• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.193-198
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• 1986

Bottom rot of Chinese cabbage (Brassica pekinensis Rupr) hitherto undescribed in Korea is caused by Rhizoctonia solani Kuhn. Development of bottom rot in fall crops was observed and the efficiencies of fungiciial control in naturally infested field in Southern region were studied. Bottom rot symptom started to develop 20 days after transplanting 20 day old seedlings, which corresponded to the middle growing stage. At the reading stage, the infection rate increased substantially, which progressed upto an average of $52\%$ at harvesting time. The overall infection rate was about $30\%$ in Chinese cabbage field under plastic film house cultivation. However, disease intensity of fall crops was less severe than that of crops in plastic film house. where plants infested earlier, stunted and their growth was extremely poor. Optimum temperature for mycelial growth of bottom rot isolates of R. solani was $20\~25^{\circ}C$ on potato-sucrose agar. This fungus was highly pathogenic on seedlings of Chinese cabbage, radish, sesame and rape resulting in high percentage of damping-off. For other crops, such as lettuce, tomato the cucumber, the germination was delayed for 2-3 days and the percentage damping-off was lower. Anastomosis group of this fungus was idenlfied as AG II-I. Soil drenching of fungicide pencycr WP., three applications at 10 day interval, was effective; indicating the most promising one with control value $80\%$.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.552-557
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• 2010

This study was performed to investigate the effect of zeolite on the reduction of soil EC level in the plastic film house. The EC level of experimental soil was 5.0 dS $m^{-1}$ and the zeolite was applied to the soil at seven levels (0.5, 1, 2, 5, 10, 15, 20%) with three replications. The reduction degree of soil EC level showed positive tendency to the mixing ratio of zeolite. Especially, the EC level reduced rapidly from 5.01 to 2.8 dS $m^{-1}$ in the plot where zeolite was mixed by 20% 10 days after treatment. The pH level of soil was in positive relation to the mixing ratio of zeolite, contrary to the negative relation to the concentration level of water soluble Ca, Mg and phosphorus (P). The water contents of soil mixed with 15% and 20% zeolite were 14% and 17.3% respectively but it was 12.7% for control soil. Therefore, we expect natural zeolite to salts reduction agent for exchangeable cation and phosphate which is difficult to reduce by watering and other methods.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.199-205
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• 1997

Water quality of streams and ground water from areas of different agricultural practices in the small catchments of the Han River basin was investigated. Water samples were collected from upper, middle and lower reaches of the Han River Basin where three types of agricultural management have been practiced : (1) highland agriculture and livestocks in Daegwanryung area, (2) typical upland and paddy farmings in Dunnae (Jucheon River) and Chuncheon (Soyang River) areas, and (3) intensive farming in the plastic film house in Guri area (Wangsuk stream). Water quality was monitored for EC, pH, COD, TSS, N, rations and anions. Concentrations of N, especially nitrate, and phosphorus in both stream and ground water exceeded the standard water quality criteria in many cases, but those of heavy metals were non-detectable or trace in most cases, except for Wangsuk stream where a high level was detected in a specific sampling time. Chemical criteria such as pH, EC and COD of the stream were suitable for irrigation purpose, but nitrate concentrations in ground water used in the intensive plastic film house were high enough to require a special management consideration. A model on the irrigation water quality incorporating EC and nitrate concentrations was suggested in view of fertilizer management and environmental quality.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.943-948
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• 2012

This study was conducted to estimate the effect of nitrogen reduction by applying ryegrass and to determine the relationship between yield and nitrate concentration of soil solution for cucumber cultivation in plastic film house. Nitrogen levels with recovery of ryegrass ($42.3Mg\;ha^{-1}$) was 0, 50, 75, 100 % of 199 kg N $ha^{-1}$ as N recommendation by determining soil EC value. Yield and nitrate concentration in soil solution was investigated during cucumber cultivation. Yields of N treatments applied ryegrass showed 64.3, 70.9, 70.3, and $76.5Mg\;ha^{-1}$, respectively, it could reduce about 25-50% of nitrogen application compared to yield ($68Mg\;ha^{-1}$) of NPK plot applied 199 kg N $ha^{-1}$. Nitrate concentration in soil solution was average 26.0, 30.1, 41.4, $58.5mg\;L^{-1}$ during cucumber cultivation and was related between yield and average nitrate concentration of soil solution following as; $Y=49.3+0.63X+0.0034X^2$ ($R^2=0.778^{**}$). However, it needs to conduct extra-experiment due to high variation of nitrate concentration during cultivation periods.

