• Horticultural Science & Technology
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• v.34 no.2
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• pp.249-256
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• 2016

This study was performed to investigate the effect of various concentrations of Diniconazole (DC) on the growth and quality of grafted tomato (Solanum lycopersicum) seedlings cultivated during the summer season. Concentrations of DC were set to 0 (non-treatment), 5, 10 and $20mg{\cdot}L^{-1}$, were treated once 3 days after grafting. Rootstock of the seedlings was shorter in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment compared to the non-treatment, and the scions were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment. Seedlings were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment compared with the non-treatment. Leaf area was lower for seedlings subjected to all treatments than for seedlings in non-treatment group, and reduction was dose dependent. In particular, the DC $20mg{\cdot}L^{-1}$ treatment inhibited both leaf and stem growth. The fresh weighs of leaves and stems of the seedlings treated with DC $5mg{\cdot}L^{-1}$ and the fresh weights of roots subjected to all treatments were significantly greater than those of the non-treatment seedlings. Dry weight per organs of the seedlings treated with DC $5mg{\cdot}L^{-1}$ was significantly greater that of the non-treatment seedlings, but the dry weight of leaves of seedling treated with DC $20mg{\cdot}L^{-1}$ was much less than that of the non-treatment seedlings. The T/R ratio of the seedlings was lower for all treatments than for the non-treatment. The relative growth rate of the seedlings was significantly lower in the DC $20mg{\cdot}L^{-1}$ treatment and, the leaf area rate of seedlings was lower in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment than in the non-treatment. Therefore, the optimal concentration of Dinoconazole used to produce a suitable grafted tomato seedling in the summer season is $10mg{\cdot}L^{-1}$ or less.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.228-235
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• 2016

This study was conducted to determine the yield of cherry tomato (Solanum lycopersicum Mill.) grown at three planting times during the uncultivated period of strawberry. Cherry tomato was planted under condition filled with strawberry dedicated culture medium on a two-story bed with April 20, April 30, and May 10 at 2015. Fruit harvest was completed on July 31. The supply concentration of nutrient solution at the time of transplanting was started as EC $1.2dS{\cdot}m^{-1}$ and it was gradually increased to EC $2.5dS{\cdot}m^{-1}$ after blooming of the first flower cluster. Netherlands PBG solution was supplied for one minute six times per day. The heights of cherry tomato plants planted at earlier were significantly greater than those of tomato plants planted later. The heights of cherry tomato plants grown at the bottom of the bed were greater than those grown in the upper bed. The yield of cherry tomatoes planted on April 20 at the bottom of the bed was greatest with an average of 2,954 g of tomatoes per plant. There were no significant differences in the average weight and sugar content of fruit according to planting times and bed position. The yield of cherry tomato plants planted on April 20 was 18% and 34% higher than that of plants planted on April 30 and May 10. We confirmed to increase the yield of the cherry tomato when early plants planted on two-story bed. These results indicate that farmers can choose the best period of producing cherry tomato during the un-cultivated period of strawberry under two-story bed conditions.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.177-185
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• 2015

The aim of this study was to investigate the amounts of glucosinolates (GSL) in kale at various development stages. Kale varieties 'Manchoo Collard' and 'TBC' were cultivated from 20 February 2012 to 3 July 2013 in the greenhouse at Chungnam National University. During the cultivation periods, samples were harvested at 35, 63, 91, 105, 119, and 133 days after sowing (DAS) and the amount of GSL quantified by HPLC. Ten types of GSL (progoitrin, sinigrin, glucoalyssin, gluconapin, glucoiberverin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were observed in 'TBC', whereas nine types of GSL (the same as above, except glucoiberverin) were identified in 'Manchoo Collard'. The amount of total GSL in 'Manchoo Collard' was comparatively higher at 133 DAS (mean $8.64{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($1.16{\mu}mol{\cdot}g^{-1}$ dry weight, DW) of cultivation. In the case of 'TBC', the amount of GSL was higher at 91 DAS (mean $13.41{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($0.31{\mu}mol{\cdot}g^{-1}$ dry weight, DW). Sinigrin was the most abundant GSL (57% of total GSL) in 'Manchoo Collard' at 133 DAS and was also highest (44%) in 'TBC' at 91 DAS. Together, progoitrin, sinigrin, glucobrassicin, and gluconasturtiin, the precursor of crambene, allylisothiocyanate, indol-3-cabinol, and phenethylisothiocyanate accounted for 94 and 78% of GSL in 'Manchoo Collard' and 'TBC', respectively. Our results demonstrate that the amounts of GSL, which have potential anti-carcinogenic activity, change during development in kale.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.1-11
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• 2018

