• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.411-417
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• 2017

Environmental and growth factors such as light intensity, vapor pressure deficit, and leaf area index are important variables that can change the transpiration rate of plants. The objective of this study was to compare the transpiration rates estimated by modified Penman-Monteith model and artificial neural network. The transpiration rate of paprika (Capsicum annuum L. cv. Fiesta) was obtained by using the change in substrate weight measured by load cells. Radiation, temperature, relative humidity, and substrate weight were collected every min for 2 months. Since the transpiration rate cannot be accurately estimated with linear equations, a modified Penman-Monteith equation using compensated radiation (Shin et al., 2014) was used. On the other hand, ANN was applied to estimating the transpiration rate. For this purpose, an ANN composed of an input layer using radiation, temperature, relative humidity, leaf area index, and time as input factors and five hidden layers was constructed. The number of perceptons in each hidden layer was 512, which showed the highest accuracy. As a result of validation, $R^2$ values of the modified model and ANN were 0.82 and 0.94, respectively. Therefore, it is concluded that the ANN can estimate the transpiration rate more accurately than the modified model and can be applied to the efficient irrigation strategy in soilless cultures.

• Food Science and Preservation
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• v.1 no.1
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• pp.37-43
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• 1994

A microcomputer system consisting of 16-bit microcomputer, PCL-711S interface board, censors, and converters have been set up in order to automatically measure temperature, humidity and weight loss which are major variables of storage of apple. This system was operated by PC-LabDAS software. It has been possible to measure continuously the weight loss of Fuji apple stored in CA with the weight converter made by a miniature load cell and a strain amplifier. The temperature was checked by a k-type thermocouple and Pt 100 $\Omega$ RTD, and humidity by PQ653JAl humidity sensor. It has been possible to set up a linear equation which showers high correlationship between the estimate of temperature, weight humidity and the output of the converter in that r2 is more than 0.99. Transpiration rate, a significant factor of quality deterioration for CA storage of apple, can be estimated with these values.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.303-309
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• 2006

The study examined the effects of $CO_2$ enrichment on growth of soybean (Glycine max). Two soybean varieties were used, Taekwang and Cheongja. The plants were grown in growth chambers with a 12-h photoperiod and a day/night temperature of $28/21^{\circ}C$ at the seedling stage and $30/23^{\circ}C$ from the flowering stage. The plants were exposed to the two elevated $CO_2$ levels of 500 and 700 ppm and the ambient level of 350 ppm. Results of the experiment showed that at the second-node trifoliate stage of the two varieties, the elevated $CO_2$ increased plant height, leaf area and dry weight. The elevated $CO_2$ also raised the photosynthetic rate of soybean as compared to the ambient level. From the beginning bloom stage to the full maturity stage of the two varieties, the elevated $CO_2$ increased plant height, leaf area, seed weight and photosynthetic rate. The stomatal conductance and transpiration rate decreased on long days relative to short days of treatment. Through the entire stages, the elevated $CO_2$ increased the water use efficiency of soybean plants because stomatal conductance and transpiration rate decreased at the elevated $CO_2$ levels relative to the ambient level.

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.305-313
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• 2019

Background: This research aims to study the effect of climate change on the phenology, growth, and physiological traits of Silene capitata Kom., a Korean endangered species II. This study increased $CO_2$ concentration in a closed glass greenhouse, with the daily mean temperature and $CO_2$ concentration respectively being $4.61^{\circ}C$ and 93.63 ppm higher than the outside temperature (ambient conditions, control). The seeds of S. capitata were sown in control and treatment environments in March 2013 while seedlings were transplanted into individual pots in May 2013. To research phenological changes, the first day of the flowering and ripening of the plants transplanted in 2013 and first day of leafing in 2014 were observed. The growth and physiological responses of mature leaves were also studied in 2013. Results: There was no difference in the first day of flowering, but the first day of ripening was earlier in the treatment group than the control group. There was no difference in the number of rosette leaves between the two groups, but leaf area was wider in the treatment group than the control group. Transpiration rate and stomatal conductance were higher in the treatment group than the control group, chlorophyll content decreased, and photosynthetic rate and water use efficiency were the same for both groups. As a result of simple regression analysis among the transpiration rate, stomatal conductance, photosynthetic rate, and water use efficiency, stomatal conductance increased when transpiration rate increased. Stomatal conductance increased with photosynthetic rate in the control unlike in the treatment group. The photosynthetic rate and water use efficiency increased with transpiration rate in the control group unlike in the treatment group. Furthermore, water use efficiency increased as photosynthetic rate increased in both groups. Conclusion: Due to high $CO_2$ concentration, the photosynthetic rate was no longer controlled by the stomata, which appeared to suppress the excessive production of photosynthetic products by reducing chlorophyll content. It is believed that the phenological responses of S. capitata under climate change conditions will advance and that stable growth will be difficult in regions lacking moisture due to the high transpiration rate.

