• Journal of Bio-Environment Control
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• 제17권3호
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• pp.188-196
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• 2008

Single span pipe greenhouses (pipe houses) are widely used in Korea because these simple structures are suitable for construction by farmers thus reducing labor cost. However, these pipe houses are very weak and frequently damaged by heavy snow and strong wind. Pipe house is constructed by pipe fabricator, which is anchored to the ground by inserting each pipe end into ground to $30\sim40cm$, so the ground support condition of pipe end is not clear for theoretical analysis on greenhouse structure. This study was carried out to find out the suitable ground support condition needed f3r structural analysis when pipe house was designed. The snow and wind loading tests on the actual size pipe house were conducted to measure the collapsing shape, displacement and strain. The experimental results were compared with the structural analysis results for 4 different ground support conditions of pipe ends(fixed at ground surface, hinged at ground surface, fixed under ground and hinged under ground). The pipe house under snow load was collapsed at the eaves as predicted, and the actual strain at the windward eave and ground support under wind load was larger than that under snow load. The displacement was the largest at the hinged support under ground, followed by the hinged at ground surface, the fixed under ground and then the fixed at ground surface independent of displacement direction and experimental loading condition. The experimental results agreed most closely with the results of theoretical analysis at the fixed condition under ground among 4 different ground support conditions. As the results, it was recommended that the pipe end support condition of single span pipe greenhouse was the fixed under ground for structural analysis.

• Research in Plant Disease
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• 제16권3호
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• pp.266-273
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• 2010

Bacterial pustule of soybean (Glycines max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean. This bacterium shows strong pathogenicity to the plants and distributes throughout Korea. However, no good control measures including bactericides and resistant cultivars are available to control the disease in Korea. Therefore, this study was conducted to develop chemical control method against soybean bacterial pustule. The present study was undertaken to find out the growth inhibitory effect bactericides (8 antibiotics, 2 copper compounds, quinoline, 18 agro-chemicals) on bacterial pustule pathogen. Antibiotics test showed that tetracycline and streptomycin sulfate significantly suppressed the growth of bacterial pustule pathogen. Also, application of oxolinic acid was found to be effective for pathogen inhibition. However, vancomycin, polymyxin B sulfate and copper compounds did not show the positive suppressive effect on growth of the pathogen. Among the eighteen agro-chemicals, streptomycin sulfate + oxytetracyclin (18.8 + 1.5%) WP, oxytetracycline (17%) WP and oxolinic acid (20%) WP were found to be effective for the inhibition of the pathogen in vitro. The selected 5 agro-chemicals were also applied on soybean in field and their control effects against the soybean bacterial pustule were tested. The foliar application of streptomycin sulfate + oytetracyclin WP and oxytetracycline WP on the naturally infected soybean (Taekwangkong) showed high control value (above 70%). Therefore, it is concluded that the bactericides used in this study showed strong inhibitory effect to soybean bacterial pustule and they can be recommend to farmers to control the disease.

• Applied Biological Chemistry
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• 제24권4호
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• pp.230-237
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• 1981

For the investigation of efficient use of fertilizer nitrogen NPK simple trials were carried out using newly bred Tongil line(japonica indica hybrid selection) and the leading local varieties with sulfur coated area in fields for two years. The yield of Tongil line was higher than that of leading local varieties by 16% in the cool year and 23% is warm year with high solar radiation from NPK simple trials including SCU and 2-split application which were carried in 130 fields at 32 locations. Warm year increased yield by 9% in Tongil but only 3% in the local than the cool year did. Optimum nitrogen level was higher in Tongil by 3.8㎏ in the cool year and 5.5㎏ in warm year than for the local. Yearly variation of optimum nitrogen in the carne variety was greater than varietal variation in the same Year. Two-split application resulted in 1 to 2% of inconsistent yield variation. Sulfur coated urea increased yield by average 2 to 4% even at 20% reduced rate of nitrogen. It was remarkably effective in same $(27{\sim}39%)$, virgin (20%) and unmatured (10%) soils.

• Journal of Bio-Environment Control
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• 제29권1호
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• pp.28-35
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• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• 제13권1호
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• pp.145-155
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• 2018

The matter of cultivating entrepreneurship and will to start a business of university students majoring in agriculture and life sciences and college students majoring in agriculture as a future leader in the sector is a very important object of study. However, the discussion on entrepreneurship, establishment of a business and venture based on creative technology and innovative management have been scarcely had, because traditionally the majority of agricultural business has been a small-sized and simple business run by a small farmer. Education for starting an agricultural business in agriculture industry has been ignored even in the developed countries. ICT and AI(artificial intelligence)-based smart agriculture in the 4th Industrial Revolution Age is emerging as a new growth potential of our agriculture industry. Thus, the interest in farmers to start a business and venture agriculture is growing in the agriculture industry. Accordingly, the study draws the influence factors regarding the effect of the planned behavior of the university students who take part in the education course for starting an agricultural business and an agricultural venture business on entrepreneurship and will to start the business and conducts the empirical analysis. The businessmen who newly join the agriculture industry should perform the technical innovation and the creative business activities to be able to compete in the agriculture industry.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• 제12권5호
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• pp.39-53
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• 2017

The purpose of this study was to investigate the effects of the rural migration factors, degree of preparation for migration, lifestyle conditions and support policies reflected against the family satisfaction of the migration. In this study family factors were used as control variables. Independent variables for this study will consist of the factors of rural migration, the degree of preparation for migration, living conditions of the farmers and the support policies, where as the dependent variable is the satisfaction of migration with an adjusting factor of the family satisfaction which will be further analysed to identify its effects on the dependent variable. For this study, a questionnaire survey was conducted for the residents and 237 valid questionnaires were collected. Multiple regression analysis was performed based on the collected data where demographic attributes being the controlling variable, and regression analysis was performed for the adjusting variable of the family. As the economic factor increases, the level of satisfaction generated to be higher in rural migration. As for the degree of preparation, living condition and support policies resulted, great quantity of green nature, safety and agriculture startup support, respectively, indicated a positive effect to the satisfaction level of migration. From the results, adjustment effect of the family factors on the economic, nature, convenience and satisfaction of the migration have appeared. The conclusion of this study is that policy support, regional stability, and economic gain are the most important factors to increase satisfaction and to reduce re-migration rate to city.

