• Korean Journal of Weed Science
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• v.1 no.1
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• pp.52-56
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• 1981

A 2-year field experiment was conducted to determine the influence of early and late soybean (Clycine max Merr) seeding times on competitive relationships between soybeans and annual weeds. Soybeans were planted on May 20 and June 20. Durations of weed competition and weed control were 0, 3, 6, 9, and 12 weeks after planting sad for full growing season. Dominant weeds were Portulaca oleracia, Centipeda minima, Rorippa cantonienais, Chenopodium album, Acalypha australis, Echinochloa crusgalli, and Digitaria sanguinalis. The dry weight of weeds increased with extended competition, especially at early seeding time of soybeans. Soybean yields were decreased as duration of weed competition was extended. More severe yield reduction occurred at late-planted soybeans with early stage weed competition but at early-planted soybeans when weeds competed with soybeans for a 2 weeds and full growing season. The dry weight of weeds emerged after weeding was decreased at early and late seeding times of soybeans as duration of weed control was prolonged. Soybean yields decreased with shortening duration of weed control end this trend of yield reduction was slightly more remarkable at late-planted soybeans than at early-planted soybeans. Late-planted soybeans were required longer than 6 weeks of weed control period to achieve maximum yield as compared to early-planted soybeans.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.139-148
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• 1987

Exochorda serratifolia, broad-leaved shrub has beautiful flowers and is resistant to cold, shade and decease. New this native plant is considered to be worth being exploited as the outstanding plant for landscaping and horticulture. So this study was executed to utilize Exochorda serratifolia as the planting material for landscaping and horticulture through the survey of its habitat environment and the experimennt of its seed physiology and germination, vegetative propagation, culture and utilization, etc.. The results are as follows ; 1. The color of the flower is white, blooming in the early and middle of May and the seeds ripen late in Sep.. 2. The elevation, elevation, gradient and direction of the native habitat were 250m, 20-25$^{\circ}$and northern side respectively. 3. The soil pH of the natural habitat was 5.3 and soil fertility was poor. 4. Exochorda serratifolia appeared as indicator within P. densiflora community and its neighboring species were Q. mongolica, Q. dentata, R. mucronulatum, L. obtusiloba, E. oxyphillus, C. heterolphylla, var thunbergii, etc.. 5. The optimum temperature for seed germination was found at 20$^{\circ}C$ and the longer the stratification period at 5$^{\circ}C$ was, the lower the germination rate was. 6. The treat merits of GA and Kinetin increased the seed germination rate, especially under the dark condition but their high concentrations decreased the seed germination rate. 7. The rooted rate of the greenwood cutting was the highest at IBA 100ppm plot of vermiculite bed but its high concentration decreased the rooted rate conspicuously. 8. In the tissue culture, the each 1.0 ppd plot of NAA, Kinetin and NAA 1.0ppm + Kinetin showed the best growth. And the mixture of NAA 1.0ppm and Kinetin showed better growth than the single treatment of NAA or Kinetin did. 9. Transplanted Exochorda serratifolia showed healthy growth with shaded environmental condition(42.1% light intensity), therefore they can be cultivated as a shade tolerant landscape plant. 10. It was considered that Exochorda serratifolia was applicable to group planting at shade places or under trees in parks, homes, etc..

• Korean Journal of Medicinal Crop Science
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• v.3 no.3
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• pp.259-264
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• 1995

This study was carried out to find cultivation condition of peony in Euiseong district from 1994 to 1995. 1. Age distribution in cultivation of peony was from 30's to 50's and cultivated years was mainly from 5 years to 10 years, but there was more than 15 years 2. Cultivating area per house hold were 1300 pyeong average, there were moderate $400{\sim]1000$ pyeong and also those are occupied 22.6% more than 2000 pyeong. 3. The mothods of transplanting in Euiseong peony which Euiseong district was mostly divided peony but Yeongchen district used seedling stock. No. of sprout was mostly $3{\sim}4$ and planting time was mainly from Mid to Late of October. 4. The percentage of sterilization of soil and seedling stock was 77. 4%, in mulching by vinyl in tran­splanting 64. 5% in black vinyl and 25. 8% in white one. 5. Number of plant in peony planting was $3000{\sim}4000$ plant per l0a even more there was more than 8000 plant. 6. Chemical spraying time in peony field was 2 time in $1{\sim}2$ years cultivating, and $3{\sim}4$ time in $3{\sim}4$ years one. 7. Condition of fertilizer application in peony field was 40% in non-application, but $56.7{\sim}76.7%$ in 2 year to 3 years, and the time of fertilizer was mainly 3 time. 8. Drying time peony after havesting was from 12 to 24 hours by briquet stove and 24 hours by ma­chine of hot wind, also dry method of peony was mixed briquet stove and hot wind machine.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.285-292
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea atata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. from about 150-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 140-days and continued to the 190-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.91-97
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• 2010

