• Korean Journal of Organic Agriculture
• /
• v.18 no.4
• /
• pp.587-598
• /
• 2010

This study was carried out to elucidate the effects of mulching materials on the growth of potato and weed control at the experimental farm of Chungbuk National University from August 9 in 2008 to June 28 in 2009. Tested potato, cv. 'Superior', was grown under the different mulching materials such as pine tree leaf, oak tree leaf, rice straw, rice hull and sawdust, and control(non-mulching). We tested two times with autumn and spring culture season. The obtained results from this study were summarized as follows; There was significantly difference in plant height, stem length, leaf length, leaf weight and tuber weight in pine tree leaf mulching treatment in autumn season among the treatments. The dominant weeds were Echinochioa crus-galli var. fadmerntacca and Cyperus amvuricus in autumn culture season, while were Echinochioa crus-galli var. fadmerntacca and Digitaria sanguinalis in spring culture season. The appearance of weeds in all of mulching treatment was significant reduced compared to control. The soil moisture content was the highest in rice hull mulching treatment, and that of mulching treatments was significantly higher than control. The soil temperature of mulching treatments was lower than that of control by from $1.0^{\circ}C$to $2.8^{\circ}C$ in autumn season and from $0.7^{\circ}C$ to $2.3^{\circ}C$ in spring season. The soil temperature was low in the order of pine tree leaf, rice straw, oak tree leaf, rice hull, sawdust, and control.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.3
• /
• pp.255-263
• /
• 2011

Projected increases in atmospheric $CO_2$ concentration ([$CO_2$]) and temperature ($T_a$) have the potential to alter in rice growth and yield. However, little is known about whether $T_a$ warming with elevated [$CO_2$] modify plant architecture. To better understand the vertical profiles of leaf area index (LAI) and the flag leaf morphology of rice grown under elevated $T_a$ and [$CO_2$], we conducted a temperature gradient field chamber (TGC) experiment at Gwangju, Korea. Rice (Oryza sativa L. cv. Dongjin1ho) was grown at two [$CO_2$] [386 (ambient) vs 592 ppmV (elevated)] and three $T_a$ regimes [26.8 ($\approx$ambient), 28.1 and $29.8^{\circ}C$] in six independent field TGCs. While elevated $T_a$ did not alter total LAI, elevated [$CO_2$] tended to reduce (c. 6.6%) the LAI. At a given canopy layer, the LAI was affected neither by elevated [$CO_2$] nor by elevated $T_a$, allocating the largest LAI in the middle part of the canopy. However, the fraction of LAI distributed in a higher and in a lower layer was strongly affected by elevated $T_a$; on average, the LAI distributed in the 75-90 cm (and 45-60 cm) layer of total LAI was 9.4% (and 35.0%), 18.8% (25.9%) and 18.6% (29.2%) in ambient $T_a$, $1.3^{\circ}C$ and $3.0^{\circ}C$ above ambient $T_a$, respectively. Most of the parameters related to flag leaf morphology was negated with elevated [$CO_2$]; there were about 12%, 5%, 7.5%, 15% and 21% decreases in length (L), width (W), L:W ratio, area and mass of the flag leaf, respectively, at elevated [$CO_2$]. However, the negative effect of elevated [$CO_2$] was offset to some extent by $T_a$ warming. All modifications observed were directly or indirectly associated with either stimulated leaf expansion or crop phenology under $T_a$ warming with elevated [$CO_2$]. We conclude that plant architecture and flag leaf morphology of rice can be modified both by $T_a$ warming and elevated [$CO_2$] via altering crop phenology and the extent of leaf expansion.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.298-302
• /
• 2008

In this study, we have carried out the test to examine the ignition characteristics, such as a relation of moisture content and combustibility, and ignition temperature using KRS-RG-9000 tester, living leaves and dead leaves of significant 7 species of Young Dong Provinces of Korea after and before the rainfall. After 144 hours at normal temperature, the percentage of water content of the needle-shaped leaves was less than 10%. So it is suppose to be ignite easily. On the other hand, the self-temperature to ignite of broadleaf is higher. So the retard time at lower temperature is more long than needle-shaped leaf. Consequently, the fire-resistant qualities of broadleaf is higher than needle-shaped leaf.