• Journal of Mushroom
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• 제5권1호
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• pp.34-38
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• 2007

The white-colored and the dark gray-colored mutants were frequently happened in cultivated areas of Pleurotus ostreatus (Wonhyeong-neutari). These caused conflicts between farmers and spawn companies. Our studies were conducted to elucidate the mechanism of mutagenesis. The results from the studies would provide valuable informations that could be used to prevent the color-related mutation, and also will be applied in breeding programs of P. ostreatus. Oyster mushroom variety, Wonhyeong-neutari, is somatic hybrid of Pleurotus and has genetic makers for arginine, ornithine, proline, riboflavine. Genetic markers analysis of monospore isolates derived from color mutants show identical tendency with that of Wonhyeong-neutari, these results indicate that color mutants were derived from Wonhyeongneutari. Twenty-one and four homokaryons were selected from the white-colored mutant MGL 2205 and gray-colored ASI 2029. All 34 F1 hybrids derived from the white-colored mutant MGL 2205 produce white-color fruiting bodies, indicating that the white color trait is heritable. In the first generation hybrids between the white-colored MGL 2205 and the gray-colored ASI 2029, all 16 hybrids produced pigmented fruiting bodies. Homokaryons isolated from the hybrid MGL 2205 X ASI 2029 were mated with homokaryon tester strains derived from MGL 2205. By these result, we could assumed that white color trait is a heritable character which is controlled by more than one recessive gene.

• Journal of Sericultural and Entomological Science
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• 제53권1호
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• pp.38-43
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• 2015

To increase the income of sericultural farms and expand sericulture industry, new high value-added products of sericulture which are beyond current products like 5th instar 3 day dried silkworm, male pupa and silkworm dongchunghacho are needed. For this sericulture product diversification, it is in desperate need of the edible processing method after 5th instar 4 day silkworm that silkgland formation is rapidly in progress during the larva periods. So far it was hard to eat because of silkgland formation in their body. So we try to boil and steam frozen-, dried-, and living-silkworm to develop low-cost edible processing methods for farmers. As the result, the silkgland of frozen and dried silkworm was not degenerated, so silkgland in their body was not edible. But in the case of living silkworm, the silkgland of mature silkworm was degenerated by boil and steam treatment, so the body and silkgland of silkworm were not only edible but also tasted good. Then the dried silkworm was easily powdered and there was no problem when it was eaten. This source technology can be widely used in the general food industry, health functional food cosmetics, pet food and so on, so it is predictable that this will contribute to increase the income of sericulture farms and expand sericultural industry.

• Horticultural Science & Technology
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• 제28권6호
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• pp.1039-1050
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• 2010

Carrot is one of the useful crops used abundantly in cooking in Western as well as Asia regions such as China and Korea. However, seed coats have hairs which should be removed to increase germination rate. Furthermore, because of seed hairs, farmers face several additional losses, such as time consumption, manpower, capital and so on, for seed handling. To prevent these problems, study of gene related hair formation using short-hair seed lines is required. We analyzed genes related to hair formation from seed through expressed sequenced tag (EST) profiling, based on the fact that the development of carrot seed hair is related to cellulose synthesis pathway in secondary cell wall synthesis stage. To study the gene expression related to hair formation of the carrot seed, a cDNA library was constructed by using the early maturation stage of the short-hair line (659-1) and hairy seed line (677-14). In short-hair (659-1) and hairy seed (677-14) lines, results from of EST profiling through BLASTX search analysis using the NCBI database showed that 172 and 224 unigenes had significant homology with known protein sequences, whereas 233 and 192 unigenes were not, respectively. All ESTs were grouped into 16 categories according to their putative functions. Twenty nine unigenes among all ESTs were considered to be genes regulating seed hair development from cellulose synthesis pathway during secondary cell wall synthesis stage; in results, 14 unigenes related to seed hair development were found only in hairy seed line.

• Journal of Food Hygiene and Safety
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• 제32권1호
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• pp.14-19
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• 2017

The purpose of the study was to simplify standard HACCP manual for improving the on-site applicability and increasing the implementation rate of HACCP program for small- and medium-sized dairy farms (SMDF). A survey was carried out in 32 SMDFs using a structured questionnaire. The results indicated that the number of workers had a positive correlation with HACCP certifications (p < 0.05). Most of HACCP non-certified farms (66.7%) were run by two workers with 40-60 cows and milking yields of 1,000-1,500 L per day. Major drawbacks for dairy farmers to implement current HACCP system were the difficulties in daily recording and facility management (40%). On the basis of the survey results, it was suggested that the development of on-site standard HACCP manual and user-friendly record chart with O/X checklist were the most urgent factors to increase HACCP implementation rate. In addition, the alternative third party service for microbial and chemical tests could also be accompanied for small-sized dairy farms.