• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.3
• /
• pp.334-339
• /
• 1985

A sweet corn hybrid, Honey Bantam, was planted on 24 May, 1984 in a silty clay loam soil to investigate the effects of polyethylene(P.E.) mulch and different levels and placements of Nitrogen(N) on soil properties and sweet corn growth. A split-split plot design with three replications was employed; P.E. mulch and bare soil were main plot, N levele of 8, 12, 16, and 20 kg/10a were subplot, and band and broadcast of fertilizers were sub-subplots. At early growth stage soil temperature under P.E. mulch was higher than that in bare soil by 5-10$^{\circ}C$, but the differences decreased as plant growth advanced. Soil hardness increased with soil depth while P.E. mulch reduced soil hardness probably by holding high soil moisture. Soil pH decreased up to the 6th week after planting and then increased in bare soil, but it contineously decreased up to the 8th weeks under P.E. mulch regardless N levels and placements. Electrical conductivity(EC) of soil increased up to the 6th weeks after planting and then decreased in all treatments except broadcast of fertilizers under P.E. mulch where EC increased contineously. Generally, soil EC under P.E. mulch was higher than that in broadcast. Broadcast of fertilizers did not affect emergence of seedlings in all N levels under P.E. mulch and bare soil, but band of fertilizers at all N levels under P.E. mulch and higher levels of N in bare soil reduced emergence rate significantly. Percent stand was possitively correlated with soil EC and it strongly influenced the number of marketable ears. Plant growth was enhanced and silking date was earlier by 14-19 days under P.E. mulch compared to bare soil probably due to increased soil moisture, reduced soil hardness and higher soil temperature.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.129-136
• /
• 1991

Dry matter productivity at silage stage of two corn hybrids varying resistance to rice blackstreaked dwarf virus(RBSDV) and two sorghum hybrids varying growth duration was evaluated at six planting dates (Apr. 1, Apr. 15, Apr. 29, May 13, May 27, and June 10) in Kyongsan where RBSDV is prevalent.Corn was harvested 38-40 days after silking. For sorghum 1st-cut was made 19-22 days after heading and some regrowth (2nd-cut) on October 13. 1. Percent stand of both corn hybrids was over 91% at all planting dates, but that of sorghum ranged 37.2-80.3% depending on hybrids and planting dates. 2. The number of days from planting to emergence decreased as planting date delayed in both crops. The number of days from emergence to silking of both corn hybrids and a sorghum hybrid(P 956) decreased as planting date delayed, but that of the other sorghum hybrid(P 931) increased significantly after May 13 planting. 3. RBSDV infection rate of corn hybrids was highest at April 1 planting (Kwanganok 24.896, Jinjuok 63.0%) and decreased up to April 29 planting and then increased as planting date delayed. Sorghum was not infected by RBSDV at all. 4. EarfTotal dry matter ratio of corn ranged 30.6-47.9% and that of sorghum 3.1-30.7% depending on hybrids and planting dates. All the hybrids developed grain normally at all planting dates except a sorghum hybrid (P 931) which developed few grains after May 13 planting. 5. Crude (C) protein and C. fat contents were similar among all treatments. C. fiber content of P 931 was higher than that of both corn hybrids and P 956, but nitrogen free extract (NFE) was lower. C. fiber and NFE of both corn hybrids and 1st-cut sorghum were similar among the planting dates, but C. fiber and NFE of 2nd-cut of sorghum decreased and C. protein increased as planting date delayed due to plants were younger. 6. Dry matter (DM) yield of all hybrids decreased as planting date delayed except Jinjuok of which yield was highest at April 29 planting. DM yield of corn was similar to 1st-cut sorghum, but lower than total DM yield of sorghum at April 1 and 15 plantings where regrowth yield was high.

• Korean Journal of Weed Science
• /
• v.17 no.3
• /
• pp.295-302
• /
• 1997

The study conducted to know the effect of growth and yield by different weed control duration using by 'chalok 1 ho', waxy maize, at Suweon in 1995. The emergence of weed and growth and yield of waxy maize on weedy check and 10, 20, 30, 40, 50, 60, 70, 80, and 90 days weed control and whole season weed control during cultivation summrized as follows; 1. Chenopodium album, Echinochoa crus-galli, Persicaria hydropiper and Panicum bisulcatum emerged as major weeds and dominant weed was Chenopodium album. 2. The number of emerged weeds grouped by mophologically ordered broad leaf weeds, grass weeds and sedge weeds. 3. 30 days weed control duration from the sowing effect to silking stage and 40 days weed control duration from the sowing decreased stem length, ear length, ear weight, number of plant, and number of ear. 4. The yield of weedy check, and 10 days weed control from the sowing showed no yield and 20, 30 and 40 days weed control from the sowing decreased to 76, 64 and 33 %, individually. 5. The yield loss of waxy maize on weeds can be prevent by 40 days weed control duration from the sowing.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.39 no.3
• /
• pp.64-73
• /
• 2011

