• Journal of Environmental Science International
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• v.27 no.4
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• pp.275-279
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• 2018

Water status of intact plants has been optically estimated by measuring reflectance at the wavelengths 1,450 nm and 1,900 nm based on their signal strengths. Although another water band at 970 nm is considered to have very small signals, the band apparently lies within the detection range of inexpensive spectrometer and plain charge-coupled device (CCD) camera used in wild fire studies. However measurement of the reflectance at 970 nm has been rarely applied to estimate the water status of dead plant materials such as fallen branch, twig, and leaf. To test the possibility of applying water reflectance at 970 nm to estimate the water content (WC) in leaf litter, the reflectance in various WC values were measured in the leaf litter of three Quercus species (Q aliena, Q aliena, Q mongolica, and Quercus variabilis). The results showed that the WC in the leaf litter can be determined by reflectance water index (WI) in the three Quercus species ($WC=1,450{\times}WI-1,378.8$, r=0.865). However, there was no interaction effect in the relationship between WI and WC among the litter of the three Quercus species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.214-219
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• 1991

To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.76-79
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• 1981

This thesis emphasize on diurnal changes of leaf water potential in relation to differences of cutting arrangement. 1. The more is leaves attached to the cutting, the higher is water stress in the cutting compared with less leaves. 2. The less is diameter of cut-part, the more are shown changes in increased and decrease in diurnal leaf water potential. 3. The more is length of stem, the more are shown water stress in diurnal leaf water potential 4. There is no differences between earthen-ball cutting and non-earthen ball cutting in diurnal leaf water potential. 5. Cuttings with two year's slip, compared with one year's leaf water potential increases slowly, dry weigh of root and numbers of rooted cutting are most likely dependent upon other factors rather than the water stress.

• The Korean Journal of Ecology
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• v.13 no.1
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• pp.59-66
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• 1990

Changes in water potential, lethal temperature and carbohydrate content in the leaves of wintergreen (Pyrola japonica) during overwintering were investigated. Leaf water potential was kept at -2 bars in the tender stage before October, decreased to -46 bars in the dormancy stage and increased to -2 bars again after dehardening Lethal temperatures of the leaf tissue were $-7^{\circ}C$ in the tender stage and $-7^{\circ}C$ in the dormancy stage, but did not recover up to that of the tender stage during dehardeding. Peak of soluble sugar content coincided with the nadir of the leaf water potential. There were close relationships among daily minimum air-temperature, leaf water potential and lethal temperature in changing patterns during overwintering.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.367-372
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• 2022

Leaf spot symptoms were observed in water spinach (Ipomoea aquatica) plants growing in fields in Ansan and Hongseong, Korea, during disease surveys in 2019 and 2020. The symptoms appeared as brown to dark brown circular or irregular spots on the leaves of the plants. The disease incidence on the plant leaves in the fields investigated at the two locations ranged from 1% to 20%. Five single-spore isolates of Phoma sp. Were obtained from lesions of the diseased leaves. All the isolates were identified as Ectophoma multirostrata based on their cultural and morphological characteristics, as well as molecular analysis. Two isolates of E. multirostrata were tested for pathogenicity on water spinach leaves using artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants. These symptoms were similar to those observed in plants from the investigated fields. To our knowledge, this is the first report of E. multirostrata causing leaf spot in water spinach.

• Journal of Life Science
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• v.8 no.5
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• pp.557-562
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• 1998

This study was conducted to investigate the influence of soil moisture on the photosynthetic rate, transpiration rate, stomatal conductance, leaf water content and its any correlation in soybean. Followings were achieved as a conclusion. At the soil moisture was moved from drought condition to saturation condition, the photosynthetic rate, transpiration rate, stomatal conductance and leaf water content were gradually increased on the period of re-watering treatment. The recovery of photosynthetic rate was faster than others. There were positive correlation with the photosynthetic rate and leaf water content, the stomatal conductance and leaf water content, the photosynthetic rate and stomatal conductance respectively, but the correlation coefficient of photosynthetic rate and leaf water content was high.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.43-47
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• 2000

In vitro cytotoxicity and antioxidative effects of water extracts prepared from Mustard Leaf Kimchi (MLK) during its fermentation period were investigated. The cytotoxicity against HepG2 (human hepatic cancer) by water extracts from the well fermented Mustard Leaf Kimchi was higher than others (fermented for 0 to 6 days at 18$^{\circ}C$), and IC50 of water extracts at the points of 6, 8, 10, and 14days during fermentation were 213.4, 99.2, 99.9, and 109.8${\mu}{\textrm}{m}$/ml, respectively. Antioxidative activity of water extracts from MLK during various fermentation periods was higher than that of blank distilled water. However, the antioxidative activity of well-fermented water extracts of MLK (fermented for 8-14 days) did not show any difference from that of others (fermented for 2-6 days). Thus, water extracts of well-fermented MLK (fermented during 8-14 days) significantly inhibited the growth of cancer cells in vitro, but little antioxidative activity was influenced by the various fermentation periods.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.307-314
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• 1998

The response of water stree under high and low temperatures, was shown differently according to the longer the suspension period of water supply. Leaf photosynthetic rate(LPS), leaf water potential(WP), relative leaf water content and relative soil water content were lower. At the higher temperatures, the percentate of reduction in LPS and WP was greater than at low temperatures. It is suggested that evaporation rate should be higher in the high temperature than the lower temperature. Also leaf water potential was lower at high temperature than at low temperature. After the 9 th day of treatment , LSP was remarkably reduced at high temperature, but the reduction of LPS was not significant at low temperature. Solidago virga-aurea var. asiatic that maintained LPS of 3rd day after treatment was more strong than other varieties at low temperatures. The silting and curling of leaves were observed symptoms of stress on the 9th day at the both temperatures. The leaves of aster scaber and Ligularia fischeri turned red on the 9th day after treatment at low temperature.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.17-22
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• 1998

To investigate the detoxificative effect of tea, five kinds of tea(mulberry, anaerobic treated mulberry, green, barly tea and corm tea) were selected and determined their dotoxication activities for Cd and Pb in drinking water. The effect of tea on the removal of Cd and Pb were increased proportionally to the contents of teas. Anaerobic treated mulberry leaf tea showed stronger detoxication activity than the others. In drinking water contaminated with Cd, the removal effect of Cd was high 27% by anaerobic treated mulberry leaf tea and 14% by mulberry leaf tea as compared to green tea. Also, in drinking water with Pb, the removal effect of anaerobic treated mulberry leaf tea was the best among five kinds of tea. Pretreatment method on the removal effect of Cd was better than post-treatment method in the treatment method.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.103-112
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• 2001

The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.