• Korean Journal of Organic Agriculture
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• v.14 no.2
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• pp.179-189
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• 2006

After examining the difference in the photosynthesis rate of corn according to the planting distance, the distance of $40{\times}40cm$ showed the lowest rate by 23 days after transplanting (May 31); however, there was no significant difference in the photosynthesis rate due to increased salt tolerance in the plant as time went by. As for the difference in growth features of a plant, the planting distance of $40{\times}40cm$ showed a growing disorder due to the influence of salt by 23 days after trans-plantation (May 31); however, there was a desirable growth as time went by. For the difference in the salt content within a plant, the planting distance of $40{\times}40cm$ tended to be higher than other planting distances, and the K+ content is much higher than other kinds of salt after examining the difference in salt absorption. As for the correlation between saline components within a plant, there was a significant negative correlation among $K^{+},\;Ca^{2+},\;and\;Na^{+}$ while there was a significant positive correlation among $Mg^{2+},\;Ca^{2+}$, and Na+. After examining the effectiveness of salt removal from soil according to com cultivation, the planting distance of $30{\times}30cm$ showed a remarkable decrease by 37 days, compared with 23 days, after transplantation in $K^{+}$ by 28%, $Ca^{2+}$ by 36.6%, $Mg^{2+}$ by 30.6%, and $Na^{+}$ by 22.9%. And the salt content is higher in surface soil than in subsoil.

• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.130-134
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• 2010

To investigate effects of deep tillage before planting on physicochemical properties of soil, growth and fruit characteristics in cultivation of watermelon (Citrullus vulgaris L. cv. 'Uriggul') under plastic film house, this study was conducted in cultivating field of Gochang Junbuk. pH in soil after harvest compared with soil before planting of watermelon had almost no change, but EC lowed greatly in the two treatments. Available phosphate concentration in the soil with the deep tillage treatment was lower, K concentration of exchangeable cation decreased greatly than these with conventional tillage treatment. In the growth at 27th day after planting plant, stem length to 10th node from the first node, leaf width with deep tillage treatment were longer, bearing node of the first and second flower and wilting degree were lower than these with conventional tillage treatment. In the growth of harvesting time, the stem length to 30th node from the first node with the deep tillage treatment were longer, leaf discoloration degree was lower than these with conventional tillage treatment. Also, the harvested fruits length, diameter, peel hardness, and weight were significantly better than these with conventional tillage treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.304-310
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• 2003

Effects of different amounts of fertilizer and manure application on changes of chemical and biological properties of soil were studied in plastic film house. Application amount of fertilizer was determined on the basis of soil test, standard application rate, and conventional rate of farmers. Lettuce in the first and second seasons and spinach in the third season were cultivated. Crop yields were highest in the plot fertilized on the basis of soil test during the three crop seasons. In the third crop season, spinach yield was lower in conventional plot applied with larger amount of pig manure compost than any other treatment. Organic matter, available phosphorus, and exchangeable potassium were accumulated in soil of the conventional plot with successive cropping. There was no difference in the abundance of soil invertebrates among the treatments, but soil enzyme activity was highest in the conventional plot.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.18-23
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• 2012

To determine the effect of winter green manure crops for tillage and no-tillage organic pepper cultivation in plastic film house, five different green manure crops were cultivated during winter season. In nutrition composition of green manure crops, total nitrogen contents were higher in Vicia hirsuta and Vicia angustifolia than any other crops. The average dry weights of green manure crops were 8.3 ton per ha in tillage and 7.0 ton per ha in no-tillage, among green manure crops that of Secale cereale was the highest. Fertilizer supply was depended on the biomass of the cultivated green manure crops and nutrition contents, total nitrogen supply of V. angustifolia was 226 kg and that of S. cereale was 251 kg per ha in tillage field. In no-tillage field, N-supply of V. angustifolia was 197 kg and that of S. cereale was 222 kg per ha. In yield components of red pepper, fruit numbers per plant were 55.5 in green manure crop tillage and 37.0 in no-tillage cultivation. Among green manure crops, the yield of dried red pepper was the highest for V. angustifolia in both green manure crop tillage and no-tillage cultivation.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.207-212
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• 2018

