• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.491-497
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• 2015

Small-sized tuber of sweet potato (Ipomoea batatas Lam.) is more preferred by Korean consumers, because it is convenient to eat with hands, and can easily be steamed or roasted in small pan as a healthy snack for a small family. The present study was aimed to investigate the effect of high-density plantings and harvesting times on production of smallsized tuber (50~200 g). Four varieties ('Annobeny', 'Daeyumi', 'Shinzami', and 'Yeonhwangmi') were planted in 2-row zigzag high-density planting ($75{\times}30cm$, A; $75{\times}25cm$, B) and 1-row planting ($75{\times}25cm$, control) covered with black vinyl film on May 23th, 2014. Marketable yields and small-sized tuber yields were compared between 120- and 150-day harvesting. Vine length and fresh weight per plant were significantly decreased in 2-row planting A and B plots compared to the control at 120 days after planting. Weight of tuber per plant, mean weight of tuber and number of tuber per plant were significantly decreased in 120-day harvesting of A and B plots than in the control. Marketable yields per 10a were increased by 17% ($2.4ton{\cdot}10a^{-1}$) and 8% ($2.6ton{\cdot}10a^{-1}$) in 120-day harvesting of A and B plots compared to the control ($2.4ton{\cdot}10a^{-1}$), and those were largely increased by 29% ($4.0ton{\cdot}10a^{-1}$) and 26% ($3.9ton{\cdot}10a^{-1}$) in 150-day harvesting than in the control ($3.1ton{\cdot}10a^{-1}$). Proportions of small size tuber (50~200 g) were increased by about 65% in 150-day harvesting of A and B plots compared to the control (55.3%). Small-size tuber yield and marketable yield were highly increased in 150-day harvesting of 2-row zigzag high-density planting A ($75{\times}30cm$).

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.10a
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• pp.233-248
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• 1998

Food Self-sufficiency rate in Korea was 26.4 percent in 1996. It include $89.9{\%}$ for rice, $99.6{\%}$ for root and tuber crops, and $73.5{\%}$ for barley. To make things worse, self-sufficiency for wheat and corn were far less than 1 percent. As food is considered as weapon, every effort should be given to increase the self-sufficiency. In order to cope with expected food crisis, we suggest wheat and barley be grown in winter period, where there is climate fit. The aim of this paper is to survey systematically the status of food supply and demand of wheat and barley and to encourage farmers make double cropping systems with better stability in yield and economic return.

• Journal of Environmental Science International
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• v.30 no.12
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• pp.1015-1025
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• 2021

Our research work aimed to evaluate cover crop effects of winter rye on soil characteristics, soil conservation, and yield productivities on potato fields with 15% slope during a fallowed period. There were two controls of bared field without any cultivation and conventional potato cultivation without winter rye. Potato cultivation increased soil pH, organic matter, available phosphate, and exchangeable cation regardless of cover crop cultivation. Sub-soil, particularly, all components of soil chemical properties showed higher value in winter rye cultivation than conventional cultivation. Higher soil density was observed on cover crop cultivation than conventional cultivation resulting from root residues of the cover crop both topsoil and subsoil. Cover crop residues positively affected plant growth and reduced the amount of soil erosion by holding the soil. Although severe soil erosion was seen in conventional cultivation, winter rye cultivation declined soil erosion by 47% during the fallow period on potato slope fields. Distinct soil bacterial communities were detected among treatments and some OTU(Operational Taxonomic Unit)s showed significantly higher abundance in winter rye treatment. Total yield and commercial rate demonstrated no significant differences while higher tuber phosphate, K⁺, and Mg²⁺ contents were observed in winter rye cultivation.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.188-196
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• 2020

