• Journal of Bio-Environment Control
• /
• v.13 no.1
• /
• pp.33-38
• /
• 2004

This experiment was conducted to screen the suitable rootstocks for the soil cultivation of paprika (Capsicum annuum L.) in highland. Sixteen kinds of rootstocks were grafted to the red colored 'Spirit' scion for the resistances to diseases like fruit lot (Phytophthora capsici) and bacterial wilt (Ralstonia solanacearum). Four varieties among the rootstocks, 'Tantandaemok', 'Skurt-S', 'AC 2258', and 'PST 8301' were selected for the high resistance to fruit rot of paprika. However non-grafted control plants were totally dead at five days after inoculation. Furthermore, seven varieties including 'Yeokgang', ;Tantandaemok', 'TE412', 'MC 4', 'PST VK', and 'PST NV' were selected for the high resistance to bacterial wilt. The grafting with pest resistant rootstocks could enhance the rhizophere environment through root fresh weight increase. High yielding rootstocks for paprica 'Spirit' were PST 8301, MC 4, and Wanggeun.

• Journal of the Society of Naval Architects of Korea
• /
• v.53 no.2
• /
• pp.85-91
• /
• 2016

The most important factor in the structural design of ships and offshore structures operating in arctic region is ice load, which results from ice-structure interaction during the ice collision process. The mechanical properties of ice related to strength and failure, however, show very complicated aspect varying with temperature, volume fraction of brine, grain size, strain rate and etc. So it is nearly impossible to establish a perfect material model of ice satisfying all the mechanical characteristics completely. Therefore, in general, ice collision analysis was carried out by relatively simple material models considering only specific aspects of mechanical characteristics of ice and it would be the most significant cause of inevitable errors in the analysis. Especially, it is well-known that the most distinctive mechanical property of ice is high dependency on strain rate. Ice shows brittle attribute in higher strain rate while it becomes ductile in lower strain rate range. In this study, the simulation method of ice collision to ship hull using the nonlinear dynamic FE analysis was dealt with. To consider the strain rate effects of ice during ice-structural interaction, strain rate dependent constitutive model in which yield stress and hardening behaviors vary with strain rate was adopted. To reduce the huge amount of computing time, the modeling range of ice and ship structure were restricted to the confined region of interest. Under the various scenario of ice-ship hull collision, the structural behavior of hull panels and failure modes of ice were examined by nonlinear FE analysis technique.

• Natural Product Sciences
• /
• v.27 no.1
• /
• pp.36-44
• /
• 2021

The essential oils from the aerial parts (leaves and flowers) of Spiraea hypericifolia L. (Rosaceae), collected in Northern Kazakhstan, were obtained by distillation in two dispersion media (distilled water and 15% NaCl solution). The chemical composition of the essential oils was evaluated by GC-MS for the first time. The yield of the essential oil was 0.04% (in fresh growth conditions) and 0.02% (in dry growth conditions) respectively regardless of which dispersion media (H2O or 15% NaCl solution) was used at the isolation of essential oil. The main compounds were aliphatic hydrocarbons (alkanes) (40.6-53.2%), aldehydes (8.4-17.4%), diterpenoids (9.1-16.7%) and ketones (6.2-8.7%). Content of monoterpenoids was depended on dispersion media (2.2-3.6% where H2O was dispersion media and 8.4-8.5% where 15% NaCl solution was dispersion media). n-Heneicosane (17.4-34.1%) and n-tricosane (14.3-19.5%) were the main constituents of the essential oil of S. hypericifolia. There were many insects from different classes in S. hypericifolia at flowering. Important components such as α-methylene-γ-butyrolactone (0.8-2.8%), benzyl cyanide (0.7-1.1%), β-damascenone (1.2-2.9%), (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (1.8-2.7%), β-ionone (0.5-1.8%) and others were detected in small amounts.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.12
• /
• pp.21-24
• /
• 1972

