• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3677-3684
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• 1975

A newly devised dryer with heated air for the farm products, especially suited for high water content materials such as red pepper, Beer ground, each Vegetables, and Low water content materials such as Rough rice was tested for its thermal efficiency and drying mechanism, and the optimum conditions for each sample were established. In order to improve the present rural situation of drying farm products which entirely dependent upon natural solar radiation, a study upon an economic multi-parpose dryer was conducted. A series of drying tests were run first with red pepper which is one of the important cash crop in Korean farm. And successive series of tests were also run with such proaucts as garlic, sweet potatoes, green onion, radish, Beer ground and Rough rice. The results from the above experiment in drying system with heat dryer can be summarized as follows. 1. Drying duration could be shortened by the tempering effect in high water content crop such as red pepper and beer ground. 2. The color changes occured in around 20% water content in red pepper. The degree of color change was heavily affected by high temperature and short drying duration. 3. The drying condition of red pepper was most favourable at the temperature of 85$^{\circ}C$ in early stage and 80$^{\circ}C$ in middle stage and 75$^{\circ}C$ at the final stage, and with the air rate of 0.81㎥/sec and with sample amount of 200kg. 4. The drying condition of Rough rice(I.R.667) was most favourable at the templature of 40$^{\circ}C$ in early stage and 35$^{\circ}C$ in middle stage and final stage and with the air rate of 0.2㎥/sec and with sample amount of 75kg. 5. In order to prevent the color change of red pepper and to assure high efficiency in drying mechanism, it was necessary to lower the temperature as the time passes in drying process. 6. For vege tables, the drying rate were short in early stage and there was also tempering effect. However, for garlics, Constant drying rates through the early and final stages were observed and there were no tempering effects. 7. The drying condition or capability were as follows; Sample drying temp($^{\circ}C$) amount of material(kg) drying time(hr) Red pepper 85 200 9 Garlic 85 150 7 Sweet potato 85 200 6 Green Onion 85 200 4 Carrot 85 200 4 Radish 90 250 4 Rough rice(I.R.667) 35 75 4 Beer ground 90 320 3 Considering the above result of experiments, if this kind of dryers were distributed Korean farm and the optimun process were practiced in rural area, it would certainly help them improving the qualites of their product preventing their undue losses, and thus assuring an increase of Korean farm income and promotion of their living standards.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.115-119
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• 1999

The single node cuttings of sweet potato (cv. Mokpo #29) plantlets maintained in vitro were cultured with (MF+) or without membrane filter (MF-) under photomixotrophic (PM), hetrotrophic (HT) and autotrophic (AT) conditions. Shoot length was the greatest (11.9cm) in 3$0^{\circ}C$ (HT) treatment and it was the shortest (3.4 cm) in $25^{\circ}C$ (PM) treatment. Nodal explants cultured in 3$0^{\circ}C$ treatment looked more vigorous than those of $25^{\circ}C$ in appearance, and node number was the greatest (10.5 per plantlet) among the treatments. But plantlets grew in 3$0^{\circ}C$ (HT) treatment were observed all overgrown. The size in leaf area was about 2 times greater and shoot length was about 2 times shorter in PM than in HT condition. Percent dry matter of shoots was 5.9% (HT) and 7.4% (PM) in $25^{\circ}C$ treatment and 6.1% (HT) and 7.4% (PM) in 3$0^{\circ}C$ treatment. Plantlets cultured in the MF+ treatments were less succulent than those cultured in the MF- treatment. Vitrified plantlets were examinated 14.8% (both $25^{\circ}C$ and 3$0^{\circ}C$) in PM condition and 22.2% ($25^{\circ}C$) and 31.5% (3$0^{\circ}C$) in HT condition. Sucrose was necessary for the survival of in vitro plantlets. In the sucrose-free medium, explants cultured in the MF- had turned yellow and were dead after 30 days of culture. But explants cultured in the MF+ were alive and produced plantlets with shoot and root (AT). On the other hand, the survival of explants on the MS basal medium (sucrose-free and hormone-free) depended entirely upon the MF attachment.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.792-800
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• 2012

The study was performed to simulate the reduction efficiency of suspended solids (SS) for cultivated land located at riverine area at the Namhan River and the Bukhan River watershed sites (site A, B, C) under the rainfall conditions using HUFF & SCS UH-based VFS Design module of Web GIS-based VFSMOD System. The study indicates that the field 5% sloped, located at Bukhan River watershed (site A), requires at least 0.5 m width of Vegetative Filter Strip (VFS) to reduce 70% of SS while the field 10% sloped requires the at least 1.0~1.5 m width of VFS to reduce 70% SS, under the condition 106.2 mm of rainfall event and bell pepper or corn of crops. Against the conditions 95.1 mm of rainfall event and sweet potato or soy bean of crops, the field 5% sloped, located at Namhan River watershed (site B) requires at least 0.5 m width of VFS to reduce 70% of SS while the field 10% sloped requires at least 1.0 m width of VFS to reduce 50% SS. The crops sweet potato and soy bean are cultivated in the site C, located at Namhan River watershed, 1 m of VFS is capable of 64.0% and 62.0% of SS reduction against 102.6 mm and 151.2 mm rainfall conditions respectively, for the 5% sloped field. The result supports that VFS is one of most potential methods to reduce SS from cultivated area, which is environment-friendly hydrologic structure. The VFS design, however, needs to be simulated before its installation in the field, the simulation needs to consider not only various characteristics of the field but also different conditions affecting the VFS, using a model capable to consider a lot of factors.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.385-391
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• 2012

