• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.432-437
• /
• 2022

In this study, strawberries were grown during the two cultivation periods (first: 2020-2021, second: 2021-2022) to analyze the effect of the external light environment and growing degree days (GDD) on crop production. The temperature and humidity during day in a greenhouse in each cultivation period were similarly managed. At night, there was a statistical difference in temperature and humidity in the greenhouse between two periods. The accumulated solar radiation during the first cultivation period was high in September and October. Since January, the accumulated solar radiation during the second cultivation period was high. In the second cultivation period, the initial yield was small because the accumulated solar radiation and GDD was small. But accumulated yields and potential maximum yields in second cultivation period were larger than yields in the first cultivation period as the accumulated solar radiation and GDD increased. The sugar contents of strawberry decreased as GDD increased.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.393-400
• /
• 2022

Postharvest quality of sweet pepper fruits was mainly defined as external appearance, i.e., shape, fruit weight and surface color. These quality traits tend to involve esthetic appeal, it disregards gustatory properties and nutritional value. However, comparative studies according to the marketability of sweet pepper fruits are insufficient. This study was carried out to compare the physicochemical components, antioxidant activity and carotenoid contents of marketable and unmarketable sweet pepper fruits (Capsicum annuum L.). Physicochemical components (proximate composition, minerals and total phenolic contents) and antioxidant activities using various methods were investigated. The proximate composition values (%) of marketable and unmarketable fruits were: moisture (90.28 and 90.29), ash (0.74 and 0.26), crude protein (0.67 and 0.72), crude lipid (0.38 and 0.32). There were no significant differences in antioxidant activity, while total phenolic content was higher in marketable fruit. Carotenoids contents were 29.3 ± 2.6 and 31.9 ± 2.9 ㎍·g^-1 in marketable and unmarketable fruits respectively, and identified β-carotene, violaxanthin, neoxanthin, and zeaxanthin. Lutein and capsaicin were not detected. In this study, potential value of unmarketable sweet pepper fruit could be identified to be applied as a food ingredient and functional food material.

• Journal of Animal Science and Technology
• /
• v.64 no.1
• /
• pp.38-51
• /
• 2022

Whole-plant corn (Zea may L.) and sorghum-sudangrass hybrid [Sorghum bicolor (L.) Moench] are major summer crops that can be fed as direct-cut or silage. Proso millet is a short-season growing crop with distinct agronomic characteristics that can be productive in marginal lands. However, information is limited about the potential production, feed value, and ensilability of proso millet forage. We evaluated proso millet as a silage crop in comparison with conventional silage crops. Proso millet was sown on June 8 and harvested on September 5 at soft-dough stage. Corn and sorghum-sudangrass hybrid were planted on May 10 and harvested on September 10 at the half milk-line and soft-dough stages, respectively. The fermentation was evaluated at 1, 2, 3, 5, 10, 15, 20, 30, and 45 days after ensiling. Although forage yield of proso millet was lower than corn and sorghum-sudangrass hybrid, its relative feed value was greater than sorghum-sudangrass hybrid. Concentrations of dry matter (DM), crude protein, and water-soluble carbohydrate decreased commonly in the ensiling forage crops. The DM loss was greater in proso millet than those in corn and sorghum-sudangrass hybrid. The in vitro dry matter digestibility declined in the forage crops as fermentation progressed. In the early stages of fermentation, pH dropped rapidly, which was stabilized in the later stages. Compared to corn and sorghum-sudangrass hybrid, the concentration of ammonia-nitrogen was greater in proso millet. The count of lactic acid bacteria reached the maximum level on day 10, with the values of 6.96, 7.77, and 6.95 Log₁₀ CFU/g fresh weight for proso millet, corn, and sorghum-sudangrass hybrid, respectively. As ensiling progressed, the concentrations of lactic acid and acetic acid of the three crops increased and lactic acid proportion became higher in the order of sorghum-sudangrass hybrid, corn, and proso millet. Overall, the shorter, fast-growing proso millet comparing with corn and sorghum-sudangrass hybrid makes this forage crop an alternative option, particularly in areas where agricultural inputs are limited. However, additional research is needed to evaluate the efficacy of viable strategies such as chemical additives or microbial inoculants to minimize ammonia-nitrogen formation and DM loss during ensiling.

