• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.2
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• pp.115-122
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• 2004

This study was conducted to investigate the effect of the seeding and harvesting dates on the growth characteristics, dry matter yield and quality of com for silage in alpine area(altitude 800m a.s.l.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three seeding dates, 10 May, 20 May and 30 May. Sub plots consisted of harvesting dates, 15 September, 25 September and 5 October. Tassel height of com was decreased with seeding dates, 30 May, 10 May and 20 May in order, and harvesting date of 5 October was apt to be high. Ear height of com was decreased with seeding dates, 20 May, 30 May, and 10 May in order, and harvesting date of 15 September was the lowest of all treatments. Ear rate of com was decreased with late seeding dates, and it was the highest with harvesting date of 5 October. Dry matter yield was decreased with late seeding dates(P<0.05), and it was increased with late harvesting regardless of seeding dates(P<0.05). Crude protein content of com stover was increased with late seeding dates, and that of com ear was the highest with seeding date of 20 May. And crude protein contents of com stover and ear were the highest with harvesting date of 15 September. NDF contents of com stover and ear were the highest with seeding date of 10 May and 20 May, respectively, and NDF content of com stover was the highest with seeding date of 10 May and there was no difference among treatments in NDF content of ear. ADF content of com stover was 42.1 to 42.6% regardless of seeding dates, and that of com ear was the highest with seeding date of 30 May. ADF content of com stover and ear was increased with early harvesting date excepting for harvesting date of 20 May. These results indicate that 20 May and 25 September would be the optimum seeding date and harvesting date, respectively, for dry matter yield and nutritive value of silage com in alpine area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.239-244
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• 2005

This study was conducted to investigate the effect of the planting densities and nitrogen levels on the growth characteristics, dry matter yield and nutritive value of corn for silage in alpine area(altitude 800m a.s.1.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three planting densities, low(67,000 plants/ha), medium(89,000 plants/ha) and high(95,000 plants/ha). Sub plots consisted of three nitrogen levels, 150 kg/ha, 200 kg/ha, and 250 kg/ha. Tassel height of corn was increased with decreasing planting density, and nitrogen level of 200 kg/ha in all main plots. Ear height of corn was decreased with increasing planting density, and 150 kg/ha of three nitrogen levels. But there were no significant differences among treatment in tassel and ear height. Although dry matter ear ratio of whole com was increased with decreasing planting density, there were no significant differences among treatments. But there were significant differences among nitrogen levels(P<0.05). Dry matter yield of com was high with increasing planting density, but there were no significant differences among treatments. And DM yield of corn was significant difference among nitrogen levels(P<0.05). Crude protein content of corn was the highest with high planting density and low nitrogen level. NDF and ADF content of com was the highest with low planting density and nitrogen levels of 200 kg/ha in all main treatments. These results indicate that low planting density(67.000 plants/ha) and nitrogen of 150-200 kg/ha would be the optimum level fur dry matter yield and nutritive value of silage com in alpine area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.67-74
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• 1997

This experiment was conducted in 1992 and 1993 at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon to determine timing of rye(Secde cemde L.) harvest and residue chemical treatment prior to tillage in minimizing the adverse effects of the rye residue on growth and yield of succeeding corn(Zea muys L.). Eight treatments were established in 1993 which included four treatments such as no paraquat (1, l'diiethyl- 4, 4'-bipyridinium dichloride), paraquat treatment at 10, 23, and both 23 and 10 days prior to tillage when rye was harvested on April 14, and another four treatments such as no paraquat, paraquat treatment at 1, 5 and 10 days prior to tillage when rye was harvested on April 26. No paraquat treatment significantly resulted in reductions in corn plant height on June 3 and 10 when rye was harvested on April 14, but differences in the plant height and leaf number of corn among treatments were generally nonsignificant. Corn LA1 and silk emergence were not affected by paraquat treatment times regardless of rye harvested dates, but silk emergence was delayed by 1 to 2 days with no paraquat when rye harvested on April 14. Corn dry matter and TDN yields were significantly increased by paraquat treatment at 10 and 5 days prior to tillage treatment when rye was harvested on April 14 and 26, respectively, but other agronomic characteristics such as dry matter percentage, ear percent to total dry matter, and stover and ear yields of corn at harvest showed little or no response to paraquat treatment times.

