• Title/Summary/Keyword: Agricultural research

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Quality Changes as Affected by Storage Temperature and Polyamide Film Packaging in Paprika (Capsicum annuum L.) (파프리카 저장 온도 변화와 폴리아미드 필름 포장 적용에 따른 품질 변화)

  • Erdene, Byambaa Bayar;Lee, Jung-Soo;Park, Me Hea;Choi, Ji Won;Eum, Hyang Lan;Malka, Siva Kumar;Yun, Yeoeun;Kim, Chae-Hee;Kim, Ho Cheol;Lee, Jinwook;Park, Ki Young;Bae, Jong Hyang;Lee, YounSuk;Jeong, Cheon Soon;Park, Jong-Suk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.2
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    • pp.115-125
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    • 2022
  • The purpose of this study was to examine the effect of packaging on quality maintenance of paprika (Capsicum annuum L. cv. Nagano RZ) stored at three different temperatures. In Korea, paprika is stored and distributed under ambient conditions. To ensure the freshness maintenance, determining optimal storage temperature is necessary. Paprika were unpacked (control) or packed with polyamide film and stored at 5℃, 10℃ and 20℃ for 35 days. Quality characteristics such as weight loss and appearance were examined. Paprika packed with polyamide film showed less quality changes compared to unpacked paprika under all the storage temperatures. The commercial properties tended to decrease rapidly during storage at 20℃ regardless of packing. The degree of weight loss was significantly lower in packed paprika compared to unpacked paprika. It was found that soluble solids, pigments, hardness, etc. were complexly affected by storage temperature and film packaging. For paprika, the storage temperature of 5℃ or 10℃ was effective in maintaining freshness; paprika packed in polyamide film packing maintained greater freshness than unpacked paprika. Our results showed that, packaging is required to preserve the freshness and to improve the marketability of paprika in the domestic market. It seems that it is necessary to continuously search for an effective packaging method.

A preliminary assessment of high-spatial-resolution satellite rainfall estimation from SAR Sentinel-1 over the central region of South Korea (한반도 중부지역에서의 SAR Sentinel-1 위성강우량 추정에 관한 예비평가)

  • Nguyen, Hoang Hai;Jung, Woosung;Lee, Dalgeun;Shin, Daeyun
    • Journal of Korea Water Resources Association
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    • v.55 no.6
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    • pp.393-404
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    • 2022
  • Reliable terrestrial rainfall observations from satellites at finer spatial resolution are essential for urban hydrological and microscale agricultural demands. Although various traditional "top-down" approach-based satellite rainfall products were widely used, they are limited in spatial resolution. This study aims to assess the potential of a novel "bottom-up" approach for rainfall estimation, the parameterized SM2RAIN model, applied to the C-band SAR Sentinel-1 satellite data (SM2RAIN-S1), to generate high-spatial-resolution terrestrial rainfall estimates (0.01° grid/6-day) over Central South Korea. Its performance was evaluated for both spatial and temporal variability using the respective rainfall data from a conventional reanalysis product and rain gauge network for a 1-year period over two different sub-regions in Central South Korea-the mixed forest-dominated, middle sub-region and cropland-dominated, west coast sub-region. Evaluation results indicated that the SM2RAIN-S1 product can capture general rainfall patterns in Central South Korea, and hold potential for high-spatial-resolution rainfall measurement over the local scale with different land covers, while less biased rainfall estimates against rain gauge observations were provided. Moreover, the SM2RAIN-S1 rainfall product was better in mixed forests considering the Pearson's correlation coefficient (R = 0.69), implying the suitability of 6-day SM2RAIN-S1 data in capturing the temporal dynamics of soil moisture and rainfall in mixed forests. However, in terms of RMSE and Bias, better performance was obtained with the SM2RAIN-S1 rainfall product over croplands rather than mixed forests, indicating that larger errors induced by high evapotranspiration losses (especially in mixed forests) need to be included in further improvement of the SM2RAIN.

