• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.540-544
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• 1991

Pod dehiscence in six rape varieties drying after harvest in the field was investigated with use of strain gauge. The development of rape pods was observed after 3-4 days of flowering. The length of pod and seed reached of their maximal size at the 20th and 35th days after flowering, respectively. The seed shape was nearly spherical 40 days after flowering, and pod width was maximal at the 45th days of flowering. Moisture content of seeds was 70% at cutting time, reduced to 30% at 5 days of drying in the plastic film house and 10% at 14 days. Pod dehiscence showed a diurnal change with moisture content of pods and relative humidity, and the dehiscence became difficult under low moisture content of pods and relative humidity of which seems to be related to the rapid drying condition of pod.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.259-267
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• 1998

This study was carried out to investigate the effect of mulching materials on the fruit quality of Miyagawa Early Satsuma Mandarin in the plastic house. The mulching time was 10 days after water irrigation breakage. The mulching materials used, in order of decreasing light reflectivity, were; micro-perforated vinyl sheets, non-woven fabric film, porous black P.E. film and non-mulching(control). Peel coloration by a values in the treatment of the micro-perforated vinyl sheets showed a 6.93 increase over the control group. The a/b values were similar to this trend, but there were no significant difference among the mulching treatment groups. The glucose level of fruit juice was much higher in the mulching treatment groups as compared with that of the control group, but there was no significant difference among the mulching treatments. Fructose content in the treatment of the micro-perforated vinyl sheets a 0.31mg%.m $L^{-1}$ increase over the control group. This group also showed a 1.36%.m $L^{-1}$ increase in sucrose and a similar increase trend in total sugar. The Brix value was 0.9 $^{\circ}$Brix higher in the micro-perforated vinyl sheet group(12.4 $^{\circ}$Brix) than in the control group(11.5 $^{\circ}$Brix) which result in a significant increase with micro-perforated vinyl sheet usage. However, the acidity level did not differ significantly among mulching treatments.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.38-44
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• 2003

This work was conducted to estimate amounts of irrigating water during the growing periods of pepper after estimating water consumption in the plastic film house in 1997 and 1998. Evapo-transpiration (ET) under conditions of a black and white PE mulch and sandy or clay loam soil which enhanced the growth and yield of red peppers was greater than that at the bare and sand soil. Average ET of pepper grown in pots accounted for 56.5%∼79.7% of total supplying water in 1997 and 1998. Most of ET was proportioned to the transpiration amount (91∼94%), but there was some difference between amounts of ET and transpiration plus evaporation. Although 57 depended on conditions of the soil texture and plant growth, transpiration for pepper growing periods was amounted to 337.7∼774.3 m in the clay soil,910.6 m in the sandy loam soil, and 253.1 mm in the sandy soil.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.655-668
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• 2012

Foliar diseases are major constraints to profitable organic tomato production. Especially, powdery mildew, leaf mold and gray mold of tomato occur severely on organic cultured tomatoes in Korea. This study was conducted to develop organic tomato cultivation technology using environmental-friendly disease control methods (resistance cultivar planting, air circulation fan installation, oil-egg yolk mixtures, and microbial agents). When tomatoes were cultivated in plastic film house installed with air circulation fan, daily range of temperature was decreased by $2{\sim}7^{\circ}C$, average relative humidity was decreased by 1~5% compared to those in plastic house without air circulation fan. Consequently, incidence of tomato leaf mold and tomato gray mold was reduced by 55.0% and 24.4%, respectively. Control effect of microbial agents and oil-egg yolk mixtures against major tomato diseases was examined in plastic house. As a result, the control value of microbial agents against tomato gray mold and tomato leaf mold showed at the range of 49.0~55.9 %(gray mold) and 39.2~58.2%(leaf mold), respectively. The control value of oilegg yolk mixtures against tomato powdery mildew showed 97.6%. Fifteen tomato cultivars were evaluated for disease resistance against leaf mold and powdery mildew in organically cultivated tomato field. Among 15 tomato cultivars, seven cultivars including 'Super-top' were found to be high resistant to tomato leaf mold. Also 'Powerking', one of fifteen tomato cultivars, showed to be high resistant to tomato powdery mildew.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.5
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• pp.27-34
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• 2018

Concrete placed under hot weather condition suffers from larger slump loss, rapid moisture evaporation due to high air temperature. Proper measures for material, transportation and curing should be taken to prevent the quality deterioration of the concrete under hot weather condition. In Korea, Although the period of hot weather concrete in Korea occupies only 2 months, there are a lot of quality problems including plastic, drying shrinkage and cold joint. Therefore, the objective of this paper is to investigate and compare the temperature history and crack occurrence of the concrete, which was placed in the actual apartment house construction field under hot weather condition, in response to the application of surface covered curing blankets including PE film, single layer clear bubble sheet, white colored bubble sheet and aluminum metalized bubble sheet. Test results indicated that the application of white colored bubble sheet and aluminum metalized bubble sheet showed most favorable results in terms of reduction in temperature rise and crack occurrence as well as easiness in handling. But, due to light reflection by aluminum metalized bubble sheet, it is believed that white colored bubble sheet is preferable.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.107-114
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• 1985

