• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.2
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• pp.49-58
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• 2019

This study aimed to determine of water quantity in pot for water flooding culture of Pinus thunbergii Parl., Chaenomeles japonica Lindl. ex Spach and Osmanthus fragrans Lour. The survival rate of P. thunbergii Parl. and C. japonica Lindl. ex Spach in the water quantity in pot 60% or 40% was 100% and the rate of O. fragrans Lour. in the 60% or 40% water was 90.0% or 93.3%. However the survival rate of the 100% water was less than 90% in P. thunbergii Parl, C. japonica Lindl. ex Spach and less than 60% was in O. fragrans Lour. The increasing rate of plant height for P. thunbergii Parl. in the water quantity in pot 40% or 60% was above 50%, and the C. japonica Lindl. ex Spach or O. fragrans Lour. was above 90%. However the increasing rate of plant height in the water 100% was less then the others as a 38.2%, 65.4% or 66.7% in respectively in P. thunbergii Parl., C. japonica Lindl. ex Spach and O. fragrans Lour. The increasing rate for leaf number for P. thunbergii Parl. in the water quantity 40% or 60% was above 80%, and the C. japonica Lindl. ex Spach or O. fragrans Lour. was above 70%, however the 100% water was below 60% in all treatment. Therefore, the survival rates in some woody plants of the 40% or 60% water in the pot was above 90% and the plant growth of plant height, plant width, leaf number or fresh weight was proper increased. But the survival rates and growth of the 100% water in the pot was decreased

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.335-339
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• 2006

Effects of deficit irrigation by different soil moisture-based water potential on total soluble solids and fruit yields in fresh tomato were investigated. Amount of irrigation was saved about 11%, 25% and 41% at -20 kPa,-30 kPa and -40 kPa treatment compared to the -15 kPa treatment as a standard practice, respectively. Deficit irrigation with -30 kPa and -40 kPa treatment significantly increased total soluble solids by 11% and 24% at first truss compared to the -15 kPa treatment, with no significant loss of yield, respectively. However, deficit irrigation with -30 kPa and -40 kPa treatment significantly increased total soluble solids at second and third truss, but resulted in substantial yield loss compared to the standard practice. Total fruit yields at -30 kPa and -40 kPa treatment was decreased by 16.5% and 25.1% compared to the -15 kPa treatment. However, marketable fruits based on fruit size (150$\sim$250g) was increased by 27.8% at -30 kPa treatment compared to the -15 kPa treatment.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.11a
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• pp.34-35
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• 1997

무토양재배에서의 효율적인 관수량 결정은 정확한 증산량에 근거한다. 작물의 생육과 환경과의 관계 분석을 위해서 실제의 재배시스템 전체를 대상으로 하여 증산량을 연속적으로 측정하는 것은 현실적으로 어려우며, 가능하더라도 대규모의 시설이 필요하다. 따라서 작물의 실제 증산량을 위해서 개체 측정 등의 대표치를 이용하는 방법이 적용되고 있다. 본 연구에서는 일반적인 증산량 측정을 위해서 정량펌프를 이용한 측정 시스템의 구축 및 이 방법을 이용하여 관수량 제어를 위한 환경과 증산량과의 관계를 분석하였다. (중략)

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.683-689
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• 2012

This research was carried out to investigate the effect of installation spacing of subsurface drip irrigation pipe on the mineral content, nutrient uptake, yield of lettuce, water requirement for irrigation, and soil chemical properties in greenhouse cultivation. Semi-forcing and retarding culture were implemented in this experiment, with four treatments containing overhead spray irrigation and three subsurface irrigation lateral spacing intervals of 30, 40, 50 cm at a depth of 30 cm from soil surface, respectively. Each mineral content of lettuce grown under subirrigation system did not show significant difference between treatments, however the uptake of nutrients was lower at 50 cm-distance. The yield was largest in 30 cm-subirrigation (SI), followed by 40 cm-SI, overhead spray, and 50 cm-treatment. Water requirement for irrigation was highest in overhead spray, and it was in reverse proportion to the distance of irrigation pipes. $NO_3$-N content in the soil, at a depth of 10 cm, showed a higher value in 50 cm-SI, followed by 40 cm-SI, overhead spray and 30 cm-SI. Exchangeable K content was highest in 50 cm-SI, Mg was highest in 40 cm-SI, and Ca was lowest in 30 cm-SI. In conclusion, the lettuce yield was not different between 30 and 40 cm-SI, but water requirement for irrigation was lower as the distance of irrigation pipes was further. And it seems to be needed more precise research on this theme, because crop yield and the dynamics of soil minerals in subsurface irrigation can vary with the depth and distance of irrigation pipes, dripper, water flow depending on the soil texture, and plant response to soil minerals.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.357-362
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• 1981

This study was conducted to examine the best population density and agronomic characteristics affected by different row-widths and planting-spaces within row in safflower. As both row-width and spacing were narrowed, plant height and height to first branch were increased, and the number of branch per plant showed decrease. Plant height showed negative correlation with row-width, height to first branch showed negative correlation with row-width x spacing, and number of branch per plant had positive correlation with row width, and row-width x spacing but negative correlation with plant height. Yield was affected by spacing and row-width x spacing. In spacing, 5cm plot performed the best yield, and 30 x 5cm population density was the best cultural method to increase safflower yield. Yield had negative correlation with spacing and row-width x spacing, but positive correlation with height to first branch.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.288-292
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• 2008