BACKGROUND: In order to cultivate upland crops in reclaimed land, economically appropriate crops should be selected. Jerusalem artichoke (Helianthus tuberosus L.) is one of the primary sources for inulin in higher plants. The objective of this study was to evaluate and compare growth and inulin of H. tuberosus L. according to the cultivation region in Korea. METHODS AND RESULTS: 21 varieties of H. tuberosus L. were collected in Korea, and then 7 varieties of H. tuberosus L. were selected for this study. To compare growth and inulin, those varieties were cultivated in reclaimed land and upland soils. The growth of H. tuberosus L. significantly decreased when cultivated in reclaimed land. There was an increas at 17.8% in the content of white H. tuberosus L. tuber inulin in reclaimed land. CONCLUSION: The content of inulin in H. tuberosus L. tubers was found to be dependent on cultivation region and tuber color. There was a difference of the inulin content between the tubers with different colors in reclaimed land. Purple tubers of P20 were considered suitable varieties for cultivation in reclaimed land. White tubers of W1 and W8 were also considered suitable varieties for cultivation in reclaimed land.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.24-31
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• 2013

This study was conducted to determine the characteristics of quality and yield in potatoes grown at paddy field before rice transplantation during the spring season. Three potato cultivars ('Jowon', 'Haryeong', and 'Goun') were grown in Gangneung (asl 5 m) and Seocheon (asl 20 m). In both locations, weather condition belonged to the fourth zone (spring cropping) in potato production location's distribution of Korea. Daily mean soil temperature in both the locations was $0.2-0.6^{\circ}C$ lower than air temperature, while soil moisture was adequate level to potato growth in spite of spring drought. TR ratio was not affected by location, but by cultivar. Specific gravity, starch content, dry matter rate, and yield were significantly influenced by location and by cultivar. There was no difference in total tuber number by location, however there was a large gap in marketable tuber yield according to locations and cultivars. There were high negative relationships between yield and main qualities such as dry matter rate and starch content, while high positive correlation was observed between main qualities. It was possible to produce potato before rice transplanting at drained paddy fields located in representative two locations of potato spring cropping and their characteristics in growth and quality were similar to those generally well known in upland cultivation. Paddy field was thought to be more favorable than upland in terms of available soil moisture supply against spring drought. Further research, however, was needed to increase soil temperature and also preliminary review on proper cultivar according to location seemed to be needed for high yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.9-15
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• 1995

This study was carried out to investigate the effects of the optimal fertilizer application levels and planting space at different seeding parts on Chinese yam from 1992 to 1993. The results obtained was as follows： The earlist day to emergence was 42~56 days at tuber section, 37~46 days at an aerial tuber, and 50~56 days at an exposed parent material. in turn. The days to emergence were delayed by increasing fertilizer application levels. In the growth of the under-ground parts, vine length was increased in a tuber section, aerial tuber, and an exposed parent material in turn. The tuber section by 60${\times}$20cm at planting space, 56-56-64 Kg/10a at fertilizer application levels was appeared to be good growth among underground parts. As planted close, the growth of tuber section was decreased. The totoal yield was appeared to be increased about 19% in a tuber section planted as 30${\times}$20cm compared with 60${\times}$20cm. In an exposed parent ma-terial, the planting space, 30${\times}$15cm, was increased 10% compared with 45${\times}$15cm, and in an aerial tuber, the planting space, 10${\times}$10cm, was increased about 10% comparing 30${\times}$10cm. Fertilization level(N-$P_2O_2K_2O$) in 56-56-64Kg/10a was increased 39 to 47% comparing 28-28-32 Kg/10a. And the heavy dressing and the close planting space were appeared to be produced the highest yield. In considering commercial quality, the optimal combination between seeding parts and planting space is recommended to improve commercial qualities and high yield.

• The Korean Journal of Ecology
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• v.14 no.1
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• pp.63-73
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• 1991

Nakdong estuary provides the largest wintering grounds for migrating waterfowls in Korea, and was designated Natural Monument No. 179 in 1966. Nakdong barrage and related construction-projects finished in 1987 to increase freshwater-supply to nearby Pusan metropolitan area and to reclaim the vast intertidal areas for land development. Changes on distribution, primary productivity, and standing crop of Schoenopluctus triqueter, the dominant species in this intertidal flats, were investigated after the construciton, during the 1988-1990, and were compared to those before the construction. Total standing crop. tuber biomass and net primary productivity of S. triqueter increased in 1988 and 1989, but decreased slightly in 1990. Increase of tuber biomass means an increase in available food, thus the carrying capacity, for swans wintering in this area. Habitat environment of this estuary should be protected and managed as a wintering ground for migrating waterfowls, inspite of the construction of the barrage.

