Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2525/ecb.62.29

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1541/ieejsmas.144.50

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/access.2024.3469784

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.3130/aije.89.479

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.17660/actahortic.2023.1377.8

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1109/SENSORS56945.2023.10325303

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Other Link： https://dblp.uni-trier.de/db/conf/ieeesensors/ieeesensors2023.html#MatsushitaYDCTTSN23

Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11450/seitaikogaku.35.59

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：International Society for Horticultural Science (ISHS)  

DOI： 10.17660/actahortic.2023.1364.1

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A system was developed for measuring the time course of photosynthesis and transpiration. The system was applied to ornamental plants in an office under different root environmental conditions: soil and non-soil aerations. This system composes an automated-closed chamber and a sensing unit. The shoot part of a fully grown ornamental plant enclosed by a transparent film in the chamber. Two circulation fans are installed at the center of the chamber to continuously stir the air. One ventilation fan located at the bottom of the chamber to exhaust air and create an upward airflow in the chamber. When the ventilation fan is turned off, the chamber becomes a closed space. The changes in the concentrations of CO2 and H2O during the period over which the chamber is closed are used to calculate the photosynthesis and transpiration rates of the plant. Two types of ornamental indoor plants were observed under the aforementioned root conditions. Soil aeration was found to produce an increase in the photosynthetic rate, transpiration rate, and total conductance. These results indicate that the measuring system could be a particularly helpful tool for evaluating temporal changes in the photosynthesis and transpiration of ornamental plants in an indoor environment.

DOI： 10.1088/1755-1315/1268/1/012014

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers (IEEE)  

DOI： 10.1109/access.2023.3252003

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s12562-022-01657-3

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Other Link： https://link.springer.com/article/10.1007/s12562-022-01657-3/fulltext.html

Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1016/j.ifacol.2022.11.124

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2525/ecb.60.143

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

Abstract

In this study, we proposed a miniaturized system that can detect chlorophyll content and its a/b ratio simultaneously to measure the health condition of plants. In order to solve the problems of general measurement systems such as large-scale equipment and fracture measurement, a filter-free multiple wavelength sensor was used to evaluate the current ratio due to wavelength changes. Current characteristics demonstrated that the sensor due to the chlorophyll a/b ratio and changes in their concentrations are proportional to the spectral characteristics. As a result of measuring the extracted chlorophyll of plants and leaves, the centroid wavelength value of the transmission spectrum showed linear data from the current ratio of the sensor. The proposed method enabled simultaneous measurement of the chlorophyll content and its a/b ratio of plants with a non-destructive and compact device and is expected to be applied to the agricultural field.

DOI： 10.35848/1347-4065/ac6387

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Other Link： https://iopscience.iop.org/article/10.35848/1347-4065/ac6387/pdf

Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

DOI： 10.2525/ecb.60.13

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.rsma.2021.101957

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：International Society for Horticultural Science (ISHS)  

The application of phosphorus fertilizers in liquid form has been developed in recent years to produce high yields of tomatoes. The liquid form easily penetrates to growing substrate and fasten the access of nutrients into plant, but it is considered as a major source of eutrophication when running off into water environment. Therefore, efficient use of phosphorus fertilizer is important for cost benefit as well as minimizing environmental risks. For this reason, we have been conducting an investigation at large scale (3.5 ha) tomato production greenhouse (Inochio Farm, Japan) to clarify the adequate dosage of phosphorus fertilizer for tomato growth. Tomatoes were graftage of two popular fruity species in Japanese commercial farms, cultivated in soilless growing media filled with coconut coir, and connected with a supply system of water and nutrient solutions. The proportion of phosphorus fertilizer in nutrient solution was gradually reduced by 10, 20 and 30% while the growth parameters including photosynthesis and transpiration at canopy level, number of leaves, leaf area index, contents of chlorophyll were carefully being monitored. The results showed well monitoring of the photosynthetic rate and transpiration of tomato at canopy level. There was not adverse effect on tomato even when the phosphorus content in fertilizer solution was remarkably reduced by 30%. However, the values of chlorophyll tended to decrease as lack of nutrient. The leaf area decreased while the number of leaves increased. The research is in progress but the results implied promising prospects to reduce phosphorus fertilizer dosage in tomato commercial greenhouse.