This study was conducted to identify the effects of irrigation amount to produce high quality melon fruit in fertigation culture. Irrigation amount of during fruit harvesting period was doubled at the low irrigation point ($(-45{\sim}50\;kPa$) treatment as 115 mm as than that of the high irrigation point ($-20{\sim}25\;kPa$) treatment. The plant growth rates such as stem length, leaf weight and plant height were a little diminished at the low irrigation point ($-45{\sim}50\;kPa$) than those of the other treatments. Internode length was however not affected by irrigation amount. Fruit weight was lighter at the low irrigation point ($-45{\sim}50\;kPa$) than that of at the high irrigation point and fruit height was shorter, but fruit diameter was not affected by irrigation amount. Fruit soluble solid was $0.9^{\circ}Bx$ higher at the low irrigation point ($-45{\sim}50\;kPa$) than at the high irrigation point ($-20{\sim}25\;kPa$) and net index was higher. Total marketable yield was highest by 3,937 kg/10a at the high irrigation point ($-20{\sim}25\;kPa$), but the excellent marketable yield was highest by 2,531 kg/10a at the low irrigation point ($-45{\sim}50\;kPa$). Inorganic contents of the soil N, K, Ca and Mg were not affected by irrigation amount. It was therefore thought that optimum irrigation point to produce high quality melon fruit by fertigation culture was $-45{\sim}50\;kPa$ at ripening stage.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.242-249
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• 1999

This study was conducted to investigate the effect of seedling age and irrigation set point on the growth and yield of white spined cucumber cv Sharp-1. Leaf area, number of lateral vines and root weight measured 70 days after planting were the greatest in 30 day-old seedling treatment. Inorganic element content measured 30 days after planting was the greatest in 30 day-old seedling treatment. Total and marketable yields were greater in 30 day-old seedlings than those of 20 or 40 day-old seedlings. The early yield was the least in 20 day-old seedlings. 40-day old seedlings lost vigor quickly. No significant differences in growth and yield observed as affected by irrigation set point.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.229-234
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• 1989

In flue-cured tobacco, the relationships between the quality of tobacco leaves (productivity according to quality grade) and specific meteorological factors were noted showing different significances according to different seasons during the growing period of the tobacco plants. The thick leaf high quality was significantly correlated with average temperature in late April, late May, early July and late July. The degree of contribution was greatest in middle May and lowest in late May. In the highest and lowest temperatures, the relations to leaf quality had similar tendency like in the average temperature; the thick leaf low quality showed opposite tendency relative to the high quality in the degrees of correlations and contributions. Amount of precipitation was significantly correlated with the thick leaf high quality in late April, early May, middle May, late June and late July. The degree of positive contribution was shown in order of late April, middle July and early July, and that of negative one was in order of middle June, early June and late June, respectively. Duration of sunshine period was highly associated with thick leaf high quality of tobacco leaves in all of the growing season except for middle April and middle July. The degree of positive contribution was in order of late May, late April, early July and middle July, and that of the negative one was in order of late June, early May, middle June and middle May.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.394-404
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• 2022

This study was conducted to optimize the amount of drip irrigation for Prunus×yedoensis Matsum., one of the major medium-sized landscaping trees used mainly for streetscapes and as ornamentals. The experiment was conducted in a container nursery, where we assessed the growth and physiological characteristics of 4- and 8-year-old seedlings watered at different rates (x) by a drip irrigation system. The relative growth rates (based on height and root collar diameter (RCD) measurements) were highest at 288 and 416 L/year/tree for the 4- and 8-year-old containerized seedlings, respectively. These age and treatment combinations also produced significantly different dry weight and seedling quality index values, indicating good growth. The two age groups had significantly different total root lengths, root diameters, and root volumes under these respective irrigation treatments. In addition, the 4-year-old containerized seedlings irrigated at 288 L/year/tree and the 8-year-old containerized seedlings irrigated at 416 L/year/tree had the highest activations in their chlorophyll contents. Overall, the results (differences in irrigation amounts affect the seedlings morphological relative growth, biomass growth, seedling quality, and physiological reaction) indicate that the optimal irrigation amounts for container-grown Prunus×yedoensis are 288 L/year/tree for 4-year-old (RCD class, 3cm) and 416 L/year/tree for 8-year-old (RCD class, 7 cm) containerized seedlings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.59-64
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• 1977

The relationship between grain yield. protein content and sedimentation value in wheat were studied using 9 varieties cultivated at 8 locations in Korea. The grain yields of wheat varied widely, according to varieties and locations. Negative correlations between grain yield and protein content, and grain yield and sedimentation value were observed, while a positive correlation between protein content and sedimentation value was observed. Specific sedimentation values of soft wheats were below 4, while those of hard wheats were above 5. The intermediate varieties had sedimentation values of 4-5. This showed that specific sedimentation values could be used as a criterion in the classification of wheat quality.