Efficacy of Three Antiviral Agents and Resistant Cultivars on Tomato Yellow Leaf Curl Virus in Tomato (토마토황화잎말림바이러스병에 대한 저항성 품종과 항바이러스 활성 물질 3종의 효과 검증)

  • Kwon, Yongnam;Cha, Byeongjin;Kim, Mikyeong
    • Research in Plant Disease
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    • v.28 no.2
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    • pp.82-91
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    • 2022
  • Recently, several in vitro studies have reported antiviral activity of agents of systemic acquired resistance against plant virus infection, but the approach has not been applied in a wide range of agricultural fields. The objective of this study was to evaluate the inhibitory effect of the exogenous application of salicylic acid (SA), chitosan (CH), or eugenol (EG) in tomato yellow leaf curl virus (TYLCV) infection of greenhouse-grown tomato plants. In vitro, the initial time of symptom was observed in TYLCV-infected plants (VP) of the resistant cultivar 'Superdotaerang' at 12 days post inoculation (dpi) after application of antiviral agents. At 32 dpi, the disease rate of TYLCV in the CHT+VP (0.1% chitosan and virus infected control) treated plants was 87.5%, lower than that of the other treatment. However, the virus content in the CHT+VP treated plants was higher than those of the other treatments, and SA, EG, and CH did not show significant effect on plant height or shoot and root fresh weight. Our results from summer-cultivated greenhouse-grown tomatoes show that none of the tested agents had an inhibitory activity on viral infection or yield of tomato 'Dotaerangsola'cultivar. In contrast, all treated 'TY Giants' cultivars that possessed TYLCV resistance genes Ty-1 and Ty-3a did not show typical symptoms and the virus content was remarkably lower than those in the TYLCV treated plants in 'Superdotaerang'. The results of this research indicated that the planting of resistant tomato cultivars was effective method instead of using SA, EG, and CH (known as resistance-inducing factors for control) of TYLCV in the field.

Studies on Growth Characteristics and Propagation Method of Introduced Hop (Humulus lupulus L.) Cultivars (홉(Humulus lupulus L.) 도입 품종의 생육특성 및 영양번식 연구)

  • Tae Hyun Ha;Jae Il Lyu;Jun-Hyung Lee;Jaihyunk Ryu;Sang Hoon Park;Si-Yong Kang
    • Korean Journal of Plant Resources
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    • v.36 no.2
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    • pp.181-190
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    • 2023
  • Domestic hop (Humulus lupulus L.) production has been suspended since the early 1990s due to foreign imports, but interest in local production is rising due to the recent craft beer boom in Korea. This study was conducted focusing on the development of growth characteristics and propagation technology for 6 introduced hop cultivars as a basic study for domestic hop production and breeding program. In the hop growth survey conducted in 2021 and 2022, the 5-year-old plants after planting generally showed a tendency to increase the height of strobile setting, strobile size, number and weight of strobile per hill compared to the 4-year-old plants. As a result of the experiment with hop vine cuttings, the average rooting rate of all cultivars was as high as 88% even in only water treatment that were not added with Atonik (Atonik, Arysta, Japan), a rooting agent. There were differences between cultivars in rooting length and rooting rate according to the Atonik treatment method. When checking the survival rate of the rooted cuttings seedlings after transplanting into the soil, it was confirmed that the survival rate of the cuttings in the tissue culture room was significantly lower than that of the cuttings in the greenhouse. However, in transplanting step, cutting plants from culture room condition was strongly inhibited plant growth because of changing environment conditions. As a results of tissue culture, the thidiazuron (TDZ) 1 ㎎/L treatment in the media generated 6 to 9 shoots/explant, while the 6-benzylaminopurine (BAP) 1 ㎎/L treatment generated only 1 to 2 shoots/explant. Therefore, it is more effective to culture by adding TDZ rather than BAP. These results indicated that the development of technology to manage stably after transplanting of cutting or micropropagating plants into potting soil is important for mass propagation of hops.