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.276-284
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• 2007

To investigate the influence of shading materials with growing stages in Panax Ginseng C. A. Meyer, the diurnal change of photosynthesis, stomatal conductance, transpiration and its any correlation were measured. The net photosynthetic rate and stomatal conductance of ginseng were higher in the morning than in the broad day. The net photosynthetic rate was increased as the PAR (Photosynthetically Action Radiation) was increased and it was reached the maximum at the $200\;{\mu}mol/m^2/s$ of PAR in overall leaves. Transpiration rate was increased in the afternoon compared to in the morning. The transpiration rate was higher in rain shelter shading plate than in polyethylene net. A linear equation was obtained between net photosynthetic rate and stomatal conductance in the morning. SPAD was higher in rain shelter shading plate than in polyethylene net through all growth stages. It may result from the decrease of growth progress. From investigating photosynthetic characteristics, we concluded that shading plate of rain shelter was more an efficient material to ginseng growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.209-214
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• 2001

Physiological responses of rice to the flooding time of different water turbidity (clear water, sub-muddy water, muddy water) were analyzed as photosynthesis, chlorophyll fluorescence, transpiration, and physiological recovery. Photosynthetic rate was higher as turbidity increased and decreased as flooding time was extended. Floodings of 36 hrs and 42 hrs were resulted in 25% and 50% decrease of photosynthetic rate, respectively. Transpiration rate was higher in high turbidity (increased 30%, 25%, and 20% in clear, sub-muddy, and muddy water, respectively) and in increased floodings. Fv/Fm decreased as increased turbidity and flooding time. About 20% decrease of Fv/Fm was recorded in 48 hrs and 36 hrs after flooding with clear water and sub-muddy water(including muddy water), respectively. Total nitrogen was decreased with flooding treatment. Significant decrease of total nitrogen was occurred 36 hrs after flooding with muddy water, Dry weight measured 2 weeks after flooding treatment as an indication of recovery of flooding stress didn't show significant difference with turbidity, but significantly decreased as flooding time was prolonged. About 25% and 50% decreases were found in 24 hrs and 42 hrs flooding time, respectively. furthermore, 48 hrs of flooding with sub-muddy and muddy water resulted in no physiological recovery. Photosynthetic rate was decreased 15% and 10% with clear water and muddy water(including sub-muddy water), respectively. The rate was dramatically decreased 42 hrs after flooding. Transpiration rate increased about 20% regardless of turbidity and flooding time. We found transitory decrease of photosynthetic and transpiration rate at the point of 24 hrs after flooding and right after do-flooding.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.33-43
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• 2016

Drought tolerant species from 26 Korean native plants were selected using different physiological indicators. Arundinella hirta, Solanum carolinense and Carpesium divaricatum were withered after 8days of the stopping of irrigation. Plants except Kummerowia striata, Lespedeza cuneata and Ulmus parvifolia were withered in over 80% at 9-10days of the irrigation stopping. K. striata was withered after 10days, and L. cuneata and U. parvifolia were withered in over 90% after 11days of the stopping of irrigation. As stopping experiment of irrigation, A. hirta, S. carolinense, C. divaricatum, K. striata, L. cuneata and U. parvifolia were proved to be drought tolerant species. Among those plant species, transpiration rate of Cassia mimosoides var. nomame Makino was high as 0.042ml/㎠·4hr. However, unit transpiration rate of U. parvifolia and L. cuneata were 0.005 and 0.010ml/㎠·4hr, respectively. In testing of physiological indicators, leaf area and transpiration rate were different among plant species. Unit transpiration rate of U. parvifolia was lower compared with other plant species. L. cuneata, U. parvifolia, Kummerowia striata, Arundinella hirta and C. divaricatum were high in relative water content and low in relative water loss. As this results, L. cuneata and U. parvifolia. were identified as drought tolerant species.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1097-1101
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• 2023

As paprika plants grew in a glass greenhouse from November 2022 to March 2023, the amount of light at each plant height, leaf temperature, transpiration rate, and water vapor pressure were measured. Accumulated leaf temperature was higher at the top of the plant than at the bottom. Over time, the leaf temperature measured around 11-13 AM changed from 26.55→23.21→22.80→26.67℃ in the lower part (pL), and from 26.52→24.48→24.55→27.78℃ in the upper part (pAs). And VPD changed from 1.45→0.94→0.74→1.46kPa in pL and from 1.11→0.86→0.71→1.28kPa in pAs. Accordingly, the transpiration rate changed from 4.25→0.17→4.08→0.52mmol·m^-2·s^-1 in pL, 7.61→2.45→1.94→4.39→0.52mmol·m^-2·s^-1 in pAs, and from pAs to pL. It was significantly higher than The difference between the lower and upper parts (pL-pAs) was higher in pAs than pL in leaf temperature, light intensity, and transpiration rate, but the water vapor pressure difference was higher in pL. In this way, paprika shows differences in the environment and photosynthetic factors between the upper and lower parts during the cultivation period, so it is judged that this needs to be taken into consideration in future research.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.51-54
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• 1986

The good growth of Populus alba ${\times}$ P. glandulosa is shown at the foothill of the mountain where good soil moisture is available, but its growth is poor at the upper part of the mountain where soil moisture is limitted. Stomatal frequency, stomatal size and transpiration rates that affect soil moisture demand were determined in order to know how this character is inherited from its parents. Number of stomata per $mm^2$, length and width of stomata from the abaxial leaf and transpiration rate ($g/cm^2$) per day in P. alba ${\times}$ P. glandulosa showed intermediate values between those of their parents, while P. alba showed the highest values and P. davidiana the lowest values. The values of stomatal frequency of P. alba ${\times}$ P. glandulosa were close to the expected mean values of parents in the $x^2$ test, and in the regression analysis the transpiration rates for the hybrid and its midparent had strong relationship with 0.97 of regression coefficient. The fact that these intermediate characteristics were observed in the hybrid suggests incomplete dominance in the hybrid. It is concluded that soil moisture demand in P. alba ${\times}$ P. glandulosa and its parents is closed related to stomatal frequency, stomatal size and transpiration rate.