BACKGROUND: Recently, the need for a method to cultivate 'Haryejosaeng' Satsuma mandarin has been increasing. However, there is limited information available as this is a new Satsuma mandarin cultivar, which was bred by the RDA in 2004. Many farmers who cultivate this cultivar follow the cultivation method similar to that used for 'Miyagawa' Satsuma mandarin, and suffer low production of optimum-sized fruits. METHODS AND RESULTS: This study was conducted to find out the optimum ratio of leaf-to-fruit for the stable production of high quality 'Haryejosaeng' Satsuma mandarin fruits in a non-heated plastic film house. Seven-year-old 'Haryejosaeng' Satsuma mandarin trees were used in the study. Before the treatment, the leaf-to-fruit ratio ranged from 5.7 to 17.9. The treatments included 10, 20, 30, and 40 leaves per fruit. The fruits were removed if over fruiting was observed at day 60 after full bloom. We investigated the fruit size and quality on the day of harvest. Flowering and fruiting patterns in each treatment were recorded for the following year. In the experiments, the flower-to-leaf ratio was 1.12 to 1.74. As the leaf-to-fruit ratio decreased, the fruit size and weight also decreased. Contrarily, the higher the ratio of leaf-to-fruit, the higher fruit size and weight were. It was noted that the ratio of 20:1 was ideal to produce the M grade optimum-sized Satsuma mandarin fruits on the day of harvest. However, higher ratio might result in fruits weighting above 100 g. There was no difference among the treatments in terms of fruit quality, such as total soluble solid contents, titratable acid, and color. In the subsequent years, flowering and fruiting in the treatments were lowered when the leaf number per fruit was 10, but they were improved when the leaf number per fruit was above 20. CONCLUSION: Based on the above results, the optimum ratio of leaf-to-fruit was found to be 20:1 for flowering and fruiting of 'Haryejosaeng' Satsuma mandarin. It is important that optimum ratio of leaf-to-fruit is set as a standard to produce good grade and quality of 'Haryejosaeng' Satsuma mandarin fruits.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.59-73
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• 1994

The purpose of this study is to experiments the environmental conditions and the adaption of the human body in the vinyl house. The study was done in spring and winter and experimental clothes were used working clothes in the vinyl house. The results are as follows. 1. Environmental Conditions In the spring season, the indoor air temperature was $27.4{\pm}3.7^{\circ}C$ and the outdoor air temperature was $14.4{\pm}2.7^{\circ}C$. In the winter season, the indoor air temperature was $18.3{\pm}4.8^{\circ}C$ and the outdoor air temperature was $7.6{\pm}2.5^{\circ}C$ on the average. 2. Skin Temperature In the spring season, the mean skin temperatures indoor and outdoor were $33.81{\pm}0.7^{\circ}C\;and\;31.57{\pm}0.8^{\circ}C$ respectively, a difference of $2.24^{\circ}C$. In the winter season, they were $31.95{\pm}1.93^{\circ}C\;and\;29.86{\pm}0.55^{\circ}C$ respectively, a difference of $2.09^{\circ}C$. 3. Clothing Climate In the spring season, the temperature and humidity in the inner layer of clothing were $34.77{\pm}0.80^{\circ}C\;and\;70.75{\pm}1.65%$ indoor, $31.9{\pm}0.52^{\circ}C\;and\;51.9{\pm}3.70%$ outdoor respectively. In the winter season, those were $32.52{\pm}1.04^{\circ}C\;and\;64.65{\pm}3.68%$ indoor, $30.27{\pm}0.96^{\circ}C\;and\;45.07{\pm}2.68%$ outdoor respectively. 4. Physiological Factors Body temperature increased slightly and the pulse rate also rises, but blood pressure decreased a little with the rise of environmental temperature both in the spring and winter seasons. 5. Psychological Factors Thermal sensation in the spring season was expressed as 'slightly warm' or 'warm' indoor and as 'neutral' in the open air, while in the winter it was expressed as 'neutral' or 'slightly warm' outdoor the house and as 'cold' in the open air. Comfort sensation was characterized as 'uncomfortable' or 'slightly uncomfortable' indoor both in the spring and winter seasons, but in the open air it was characterized as 'comfortable' in the spring and as 'slightly uncomfortable' in the winter.