The growth of terminal shoots of persimmon (Diospyros kaki) was analyzed during the first two months from the time of bud sprout to understand the dynamics of their early growth. Field-grown, mature 'Fuyu' and 'Nishimurawase' trees were used in a three-year study at two locations in Gyeongnam province. The growth of terminal shoots was most active from late April, about 10 days after foliation, to early May, followed by a gradual decline by late May. The increase in leaf area continued unabated throughout May. The weight of a flower bud increased slowly until early May and rapidly after flowering. Although its extension growth had been ceased by late May, dry weight (DW) of a terminal shoot continued to increase almost linearly throughout May due to shoot thickening and continued growth of leaves and fruits. In late May, the leaves and the stem accounted for more than 60% and less than 20% of total DW of a shoot respectively; fruit proportion increased to 7 to 17% by then. Relative growth rate (RGR) of the terminal shoot was higher than 213 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late April, but declined to less than 63 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late May. Like the pattern of seasonal changes in RGR, net assimilation rate (NAR) of the shoots decreased from 1.9 to 2 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$ to 0.5 to 0.8 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$. An early-season 'Nishimurawase' did not differ from a late-season 'Fuyu' in RGR and NAR during the first two months of growth. The early growth of the shoots was affected mainly by the reserves redistributed from permanent organs, however, environmental conditions at the time was also involved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.192-197
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• 1989

Two sweet corn hybrids, 'Tanok l' and 'Golden Cross Bantam 70 (GCB 70)' were grown at five plant densities, of 4, 167. 5,556, 6,667. 8, 333, and 11, 111 plants per 10 ares, with or without tiller removal, to determine effects of tiller removal on growth and yield of sweet corn hybrids at various plant densities. Tillers were pulled when less than 15 cm tall. The number of tillers per plant linearly decreased as plant density increased. The two hybrids had similar plant height, ear length and diameter, ear weight and the number of ears per plant and 10 ares. Tanok 1 lodged approximately 20％ at above 8,333 plants per 10 ares, while GCB 70 did not lodge at all, at any plant density. Tanok 1 had higher leaf area index (LAI), ear and stover yields than GCB 70. Except for root lodging and LAI, hybrid x plant density interaction was not significant at 5％ probability level. Plant density did not affect silking data. Increasing plant density linearly increased plant height, LAI, and stover yield, but linearly decreased ear length, ear weight, and the number of ears per plant. Increase in LAI was greater in Tanok 1 than in GCB 70, with increasing plant density. The relationships between the number of ears and ear yield per 10 ares and plant density were Quadratic. The optimum plant density was estimated to be approximately 6500 plants per 10 ares, using the equation based on ear yield. Except for ear height and LA I, hybrid x tiller removal and plant density x tiller removal interactions were not significant. Hybrid x plant density x tiller removal interaction was not significant for any characters. When averaged over hybrids and plant densities, tiller removal reduced plant height and ear and stover yields by about 3, 10, and 16％, respectively, but did not significantly affect silking date, root lodging, ear length and diameter and the number of ears per plant and per 10 ares. The results indicate that the optimum plant density is approximately 6500 plants per 10 ares, regardless of tiller removal and tillers are not to be removed at any plant density.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.565-572
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• 2013

The objective of this study was to describe and analyze the effect of high pressure sodium lamp lighting (HPS) on dynamics of growth and dry matter partitioning, and light use efficiency of sweet pepper crop grown over winter season. Young sweet pepper seedlings were planted at 3.75 plants per $m^2$ on September 29, 2010 and treated with HPS for 16 hours from December 14, 2010 until March 18, 2011. The number of leaves per plant were significantly increased with HPS, whereas the number of internodes and leaf area were less affected. HPS reduced the plant height with higher number of fruits per stem compared to those of without HPS lighting (CON). There were large differences in total dry mass production, stem and fruit dry mass between HPS and CON and those with HPS increased by 67.8%, 28.5%, and 97.1% compared to CON, respectively. Each organs of dry mass partitioning was calculated by leaf, stem or fruit growth rate divided by total plant growth rate. Dynamics of dry mass partitioning to leaf and stem between HPC and CON was measured in range of 45-47% at beginning of growth phase and drastically decreased after starting fruit growth in both treatments. Dry matter partitioning to vegetative organs was 4% higher compared to the plant grown under HPS lighting. Averaged dry matter partitioning to fruit with HPS, however, was largely increased by 14.2% compared to CON. Dynamics of the plant growth were well described by expolinear growth equation with three parameters of maximum relative growth rate, absolute growth rate and lost time to reach linear phase. The maximum growth rate of leaf, stem and fruit with HPS was increased by 18.6%, 74.7%, and 143.5% compared to CON. There was a linear relationship between intercepted light integral and vegetative organs (leaf and stem), fruit or total dry mass production. Light use efficiency (LUE, $g{\cdot}MJ^{-1}$) of total dry mass was $4.90g{\cdot}MJ^{-1}$ for HPS and $3.84g{\cdot}MJ^{-1}$ for CON, LUE of vegetative organs was $1.56g{\cdot}MJ^{-1}$ for HPS and $1.61g{\cdot}MJ^{-1}$ for CON and LUE of fruit dry mass was $3.34g{\cdot}MJ^{-1}$ for HPS and $2.23g{\cdot}MJ^{-1}$ for CON. The difference in LUE of total dry mass between treatments, therefore, occurred mainly from the different in LUE of fruit dry mass.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.237-243
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• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.6
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• pp.17-27
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• 2014

