• Proceedings of the Korean Society of Crop Science Conference
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• 1999.05a
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• pp.168-169
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• 1999

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.843-852
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• 2010

Hydroxycinnamic acid derivatives (HADs) and anthocyanins in corn (Zea mays L.) have recently been reported to have anticarcinogenic, anti-hypertensive, antidiabetic, antifungal, antioxidant, and anti-melanogenic activities. Five HADs and anthocyanins in corn were quantified by HPLC according to cultivars and heat processes. In addition, major anthocyanin of a black waxy corn was isolated and identified by several instrumental analysis, and its content was also quantified by HPLC according to heat processes. Of the ten corn cultivars, five waxy corn cultivars had moderate five HADs contents except "Baksa" waxy corn with higher two free cinnamic acids (FCAs), p-coumaric and ferulic acids. In contrast, three dent corn cultivars contained higher levels of three polyamine conjugates (PCs), CFP, DCP and DFP, and especially "P3394" had the highest amount of the three PCs. Two sweet corn cultivars had generally intermediate HADs levels between waxy and dent corn cultivars. Of the three colored-waxy corns, a black Mibaek waxy corn had the highest anthocyanin content. During heat processes, levels of two FCAs in the black waxy corn generally increased, whereas no significant change on three PCs contents was observed except the puffing process. Roasting, retort and puffing processes significantly increased two FCAs and especially, the puffed black waxy corn had the highest amount of FCAs. Meanwhile, most heat treatments except retort process, considerably decreased total anthocyanin contents, and especially the puffed black waxy corn had nearly no anthocyanin. Level of one major anthocyanin, pelargonidin 3-glucoside (P3G) isolated from a black waxy corn was appreciably decreased by heat treatments except retort process, which greatly increased P3G content. These results suggest that the retorted black waxy corn may be a promising high quality functional corn product.

• Journal of Plant Biology
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• v.32 no.3
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• pp.137-144
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• 1989

In order to clarify the effect of the associative nitrogen fixing bacteria on the growth of corn(Zea mays L. Suwon19), we inoculated corn seedlings with Azospirillum amazonense Y1, a micro-aerobic and acid-tolerant nitrogen fixer, and analyzed the growth and dry matter production and changes of nitrogen and phosphorus quantity of the plant during the growing period. The inoculation of associative N-fixing bacgteria increased the growth of height, leaf area, dry weight and total nitrogen quantity of the plant by 15.4%, 65.4%, 33.7% and 38.0%, respectively, on the day of 56th after sowing. Especially the inoculation of A. amazonense Y1 showed two to three-fold accumulation of phosphorus in each organ of plant. The associative bacteria accelerated the growth of the under ground parts more than those of the upper ground parts of corn plant, and caused decrease in T/R ratios.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.531-540
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• 2016

The adoption of legume cover crops in no-tillage system can contribute to improve soil fertility by providing several benefits, including reduction in soil erosion, suppression of weed growth and N supply to subsequent crops. We conducted a field study to investigate the effect of cover crops and nitrogen fertilization rates on yield and nitrogen use efficiency of waxy corn (Zea mays L.) in no-tillage upland field. Two legume cover crops, hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnuturn L.) were mechanically terminated with roller in early June. For each cover crop treatment, nitrogen (N) fertilizer was applied at three different rates (145, 72.5 and $0kg\;N\;ha^{-1}$). The growth and yield characteristics of corn were significantly affected by the N fertilization rates in crimson clover plots, which suggest N mineralization from the cover crop residue was not sufficient. In contrast, N fertilization rates had no significant effect on growth and yield of corn in hairy vetch plots, indicating that the amount of N released from the cover crop is large enough to meet most of the N requirement of corn. However, the application of N fertilizer in hairy vetch cover plots resulted in slight increase of crop yield, though not statically significant, and high levels of N concentration in corn plant tissue possibly due to luxury consumption of N. Organic residues on the soil surface in hairy vetch cover plots had substantial amounts of N after harvest, ranging from 100 to $116kg\;N\;ha^{-1}$, which is presumably retained during winter season and released by microbial mineralization in subsequent year. The highest nitrogen yield efficiency was achieved in the plot with hairy vetch cover and no N fertilizer application, followed by the plot with hairy vetch cover and $72.5kg\;N\;ha^{-1}$ fertilization rate. In conclusion, hairy vetch showed better performance in corn productivity as compared with crimson clover. In addition, it was concluded that the application of N fertilizer between 0 and $72.5kg\;N\;ha^{-1}$ in combination with hairy vetch cover crop might be most efficient for corn yield under no-tillage system with climatic and soil characteristics similar to those of the experimental site.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.59-66
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• 1997