This study starts from the hypothesis that the information society has affected the layman's interpretation and production of content. Specifically, the manner and contents of communication concerning the landscape of Soonyoo-do Park in blogs are surveyed and the possibilities and limitations of this phenomenon are discussed. The following topics are dealt with. Firstly, what is the landscape of Seonyoodo Park as captured by bloggers? What type of landscape do bloggers respond to? Secondly, what is the unique way that bloggers capture and interpret the landscape? Thirdly, What are the possibilities and limitations discovered from the landscape as captured and interpreted by bloggers? Thus, 1,000 blog posts concerning Soonyoo-do Park, as culled from the Internet, were categorized into three areas, First are blog posts browsed by keywords such as 'photo', 'a photographer's visit', 'a good p1ace for taking photos', and 'landscape'. These are focused on the visual aspects of the landscape. The second category is posts under the keywords 'domestic travel', 'Seoul travel', 'travel', and 'recommendation'. They contain introductory information on Seonyoodo Park; that is, they focus cm the more utilitarian functions of Seonyoodo Park as a place. The third one is posts that record personal experiences. The subjects for photography are the bloggers themselves and their companions. As a result of studying the way bloggers deal with landscape, it was found that first, people have developed the ability to capture the landscape and interpret the landscape actively and independently. This process can be regarded as the reproduction of landscape and place. In addition, the recording of their appreciation and feeling overlaps with evaluation and assumption. One negative aspect, however, is that many bloggers dramatize and repeat similar scenes. This can be seen as a make-up of image. The limitations of this study include difficulty in interpretation because blogs, which are the objects of this study, are very subjective and personal. In addition, it was not easy to categorize posts because there were diverse images and a broad range of writing. Nevertheless, practitioners of landscape architecture should continue to monitor and use one-person media like blogs, because the relationship between modern man and the landscape can be better understood through them.

• Journal of Chest Surgery
• /
• v.30 no.5
• /
• pp.479-485
• /
• 1997

We investigated changes of the size of neoaortic annulus, root, and aortic anastomosis after arterial switch operation for complete transposition of the great arteries performed in infancy. A total of 23 patients were included in this study. Age ranged from 6 to 153 days. Body weight averaged 3.9$\pm$0.8kg and 17 patients were male. The preoperative angiocardiographic dimensions of the pulmonary annulus, the pulmonary root, and the sinotubular junction, standardized to the diameter of descending aorta at the level of diaphragm, were compared to the size of postoperative measurements of the neoaortic annulus, the neoaortic root, and the aortic an stomosis at a mean interval of 17.2$\pm$ 9.4 months. Mean dimensions of the neoaortic annulus and the neoaortic root were significantly increased postoperatively(n=23, annulus; p<0.01, root; p<0.01), however, those of the aortic anastomosis did not reveal significant change(n=23, p=0.06). There were no significant differences in changes of diameters of the neoaortic annulus, the root, and the aortic anastomosis between patients with(n=8) and without(n=15) postoperative neoaortic regurgitation(annulus; p=0.32, root; p=0.29, anastomosis; p=0.86). Postoperative dimensions of the neoaortic root and annulus between patients with ventricular septal defect(n: 10) and without ventricular septal defect(ni 13) were not significantly changed compared to the preoperative measurements(annulus; p=0.09, root; p=0.07) but mean diameters of the aortic anastomosis decreased significantly after operation in patients with ventricular septal defect(p=0.04). This study revealed that the site of the aortic an stomosis grows in proportion to patient's somatic growth after arterial switch operation. Although we could not demonstrate the relation between the aortic root dilatation and the postoperative neoaortic regurgitation in this study, a continuous close follow-up might be necessary to detect a possible progression of the aortic root dilatation and the resulting significant aortic valve regurgitation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.22 no.3
• /
• pp.197-204
• /
• 1989

To evaluate the effect of soil improvement on the chemical properties and corn silage yield, this experiment was carried out in the newly-reclaimed sloped land. Corn (Suwon 19) was cultivated under the six different treatments including integrated improvement plot at Songjeong loam, 20 percent slope, from 1985 to 1987 and various soil chemical properties and silage yield were investigated. pH of topsoil was above 5.0 except for control and phosphate plot, but lime and integrated improvement plots were above 5.0 in subsoil. The contents of organic matter of topsoil were above 2.0% except control and subsoiling plot. Except control, the range of cation exchange capacity was 7.4-7.8 me/100g in topsoil, 7.0-7.7 me/100g in subsoil. Soil bacteria density of root zone was the highest in integrated improvement than the other treatments, and it was higher at the harvesting stage than the heading stage. Mean density of microorganism was $61.3{\times}10^5$ in bacteria, $21.5{\times}10^4$ in fungi and actinomycetes was B/F ratio was 28.5 and B/A ratio was 2.9. Vertical root distribution of total and 10cm depth below was more in the integrated improvement and subsoi ling plot than the other plots. Total nitrogen (T-N) content was higher in integrated improvement plot, and phosphate content of leaves was higher in compost and integrated improvement plot, but stem and grain were not different. Potassium content of the plant was higher in integra ted improvement plot. Correlation between dry matter yield and T-N was more significant than the other elements. And the contents of phosphate, calcium and magnesium were significant at 5%, but potassium was not.