The growth, yield and chemical properties of waxy corn $Sonjajang{\times}KNU-7$ and $Asan{\times}KNU-7$ planted in different dates and mulch types in a converted paddy field was investigated. Experiment was carried out in a randomized complete block design in a split split-plot arrangement with four replications. Planting dates (D) [May 16 (D1, early), June 1 (D2, middle), June 6 (D3, late)] represented main plots, plastic mulch (M) [(BM, black mulch; TM, transparent mulch)] for subplots while waxy corn crosses [$Sonjajang{\times}KNU-7$ (‘Sonja’) and $Asan{\times}KNU-7$ (‘Asan’)] for sub-subplots. Results showed that D had a significant effect on growth characters except emergence, ear quality except ear diameter, and yield whereas M showed significant effect on growth characters only. Superior growth and ear quality performance were recorded in D1 and BM. In terms of crosses, ‘Sonja’ had better growth performance than ‘Asan’ regardless of D and M, but performed better at D1 and BM. Highest yield was obtained in D1 for BM (2,131 kg $10a^{-1}$) and TM (1,655 kg $10a^{-1}$) but no significant difference in the yield across V was recorded. In terms of starch and sugar contents, a decreasing trend was observed from D1 to D3 regardless of M and V.

• Korean Journal of Organic Agriculture
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• v.10 no.4
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• pp.69-78
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• 2002

This experiment was conducted to investigate the changes of sugar contents and chip color during 104days storage after harvesting of five potato varieties. The potato varieties were planted on 1st April in 1999 and harvested on 10. July in 1999. $No_2$ contents in potato petiole tended to decrease repidly at tuber maturing stage. $K^+$ contents in potato petiole tended to in crease at 70 days ofter planting on medium maturing varieties, and at 90 days after planting on late maturing variety. Snowden variety was no desirable cultivar for processing on spring cultivation due to long growth period. Contents of solid and sugar in potatoes affected on potato chip color. Higher contents of solid in potato varieties showed low sugar contents and no change on chip color during storage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.145-145
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• 2022

South Korea greenhouse gas emissions have increased year by year, resulting in a total emission of 727.6 million tons of CO₂ eq in 2018, a 2.5% increase compared to 2017. Among them, the agricultural sector emitted 21.2 million tons of CO₂ eq., accounting for 2.9% of the total. Among the greenhouse gases emitted from the agricultural sector, a particularly problematic is methane gas emitted from rice paddies. Methane is one of the important greenhouse gases with a global warming potential (GWP) that is about 21 times higher than that of carbon dioxide due to its high infrared absorption capacity despite its relatively short remaining atmospheric period. Since the pattern of methane generation varies depending on the rice variety and ecological type, research related to this is necessary for accurate emission calculation and development of reduction technology. Accordingly, a study was conducted to find out the changes in greenhouse gas emission according to rice varieties and ecology types. As for the rice eco-type cultivar, early maturing cultivar (Haedamssal) and medium-late rice cultivar (Saeilmi) were used. Haedamssal was transplanted on May 25 and June 25, and Saeilmi was transplanted on June 10 and June 25. The amount of methane generated according to the growing day showed a tendency to increase as the planting period was earlier. The difference between varieties was that Haedamssal showed higher methane production than Saeilmi. The total CH₄ flux in the saeilmi was 18.7 kg·h^-1(Jun 10 transplanting), 12.4 kg·h^-1(Jun 25 transplanting) during rice cultivation. Lower methane emission was observed in Saeilmi than in Haedam rice. In addition, the earlier the planting period, the higher the methane emission. This study is the result of the first year of research, and it is planned to investigate the amount of greenhouse gas emission between double cropping and single cropping using wheat cultivation after harvest for each ecological type.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.20-26
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• 2013

