• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.212-217
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• 2010

A new waxy corn hybrid 'Daedukchal 1' was developed from single cross between CNU 504 and CNU 2396 at Chungnam National University in 2007. Inbred CNU 504 used as a seed parent and inbred CNU 2396 as a pollen parent were collected throughout domestic regions. Tasseling date of this hybrid was seven days later than that of check hybrid, 'Chalok 1'. 'Daedukchal 1' was 19.7 cm in ear length and 4.5 cm in ear diameter. On yield trial, ear length of this hybrid was increased 29.7% compared with a check hybrid, 'Chalok 1'. 'Daedukchal 1' had white kernels and good eating quality due to high sugar content and thinner pericarp. The ratio of kernel set length/ear length was similar to 'Chalok 1'. It is moderately resistant to southern leaf blight and northern leaf blight but susceptible to corn borer. The yields of 'Daedukchal 1' in fresh ear weight and in number of fresh ear were 16% and 8%, respectively, higher than those of a check hybrid in regional yield trials for two years. Seed production for this hybrid was better because of the consistency of tasseling dates.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.259-264
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• 2002

DK 754S, a forage corn hybrid is bred by Dekalb plant Genetics Co.. Garst 8255 by Garst Seeds Co., and GW 737 by Crosbyton Co. in US, respectively. These have been tested in Suwon and Chonan for 3 years to test their regional yield trial. In result, we were able to confirm the excellence of above cultivars and these were selected as new recommended cultivars April of 2002 by NACF. The characteristics of these cultivars are as follows ; 1. DK 7545 a. This cultivar is mid-late maturing, high quality, high yielding forage corn hybrid. Its mean tasseling date is the 11th of July. It takes 78 days from emergence to tasseling date, which is almost same with Kwanganok. The culm length and the ear height are 231 cm and 127 cm. It is relatively strong to lodging. b. The color of ear is yellow, the number of ear row is nineteen. DK 7545 shows strength to H maydis and MBSDV has occurred between 0% and 4.1% in Chonan test area but it still does not affect yielding at all. It is relatively resistant to corn borer and its stay green is almost same level comparing to a check hybrid, Kwanganok. c. Dry matter yield of this cultivar is 19.6 tons, TDN is 13.4 tons per a ha, therefore these hybrids are increased by from 6 to 9% comparing to Kwanganok. The percent ear among total dry matters yield is 43.7%. 2. Garst 8255 a. This hybrid is mid-late maturing, high quality, high yielding forage corn like as Kwanganok. Its the mean tasseling date and the period from emergence to tasseling date are almost same with a check hybrid, Kwanganok. The Culm length and the ear height are 259 cm, and 146 cm which are tall. It resists to lodging and shows excellence of stay green. b. Garst 8285 resists to H maydis, and MBSDV, and corn borer as much as Kwanganok has. c. Dry matter yield of this cultivar is 21,735 kg. TDN is 14,627 kg per a ha, therefore this is increased by 21%, 16%, respectively, comparing to a check hybrid, Kwanganok. The percent ear among total dry matters yield is 44.2%. 3. GW 737 a. This hybrid is mid-late maturing, high quality, high yielding forage com hybrid like as Kwanganok. Its mean tasseling date is 13th of July which is 2 days late comparing with a check hybrid, Kwanganok and the period from emergence to tasseling date is 80 days. b. The culm length and the ear height are 274 cm and 150 cm, which are tall. It resists to lodging moderately and shows excellence of stay green. c. GW 737 resists to H maydis and MBSDV very well, corn borer moderately resistance. d. Dry matter yield of this cultivar is 18,025kg, TDN 15,164kg per a ha, therefore this hybrid remarkably increased by 26%, 20%, respectively, comparing to a check hybrid, Kwanganok.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.44-48
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• 1986

This field experiment was conducted to determine the optimum nitrogen level and plant population for silage and grain corn cv. Suweon No. 19 at Suweon from 1981 to 1982. The results obtained are summarized as follows: 1. Leaf Area Index (LAI), Loding Index (LI) and stalk diameter were increased by raising nitrogen level but ear height was decreased. And tasseling date and stalk height were not influenced by nitrogen level. 2. LAI, LI and ear height were increased by raising plant population but tasseling date, stalk height and stalk diameter were decreased. 3. Numbers of missing hill and barren plants were increased by raising nitrogen and dense plant population respectively. Grain yield and total digestible dry matter yield in 5,550 plants with 10kg of nitrogen fertilization per 10a were recommendable for grain and silage corn respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.253-258
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• 2002