This experiment was performed to see the possibility if soil-borne disease in green house can be controlled by soil solarization in Korea. Thermal death profiles of propagules of some soil-borne fungi, Fusarium oxysporum f. lycopersici, Fusarium oxysporum f. niveum, Rhizoctonia salani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Pythium debaryanum, were obtained under the conditions in water-suspension and in soil. Except Pythium debaryanum, all the fungal units in water-suspension that were colonized on barley grains lost a viability within 7 days in water bath at $45^{\circ}C$. When the soil in test tubes in which barley grains infected with the fungi were also buried all the fungi tested including Pythium debaryanum were completely killed within 7 days in water bath at $45^{\circ}C$. From July to August in Korea, soil temperature at depth of 5cm and 15cm within tunnel in plastic house reached $38^{\circ}C\;to\;57^{\circ}C$ and $40^{\circ}C\;to\;47^{\circ}\C$, in 1982 and 1983 respectively. Even at 15cm depth, soil temperature were kept over $43^{\circ}C$ for 12 hours a day. Adiabatic material set under ground or under mulching with the transparent polyethylene-film on the soil surface had a boostering effect for higher soil-temperature and longer duration. Fungi buried in adiabatic block of the soil in plastic house were completely killed at 15cm depth 14 days after, and at 20cm depth 21 days after soil solarization. The exposure of the pathogens to fluctuating temperature was much more effective than to constant. From the above results, soil-borne diseases may be effectively controlled by soil solarization in the closed plastic house in hot summer season in Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.185-186
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• 2003

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.360-365
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• 2003

최적화의 개념은 목적에 따라 다양하겠으나 수치해석에서는 기본적으로 설계변수를 움직여 목적함수를 최소화 혹은 최대화하는데 있다. 열전달에서는 최소온도, motor를 설계할 때는 최대토크 등이 있고, 구조물설계에 있어서는 최소무게(Weight or Volume) 혹은 최대의 Frequency를 구하는데 최적화 수치해석이 이용되고 있다. 오늘날 컴퓨터하드웨어의 발달과 더불어 전산수치해석의 영역이 급속히 높아져가고 있으며 PC에서의 계산처리능력이 90년대의 work station급을 초가 함으로써 보다 쉽게 전산수치해석이 가능하게 되었다. (중략)

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.156-161
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• 1982

Three plastic film solar dryers covered with different film layer were constructed by modifying farm vinyl house and studied their performance. The collection efficiency and temperature raising of type C which was covered with double layers of transparent PE and black PVC film was most efficient, followed after B covered with double layer of transparent PE film and type A covered with single layer transparent PE film. The inside temperature of type C was average $18^{\circ}C$ higher than ambient temperature and its collection efficiency showed 31.5% with air flow rate of $3.8m^3/min$. The solar energy collection efficiency of type C was increased in proportion to air flow rate up to 60.2% at $11.3m^3/min$. In demonstration drying test of red pepper in type C, drying capacity per unit area was 2.5 times higher than that of conventional solar drying on straw mat and drying time shortened to about half.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.27-49
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• 1994

Root colonization of biocontrol agents via seed treatment was investigated and a compatible combination, Gliocladium virens G872B and Pseudomonas putida Pf3, in colonizing cucumber rhizosphere was confirmed through the study. Much higher number of fungal and bacterial propagules were detected when two isolates were inoculated together. The presence of Pf3 in root system was greatly helpful to G872B to colonize at root tip. The mechanism of this phenomenon is partially elucidated through the results of in vitro experiments and the observations of scanning electron and fluorescence microscope. Addition of Pf3 cells resulted earlier germination of G872B conidia and increased mycelial growth. And the more number of germinated conidia on seed coat, the more vigorous hypal streching and sporulation on the root surface were observed in coinoculated treatment. The propagules of G872B on the cucumber root when they were challenged against the pathogenic Fusarium oxysporum, were even higher than that of G872B treated alone, and the magnitude of such a difference was getting grater toward the root ip and the population of F. oxysporum on the root was reduced by seed inoculation of G872B. The rhizosphere competence was obviously reflected to disease suppression and plant growth promotion that induced by the given isolate. Green house experiments revealed that the combined treatment provided long-term disease suppression with greater rate and the larger amount of fruit yield than single treatments. Through this study the low temperature growing Pseudomonas fluorescens M45 and MC07 were evaluated to apply them to the winter crops in field or plastic film house. In vitro tests reveal that M45 and MC07 inhibited the mycelial growth of Pythium ultimum, Rhizoctona solani and Phytophthora capsici and enhanced growth of cucumber cotyledon in MS agar. This effect was more pronounced when the bacteria were incubated at 14$^{\circ}C$ than at 27$^{\circ}C$. And disease suppression and plant growth promotion in green house were also superior at low temperature condition. Seed treatment of M45 or soil treatment of MC07 brought successful control of damping-off and enhanced seedling growth of cucumber. The combined treatment of two isolates was more effective than any single treatment.