• Korean Journal of Plant Resources
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• v.24 no.6
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• pp.688-695
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• 2011

The composition of free sugar, free amino acid, and fatty acid in tubers of the cultivars 'Superior', 'Sinnamjak', and 'Chubaek' were evaluated at the two sites with different altitude, Gangneung (20 m altitude) as lowland and Daekwallyeong (760 m altitude) as highland. The average reducing sugar content of the three potato cultivars harvested in Daekwallyeong and Gangneung was 1.1% and 2.3%, respectively, which showed two-fold difference between the two locations. Average total sugar content was also two-folds lower in potatoes harvested in Daekwallyeong (6.3%) than those harvested in Gangneung (12.2%). Average content of free amino acids of the three potato cultivars harvested in Daekwallyeong and Gangneung was 1,325 mg/100g and 1,051 mg/100g, respectively. The cultivar 'Chubaek' has the highest amino acid content among the three tested cultivars. Potatoes from Daekwallyeong have higher unsaturated fatty acid levels than those from Gangneung. During the tuber development, unsaturated fatty acids levels increased in tubers grown in Daekwallyeong, but decreased in those grown in Gangneung. These results indicate that the quality of potatoes from Daekwallyeong is from Gangneung for food processing purpose for human consumption.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.468-476
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• 2020

This study was performed to establish light intensity conditions for producing stem cuttings for aeroponic systems suitable for seed potato production using a closed-type plant production system. Shoot tip cultured plantlets of 'Sumi' and 'Chubaek' potato (Solanum tuberosum L.) were acclimatized, cuttings were collected, and stem cuttings were planted. The seedlings were raised for 40 days at different LED light intensities (60, 120, 180, and 240 μmol·m^-2·s^-1), and were cultivated in an aeroponic system for 80 days. When stem cuttings were raised at 60 μmol·m^-2·s^-1 LED light intensity, the plant height was the longest, at 17.3 cm for 'Sumi' and 16.1 cm for 'Chubaek', and the number of nodes was the highest in both cultivars. The higher light intensities, produced smaller plants with fewer nodes. The leaf areas, SPAD values, and Fv/Fm values differed slightly between cultivars. The fresh weight of stem cuttings, and the production rate of healthy stem cuttings were the highest at 60 μmol·m^-2·s^-1. In the aeroponic system, seedlings raised at 60 μmol·m^-2·s^-1 with LED light intensity showed a difference between the cultivars, but the fresh weight of stems and leaves above the planting plate was the heaviest. In addition, below the planting plate the stem cuttings were longest and the root weight was heaviest at 60 μmol·m^-2·s^-1 LED light intensity. The number of stolons also differed between cultivars, but was greatest for seedlings raised at 60 μmol·m^-2·s^-1 LED light intensity, at 4.2/plant for 'Sumi' and 7.7/plant for 'Chubaek'. At 60 μmol·m^-2·s^-1 LED light intensity, the tuber number and total tuber weight were the best, but the higher the light intensity, the smaller the total tuber number and total tuber weight for both cultivars. In conclusion, when producing potato stem cuttings for aeroponic systems using a closed-type plant production system, the most suitable LED light intensity for raising seedlings was found to be 60 μmol·m^-2·s^-1.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.69-73
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• 2000

To investigate proper method of nitrogen application, six levels of nitrogen fertilizer and five different split applications were tested in Liriope platyphylla. Leaf length and content of total nitrogen in plant increased with the increase of nitrogen application level from zero to 360kg per ha. Number and weight of tuber increased with the increase of nitrogen level and tuber production reached to highest level of 4.44M/T per ha with the level of 220kg nitrogen. And then, tuber production decreased with the addition of extra nitrogen fertilizer to level of 360kg per ha. In the research of proper nitrogen split application, tuber yield (3.52M/T per ha) was increased by 18% at the combination of 40% basal application and three times of top dressing, than that of 100% basal application.