• Korean Journal of Plant Resources
• /
• v.35 no.4
• /
• pp.445-454
• /
• 2022

The aim of this study was to provide basic data for breeding new varieties of Angelica gigas Nakai by identifying the growth characteristics and useful components of its below- and above-ground parts. The basic varieties expressing dark purple (N79-A), light blue-pink (62-C), and white (NN115-C) flowers were identified and collected in the cultivation area, and their seeds were cultured for use as experimental materials. Qualitative growth characteristics of the above-ground parts were then examined. Purple coloration was evident throughout the entire plant body in the N79-A group, whereas the 62-C and NN115-C groups displayed yellow-green coloration. In terms of quantitative growth characteristics, the 62-C group displayed significantly lower above- and below-ground growth than the other two groups. Levels of nodakenin and decursinol-angelate were high in the NN115-C group (0.88 ± 0.13%) and N79-A group (2.56 ± 0.12%). However, the overall results were not statistically significant. The results could provide a foundation for breeding new varieties of Angelica gigas Nakai, which are used predominantly for medicinal purposes and have low bolting and high yield potential.

• Journal of Plant Biotechnology
• /
• v.49 no.4
• /
• pp.356-361
• /
• 2022

Bacillus sp. is a useful strain for agriculture because it promotes plant growth and controls plant pathogens through a variety of mechanisms. In this study, we obtained a microbial preparation with a high number of viable cells by culturing newly isolated soil bacteria on an optimized medium. Subsequently, we applied this preparation to lettuce to enhance its growth and yield. First, B. amyloliquefaciens ISP-5 was isolated from soil. Next, optimization of culture medium was carried out using 5 L scale fermenters. When culturing B. amyloliquefaciens ISP-5 on this optimized medium, the number of viable cells was approximately 1000 times higher than that obtained from culturing on the commercial medium. Afterwards, the plant growth promotion properties of the ISP-5 strain were evaluated using lettuce as a test plant. Foliar spray treatment of lettuce was carried out by inoculating half the standard concentration suspension (0.5 × 10⁷ cfu/ml). As a result, leaf width increased by 8.6% and leaf length increased by 12.9% compared to the control group. Live weight also increased by 24.2% and dry weight by 23.9%. Considering the results from field test, B. amyloliquefaciens ISP-5 showed potential as a plant growth-promoting bacteria.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.6 no.1
• /
• pp.50-62
• /
• 2004

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Tubers of round yam was initiated to form at 60 days after planting and then enlargement of tubers lasted by 160 days after planting. Compared to short typed yam(108g), tuber weight of round yam was higher(127g) on the basis of dry weight at 200 days after planting. In comparison of general component between round yam and short yam, protein of round yam(3.62%) was higher than short yam(2.10%). Water content in round yam(64.5%) was lower in short yam(79.4%), indicating a higher dry weight ratio of round yam. Hardness of round yam was 2787.6 while short yam showed about two times higher hardness(4946.9). Lightness was higher in round yam(77.4). In tuber extracts analysis, diosgenin content was respectively 3.32% in round yam and 2.61% in short yam.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.1
• /
• pp.28-34
• /
• 2023

Nitrogen fertilizers applied to agricultural lands for crop cultivation can be volatilized as ammonia. The released ammonia can catalyze the formation of ultrafine dust (particulate matter, PM2.5), classified as a short-lived climate change pollutant, in the atmosphere. Currently, one of the prominent methods for fertilizer application in agricultural lands is soil surface application, which comprises spraying the fertilizers onto the soil surface, followed by mixing the fertilizers with the soil. Owing to the low nitrogen absorption rate of crops, when nitrogen fertilizers are applied in this manner, they can be lost from land surfaces through volatilization. Therefore, investigating a new fertilization method to reduce ammonia emissions and increase the fertilizer utilization efficiency of crops is necessary. In this study, to develop a method for reducing ammonia emissions from nitrogen fertilizers applied to soil surfaces, deep fertilization was conducted using a newly developed deep fertilization device, and ammonia emissions from barley, garlic, and onion fields were examined. Conventional fertilization (surface application) and deep fertilization (soil depth of 25 cm) were conducted for analysis. The fertilization rate was 100% of the standard fertilization rate used for barley, and deep fertilization of N, P, and K fertilizers was implemented. Ammonia emissions were collected using a wind tunnel chamber, and quantified subsequently susing the indole-phenol blue method. Ammonia emissions released from the basal fertilizer application persisted for approximately 58 d, beginning from approximately 3 d after fertilization in conventional treatments; however, ammonia was not released from deep fertilization. Moreover, barley, garlic, and onion yields were higher in the deep fertilization treatment than in the conventional fertilization treatment. In conclusion, a new fertilization method was identified as an alternative to the current approach of spraying fertilizers on the soil surface. This new method, which involves injecting nitrogen fertilizers at a soil depth of 25 cm, has the potential to reduce ammonia emissions and increase the yields of barley, garlic, and onion.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.3
• /
• pp.231-240
• /
• 2023