• Fashion & Textile Research Journal
• /
• v.14 no.2
• /
• pp.320-330
• /
• 2012

The natural dyeing of cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing are $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics were dyed in pre-mordanting. The K/S value of dyeing fabrics could be increased with repetitive dyeing and mordanting. Compared to untreated dyed fabrics, the K/ S values of fabrics which had been treated with soybean milk, chitosan and gall nut tannin were increased. The changed surface colors of fabrics that were treated with soybean milk, chitosan and gall nut tannin were Y, YR and achromatic colors. Fabrics dyed with alkaline water extract showed reddish color. Sn-mordanted fabrics dyed with acidic water extract showed vivid yellowish color, and Cu-mordanted fabrics dyed with ethanol extract showed yellowish green color. In case of Sn-mordanted fabrics, the washing fastness was level 4. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness was better in dry rubbing than in wet rubbing of the fabrics. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the powder of guava leaf extract and the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. All dyed fabrics showed higher deodorization and UV protection rate than control fabric.

• Applied Chemistry for Engineering
• /
• v.27 no.3
• /
• pp.276-279
• /
• 2016

In this study, we extracted active components from thistle, persimmon leaf, and new green which are known to have a high content of antioxidants and also analyzed the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavening activity and flavonoid content. Both ultrapure water and alcohol were used as extraction solvents and the ratio of both solvents, sample, amunts extraction time, and extraction temperature were varied. The optimal extraction condition of each natural compounds were 2.5~3.5 h of the extraction time and 50 g/L of the sample amount. The optimal ratio of ultrapure water and alcohol and extraction temperature were as follows; persimmon leaf (55~65 vol%, $50{\sim}60^{\circ}C$), thistle (40~50 vol%, $55{\sim}65^{\circ}C$) and new green (55~65 vol%, $50{\sim}60^{\circ}C$). In addition, the antioxidant capacity and flavonoid content of the extract increased in the order of persimmon leaf, thistle, and new green.

• Journal of Ginseng Research
• /
• v.13 no.1
• /
• pp.92-97
• /
• 1989

This study investigated the effects of high light intensity (100 KLw) and high temperature (45 ℃, dark) on enzyme (glucose-6-phosphate dehydrogenase, acid phosphatase, catalase, peroxidase, and proteinase) activities and characteristics of Panax ginseng C.A. Meyer leaves. Enzyme activity and protein content decreased rapidly under treatment with high light intensity In P ginseng the thermal stabilities of catalase and peroxidase were high (above 70%), and the coagulation rates of soluble proteins were low (below 17%). Therefore, the decrease in enzyme activity and protein content was not caused by increase in leaf temperature due to the high light intensity, but by increase in proteolytic activities. The photochemical formation rate of superoxide radical (O-2) was higher in the P ginseng leaf extracts than in Solanum nigmm, and was accelerated by addition of crude saponin to the buffer extracts.

• Korean journal of food and cookery science
• /
• v.23 no.2 s.98
• /
• pp.165-172
• /
• 2007

This study was conducted to investigate the antioxidant amounts and properties of barley leaf tea and green tea at under various leaching conditions. The leaching temperatures and times of the distilled water were 50, 70 and $90^{\circ}$C for 1, 3 and 5 min, respectively. The levels of crude fat and ash in the barley leaf tea were higher than those in green tea. Brown color intensity and flavonoid absorbance increased with leaching temperature. The highest vitamin C levels and water-soluble phenol resulted at $90^{\circ}$C for 3 min. The DPPH radical scavenging activities of the barley leaf tea and of green tea were 11.06 and 50.56%, respectively, compared to 2.9% for L-ascorbic acid (150 ppm). The nitrite scavenging activities of barley leaf tea and green tea were 95.11 and 74.88%, respectively. The SOD-like activities of barley leaf tea, green tea, and L-ascorbic acid (150 ppm) were 12.99, 8.33, and 12.75%, respectively. The antioxidant effect of green tea was higher than that of barley leaf tea and lastly, the SOD-like activity of barley leaf tea was as high as that of green tea.