It is ten years since the Good Agricultural Practices (GAP) certification system was implemented in Korea, and the government aims to acquire GAP certification up to 25% of the total agricultural areas by 2022. As of the end of 2017, 6.3% of the total cultivated area and 8.1% of the total farm households were certified, which is slower than expected. The purpose of this study was to investigate the causes of the GAP accreditation through the surveys and on site inspections of the GAP certified farmers and to propose the development plans according to the problems analysis of the current system in order to expand the GAP certification. Certified farmers recognized the need for agricultural safety and hygiene, but there were a lot of nonconformities regarding practical practices. This is due to the ambiguity of the certification standards and the wrong ways in the training method for the producers. GAP certification is slow to expand to farmers and low consumer awareness is considered a structural problem of GAP certification system, and improvement measures are needed accordingly. It is necessary to convert the state-led GAP certification system into a state-led private certification system. It is necessary for the government to focus on policy, research and follow-up management. In addition, it is necessary to establish a separate organization in the form of a contribution organization for the certification, education, and public relations. In addition, long-term plan must be established and systematically carried out. It is necessary to integrate too many certification agencies compared to the farming scale of Korea, and it is necessary to realize the application fee for realizing the financial independence of the certification body and correct certification work. In addition, inspector qualification standards should be strengthened and training system should be improved to nurture high quality inspectors. Simplified certification standards based on statutes need to be subdivided into practical action plans. In order to improve the GAP certification system, it is necessary to have a discussion through a committee composed of specialists from industry and academia, and it will be possible to contribute to the safety of the food of the people through the production of safe by drawing concrete development plans.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.215-222
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• 1999

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. This study was conducted to determine the cultural environment and soil morphological characteristics of platycodon. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheong 6 fields in Kangwon province. The average continious cropping year was highest Chinju 8.0-years old, whereas lowest Hongcheon 2.3-years old. The average cropping area and compost application were highest Hongcheon 1.3ha and $108Mg\;ha^{-1}$ respectively than other areas. The slope was in order to Koseong steep slope with 35%. Koechang 28%, Flaman 16%, Chinju 11.7%, Kimhae 11% and Hongcheon 7.5%. The drainage classes was well drained in Koechang. Kimhae, Chinju and Koseong, while it s poorly drained in Hongcheon and Haman. Distribution of topography was highest rolling 37.9% and drainage classes was highest well drained 48.3%. The root disease incidence rate was in the order of Haman 56.8%, Hongcheon 52.5%, Kimhae 36.7%, Koechang 35.3%, Chinju 32.3% and Koseong 30.0%. The yield at the Chinju $36.17Mg\;ha^{-1}$ was higher than that of Koseong $25.00Mg\;ha^{-1}$, Kimhae $13.57Mg\;ha^{-1}$, Koechang $11.75Mg\;ha^{-1}$, Haman $9.50Mg\;ha^{-1}$ and Hongcheon $5.24Mg\;ha^{-1}$. The average temperature was correlated with the disease incidence rate by $Y=3.07X^2-87.16X+649.26(R^2=0.947^{**})$ and yield by $Y=-478.68X^2+13403X-90836(R^2=0.763^*)$. The root disease incidence rate was correlated with drainage classes Y=19.1X-5.26($R^2=0.592{***}$), topography Y=9.68X+10.77($R^2=0.205^{**}$) and slope Y=0.85X+-27.88 ($R^2=0.143^*$). The yield was correlated with drainage classes Y=-10X+42($R^2=0.348^{**}$), topography Y=-5.34X+34.5 ($R^2=0.134^*$) and slope Y=-0.68X+25.48($R^2=0.129^*$). The optimum cultivated land of perennial platycodon was average temperature $14^{\circ}C$, direction of southeast, topography of flat or undulating, slope of 0-6%, well drained.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.201-219
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• 1989