This experiment was conducted at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon in 1992 and 1993 to investigate the effects of tillage method-conventional and rotary-till, rye (Secde cereale L.) harvest date-early (April 14) and late (April 26), and rye residue treatmentno paraquat(1, 1-dinethyl-4,4'-bipyridinium dichloride) and paraquat in minimizing the adverse effects of the rye residue on growth and yield of succeeding corn(Zea mays L.). Corn plant height during the growing season was slighly taller with conventional tillage relative to rotary-till when rye was harvested in early and treated by paraquat. Corn LA1 during the growing season was slighly increased when rye was harvested in early and where conventional tillage was used with paraquat treatment. There were no differences in the leaf number and silking dates of corn among the tillage methods, harvest dates of rye and paraquat treatments. The dry matter yield of corn was significantly increased by paraquat treatment when rye was harvest in early, but no differences were found in the dry matter percentage, ear percent to total dry matter, and stover, ear and estimated TDN yields of corn among the treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.323-328
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• 1997

Com(Zea mays L.) hybrid is recognized as the principal cmp in a double-cmpping system. Rye(Secale cereale L.), seeded after corn hybrid harvest, is the second crop in the system. Under this forage production system, corn planting is mostly delayed beyond mid-May due to delayed rye harvest on May, but the corn should be harvested until mid-August before the autumn rain started. It is for this reason that early maturing corn hybrids are preferred for silage crops in this system. Twenty eight cultivars of early maturing corn hybrids evaluated in this experiment at three locations (Suweon, Sunghwan and Cheju) for 3 yr(1994-1996) were compared for agronomic characteristics, forage yield and quality. Among the com hybrids tested, DUO1 and GL499 were recommended as the government superior corn hybrids due to their promising agronomic traits, such as short plant and ear heights, adquate dry matter percentage for silage on mid-August, good staygreen along with good lodging and disease resistance, better ear retention, similar yield compared to the control hybrid, Suweon 19 and above average stover quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.305-311
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• 1993

Although corn (Zea mays L.) hybrids are now widely grown as a silage crop in Korea, but agronomic data and silage quality of the corn hybrids produced from farmer's fields have not been published. Therefore, a research survey assessing forage yield and quality of the corn hybrids was conducted at 8 and 13 dairy farms in 1988 and 1989, respectively. in Yoju and Ichon. Kyeongi Province. In 1988, percent ear bearing plants, plant population, ear/total dry matter ratio. percent dry matter and dry matter yield of corn hybrids were 75.3%, 75,826 plants/ha, 38.3%, 23.8% and 12,661 kg/ha. respectively. compared with corresponding values of 79.5%. 79,981 plants/ha, 41.1%. 20.7% and 16.152 kg/ha in 1989, but 11.9% of rice black streaked dwarf virus (RBSDV) was recorded in 1989. The Flieg's score of corn silage made by dairy farmers ranged from 70 to 100 and averaged 91. The corn silage produced from dairy farms was characterized as a high quality grade. Survey data indicated that late maturing types of corn hybrids with a higher plant population were grown at farmer's fields. As a result, the performances of the corn hybrids produced by farmers were much lower than those of research institutes. Therefore, dairy farmers in the mid-northern regions of Korea should grow more early maturing corn hybrids and use much lower plant population than those of the present.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.184-190
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• 2016

