• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.4
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• pp.45-52
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• 1979

This study was conducted to determine the proper time of corn marketing by cultivating time movement and cultural practice system establish. The rate of development of corn from planting to anther is a function of temperature rather than of photosynthesis. The major yield components of sweet corn for yield increase are more ear heavier grain weight, greater of kernels and heavier 100 grain weight. Early sowing has show yield decrease because yield capacity decreased with the shorting of vegetative growth and it was relatively susceptible to maize black streaked dwarf virus.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1018-1033
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• 2021

In this study, we aimed to assess the effect of flaking on the nutrient digestibility of corn grain in ruminants. In this regard, in vitro rumen fermentation, in situ rumen degradability, and in vivo metabolic experiments were performed. The automated gas production technique was used for the in vitro fermentation experiments. Six types of corn flakes with various degrees of gelatinization (32%, 41%, 48%, 66%, 86%, and 89%) were ground and incubated in rumen fluid to measure rumen fermentation characteristics and digestion rate. The in situ degradability of ground corn, whole corn, and corn flakes with 62% and 66% gelatinization was measured by incubation in the rumen of two cannulated Holstein cows. In vivo metabolic experiments were performed using 12 crossbred goats (29.8 ± 4.37 kg) using a 3 × 3 Latin square design. The dietary treatments consisted of ground corn and flaked corn with 48% or 62% gelatinization. In vitro experiments showed that as the degree of gelatinization increased, the digestion rate increased linearly, while the discrete lag time decreased linearly (p < 0.05). The effective rumen dry matter degradability, determined by in situ fermentation, was 37%p lower in corn flakes than ground corn, assuming a passage rate of 6%/h (p < 0.01), and there was no difference between the two flakes. In the in vivo experiment, there was no difference in dry matter intake, average daily gain, feed efficiency, and nitrogen utilization among the treatment groups (p > 0.05); however, the crude fat digestibility was lower for corn flakes than for ground corn (p < 0.05). To summarize, the rate of fermentation of corn flakes increased as the degree of gelatinization increased. However, non-ground corn flakes had lower rumen digestibility and did not improve in vivo apparent nutrient digestibility, compared with ground corn. In contrast to the assumption that flaked corn provides more energy to ruminant animals than ground corn, we conclude that the digestibility and energy value of corn flakes are lower than those of ground corn if mastication does not sufficiently reduce the particle size of corn flakes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.183-189
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• 2023

It is widely known that forage corn is one of the most important crops in the production of silage and green chops during the summer months. In this study, the characteristics and the productivity of Kwangpyeongok, AGR 41, and Nero IT corn cultivars were evaluated in the regions of Jeju and Cheonan, Korea between 2021 and 2022. In each year, different corn cultivars were sown in different parts of the country on April 7 in Jeju and May 3 in Cheonan. The yield of three cultivars, Kwangpyeongok, AGR 41, and Nero IT were measured at the yellow-ripening stage, including the leaves and stems (Stover) and corn grain. Kwangpyeongok stover and total dry matter (DM) yields were slightly higher in Cheonan than in Jeju over the past two years. The quantity of corn cultivated in all cultivated areas was similar. The average yield of AGR 41, corn quantity and total DM were slightly higher in Jeju than in Cheonan. In terms of stover yield, and total dry matter content of the Nero IT cultivar cultivated in Jeju had a slightly higher yield than the cultivar cultivated in Cheonan. Based on this study, all cultivars can show some variations but not too much in terms of growth productivity and distinct characteristics depending on their location. Overall, AGR 41, and Nero IT cultivars in Jeju exhibit slightly higher levels of productivity than the same cultivars in Cheonan.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.330-335
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• 2010

Soybean (Glycine max Merr.) and corn (Zea mays L.) transplanting has increased because soybean and corn crops cultivated by the direct seeding method were often damaged by wild birds. The purpose of this study is to develop a seeder to sow soybean (Glycine max Merr.) and corn (Zea mays L.) in a plug tray. In order to find out design factors for a metering device of the seeder, metering characteristics on metering hole size and roller speed were experimentally investigated. Soybean (cv. 'Daewon') and corn (cv. 'Mibaekchal') were used as a materials for testing the seeder in this experiment. The metering hole size of roller suitable for Daewonkong and Mibaekchal was determined. Daewonkong was suitable for hole diameter of 10 mm and hole depth of 5.5 mm, and Mibaekcal was suitable for hole diameter of 9 mm and hole depth of 5.5 mm. At a brush length of 4 mm, one grain seeding rates of Daewonkong and Mibaekchal was 99% and 93% respectively. By inducing Mibaekchal to the hole by swing, one grain seeding rate of that increased from 91.9% to 97.7%. When roller speed is 4 m per minut, seeding efficiency of prototype was 110 sheets per hour.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.177-184
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• 2013

This work was conducted to assess the use of Near-infrared reflectance spectroscopy (NIRS) as a technique to analyze nutritional constituents of Distillers dried grain with solubles (DDGS) and corn quickly and accurately, and to apply an NIRS-based indium gallium arsenide array detector, rather than a NIRS-based scanning system, to collect spectra and induce and analyze calibration equations using equipment which is better suited to field application. As a technique to induce calibration equations, Partial Least Squares (PLS) was used, and for better accuracy, various mathematical transformations were applied. A multivariate outlier detection method was applied to induce calibration equations, and, as a result, the way of structuring a calibration set significantly affected prediction accuracy. The prediction of nutritional constituents of distillers dried grains with solubles resulted in the following: moisture ($R^2$=0.80), crude protein ($R^2$=0.71), crude fat ($R^2$=0.80), crude fiber ($R^2$=0.32), and crude ash ($R^2$=0.72). All constituents except crude fiber showed good results. The prediction of nutritional constituents of corn resulted in the following: moisture ($R^2$=0.79), crude protein ($R^2$=0.61), crude fat ($R^2$=0.79), crude fiber ($R^2$=0.63), and crude ash ($R^2$=0.75). Therefore, all constituents except for crude fat and crude fiber were predicted for their chemical composition of DDGS and corn through Near-infrared reflectance spectroscopy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.379-385
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• 1983