Study of Spatiotemporal Variations and Origin of Nitrogen Content in Gyeongan Stream ( 경안천 내 질소 함량의 시공간적 변화와 기원 연구)

  • Jonghoon Park;Sinyoung Kim;Soomin Seo;Hyun A Lee;Nam C. Woo
    • Economic and Environmental Geology
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    • v.56 no.2
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    • pp.139-153
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    • 2023
  • This study aimed to understand the spatiotemporal variations in nitrogen content in the Gyeongan stream along the main stream and at the discharge points of the sub-basins, and to identify the origin of the nitrogen. Field surveys and laboratory analyses, including chemical compositions and isotope ratios of nitrate and boron, were performed from November 2021 to November 2022. Based on the flow duration curve (FDC) derived for the Gyeongan stream, the dry season (mid-December 2021 to mid-June 2022) and wet season (mid-June to early November 2022) were established. In the dry season, most samples had the highest total nitrogen(T-N) concentrations, specifically in January and February, and the concentrations continued to decrease until May and June. However, after the flood season from July to September, the uppermost subbasin points (Group 1: MS-0, OS-0, GS-0) where T-N concentrations continually decreased were separated from the main stream and lower sub-basin points (Group 2: MS-1~8, OS-1, GS-1) where concentrations increased. Along the main stream, the T-N concentration showed an increasing trend from the upper to the lower reaches. However, it was affected by those of the Osan-cheon and Gonjiamcheon, the tributaries that flow into the main stream, resulting in respective increases or decreases in T-N concentration in the main stream. The nitrate and boron isotope ratios indicated that the nitrogen in all samples originated from manure. Mechanisms for nitrogen inflow from manure-related sources to the stream were suggested, including (1) manure from livestock wastes and rainfall runoff, (2) inflow through the discharge of wastewater treatment plants, and (3) inflow through the groundwater discharge (baseflow) of accumulated nitrogen during agricultural activities. Ultimately, water quality management of the Gyeongan stream basin requires pollution source management at the sub-basin level, including its tributaries, from a regional context. To manage the pollution load effectively, it is necessary to separate the hydrological components of the stream discharge and establish a monitoring system to track the flow and water quality of each component.

The effect of RGB LED lights on oyster mushroom (Pleurotus spp.) fruit-body characteristics (RGB LED 광원이 느타리류의 자실체 특성에 미치는 효과)

  • Jae-San Ryu;KyeongSook Na;Jeong-Han Kim;Jeong Woo Lee;Hee-Min Gwon
    • Journal of Mushroom
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    • v.21 no.3
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    • pp.132-139
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    • 2023
  • Light plays an important role in fruit-body development and morphology during Pleurotus spp. cultivation. To understand the effects of light color on fruit-body properties, we evaluated the fruit-body characteristics of Pleurotus spp. Varieties cultivated under blue, red, and purple LED light sources. The main results are as follows: The overall fruit-body shape showed differences depending on the color of the LED light. The fruit-bodies of mushroom cultivated under blue and purple light were generally similar to the mushroom shapes typically produced, while those of mushroom cultivated under green light were abnormally shaped, probably due to the absence of effective light source. The average cap lightness of mushrooms cultivated under blue, green, and purple LED lights was 57.0, 57.4, and 59.4, respectively. The average cap lightness of all varieties except Wonhyeong1ho and Hwang-geumsantari cultivated under the three LED light sources were statistically significantly different (P<0.05). The cap redness varied significantly depending on the LED lighting and variety. Only Gonji7hoM, the cap color mutant of Gonji7ho, showed negative cap redness values under all three LED light sources. Among the eight varieties excluding Gonji7ho, the highest cap redness was observed when cultivated under the blue LED. The average harvest weight of the varieties cultivated under purple, blue, and green LED light were 68.0, 58.3, and 50.1 g, respectively. The yield of Gonji7ho, the mushroom variety with the highest yield, cultivated under blue, green, and purple LED light were 92.8, 77.1, and 98.6 g, respectively. The earliness when grown under the purple, blue, and green LED lights were 5.3, 5.8, and 5.8 days, respectively. Among the varieties, six, three, and two cultivars showed the shortest earliness under the purple, green, and blue LED, respectively. The fruit-body lengths were 66.4, 51.8, and 46.8 mm when cultivated under green, purple, and blue lights, respectively. These results are expected to serve as a foundation for producing mushrooms with traits demanded in the market.