• 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.16 no.4
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• pp.299-306
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• 1996

This experiment was conducted from 1991 to 1993 at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon to investigate the effects of previous crop residues on growth and yield of succeeding corn(2ea mays L.) and also to determine the best double cropping system necessary to maximize the total dry matter yield of winter forage crops plus corn for silage. In this experiment, treatments consisted of no crop as a control, late maturing Kodiak rye(Seca1e cereale L.), Bamapoli forage rape(Brassica napus Subsp. oleifera L.), G-sprinter oats(Avem sativa L.), Chief crimson clover(Trifolium incarnatum L.), Jackson Italian ryegrass(lo1ium rnultiJlorum L.), Vantage vetch(Vicia sativa L.) and early maturing Koolgrazer rye(Seca1e cereale L.). Corn leaf number and silking date were not significantly affected by previous crop residues, but the leaf number of corn following Italian ryegrass was reduced by 1.9 relative to no previous crop. The plant height and LA1 were significantly reduced during early development when corn followed Italian ryegrass and late maturing Kodiak rye (p<0.05). The dry matter and estimated TDN yields of corn were significantly reduced when corn followed Italian ryegrass and late maturing Kodiak rye. The yield reductions for corn following Italian ryegrass, late maturing Kodiak rye and early maturing Koolgrazer rye, relative to com when no previous crops were planted, were 34, 17 and 8%, respectively. Therefore, the reduction in corn growth and yield in this experiment could be explained by an allelopathic effect resulting from the Italian ryegrass and rye residues. The highest total dry matter yield of 30,509kg/ha was obtained from an early maturing rye-corn double cropping sequence in combination among the eight cropping systems.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.3
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• pp.293-304
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• 1997

A field experiment was conducted at the forage experimental plots, Seoul National University, Suweon h m 1995 to 1996 to determine the effect of legume residues as a N source and N fertilizer on corn (Zea mays L.) silage yield, N uptake, and availability of inorganic N in the soil. Corn was grown following (i) red clover (Trifolium pratense L.), (ii) crimson clover (Trifolium incarnatum L.), (iii) alfalfa (Medicago sativa L.) and (iv) winter fallow. The plots were split into two rates of fertilizer N (0 and 90kg Nlha) in a split-plot experimental plan. Compared with fallow treatment, legumes depleted soil water in the surface 15cm at corn planting by 17 to 26%. As a result, corn emergence was markedly delayed with legume residues by 8 to 11 days. Corn silage DM yield was significantly reduced in the presence of legume residues by 2.0 to 3.4 and 1.5 to 2.5 tonlha compared with winter fallow treatment at 0 and 90kg fertilizer Nlha, respectively, but no significant difference in the corn DM yield was found between legume residue treatments. There was an overall tendency for increased corn yields with 90kg fertilizer Nlha compared to Okg fertilizer Nlha, although not all yield increases were significantly greater. The corn yield response to applied N suggests that a source of N from legume residues was not sufficient for a succeeding corn crop. There was significantly more N (P

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.161-172
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• 1992

The agronomic performance of four introduced corn(Zea mays L.) hybrids and a domestic hybrid Suwon 19(control) was compared for silage production in the Middle Northwestern Coast(MNWC). Middle Southwestern Coast(MSWC) and Middle Northern Inland(MN1) regions of Korea, 1988 to 19 90. In the MNWC region, DK713 and P3144W were recorded as more resistant corn hybrids to rice black streaked dwarf virus(RBSDV) than other hybrids. P3144W, P3352 and DK689 hybrids produced higher dry matter(DM) and total digestible nutrient(TDN) than the control hybrid Suwon 19 and DK 713. In the MSWC region, P3144W and DK689 tended to yield more DM and TDN than other hybrids and a severe infection of RBSDV was observed during 3 years of experiment. In the MNI region, P3144W and P3352 corn hybrids showed higher ear and dry matter percentage and gave the highest DM and TDN yield compared with other hybrids. The RBSDV infection of the hybrids in the MNI region was moderate level compared with the two regions, but rate of stay green was the lowest. In the three regions, the control hybrid Suwon 19 gave the highest RBSDV infection, followed by P 3352, DK689, and P3144W, while DK713 was the lowest. P3144W and P3352 hybrids gave higher DM and ear percentages than all other hybrids at harvest. During 3 years of experiment, it was found that there were regional and year differences in RBSDV infection, forage DM yield, DM percentage and ear ratio to total DM yield of the corn hybrids.