1. The experiment was carried out to control the unfilled fruits in peanut with lime and potassium application. 2. There was increased tendency in branch length and numbers in accordance with the increased amount of lime and potassium, but the decreased tendency was found at over applied conditions of them. 3. Fresh weight of vegetative part was increased along with the increased amount of lime application by 100kg/10a. 4. Increased lime and potassium within the certain amount decreased the ratio of unfilled fruits. These fact raised were considered due to not only the increased number of two filled shell but the decreased number of one filled or unfilled shell. 5. Seed weight was influenced by both lime and potassium but lime seemed to have more effectiveness. Interaction between lime and potassium on seed weight was highly significant. 6. For the control of unfilled shell and obtain higher yield, it desirable to apply 15kg/10a of potassium and 100kg/10a of lime with optimum amount of nitrogen and phosphorous.

• The Journal of Economics, Marketing and Management
• /
• v.3 no.3
• /
• pp.7-23
• /
• 2015

Women are more disadvantaged than men in many fronts and this confines them to informal sector livelihood activities. Any attempt to improve women's economic status will require information on the organization, cost and returns to investment in the livelihood activities in which they predominate. This is the issue for this study which compared yield performance in artisanal fishing and fresh fish marketing. Primary data collected through multi-stage sampling method were analyzed using inferential statistics, budgeting and regression models. Empirical findings revealed that about 75.0% of fisher folks either had no formal education or acquired only primary school education while 50.0% of marketers had secondary school education. The budgeting model revealed fisher-folks' and marketers' annual net profit to be N2,882,626.00 and N640,227.00, respectively. Profit from fishing was significantly higher than that of fish marketing. At 53.2% for fishing and 40.3% for marketing, returns to investment was better in fishing. Regression model results showed the significant factors influencing returns to each livelihood strategy to include fishing ground, distance covered and years of experience. The major constraint faced by operators of both livelihoods groups was insufficient credit. Despite this, the livelihood strategies were shown to be profitable ventures which contributed to households' consumption expenditure. Organizing women informal sector operators into groups to enhance access to government support and formal credit are recommended for improving livelihood strategy performance.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.43 no.3
• /
• pp.129-137
• /
• 2023

Corn silage is extensively utilized in ruminant feeding on a global scale, with substantial research efforts directed towards enhancing its nutritional worth and managing moisture content. The purpose of this study was to assess the impact of normal cutting height and elevated cutting height on whole-crop corn silage. Corn was harvested at heights of 15 cm and 45 cm above the ground, respectively, 45 days after heading. The harvested corn was cut into 2-3 cm lengths and packed into 20-liter plastic silos in triplicate. The results showed that dry matter (DM), crude protein (CP), water soluble carbohydrates (WSC), and in vitro dry matter digestibility (IVDMD) of C45 were significantly higher than those of the control, while the neutral detergent fiber (NDF) was significantly lower in C45 (p<0.05). The C15 had higher yields than C45 (p<0.05). There was no significant difference in the total digestible nutrients (TDN) yield of whole-crop corn silage. The increase in cutting height resulted in a larger change in moisture content and NDF per centimeter. After 60 days-ensiling, C45 showed significantly lower NH₃-N concentrations. Moreover, C45 had significantly higher lactic acid concentration, lactic acid/acetic acid ratio, and lactic acid bacteria count compared to the control. Mold was not detected and the yeast count was less than 2 log10 cfu/g fresh matter in both control and C45. In summary, C45 improved the feeding value and fermentation quality of whole-crop corn silage at the expense of forage productivity.

• Journal of Soil and Groundwater Environment
• /
• v.28 no.6
• /
• pp.24-32
• /
• 2023

Continuous increase of domestic meat consumption has inevitably increased generation of livestock manure and caused severe environmental impacts on ecosystem and human beings. This work produced biochar from cattle manure samples with different composting aging stages and investigated the properties of the produced biochar. The result of thermogravimetric analysis showed that thermal decomposition of the manure initiated at <600℃. The biochar yield was higher for the manure with a longer pre-composting period due to the elimination of microbially metabolized carbons during composting process. The result of FT-IR analysis showed that the number of surface functional groups were reduced during pyrolysis while enhancing the graphitic structures of the carbon framework. Manure samples tended to leach out N and P in leaching tests, with its amount higher for aged one than fresh one. However, their leaching was substantially suppressed when the manure was produced into biochar. In XPS spectra, it was found that N and P in the manure incorporated into biochar surface to form N-doped graphitic carbon and P-N-moieties, respectively. The findings of this work suggest that the thermochemical process can be of a viable option to valorize into biochar for potential environmental applications as well as to alleviate undesired nutrients loading to the environment.

• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.967-976
• /
• 2023

Biochar is emerging as a promising substance for achieving carbon neutrality and climate change mitigation. It can absorb several nutrients via ion bonding on its surface functional groups, resulting in slow dissociation of the bonds. Biochar, like organic fertilizers, contributes to sustainable nutrient management. The purpose of this study was to investigate the effects of nutrient-coated biochar amendments on leafy vegetables production and soil fertility. The nutrient-coated biochar was produced by soaking rice husk biochar in a nutrient solution containing nitrogen (N), phosphorus, and potassium for 24 hours. Nutrient-coated biochar and organic fertilizers were applied to soil at a rate of 120 kg·N·ha^-1. The growth components of the leafy vegetables showed that nutrient-coated biochar led to the highest fresh weight (FW) of both lettuce and kale (i.e., 146.67 and 93.54 g·plant^-1 FW, respectively). As a result, nutrient-coated biochar amendments led to superior yield compared to the control treatment and organic fertilization. The elemental composition of leafy vegetables revealed that soil amended with nutrient-coated biochar resulted in higher nutrient contents, which was attributed to the high nutrient contents supplied by the rice husk biochar. Soil amendment with nutrient-coated biochar positively enhanced the soil fertility compared to amendment with organic fertilizer. Therefore, nutrient-coated biochar is a promising substance for enhancing agronomic performance of leafy vegetables and improving soil fertility.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.69 no.1
• /
• pp.1-14
• /
• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.4
• /
• pp.406-418
• /
• 1996

Tomatoes are water logged differently 0, 5, 10 and 15 cm, according to the developing stages such as germination and seedling stage under the condition of greenhouse. Along with this, they are treated according to the time condition such as 6, 12, 24, 48 and 120 hours. The results obtained are summarized as follows. 1. The result at germination stage Remarkable germination failure was observed when tomatoes were water-logged for 25 to 27 hours in the depth of 0 to 5 cm. Plant height recovered within 24 hours regardless of the water-logging depths. In the case of leaves, the recoverable time limit became shorter gradually in accordance with the increase of the water-logging depth. The decrease of the fresh weight showed acute response in the shoot rather than the root. It recovered with the 24 hours of water logging. Significant correlation was observed in all characteristics of plant height, number of leaves, fresh weight and germination rates according to the depth of water-logging. 2. The result at seedling stage Plant height recovered within the 24 hours of water-logging in the depth of 0 cm. On the deeper level, there was significant decrease regardless of time. With regard to the number of leaves, there was recovery up to 120 hours in the depth of 0 cm, up to 24 hours in the depth of 5 cm. There was, however, significant decrease when done for more than 6 hours on the deeper level. Growth of the shoot displayed the same tendency as in plant height and number of leave. The length of the longest root could be maintained by 80% in the water-logging of 0 cm compared with control. However in depth of 5 cm or more, it could not be maintained by the 120 hours water-logging. Root activity became conspicuously diminished with the logging over 0 cm. Respiration showed conspicuous decrease by the depth of 5 cm as a turning point. On the other hand, photosynthesis became decreased linearly by the depth of water-logging. Chlorophyll content displayed gradual decrease up to 48 hours, but conspicuously decreased up to 120 hours according to the varying depth of water-logging. Dieases tended to increase according to the depth and hours of water-logging. Diseases would be prevented by dint of insecticide, but there was no effect of fertilization. Weight and number of fruit per plant displayed gradual decrease as the depth and hours of water-logging became increased. Average weight of a fruit became increased. There was no statisticaly reciprocal effects between the depth and hours of water-logging. There was significant positive correlation among all the investigated characteristics, such as traits of growth and yield.