated depending on hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.2
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• pp.123-128
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• 1998

Legume winter cover crop hairy vetch(Vicia villosa Roth, HV) can supply mineral nitrogen for silage corn by HV cover killed. The purphose of this study was to understand changes of soil mineral N, yield and N uptake of silage corn by N level (0, 135kgFN/ha) and cover cmp(no cover crop: NCC, hairy vetch cover crop: HVC) at field of Crop Experiment Station in 1996. HV growth decreased soil mineral N concentration before seeding corn, but killed HV cover increased concentration of soil mineral N at surface soil (0~7.5cm) at six-leaf stage of corn. Total dry matter(DM) and N uptake of corn averaged over N level was more decreased in HVC than in NCC at silk stage, but N uptake of corn after silk was more increased in HVC than in NCC by N mineralized fiom HV killed, especially in OkgFNJha. N fertilization increased total DM and and N uptake of corn averaged over cover crop, especially more increased the DM and N uptake before silk stage. Early application of N fertilizer was recommendable in netillage silage corn using hairy vetch cover crop.

• 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.60 no.3
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• pp.308-317
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• 2015

The aim of the present study was to investigate the ear and kernel characteristics of colored waxy corn hybrids during ripening according to different sowing dates. Heukjinjuchal and Eolrukchal 1 were sown at April 20 (first cropping) and July 20 (second cropping) in 2011~2012. The accumulated temperature from silking to harvesting was about $590{\sim}610^{\circ}C$. It takes 23~24 days when Heukjinjuchal and Eolrukchal 1 were sown in April 20, but July 20 sowing takes 32~35 days. Ear weight, ear diameter, 100-kernel weight and starch content of colored 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 colored waxy corn were less compact than the first cropping. The contents of total anthocyanins, cyanidin-3-glucoside and pelargonidin-3-glucoside were increased according to ripening (p<0.05). These results will be helpful to farmers for double cropping of colored waxy corn cultivation and management.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.102-109
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• 2017

A temperature-based Beta function model was developed for corn hybrids (Zea mays L.). The beta function based on the hourly temperature was fitted to the phenology data (silking date) obtained for six years from 2008 through 2013 at four survey sites. Using the Beta function model, silking dates for two corn hybrids with the different ecotype ('Danok3', 'Ilmichal') were estimated over two years from 2014 through 2015 at four sites, and then the performance of the model was evaluated based on the data for the same period. The silking dates estimated by the model were predicted earlier than those observed at survey sites. Still, the correlation between estimates and observation was relatively high (r=0.859). The accuracy of the model differed by the survey site and the year, which was likely due to the considerably large standard deviation of the parameter calibrated in this study.