Rice culture in Korea has a long history ranging over two thousand years. In the agriculture economy of pre-mordern Korea, however, its importantce was not as great as generally assumed. In fact, rice culture reached full development only after the 1920s when the Japanese colonial government carried out its drive to increase rice production in the Korea peninsula. It was not until the mid-1930s that rice became the staple in Korean diet. This can be attributed to two factors : (1) a mountainous topography that provides little irrigated fields and (2) a climate characterized by droughts in spring and heavy precipitation in summer. The present paper attempts to answer some of these questions. Specifically it will focus on these : Did the development of rice culture actually result in population growth? What are the salient features of agricultural develdpment and population grow in traditional Korea? Does the case of Korea conform the prevailing generalization about the agriculture in East Asia? I have discussed the development of rice culture and population growth in the Chos$\breve{o}$n dynasty, focusing on the relation between the rapid spread of transplanting and the rapid growth of population from the seventeenth to the nineteenth century. Here are my conclusions. (1) The spread of transplanting and other technological innovationsc contributed to the rapid growth of population in this period. However, we should also note that the impact of rice culture on population growth was rather limited, for rice culture was not the mainstay of agricultural economy in pre-modern Korea. Indeed we should consider the influence of dry field cropsn population growth. Nevertheless, it is obvious that the proliferation of rice culture was a factor crucial to population growth and regional concentration. (2) How should we characterize the spread of rice culture in the whole period? Evidently rice culture spread from less then 20% of cultivated fields in the fifteenth century to about 36% of them in the early twentieth century. Although rice as a single crop outweighed other crops, rice culture was more then counter-balanced by dry field crops as a whole, due to Korea's unique climate and geography. Thus what we have here in not a typical case of competition between rice culture and day field culture. Besides, the spread of rice culture in the seventeenth and eighteenth centuries accomplished by technological innovations that overcame severe springtime drought, rather than extensive irrigation. Althougt irrigarion facilities did proliferate to some extent, this was achieved by local landlords and peasants rather than the state. This fact contradicts the classical thesis that the productivity of rice culture increased through the state management of irrigation and that this in turn determined the type of society. (3) We should further study other aspects of the transition from the stable population and production struture in the fifteenth and sixteenth centuries to the rapid population growth and excessive density of population thereafter. We should note that there were continuing efforts to reclaim the land in order to solve the severe shortage of land. Changes also took place in the agricultural production relations. The increase in land producrivity developed tenancy based on rent in kind, and this in turn increased the independence of tenants from their landlords. There were changes in family relations-such as the shift to primogeniture as an effort to prevent progressive division of property among multiplying offspring. The rapid population growth also produced a great mass of propertyless farm laborers. These changes had much to do with the disintegration of traditional social institutions and political structure toward the end of the Chos$\breve{o}$n dynasty.

• Journal of Mushroom
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• v.14 no.4
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• pp.142-154
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• 2016

Worldwide production of mushrooms has been increasing by 10-20% every year. Recently, Pleurotus eryngii and P. nebrodensis have become popular mushroom species for cultivation. In particular, China exceeded 8.7 million tons in 2002, which accounted for 71.5% of total world output. A similar trend was also observed in Korea. Two kinds of mushrooms-Gumji (金芝; Ganoderma) and Seoji-are described in the ancient book 'Samguksagi' (History of the three kingdoms; B.C 57~A.D 668; written by Bu Sik Kim in 1145) during the Korea-dynasty. Many kinds of mushrooms are also described in more than 17 ancient books during the Chosun-dynasty (1392~1910) in Korea. Approximately 200 commercial strains of 38 species of mushrooms were developed and distributed to cultivators. The somatic hybrid variety of oyster mushroom, 'Wonhyeong-neutari,' was developed by protoplast fusion, and distributed to growers in 1989. Further, the production of mushrooms as food was 199,829 metric tons, valued at 850 billion Korean Won (one trillion won if mushroom factory products are included) in 2015. In Korea, the major cultivated species are P. ostreatus, P. eryngii, Flammulina velutipes, Lentinula edodes, Agaricus bisporus, and Ganoderma lucidum, which account for 90% of the total production. Since mushroom export was initiated in 1960, the export and import of mushrooms have increased in Korea. Technology was developed for liquid spawn production, and automatic cultivation systems led to the reduction of production cost, resulting in the increase in mushroom export. However, some species were imported owing to high production costs for effective cultivation methods. In academia, RDA scientists have conducted mushroom genome projects since 1997. One of the main outcomes is the whole genome sequencing of Flammulina velutipes for molecular breeding. With regard to medicinal mushrooms, we have been conducting genome research on Cordyceps and its related species for developing functional foods. There are various kinds of beneficial substances in mushrooms; mushroom products, including pharmaceuticals, tonics, healthy beverages, functional biotransformants, and processed foods have also became available on the market. In addition, compost and feed can likewise be made from mushroom substrates after harvest.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.117-124
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• 2018