Study on the Physiology of Optimal reproductive age in Korean Native Cattle (한우의 최적 번식적령기의 생리적 현상에 관한 연구)

  • Seong, H.H.;Lee, J.H.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.4 no.1
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    • pp.110-118
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    • 2002
  • This study was conducted to investigate the physiology of optimal reproductive age in Hanwoo for protection to decrease of reproductivity and improvement of production of offspring. Thirty two cows were devided into 4 groups of treatments : T1(12 months of age and 0.5kg daily gain), T2(12 months of age and 0.8kg daily gain), T3(15 months of age and 0.5kg daily gain) and T4(18 months of age and 0.5kg daily gain). The days of the first heat of treated cows were 263.3±6.4 days and average weight was 181.1±11.3kg. The conception rates of first insemination were 25%(T1) and 75%(T4), and the number of insemination of T3 and T4(both 1.5) was lower than those of T1 and T2(2.3 and 2.4), respectively. With regard to estrus return after the first parturition, T1, T2, T3 and T4 showed 66.2,76.7, 62.4 and 68.5 days, respectively, indicating the average days of estrus return was 65.7. Plasma progesterone(P4) concentration was nearly the same during the observation periods of treated cows and P4 began to be detected after 12months. Only 5(15.6%) out of 32cows showed normal estrus cycle and ovulation before 12 months. During the peri-parturition period, P4 concentration was rapidly decreased and there was no detection of P4 from parturition to 40 days after milking. P4 would be released again on 45 day after parturition. The results imply that the optimal reproductive age of Hanwoo heifers would be around at the 14 months of age, 110cm height and 265kg weight.

A Study on the Gwanbang forest of Ganghwa in the Joseon Dynasty Period (조선시대 강화지역 관방림(關防林)의 특성 연구)

  • Shim, Sun-Hui;Lee Jae-Yong;Kim, Choong-Sik
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.1
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    • pp.35-46
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    • 2023
  • This study investigated and analyzed ancient records on the type, planting background, and construction process of Gwanbang forest(關防林) planned for military defense during the Joseon Dynasty to find out the purpose, location, and planting species of Gwanbang forest. The research results were as follows. During the Joseon Dynasty, Gwanbang forests were created around various government facilities(關防施設), such as Eupseong(邑城), major government offices, camps, and fortifications, for the purpose of defending against enemies. Gwanbang forest includes Yeongaeglim(嶺阨林), which was created on the crest of a strategically important hill, and Military Forest created for military purposes. Most of the spirit forest was designated as Geumsan(禁山) and protected and managed, and the Gwanbang forest was created for various purposes such as shielding, flood damage and river bank erosion prevention as well as external defense. In addition, in order to continuously and efficiently produce wood, which is a material for ships, buildings, and agricultural tools, in most cases, large areas were created as mixed forests. As for the species constituting the Gwanbang forest, there are records of tangerine tree, which is effective for defense because it has thorns, and deciduous broad-leaved trees such as zelkova, elm, willow, david hemiptelea, and oak appear. In the case of Ganghwa island, which served as the defense of the capital and the royal family during the Joseon Dynasty, several records have confirmed that a forest densely planted with trifoliate orange was created for the purpose of Gwanbang forest to reinforce the defense of the outer fortress. Based on historical research in the literature, assuming that the natural monument 'Gapgotri tangerine tree in Ganghwa Island' was planted in the 30th year of King Sukjong(1704), the first record of planting trifoliate orange in Ganghwa Island, the maximum age is estimated to be more than 319 years.