• 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.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.261-269
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• 2015

The purpose of this research is to identify the significance of climate factors related to the significance of change of dry matter yield (DMY) of whole crop maize (WCM) by year through the exploratory data analysis. The data (124 varieties; n=993 in 7 provinces) was prepared after deletion and modification of the insufficient and repetitive data from the results (124 varieties; n=1027 in 7 provinces) of import adaptation experiment done by National Agricultural Cooperation Federation. WCM was classified into early-maturity (25 varieties, n=200), mid-maturity (40 varieties, n=409), late-maturity (27 varieties, n=234) and others (32 varieties, n=150) based on relative maturity and days to silking. For determining climate factors, 6 weather variables were generated using weather data. For detecting DMY and climate factors, SPSS21.0 was used for operating descriptive statistics and Shapiro-Wilk test. Mean DMY by year was classified into upper and lower groups, and a statistically significant difference in DMY was found between two groups (p<0.05). To find the reasons of significant difference between two groups, after statistics analysis of the climate variables, it was found that Seeding-Harvesting Accumulated Growing Degree Days (SHAGDD), Seeding-Harvesting Precipitation (SHP) and Seeding-Harvesting Hour of sunshine (SHH) were significantly different between two groups (p<0.05), whereas Seeding-Harvesting number of Days with Precipitation (SHDP) had no significant effects on DMY (p>0.05). These results indicate that the SHAGDD, SHP and SHH are related to DMY of WCM, but the comparison of R2 among three variables (SHAGDD, SHP and SHH) couldn't be obtained which is needed to be done by regression analysis as well as the prediction model of DMY in the future study.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.150-158
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• 2016

This study was conducted to evaluate growth characteristics, yield and feed value of newly developed domestic teosinte (Geukdong 6) compared to widely cultivated silage corn hybrid (31N27) and sorghum ${\times}$ sudangrass hybrid (P877F). Geukdong 6, a new single cross (Teosinte ${\times}$ Suwon 19) variety, is a teosinte (Zea may L. ssp. maxicana) developed by the Geukdong 6 of agricultural company corporation (GACC) in An-dong province. This field experiment was designed in a randomized block design with three replications and consisted of silage corn (T1), sorghum x sudangrass hybrid (T2) and Geukdong 6 (T3). Leaf length, number of leaves, number of tillers and fresh yield of T3 were higher than that of T1 and T2 (p<0.05). Dry matter yield of T3 was lower than that of T1 (p<0.05). In particular, T3 ($0.1kg/cm^2$) showed to be very tender compared to other T1 ($0.5kg/cm^2$) and T2 ($0.5kg/cm^2$), (p<0.05). The crude protein content of T3 as 8.25% was higher than that of T2 (5.90%), (p<0.05). However, there was no significant differences between T1 (8.14%). The brix degree of T2 was higher than that of T1 and T3 (p<0.05). T3 showed higher content of total minerals compared to T1 and T2 (p<0.05). The relative palatability of T3 was higher than T1 and T2 (p<0.05), when fed to deer as soiling crop. However, it showed a lower than T1 in Korean native cattle and korean native goats. The relative palatability of the silage shown in order of T1> T3> T2 in korean native cattle, spotted deer, and korean native goats. As mentioned above the results, Geukdong 6 (T3) could be recommended as using of soiling and lab silage, when high fresh yield, tender stem, number of many leaf, content of high crude protein, and palatability higher than sorghum ${\times}$ sudangrass hybrid were considered.