Wild boars are one of the major wild life animals of which the number has increased a lot because there has been any predator and/or competitor in the Korean ecosystem. The increase of their number was a cause damaging crops in farm lands during the growing season in South Korea. This study was done to recognize the spatial pattern of farm lands damaged by wild boars. Totally 2,342 farms were known damaged by wild boars in 2012, and used to statistically analyze the perspectives of the farm land damages by wild boars in ArcMap v. 9.3. Damages by wild boars frequently happened in the western part of Gyeongnam Province including Jinju city, Tongyoung city and Namhae county. Most farm lands damaged were located nearby large mountains in this area. It might cause the number of wild boars increased in this area, which could finally stimulate the increase of farm land damaged by the species. Farm land damages by wild boars were also coincident with the preference of wild boars on their food. They preferred crops (e.g., sweet potato and corn) in uplands and rice paddies and orchards. The reason of their preference on rice, upland crops and fruits was related to the efficiency of their getting much more energy in a unit area. Another reason for the species to come into a rice paddy would be that they enjoy mud bath in there for scraping off parasites such as ticks and lice. Wild boars were seemed much overcrowded during the period from July to October when most of crops and fruits get ripen. About three-quarters of total farm land damages happened in this period. This analysis also said that 1,915 fields (81.8% of total targets) appeared within the 100-meter buffer from boundaries of mountain areas. This meant that wild boars were more sensitive to the anthropogenic land uses than we expected. They seemed to conservatively try their feeding activities in farm lands with paying attention to the human activity.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.618-627
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• 2019

An increase in damage to crops and facilities caused by wildlife such as wild boar causes serious social and economic problems to the rural economy in Korea. This study aims to estimate the economic losses incurred to rural households in mountain villages near protected areas in Korea due to the damage to agricultural and forestry production by wildlife. The case of mountain villages located in Toji-myeon, Gurye-gun near the Jirisan National Park was studied as an example. Data were collected by interviewing 84 households across six mountain villages in April and June 2016. The results indicate that the economic losses due to wildlife damage in 2015 were estimated to be 1.65 million KRW per household, which is a total of 138.63 million KRW for the 84 households. Among local products, the most damaged products were chestnut, fern-brake, wild pear, peach, and potato, whereas the most damaged products per production area were sweet potato, peach, corn, and potato. The potential economic losses caused by wildlife damage to agricultural and forestry production in whole Gurye-gun area was estimated to be around 4.0 billion KRW in 2015. However, the municipal government budget for the compensation of wildlife damage was only 0.9 percent of the potential rural economic losses caused by wildlife damage in 2015. The results of our study suggest that the compensation scheme for wildlife damage is inadequate in the respect of social justice. Considering the low financial capacity of the municipalities in mountain areas, the central government should take a progressive responsibility by allocating more financial resources for compensation of economic losses of rural households due to wildlife damage. The equitable and effective governance of wildlife conservation is required for sustainable development of rural communities near protected areas.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.173-183
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• 2011

Gabensis village is one of the biggest village In the Wampar Local Level Government area within the Huon Gulf District of Morobe Province with a population of around 3,000. The major staple food is banana which is well complemented by minor staples yam, cassava, Singapore/Chinese taro and sweet potato. Apart from gardening for own consumption, the villagers engage in selling of vegetables, garden staples, cocoa beans, coconuts, timber, chicken, fish and pig meat to supplement their livelihood. Livestock like pigs and chickens are also kept for meat and for commercial purpose. Bettlenut which was once one of the main cash crops has now been overtaken by cocoa due to a disease that had attacked almost the entire bettlenut tree population in the area. Even though the Wau-Bulolo highway cuts through the village and all have access to transport infrastructure, the majority of the population still encounter problems in communication due to poor telecommunication coverage. On average most people earn not more than K50 per week due to constrains in production and marketing among others. Gabensis village has the potential to develop a tourism industry given its natural attraction of Lake Wanam. Beside there is also the natural eel farming and the fish pond at the nearby Potsie village. These natural attractions pose huge tourism potential for the community. As part of government services delivery and development, education and health issues is very much important in the community however there is lack of infrastructural development and poor service delivery especially in the area of health. However, the responsibility is on the community to organize themselves to realize that potential. A well developed agro-ecotourism investments would have positive spillover effects to the community thus contributing towards improving the livelihoods of the many farming families.