In this research, our goal was to explore the potential use of cement mortar augmented with liquid red mud. To facilitate this, we neutralized liquid red mud(LR) - exhibiting a pH of 10-12 - using sulfuric acid to yield sulfuric acid neutralized red mud(SR). We then evaluated the flow, setting time, and compressive strength of the cement mortar combined with liquid red mud, while also performing a thorough examination of its chemical properties through X-ray diffraction(XRD) and scanning electron microscopy(SEM). The flow tests indicated a decrease in flow values for both MS-LR and MS-SR in comparison to the Plain. Analogously, the setting time for MS-LR and MS-SR was found to be abbreviated when juxtaposed with the Plain. With regards to compressive strength, MS-LR demonstrated a surge in strength at the 1-day mark, while MS-SR displayed a diminution at the 1-day and 3-day timepoints compared to the Plain. XRD analysis illustrated that after 28 days, the XRD patterns of Plain and MS-SR bore significant resemblance, though a new peak was detected in MS-LR. SEM imagery highlighted that the microstructures of Plain and MS-SR were alike, but MS-LR manifested a distinct microstructure, characterized by a finely fibrous formation. Based on these observations, we infer that the replacement of cement mortar with liquid red mud neutralized with sulfuric acid contributes to a noticeable enhancement in strength, thereby verifying its suitability for this application.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.1
• /
• pp.1-12
• /
• 2022

This paper examines the influence of the portion of lead investors and investors' status on the investment performance of venture syndication. According to existing literature, multiple investors in VC syndicates can positively impact investment performance by investing both tangible and intangible resources in target companies based on market influence or high visibility. On the other hand, the presence of multiple leaders can cause conflicts in formulating and implementing investment strategy or free-riding problems or increase entry barriers for potential investors, lowering additional investment from existing investors. Therefore, we hypothesize that the relationship between proportion of lead investors and investment performance is inverted-U shape. Moreover, we predict that the status of VCs in the syndication will moderate the relationship between proportion of lead investors and investment performance since high-status actors are less likely to cooperate with or yield power to others. We tested these hypotheses using 24,677 VC syndicated investment data from 1991 to 2005 and found solid supports for the hypotheses. The findings suggest that firms need to consider relationship-based power dynamics among investors within a syndication and design effective role setting and coordination systems.

• Journal of Korean Library and Information Science Society
• /
• v.54 no.4
• /
• pp.55-83
• /
• 2023

In this study, we propose the establishment of a specialized comic and webtoon library within the newly constructed library in Cheongju City. The aim is to create the library as the ultimate multi-cultural space, contributing to the enhancement of local residents' information utilization skills and future competencies. To achieve this, we conducted a foundational survey and current status analysis of a comic and webtoon specialized library, based on which we put forward a plan for its development. The research results yield the following outcomes: First, we provide concrete justifications and feasibility for the establishment of a comic and webtoon specialized library in Cheongju City. Second, we offer specific proposals for the vision, mission, roles, and functions of the comic and webtoon specialized library. Based on these research findings, if a comic and webtoon specialized library is constructed in Cheongju City, it has the potential to become a local landmark and serve as a unique cultural and tourist resource. Furthermore, by providing facilities and resources for various information services related to comic and webtoon creation and experiences, it can contribute to nurturing talents that lead the way in future industries.