Forage productivity of Job's tears (Coix lachryma-jobi L.) and adlay (C. lachryma-jobi var. mayuen (ROMAN.) STAPF) and a hybrid corn (Kwangog) and sorghum-sudangrass hybrid (Pioneer 988) was compared in the southern part of Korea where black streaked dwarf virus' (BSDV) is prevalent. Emergence of Job's tears and adlay was more delayed compared to a corn or sorghum-sudangrass hybrid under the drought field conditions. Early growth and regrowth of Job's tears and adlay were less than those of sorghum-sudangrass hybrid. Fresh weight, dry weight, and digestible dry matter of Job's tears and adlay cut once approximately 40 days after flowering were much higher than those of two cuts at every flowering stage. Dry weight of one-cut Job's tears and ad lay harvested 40 days after flowering was similar to the total dry weight of three-cut sorghum-sudangrass hybrid but higher than that of silage corn. Digestible dry matter production was greater in the order of sorghum-sudangrass, corn, one-cut and two-cut Job's tears and adlay. Corn was severely infected with BSDV, but digestible dry matter was relatively high due to its higher in vitro dry matter digestibility. Among the Job's tears and adlay varieties, a variety of Job's tears with globular fruit shape was best for forage production due to its taller plant height, thick stem, wider leaf blades, higher leaf blade/total dry weight ratio, and higher forage yield. However, hulled grain yield of ad lay varieties was higher than that of Job's tears due to a higher hulled/rough grain ratio although they had similar rough grain yields.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.141-147
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• 2019

The purpose of this study was to determine the effect of waterlogging duration on the growth characteristics and productivity of forage corn at different growth stages under paddy field conditions. Treatments consisted of waterlogging at two growth stages (V7 or V14) for four waterlogging durations (no waterlogging, 48 hours, 72 hours, and 96 hours, respectively). The V14 growth stage was more vulnerable to waterlogging than the V7 stage. Among the waterlogging durations, the lodging score increased at 48 hours. The stem height of forage corn decreased with the increase in waterlogging duration at the different growth stages (V7 and V14). Increase in waterlogging duration reduced the stem dry matter yield, ear dry matter yield, and total dry matter yield at both growing stages (V7 and V14). The waterlogging treatments at the V14 stage affected ear dry matter yield more than those at the V7 growing stage. Thus, the management of forage corn under paddy field conditions must be strengthened during early (V7) and grain fill stages (V14). When waterlogging occurs, surface and subsurface drainage should be implemented within 48 hours to control (no waterlogging) the groundwater level and, thus, minimize economic losses due to forage corn damage.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.79-87
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• 2022

The objective of this study was to investigate the variability in crude protein (CP) and amino acids (AA) content in cereal grains imported from different origins in Korea from 2006 to 2015. The values of CP and AA contents in corn, wheat, and barley were obtained from 430 and 325 samples from six countries, 83 and 56 samples from seven countries, and 60 and 58 samples from three countries, respectively. The CP concentrations in corn, wheat, and barley ranged from 7.12 (Brazil) to 7.68% (India), 10.55 (Ukraine) to 13.26% (Brazil), and 9.46 (India) to 10.49% (Ukraine), respectively. The Lys concentrations in the corn, wheat, and barley ranged from 0.18 (Argentina) to 0.24% (China), 0.26 (India) to 0.34% (China), and 0.23 (India) to 0.31% (Australia), respectively. The concentrations of CP and AA varied among different countries of origin (P<0.05), except for Met in wheat and CP in barley. The coefficients of variation for CP were 3.26, 9.06, and 5.36 from corn, wheat, and barley, respectively. The correlation coefficients (r) between CP and Lys concentrations in corn, wheat, and barley were positively correlated and were 0.322, 0.277, and 0.542, respectively. In conclusion, CP and AA concentrations varied not only from different countries of origins but also within the same country due to the geographic region in which they are produced.

• Korean Journal of Organic Agriculture
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• v.11 no.1
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• pp.79-88
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• 2003

Saved labor cost, energy conservation, reduced soil erosion, and increase of emergence rate would be expected from no-tillage cultivation of corn. Few research has been reported on the no-tillage effects for waxy corn hybrid. Five waxy com hybrids were tested under conventional and no-tillage practices to investigate responses of early growth, plant characters, ear characters, fresh yield, and grain yield. Emergence rates under no-tillage were lower than under conventional tillage. Plant heights at early growth stages under no-tillage were higher than those under conventional tillage. Plant height under no-tillage was higher than that under conventional tillage. There were no differences between conventional tillage and no-tillage for ear length, number of kernel rows, number of kernels per row, 100 kernels weight, fresh yield, and grain yield. This result indicates that no-tillage practice might be recommended for practical method for waxy com production. Days to tasseling and silking, plant height, ear height, ear length, and number of kernels per row were correlated with fresh and grain yields.

• 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.