NC+4880, a forage com hybrid, is bred by NC+hybrids Co. in US, and Gast 8396 IT is by Garst Seeds Co. We have tested these two cultivars in Suwon and Chonan over three years to test their regional yield trial. Through above experiments, the excellence is testified, in result, they are determined as new recommended cultivars by NACF. The main characteristics of these cultivars are as tallows ; 1. NC+4880 a. The seed coat is yellow, the mean tasseling date is 7th of July and it takes about 74 days from emergence to tasseling date. This hybrid is a day ahead and the culm length is 242 cm, moreless shorter comparing with a check hybrid, Suwon 19. The ear height 117 cm which is short and its stay green is moderate. b. It shows resistance to H maydis, and MBSDV is barely observed and its stay green is moderate. c. The fresh yield, dry matter yield, and TDN yield per a ha are 55.4 tons, 18.3 tons, 12.4 tons, respectively, which are increased by 6%, 7%, and 9%, respectively, comparing with a check hybrid, Suwon 19. The percent ear among total dry matter yield is 50.9%. 2. Garst 8396 IT a. The seed coat is yellow, the mean tasseling date is 9th of July and it takes about 76 days from emergence to tasseling date. This hybrid represent a day delayed compared with a check hybrid, Suwon 19. The Culm length and the ear height are 275 cm, and 138 cm, respectively. b. It resists moderately to H. maydis, and highly resists to lodging in the field conditions. MBSDV is barely observed and its stay green is moderate. c. The fresh yield per a ha is 64.9 tons, dry matter yield, 20.9 tons, and TDN, 13.8 tons, respectively, which are increased by 25%, 23%, and 22% comparing with a check hybrid, Suwon 19. The percent ear among total dry matters is 43.3%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.101-108
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• 2014

This study was conducted to investigate the effect of nitrogen rates on the growth characteristics and yield of maize in agricultural fields with the stream. This indicates the necessity and optimal level of nitrous fertilization to examine the possibilities of quantity enhancement. Plant height and ear height of maize were not significantly different among the nitrogen rates. Stem diameter and leaf area index increased in the nitrogen treatment compared to untreated control. Changes of photosynthetic rate in maize leaves depending on nitrogen treatments increased as much as nitrogen rates were increased up to the highest level, 36 kg per 10a. NDF and ADF content levels of maize were investigated with different nitrogen rates regardless of treatments. In the case of NDF, it showed a tendency to decrease after 8 days of tasseling date. ADF had also decreased after 15 days of tasseling date. Nitrogen uptake of maize leaves with different nitrogen rates showed the highest level, $4.9g\;kg^{-1}$ with 36 kg per 10a on the tasseling date. Ear length and 100-kernel weight, there were no significant differences according to yield and the components with different nitrogen rates. Ear diameter and kernel number, nitrogen rates of 18 kg and 36 kg were increased compared to nitrogen rate of 9 kg per 10a and untreated control. The pericarps in 9 kg nitrogen rate and control were thicker than those of 18 kg and 36 kg treatment. The yield, 18 kg, 36 kg, and 9 kg treatments were increased by 10.96%, 9.27%, and 3.31%, compared to control. The component analysis on maize kernel with different nitrogen rates, starch showed no significant differences among treatments. Total sugar in 18 kg nitrogen treatment represented the highest content level, 6.37%. In addition, Amylopectin in 18 kg treatment showed the highest content level of 90.38%. However, amylose in 18 kg treatment showed the lowest level, 9.62% which drew a conclusion that waxy of 18 kg treatment is considered to be the strongest one. From the results described above, nitrous fertilization is essential to grow maize in agricultural fields with the stream. The optimum level of nitrous fertilization is considered 18 kg per 10a.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.49-54
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• 1998

This experiment was carried out to investigate effect of plant density on yield and quality of corn at the forage experimental field, grassland and forage division, National Livestock Research Institute, RDA, Suwon eom 1996 to 1997. The two corn hybrids, P 3352 and G 4743, were grow at plant density of 67,000; 71,000; 83,000 ; 89,000 and 95,000 plantha in 60,70 and 75-an spaced rows. At the low density, plant and ear height were decreased but ear length and weight were increased. Plant density had little effect on the tasseling date, silking date and ear ratio to total dry matter. The total dry matter yield of two hybrids was increased kom 15,294 to 18,996 in P 3352 hybrid and 15,881 to 21,386kglha in G 4743, respectively, by decreasing plant density. Plant density had little effect on the ADF(acid detergent fiber), NDF (neutral detergent fiber) and CP(crude protein) concentrations, but the quality of late maturity hybrid, G 4743, was higher than that of early maturity hybrid, P 3352. The result of this study indicate that 67,000 plantlha plant density was recommendable for machanization and maximum DM yield of corn.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.146-154
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• 2022

This experiment was conducted to evaluate the growth characteristics and productivity of silage corn varieties developed in Korea. Corn cultivation was carried out using the experimental field in the Pyeongchang campus of Seoul National University (550 m above sea level). There have 10 domestic cultivars (Gwangpyeongok, Dacheongok, Yanganok, Jangdaok, Cheongdaok, Daanok, Sinhwangok, Sinhwangok II, Pyeonggangok, and Hwangdaok) with one imported cultivar (P1543) which tested as a control, and randomized block design with three replications. Among the 100-grains weight of the seeds, Dacheongok was the heaviest, and the germination rate for each variety was 74.6% on average, while that of Daanok and Sinhwangok were over 90%. Sinhwangok was the fastest in tasseling and silking date. The number of days required to be silking date was as slow as 85 days in Dacheongok, Cheongdaok and Pyeonggangok, and as fast as 80 days or less in Sinhwangok, Sinhwangok II and Hwangdaok. The plant height of P1543 was the highest as 344cm, and Hwangdaok and Daanok were short. In terms of the ratio of ears, Daanok had the highest rate of 60.18%, and Jangdaok and Dacheongok had the lowest. There was no significant difference in dry matter content in stover, but P1543 was generally higher in ear and total dry matter content. The dry matter yield was highest in P1543, and the yield of TDN was significantly higher in P1543 and Yanganok. There was a significant difference in the crude protein content of ears and the dry digestibility of stems (p<0.05), while there was no significant difference in the content of each part or element. Combining the above results, Yanganok was the highest in terms of yield, and Dacheongok, Sinhwangok and Pyeonggangok were also recommended for domestically grown corn varieties in the mountainous regions of Gangwon-do.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.161-167
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• 2017