Causal Relation Analysis of Foreigners' Perceptions of Korean Ginseng Products and the Purchase Intentions (한국 인삼제품에 대한 외국인의 인식도와 구매의도의 관계 분석)

  • Choi, N.Y.;Han, S.J.;Chang, K.J.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.20 no.1
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    • pp.19-34
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    • 2018
  • This study was initiated because many studies would be necessary to promote Korean ginseng products when the sales of Korean ginseng are declining and many Korean ginseng farmers are facing economic difficulties. The increase in domestic sales is important, but this study is targeting for foreigner's perceptions of Korean ginseng and how to improve the products. The goal of this study is to analyze how to increase their purchase intentions of Korean ginseng products. Questionnaire survey research methods were used to learn more about making certain improvements to ginseng products, consumers are hoping, how affect their perceptions and purchase intentions of Korean ginseng, as well as how foreigners' perceptions of Korean ginseng products affects purchase intentions. Because it's difficult to find any studies about foreigner's Korean ginseng purchase intentions, the survey was expanded to include how people take care of their health, the accessibility of purchasing ginseng products, psychological factors as well as consumer characteristics, satisfaction with Korean ginseng, and intentions of buying Korean ginseng products. The result of the analysis on how making certain desired improvements to and perceptions of Korean ginseng products affect purchase intentions indicated that Korean ginseng perceptions highly affected the purchase intentions; however making certain improvements to ginseng products showed a low impact on the purchase intentions. In other words, making certain improvements, such as convenience of the ginseng products, doesn't affected Korean ginseng purchase intentions directly. On the other hand, it showed that the usefulness, its high quality, and safety trust of Korean ginseng have a big impact on purchasing intentions. If the ginseng that is grown and processed in Korea is better promoted for its high value, the Korean ginseng farmers who are facing many economic difficulties will be able to raise their income.

Effect of 1-Methylcyclopropene (1-MCP) Treatment and MAP on Quality Changes of Peach 'Daehong' during Cold Storage (1-Methylcyclopropene(1-MCP)와 MAP 처리가 저온 저장 중 복숭아 '대홍'의 품질 변화에 미치는 영향)

  • Yoo Han Roh;Joo Hwan Lee;Yong Beom Kwon;In-Lee Choi;Haet-nim Jeong;Ho-Min Kang
    • Journal of Bio-Environment Control
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    • v.32 no.4
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    • pp.267-277
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    • 2023
  • This study is in order to the effect of 1-methlycyclopropene (1-MCP) treatment and film package as modified atmosphere packaging (MAP) on the changes in fruit quality factors of 'Daehong' peaches during cold storage. The concentrations of 1-MCP were treated at 1µL·L-1 and 2µL·L-1, and peaches in film package were stored for 28 days in cold storage at 5±1℃ and 85±5% RH. The fruits stored carton box were used as a control of MAP, and 1-MCP free fruits were used as the control of both packages. Rate of fresh weight loss during storage was not significantly different between groups with and without 1-MCP treatment, but was higher in the box package than in the MAP. The control group had a higher incidence of both gases with the 1-MCP treatment group showing statistically significantly low. Carbon dioxide in the package was lowered by about 12% compared to the non-treated group, and the ethylene concentration was maintained at 1µL·L-1, showing a significance low compared to other treated groups. As the storage period elapsed, the firmness of 1-MCP and MAP treated fruits remained significant at 5-9% compared to the control group. Regardless of the packaging method Hunter a* values of exocarp and mesocarp were significantly higher in fruit treated with 1-MCP 1µL·L-1 treatment than in the control group, and anthocyanin was significantly higher in the fruit during the storage period, especially high in MAP. In summary, fruits of MAP group with 1-MCP 1µL·L-1 had rate of lower respiration and ethylene production, and little changes in firmness, Hunter a* values of exo-carp and meso-carp, and anthocyanin, which is considered the most suitable method for preserving postharvest quality of the peach cultivar during the storage.