• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.368-372
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• 1999

The practicality of utilizing chitosan as a natural antimicrobial compound to reduce soybean sprout rot was tested. Domestic and imported soybean seeds were soaked for 6 hours in solutions containing different levels of chitosan and acetic acid (glacial), and cultured at $25^{\circ}C$ for 6 days. In case of domestic seeds, soaking with 1,000ppm chitosan increased germination percentage, hypocotyl thickness, total length, and fresh weight of sprouts by 4%, 5%, 2%, and 1%, respectively. The total sprout yield was increased by chitosan in a concentration-dependent manner in that 1,000ppm chitosan resulted in 8% increment of total yield (7.47kg sprouts/kg seed). Chitosan significantly reduced sprout rot percentage to 7.0% compared to control (13.8%), and consequently enhanced marketable sprout yield by 39%. Compared to domestic seeds, the imported soybean seeds exhibited very low germination percentage regardless of chitosan treatments. Chitosan, nevertheless, consistently induced yield increment and rot decrement in imported soybean sprouts. Although 100ppm acetic acid was effective in reducing sprout rot percentage down to 11.8%, its yield-increasing effects were not as prominent as chitosan. In conclusion, soaking soybean seeds with chitosan seems to be a practical method to enhance the efficiency of soybean sprout production.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.167-171
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• 1999

This experiment was conducted to determine effects of trenching depth on characteristics and yield of tubers in Chinese yam (Dioscorea opposita Thunb). Self-propelled trencher, ‘NF-827H’ produced by KAWABE company, was used for trenching. When trenched, tuber's length and weight were longer and heavier, tuber's shape was better, and marketable tuber yield was remarkably increased than those of conventional plowing and soil preparation by a tractor. The size and yield of tubers were greatly enhanced by trenching in long-tuber variety than that in short-tuber variety. The depth of trenching is recommended to be more than 60cm for short-tuber variety and more than 80cm for long-tuber variety considering the size, shape and yield of the tllbers.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.130-135
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• 2013

The plant growth and yield of Pinellia ternata (Thunb.) Breit. were studied by altitude and tuber weight. The emergence rates in low land area were not different by tuber weights, but it showed earlier emergence date in heavier weight of seed-tuber and low land area. The higher aerial growth such as plant height and number of leaves per plant was the heavier tuber weight in a planting year, but the growth was not different by the weight of tuber at second year after planting. The distribution pattern of tuber size per $m^2$ was not influenced by different seed-tuber weight. The number of harvested tuber was highest at more than 1 g of tuber weight, and followed 1~2 g and less than 2 g. The distribution pattern of fresh tuber yield was not influenced by different altitude and seed-tuber weight. The marketable tuber, 2 g or more, tends to be produced with more than 0.6 g seed-tuber. As the results above-mentioned, it was thought that the high yield was supposed to use seed-tuber over 0.6 g in the fertile soil.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.159-163
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• 2002

This study was carried out to investigate change of growth and yield of top part by different harvest date and number in Saururus chinensis. Top part of the first harvest date showed the most effective growth on July 16 and July 31, and that of the second harvest date was greater than that of the as first harvest date. Harvest dates up to July 31 increased yield of marketable leaf and stem, but the later Harvest date decreased yield as low as 41％ .Percentage of dry mater was higher as the harvest date was delayed.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.202-210
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• 2016

BACKGROUND: This study was conducted to determine effects of ridging systems and plastic film mulch types on growth, yield, and profitability of potato (Solanum tuberosum L.) in spring cropping using paddy field and to suggest profitable ridging system and plastic mulch type.METHODS AND RESULTS: Two potato cultivars ('Goun', and 'Atlantic') were grown at paddy field located in Gangneung in spring. For treatments, ridging systems were one-row ridge (OR) and two-row ridge (TR). Mulch types were no-mulch (NM), black plastic film mulch (BPM), and transparent plastic film mulch (TPM). Emergence of sprout was affected by the mulch types and the fastest level was shown at TPM treatment. Accumulative soil temperature during sprouting was 16.2℃ higher at TR than at OR and also higher at TPM than at BPM or NM. Stem length was not affected by ridging systems or mulch types. Leaf area index (LAI) was influenced by mulch types, while not by ridging systems. The highest LAI was shown at TR with TPM and OR of BPM. There was no significant difference in specific gravity or dry matter rate by ridging systems and mulch types. Tuber yield was significantly influenced by ridging systems and mulch types. Mean tuber weight was heavier at OR treatment than at TR and also the heaviest at TPM among mulch types. The highest marketable yield was found at OR with BPM. Based on marketable tuber yield and market price, the highest income ratio in two cultivars was found at OR with BPM and it was 20~82% higher than the ratio at TR with TPM.CONCLUSION: In spring potato cropping using paddy field, OR with BPM is better for high yield and is more profitable for farmer's income than the conventional cultivation method, TR with TPM.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.205-211
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• 2014