• Korean Journal of Agricultural Science
• /
• v.15 no.2
• /
• pp.123-131
• /
• 1988

This study was done to investigate the interplanting effects of corn, when a corn hybrid with tillers (IK derivaties) was interplanted with a corn hybrid without tillers(Jinjoo Ok). The interplanting ratios of two hybrids, IK and Jinjoo Ok, were 1 to 1, 1 to 2, 1 to 3, 2 to 1, and 3 to 1. The interp1anting effects were compared with monoculture for major agronomic characteristics. 1. The plant height was increased when interplanted regardless of the interplanting ratios of the two hybrids. The general growth of IK hybrid was a little hindered when the interplanting ratio of Jinjoo Ok hybrid increased. 2. The number of tillers produced by the IK hybrid increased until 40 days after emergence and appeared to increase as the interplanting ratio of IK hybrid increased. 3. When monocultured, the fresh weight of IK hybrid per 10a was 8,096kg and and 6,677kg at silking and dough stages, respectively and these were 77%, 53% over the fresh weight of Jinjoo Ok at the sarne stages. When IK and Jinjoo Ok hybrids were interplanted in 1 to 1 ratio, the fresh weight of IK was 20% higher than that of Jinjoo Ok monocultured. 4. The highest grain yield per 10a was obtained from the Jinjoo Ok hybrid monocultured and the yield was 434kg. Even the interplanting ratios between IK and Jinjoo Ok were 1 to 1 and 1 to 3, the grain yield of Jinjoo Ok was 16% and 13% over the IK, respectively. 5. Root and stalk lodging of IK hybrid was 29% when monocultured and seemed to increase as the interplanting ratio of Jinjoo Ok increased. The lowest lodging was found when the interplanting ratio of IK and Jinjoo Ok was 1 to 1. 6. Stem diameter of IK hybrid was also decreased as the interplanting ratio of Jinjoo Ok increased. The ear height of IK was lowered as the interplanting ratio of IK was increased. The two hybrids tested seemed to have tolerance to the black streaked dwarf virus(BSDV).

• Korean Journal of Environmental Biology
• /
• v.34 no.4
• /
• pp.223-232
• /
• 2016

Drought is one of important environmental stress for plant. Drought has deleterious effect to plant growth including maize (Zea mays L.) such as vegetative and/or reproductive growth, root extension, photosynthesis efficiency, flowering, anthesis-silking interval (ASI), fertilization, and grain filling. In this study, we screened drought tolerant maize in 21 cultivars from different sources, sixteen NAM parent lines (B73, CML103, CML228, CML247, CML277, CML322, CML333, CML69, Ki11, Ki3, Ky21, M37W, Mo18w, NC350, Oh43 and Tx303), four Korean hybrids (Cheongdaok, Gangdaok, Kwangpyeongok and Pyeonganok) and one Southeast Asian genotype (DK9955). Drought stress (DS) index was evaluated with leaf rolling score at seedling stage and ASI at silking date. The leaf rolling scoring of CML228, DK9955 and Ki11 were determined 1.28, 1.85, 1.86, respectively. However, M37W, Kwangpyeongok, B73 and NC350 were determined over the 3. ASI analysis revealed that CML228, CML103, Cheongdaok, NC350, B73, CML322, Kwangpyeongok and Ki11 are represented less than 5 days under DS and less than 3 days of difference between DS and well-watered (WW), but CML69, Ki3, Pyeonganok, M37W, Mo18w and Gangdaok were represented more than 10 days under DS and more than 8 days of difference between DS and WW. Multi-Dimensional Scaling (MDS) analysis determined CML228, Ki11, and CML322 were regarded as drought tolerance cultivars. Eventually, Ki11 showed genetic similarity with Korean cultivars by QTL analysis and MDS analysis. Ki11 has a potential for development of drought tolerance maize with Korean cultivars.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.3
• /
• pp.249-254
• /
• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.62 no.3
• /
• pp.214-223
• /
• 2017

A total of 15 different corn hybrids, Kwangpyeongok, Gangdaok, Yanganok, Singwangok, Jangdaok, Cheonganok, Cheongdaok, Andaok, Dapyeongok, Pyeongkangok, Pyeonganok, Daanok, Sunwon 184, Gangilok, and P3394 was used to investigate the growth and yield depending on the sowing date. The sowing dates were April 5, June 25, and July 5 and each experiments was performed in triplicste. The growth of Gangdaok was the highest. However, although the growth of Kwangpyeongok, was lower thanthar of Gangdaok, its stem height to ear height ratio was lower than that of Gangdaok, thus, Kwangpyeongok may be more suitable for stable cultivation. Both growth and yield of Daanok were low, regardless of planting date, but yield and ear shape of Pyeongkangok and Dapyeongok were for fresh corn. Growth and yield of the 15 different corn hybrids varied depending on the planting date, However, the growth degree days (GDD) was the most important factor governing the maturity of corn. More than $1500^{\circ}C$ of GDD was sufficient to harvest mature corn hybrids in the central region of Korea. Besides yield and growth, other characteristics, such as sweetness and taste of the hybrids, should be investigated further the selection of the best corn hybrid.