This study was carried out of investigate the effect of weed control methods on the growth of 'campbell early' grape at the vineyards which was divided into the 18 zone ($3.5m{\times}5.5m/zone$) in the grape research institute. It's investigated control effects, growth and quantity of grape and dominant weed of July~August by sprayed glufosinate ammonium and paraquat dichloride each 3 times, fabric covering, grass planting (Festuca myuros), mechanical weeding (3 times). The weed showed total of 16 species at the vineyards. Late-May to early growth stage of grape was dominated Chenopodium album and Trifolium repens, but to late growth stage of grape from mid-July was dominated Erigeron canadensis, Echinochloa crus-galli and Chenopodium album. Weed control effect of 10 day after treatment showed fabric covering 100%, grass planting (Festuca myuros L.) 95.3%, mechanical weeding 81.9%, glufosinate ammonium (3 times) 98.1% and paraquat dichloride (3 times) 90.4%, respectively. Growth of grape was higher herbicides treatment and mechanical weeding than others. Yield tended to be higher glufosinate ammonium (3 times) and paraquat dichloride (3 times) each 12.6 kg/tree, 12.3 kg/tree than others.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.179-188
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• 2020

Weeding refers to the process of removing weeds around crop trees, which cause competition in nutrients, moisture, and light, and has a great effect on the early growth and survival of crop trees for establishing forest resources. This study was conducted to find out the timing and method of weeding that is the most suitable for the major afforestation species in national forests. We investigated (1) weeding time and frequency for each afforestation species and (2) the height of crop trees and the length of weeds. Up to 99% weeding operation was carried out until 5 years following afforestation. Pinus densiflora, Larix kaempferi, Chamaecyparis obtusa, Prunus sargentii, and Betula platyphylla plantations accounted for more than 70% of the total weeding sites. Once-a-year weeding process was conducted from late June to late July (67%), and twice-a-year weeding process was the highest in June-August by 31%. Most species were shorter than the weeds until the first and second year of planting, but the height of the crop trees was higher than that of the weeds by 48% in average from the third year. Therefore, from the third year of afforestation, except for some species, it is possible to reduce the cost of weeding operations while reducing nutrient competition by the weeds through the removal of weed sprouts, mainly woody weeds, rather than clear cutting. This study contributes to efficiently develop forest resource establishment while reducing operational costs through a detailed weeding schedule and species-specific method.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.73-90
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• 1998

The construction and management of the royal garden and landscape were the most significant project in Choson Dynasty. The kind of the royal garden and landscape were the rear garden of the palace, the groves of the royal shrine and orchard, etc. As the important project of the country, these constructions were controlled by the administrative system without division into the fields of engineering, building and landscaping. The purpose of this study is to investigate the administrative system. In particular, this study is focused on the construction and management of the royal garden and landscape in Hanyang from the 18th century to the late 19th century. This study is based on the analysis of historic documents and a survey of the relics. The results were summarized as follows : 1) The administrative system of the construction and management of the royal garden and landscape was composed of the government offices under Industry Board as a permanent organization - Yongjosa, Santaeksa, Chunchonsa, Songonggam, Changwonso - and Togam as a temporary organization. In addition to these organizations, there were Revenue Board, Ceremony Board, Military Board, which served as supporting organizations. The control of the construction and management of the royal garden and landscape was held by decision makers, executors of works and management. 2) The general process of the construction and management of the royal garden and landscape included Sangji and Kyuho다 as the first step; In case of buildings and facilities, according to former examples and drawings, the most of the planning and design was already fixed. In the case of landscape, those things aimed at construction according to the existing lie of the land. The works in the 2nd step; This process was divided into the construction of facilities and planting. In case of construction of facilities, those works were done by Togam and Songonggam. The high cost works were carried out through Togam and normal repairing works were completed by Songonggam. In case of planting, those works were carried out through Chunchonsa and the military. The management in the 3rd step; This process was done by two parts like the process of works. In case of facilities, management was done 효 the officers of Pongshim. In case of groves of newly - planted trees, this management was done by Tongsanbyonlgam and Tongsanjik who served cultivation and harvest of fruit trees as an expert.