• Journal of Bio-Environment Control
• /
• v.23 no.4
• /
• pp.342-348
• /
• 2014

This study was carried out to determine the effects of temperature and shading on germination and early growth of Pimpinella brachycarpa. Experiment was performed by temperature controls ($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$) and shading treatments (control, 35% shading, 50% shading, and 75% shading). Seed pre-treatment before the germination experiment was carried out by temperature (with low temperature and wetting treatments for 0day, 20days, and 40days). Seeds of P. brachycarpa were, 20days of seed pre-treatment, germinated well at $5^{\circ}C$ and the more temperature went up, the more germination rate went down. As a result of surveying shading treatments, the height, leaf area, leaf length, leaf width etc were the highest (7.3cm, $12.8cm^2$, 5.4cm, and 2.3cm, respectively) under 50% shading. Specially, the root was grown well under 35% and 50% shading. Fresh weight of shoot (leaves+stem) was the highest under 50% and 75% shading and dry weight of shoot (leaves+stem) was the highest under 35% and 50% shading. As a result of surveying the whole experiment, it is concluded that the production of P. brachycarpa seedling is more effective under 50% shading.

• The Korean Journal of Ecology
• /
• v.6 no.1
• /
• pp.55-65
• /
• 1983

The authors reared the ash-gray leaf bug, Piesma maculata in the growth cabinet controlled as temperature groups of $15, 20, 25, 30, 40^{\circ}C$under condition of photoperiod 16L:8D, light intensity $510{\pm}240$ lus, relative humidity $65{\pm}3%$, and analyzed the effects of temperature on the development of the insect. The results are summarized as follow: There are highly significant differences the developmental periods for the temperature groups, and between the developmental periods for the developmental stages. The egg in the temperature of 15 and $40^{\circ}C$ was hatched, but the ecdysis was impossible. The thermal threshold was $12.34^{\circ}C$and the upper lethal temperature $40.39^{\circ}C$. The total developmental periods of egg to adulate in the temperature of 20, 25, 30 and $35^{\circ}C$are 40.52, 22.37, 15.91 and 13.00 days, respectively. That is, the developmental period was decreased, as the temperature was increased. In the developmental period for the developmental stages, the developmental period of egg stage was longer than that of 25, 30 and $35^{\circ}C$, and that of 25。C was longer than that of $35^{\circ}C$. But ther was not significant differences between the developmental periods for the other temperature group. The rate of hatch at$20^{\circ}C$is the greater value as 90%, and the rates of 25, 30 and $35^{\circ}C$ are 79, 79 and 67%, respectively. That is the rate of hatch was decreased, as the temperature was increased. The mortality in the temperature of $35^{\circ}C$ is the greatest value as 68%, and those of 30, 25 and $20^{\circ}C$are 59, 59 and 41%, respectively. That is, the mortality was increased, as the temperature was increased. There was not significantly differences between the developmental period of female and male.

• Journal of Ginseng Research
• /
• v.23 no.1 s.53
• /
• pp.1-7
• /
• 1999

Photosynthetic rates and leaf bleaching were measured under light of far-red, red, orange, green, blue and white in order to clarify the effect of light qualities on photosynthesis in Panax species, P. ginseng and P. quinquefolium. Photosynthetic rate of P. ginseng and P. quinquifolium showed higher in the order under the light of red > orange > blue > white > green. Degree of leaf bleaching in P. quinquifolium showed severer in the order under the light of far-red > red > white > blue > orange > green. These suggest that shading material with blue or orange color is good for ginseng growth. As for the effect of temperature, the photosynthesis was increased with increasing temperature untill $25^{\circ}C$ and thereafter decreased. Therefore, it was clarified that the optimum temperature for photosynthesis of P. ginseng and P. quinquefolium was $25^{\circ}C$. And the dark respiration rate of ginseng leaf also increased with increasing air temperature. Especially, the dark respiration rate increased by $80\%$ for P. ginseng and by $73\%$ for P.quinquefolium at above $30^{\circ}C$ as compared with $25^{\circ}C$. In general, the photosynthesis rate was higher in P. quinquifolium than in P. ginseng and ranged from 3.54 to 4.04 mg $(CO_2{\cdot}dm^{-2}{\cdot}hr^{-1})$ for P. quinquefolium and from 2.08 to 2.59 mg$(CO_2{\cdot}dm^{-2}{\cdot}hr^{-1})$ for P. ginseng.