This study aimed to examine the effect of different fruit-loads on fruit yield, quality, and plant growth of 'Seolhyang' strawberry. Fruit loads were adjusted from the first to the fourth flower cluster so that the number of fruits became 20, 25, and 30, and non-flower thinning of some was made. The more the number of fruits per plant was, the greater the total yield obtained, but marketable yield decreased and non-marketable yield increased. Compared to the treatment whose fruit load was adjusted, the control with non-flower thinning had more fruit yield in the first and second flower clusters but tended to have less fruit yield in the third and fourth flower clusters. The lower the fruit load was, the more soluble solids content of fruits increased. The lower the fruit load of a flower cluster was, the faster its harvest time reached. Harvest of fruit load of 20 was faster by 10 days in the second and fourth flower clusters relative to the control. On November 24, 2012, flowering thinning of the first flower cluster was made. On March 7, 2013, fruit dry weight of the second flower cluster was most heavy in the control. Dry weight of roots decreased in the control and the fruit load of 30 compared to November 24. On April 9, fruit dry weight of the third flower cluster did not have significant difference according to fruit load, however the more the fruit load was, the smaller dry weight of leaf, root, and crown became, which were vegetative organs. On May 12, the more the fruit load, the smaller leaf area and dry weight of vegetative organs and differences from varying fruit-loads became considerable in later period of growth. Appropriate fruit load of 'Seolhyang' strawberry were from 20 to 25. Maintaining balance between vegetative and fruit growth by adjusting fruit load is very important for stable fruit production.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.105-111
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• 2012

This study was conducted to evaluate the influence of fruit setting order by flower cluster on the fruit weight and the soluble solids content for the strawberry of 'Seolhyang' cultivar. The first flower cluster had higher fruit number, fruit weight, soluble solids content and ratio of large fruit compared to the second and third flower cluster. The fruit set on the upper position fruit in the same flower cluster had higher fruit weight and the soluble solids compared to the fruit set on the lower position fruit in the flower cluster. The fruit weight was highly positive correlated with the soluble solids content. The result indicated that the number of fruit set for marketable yield seemed to be 9-10 per the first flower cluster, 6 per the second flower cluster, 4 per the third flower cluster and 3 per the fourth flower cluster in 'Seolhyang' cultivar.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.349-355
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• 2010

This experiment was conducted to establish the optimum nitrogen application level for oriental melon at Seong-ju Fruit Vegetable Experiment Station with a fertigation system. Four different levels of nitrogen fertigation were applied to oriental melon and growth of the plant was analyzed. Plant samples were collected 8 times and were analyzed by the standard methods. The first fertigation was applied at 10 days after transplanting for the oriental melon based on the growth rates of the plants. For oriental melon, 10 day interval fertigation and 8 time split application of fertilizer could be recommended. The amounts of N, P, and K fertilizer recommended by soil testing was 249-408-315 (kg $ha^{-1}$). Treatment levels were 0, 0.5, 1.0, and 1.5 times of soil testing nitrogen with P and K level fixed. The total nitrogen (T-N) content in dried leaf showed a tendency to increase until 30 days after transplanting, then decreased. T-N content increased with increasing nitrogen fertigation rates. T-N content in dried fruit decreased slightly during the whole growing season. Fresh weight and nitrogen uptake were increased with increasing nitrogen fertigation rates. Total yield and marketable yield, 44,550 kg $ha^{-1}$ and 42,880 kg $ha^{-1}$, were maximized at 0.5 times of soil test nitrogen. Ratio of marketable fruit, 95%, was the highest at 0.5 times of soil test nitrogen. The optimum level of nitrogen for fertigation system was 0.5 times soil test nitrogen judging from total yield, commodity yield and commodity fruit.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.283-287
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• 2016

This study was conducted to examine the effects of defoliation levels during winter season on the yield and soluble solid contents of fruits. To achieve this strawberry 'Seolhyang' cultivated forcingly in the year of 2013 to 2014 as well as 2014 to 2015. The three treatments include periodical removing of leaves remaining 6 fully expanded leaves, those remaining 9 leaves, and only removing of old and infected leaves during the period from early December to end of February. In the early marketable fruit yield until the end of February and total marketable fruit yield, the treatment of non-defoliation was significantly higher than those of the treatment of 6 and 9 leaves in the year of 2014 to 2015 cropping season. Soluble solid contents of fruits among January and March increased significantly as the number of leaves get higher. Soluble solid contents were higher and stable around $12^{\circ}Brix$ in the treatment of non-defoliation. Assimilation of photosynthetic products into plant tissue are insufficient due to the lack of irradiation and short day in winter season forcing cultivation of strawberry. Thus, it is considered to manage the leaves with defoliation for only old and infected leaves from December to February for increasing of fruit yield and improvement of fruit quality.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.101-106
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• 2009

To study the effect of nonwoven fabric materials on growth and yield of korea melon, Medium denier nonwoven fabrics (MDNF), Polyster nonwoven fabrics (PENF) and 12 ounce nonwoven fabric (control) were used. Mean temperature at night was 13.1$^{\circ}C$ at control, 14.7$^{\circ}C$ at MDNF and 13.3$^{\circ}C$ at PENF from Feb. 6${\sim}$7, 2009. Because of higher temperature, early growth of korea melon of MDNF was better than control at 30 days after transplanting. Days required to harvesting (DRH) of control was 89, those of PENF and MDNF were 88, 78, respectively. First harvesting of MDNF was 11 days earlier than control. Harvested fruit of MDNF had higher weight, soluble solid and marketable fruit ratio than control. Yield ratio of control and PENF was 4:3:3 (early:middle:late harvesting season), but MDNF was 5:3:2. Using of MDNF provided earlier harvesting. Total yield of PENF was similar to control, 1,844kg per lOa, MDNF was increased by 9%.