We investigated the antioxidative and protective effects of corn silk (Zea mays L.) ethanol extracts on human HaCaT cells and erythrocytes. The NICS-2 fraction, extracted from corn silk, exhibited favorable 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activities with $IC_{50}$valuesof$13.3{\pm}0.3{\mu}g/mL$ and $14.2{\pm}0.1{\mu}g/mL$ when compared with those of ${\alpha}$-tocopherol, a positive control, with $IC_{50}=10.4{\pm}02.2$ and $22.2{\pm}3.6{\mu}g/mL$, respectively. In addition, we investigated skin protection effects of NICS extracts of corn silk in HaCaT keratinocytes. To investigate the pharmacological potential of NICS-1 and NICS-2 extracts of corn silk on UV-B-induced damage in HaCaT cells, we measured the activity of interleukin (IL) 1a. Our results showed that all the corn silk extracts inhibited the UV-B-induced activity of IL-1a. In particular, NICS-1 extracts of corn silk significantly suppressed IL-1a activity in a dose-dependent manner without inducing cytotoxicity. These results indicate that the ethanol extracts of corn silk (Zea mays L.) could function as natural cytoprotective agents and antioxidants in biological systems, particularly the skin exposed to UV radiation, by protecting cellular membrane against reactive oxygen species (ROS).

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.41-48
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• 2000

This study was conducted to investigate the effects of the application rate of fermented swine manure and additional mineral fertilizer on productivity and nutritive value of corn(Zea mays L.) for silage. Swine manures used in this study were the compost of swine manure fermented with sawdust(SMFWS) and swine sluny(SS). This study was arranged in split-split plot design. Main plots were the types of swine manure, subplots were the application rate of swine manure, such as 100, 200 and 400kgN/ha, and sub-subplots were the application rate of mineral fertilizer, such as 50 and 100kgNiha. Corn DM(dry matter) and TDN(tota1 digestible nutrient) yields increased as application rate of SMFWS and SS increased. DM and TDN yields in SS treatments were higher than those in SMFWS treatments. The effect of fermented swine manure improved positively as application rate of urea increased. Net energy for lactation(NE1) and TDN content in corn decreased as application rate of SMFWS and SS increased, but crude protein(CP) content increased by the application of SMFWS and SS. NE, and TDN contents in SMFWS treatments were lower than those in SS treatments, but CP content in SMFWS was higher than that in SS. The growth and nutritive value of corn were improved by the application of mineral fertilizer. (Key words : Swine manure, Swine sluury, Compost, Zea may, TDN, Net energy)

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.128-134
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• 1988

This experiment was carried out to compare chemical composition of corn-cowpea inter cropping and corn monocropping plants at different harvestion time and obtained the following results. 1. In both cropping systems, the contents of crude fat and nitrogen free extract (NFE) were significantly increased (P<0.01), while that of crude protein crude fiber and crude ash were decreased (P<0.01) with each harvesting time. 2. The acid detergent fiber (ADF) and crude fiber contents were decreased same patterns in growing period, however, according to maturing of corn ears the difference between ADF and crude fiber contents reduced. 3. At mature stage, crude protein yields per 10a in corn monocropping and corn-cowpea intercropping system were 127.6kg and 152.1kg, respectively. The difference of crude protein content between corn-cowpea intercropping and corn monocropping system was 19.2%. 4. TDN yields of each cropping system, at mature stage, obtained similar results and TDN yields per 10a of corn monocropping and corn-cowpea intercropping system were 1006.1kg and 990.1, respectively. 5. Conseqently, corn-cowpea intercropping system could be increased protein yield without decreasing of dry matter yield in comparison with corn monocropping system.