This experiment was conducted to comparison study on the productivity for certified varieties of import adaptability of silage corn in Pyeongchang area. Total eight varieties (Gangpyeongok, 31N27, 32P75, 32W86, P3156, P3394, DK 689 및 DK 729) were evaluated. The experimental design was 8 treatment of randomized block with three replications. Corn varieties were cultivated in experimental field of Pyeongchang campus, SNU from 1 May to 2 September, 2015 and plot size was $15m^2$. Plant height of 32W86 and ear height of Gwanpyeongok was the highest (p<0.05). Tasseling and silking date was 27 July-3 August and silking occurred after 1-3 day of tasseling. Average day to silking was 92 days and that of 31N27 variety was short (p<0.05). The varieties of DeKalbo Company (DK 689 and DK 729) required more times to silking. Average GDD (growth degree day) of eight varieties was $1,023^{\circ}C$ and P3352 was the lowest GDD. In the trials of resistance evaluation, P3394 was strong in disease, P3156 was the highest in insect. All varieties did not show the lodging and variety of DK 729 showed the highest stay green score (p<0.05). Average dry matter content was 30.77%, it showed higher trend in DM. 32W86 was the highest DM content among the varieties, but there was no significant difference among varieties (p>0.05). The weight per ear was the highest in 32W86 and the lowest in Gwanpyeongok. The ration of ear to whole plant was higher in 32W86 and P3394, but it was not found the significant difference (p>0.05). Average yield of fresh and DM was 59,017 and 13,476 kg/ha, respectively. DK 689 showed higher DM and TDN yield than others, but there was not significant difference (p>0.05). According to results, the difference of productivity was not found among certified variety of import adaptability of silage corn. The varieties Gwanpyeongok, 32W86 and 32P75 would be recommendable in Pyeongchang area for stable cultivation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.247-252
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• 2002

“DK 537”has been selected by forage crop breeding team at the National Livestock Research Institute(NLRI), RDA and has been determined by the Deliberative Council of the National Agricultural Cooperative Federation(NACF) in 2002, as a new recommended hybrid which is early maturing, good quality and hi호 yield of corn for silage. The characteristics of this hybrid are as follows ; 1. The seed coat is yellow and the mean of tasseling date is 5th of July, included in early maturing hybrid which is one day delayed than check cultivar, DK 501. The culm length is 246cm. It is resistant to lodging because of its low height from surface to ear. 2. DK 537 shows resistance to H. maydis and Maize Black-Streaked Dwarf Virus(MBSDV). It also shows strength to corn borer as much as DK 501 does. 3. Fresh yield. dry matter yield. and TDN per a ha are 50 tons, 16.9 tons, and 11.4 tons respectively. which are almost same yielding level of DK 501. Its percent ear to total dry matter is 50.8% at the same time. Through all these tests, we could make sure at DK 537 hybrid will be recommended as good forage crop.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.3
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• pp.217-222
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• 1998

This experiment was carried out to investigate effects of herbicide application method on Calysteria jcqoonica control and corn yield at the forage experimental field, grassland and forage crops division, National Livestock Research Institute, RDA, Suwon from 1996 to 1997. The experiment was arranged in a randomized block design with three replication. The herbicide application consisted of control, 2~3 leaf stage(Dicamba), 5~6 leaf stage(Dicamba) and soil treatment (Pendimethalin). The hybrid of corn used in this experiment was P 3352. The results obtained are summarized as follow; 1. The plant height was the lowest at control and the highest at Dicamba treatment in 5~6 leaf stage, but no significant difference was found among herbicide application method at ear height. Tasseling and silking date were delayed 2~3 day at control. The length and weight of ear were highest at Dicamba treatment in 2~3 leaf stage. 2. The herbicide injury of corn was very slightly after 10-20 day, but corn was recovered soon. The weed control value was 94.2~67.5% at herbicide application plot. 3. The fresh and dry matter yield of Dicamba treatment in 2-3 leaf stage was highest as 42,878 and 16,033kg/ha, respectively. The application of Dicamba increased the DM yield of corn by 13~30%. 4. Herbicide application time had little effect on the ADF, NDF and CP contents, but the forage quality of ear was higher than that of stover. The result of this experiment indicate that the application of Dicamba in 2~6 leaf stage of corn will remove almost all of Calysreria jqonica and increase DM yield of com.