The imports of Centella asiatica L. Urban are increasing year-by-year due to the fact that its extract is a raw material used for skin wounds and in cosmetics. However, studies on the cultivation and identification of native C. asiatica species in Korea have been extremely rare. Therefore, this study was conducted in order to investigate the physiological and functional activity of Korean native C. asiatica plant cultivated in Hapcheon, Gyeongsangnam-do, Korea. As a result, the highest antibacterial and anti-inflammatory activities were examined with methanol extract while skin-whitening and wrinkle improvement were examined with water extract. Seven bacterium and one fungus were treated with 50% methanol extracts of C. asiatica and most of the bacterium showed similar or low levels of antibacterial activity compared to the control group of Omiza (Schisandra chinensis) extract, except for Streptococcus pyogenes, which showed higher antimicrobial activity than that of Omiza extract. However, neither C. asiatica and Omiza extracts showed antimicrobial activity against the fungus, C. albicans. The results of anti-inflammatory effect analyses with Raw 264.7 cells confirmed that the treatment of methanol extract reduced the level of NO by 50% or more compared to the control group. In addition, the water extract showed the highest reduction of melanin content of up to 20% more than the control group when examined with B16F10 cell line, indicating a significant skin-whitening effect. Furthermore, we were able to show the significant skin wrinkle improvement caused by C. asiatica extract with NHDF cell as an indicator, but strong cytotoxicity was also observed, suggesting that further studies are necessary.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.74-82
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• 2004

This study was conducted to estimate the optimum application rate of fertilizer N based on $NO_3-N$ concentration in soils for tomato (Lycopersicon esculentum Mill.) cultivation in plastic film house. Tomato plants were cultivated with and without fertilizer in twelve soils which have different concentrations of $NO_3-N$ ranging from 46 to $344mg\;kg^{-1}$. Dry weight (DW) of above-ground part of tomato with no fertilizer ranged from 28.9 to $112.5g\;plant^{-1}$, depending on N-supplying capability of soils. The soil $NO_3-N$ was positively correlated with DW ($r=0.83^{**}$) and N uptake ($r=0.78^{**}$) by tomatoes in no fertilizer treatment, and negatively correlated with fertilizer effciencies resulted from the differences of DW and N uptake between fertilized and non-fertilized plot. The relationships between soil $NO_3-N$ concentration and DW, N uptake, and fertilizer efficiency were analyzed to determine the critical levels of soil $NO_3-N$ for tomato cultivation. The limit critical levels of soil $NO_3-N$ were estimated to be more than $280mg\;kg^{-1}$ for no application of fertilizer N and to be less than $50mg\;kg^{-1}$ for recommended application of fertilizer N. These critical levels of soil $NO_3-N$ were nearly the same as those calculated from regression equation between electrical conductivity(EC) and soil nitrate for critical levels of EC in recommendation equation of fertilizer N for tomato under the plastic film house by NationaI Institute of Agricultural Science and Technology. Consequently, the optimal application rate of ferdilizer N for tomato cultivation in the soils containing $NO_3-N$ concentration between $280mg\;kg^{-1}$ and $50mg\;kg^{-1}$ was estimated by the equation Y = -0.4348X＋121.74, where Y is the percent(%) to the recommended application rate of N fertilizer and X is the soil $NO_3-N$ concentration ($mg\;kg^{-1}$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.79-83
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• 2020

A photoelectric grain color sorter is commonly used in postharvest technology to detect and separate grains considered to be of good quality from those of poor quality based on color. In this study, the milled rice of Haedamssal cultivated under early transplanting conditions was evaluated using the color sorting device. Rice was classified according to standard grades of 64% for grade A, 18% for grade B, and 17.2% for grade C. By head rice ratio analysis, the milled rice of Haedamssal was recorded a grade A of 72.9%, representing a 24.5% improvement compared to the 48.4% of original grains. However, the grades B and C of Haedamssal rice were lower than those of original rice. In addition, grade A whiteness of Haedamssal rice was 45.3, which was lower than that of original grains. The color affinity redness was significantly lower in Haedamssal rice than in the screening control. No significant difference was found in the amylose and protein contents of rice before and after selection by the grain color sorter. In contrast, grain viscosity analysis revealed an increase in peak and final viscosities, while the consistence viscosity increased in low grade levels. Our results suggest that the photoelectric grain color sorter could improve the head rice ratio and palatability of early transplanted Hadamssal rice.