File： 2021_Nguyen et al_ActaHortic.pdf

DOI： 10.17660/actahortic.2021.1317.12

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/transducers50396.2021.9495450

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.11450/seitaikogaku.33.39

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

DOI： 10.1088/1755-1315/686/1/012044

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Other Link： https://iopscience.iop.org/article/10.1088/1755-1315/686/1/012044/pdf

Language：Japanese   Publisher：The Japan Society of Applied Physics  

DOI： 10.11470/jsapmeeting.2021.1.0_2228

CiNii Research

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Language：Japanese   Publisher：The Japan Society of Applied Physics  

DOI： 10.11470/jsapmeeting.2021.1.0_2237

CiNii Research

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP Publishing  

DOI： 10.1088/1755-1315/623/1/012095

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Other Link： https://iopscience.iop.org/article/10.1088/1755-1315/623/1/012095

Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Society of Agricultural Meteorology of Japan  

DOI： 10.2480/agrmet.d-21-00029

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Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC ECO-ENGINEERING, ENV SCI & TECH, GRAD SCH LIFE & ENV SCI  

The Speaking Plant Approach (SPA) is regarded as a desirable concept which defines that the environmental factors should be adjusted to the crop's physiological status. The first and most important step in the SPA concept is to obtain physiological information from a living plant. Especially for environmental control in highly sophisticated greenhouse, daily measurement of plant growth must be indispensable in SPA concept. In our previous study, a robotized chlorophyll fluorescence (CF) imaging system that evaluates daily changes in photosynthetic function of tomato canopy has been developed and came onto the market in 2015. In this study, we applied the robotized CF imaging system to measure the daily stem elongation of tomato plants grown in greenhouse. CF images of shoot apex of tomato plants were taken by using the robotized CF imaging system and detected the shoot apex manually by using commercially available image analysis software to obtain the average plant height. Then, the daily stem elongation was calculated by subtracting the average plant height of one day before from that of the day. The performance verification test proved that the spatial resolution of CF image was 1.6 mm pixel(-1) and the reproducibility of average height measurement was within 0.01 %. And, a long-term stem elongation monitoring for consecutive 70 days, which was done with the conventional weekly stem elongation monitoring by using a measuring tape, suggested that daily stem elongation is able to be monitored with the robotized CF imaging system.

DOI： 10.11450/seitaikogaku.32.15

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC ECO-ENGINEERING, ENV SCI & TECH, GRAD SCH LIFE & ENV SCI  

As a highly sophisticated strategy for environmental control in greenhouses, the concept of speaking plant approach (SPA) has attracted a great deal of attention. Sensor-based plant diagnosis techniques to monitor plant physiological status are the first and most important step in SPA. Currently, imaging systems for plant growth monitoring are especially required in wide range of agricultural production not only in advanced greenhouses but also in traditional vinyl houses. In this study, we developed a compact- and lightweight-multiple imaging system that is consist of an infrared camera filtered with a long-pass filter (lambda > 620 nm), a color camera, and blue/red/infrared/white LEDs. The developed imaging system enable us to conduct chlorophyll fluorescence imaging, NDVI imaging, and color imaging at the same time. We applied the system for imaging of tomato plant grown under greenhouse condition and successfully obtained an obvious chlorophyll fluorescence induction curve derived from a series of chlorophyll fluorescence images and NDVI and color images that are useful to identify the matured tomato fruits.

DOI： 10.11450/seitaikogaku.32.33

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Language：English   Publishing type：Research paper (scientific journal)  

© 2019 Elsevier Ltd The effects of ecologically relevant concentrations of Irgarol 1051, a representative PSII herbicide, on hermatypic corals were studied in the laboratory. The colour and chlorophyll fluorescence of Acropora tenuis were examined following exposure to around ambient concentrations of Irgarol 1051 (20 ng/L and 200 ng/L) for 7 days. While the colour of corals was stable throughout the experiment at both concentrations, the maximum effective quantum yield (ΔF/Fm′) of symbiotic dinoflagellates decreased with increasing Irgarol 1051 concentration (day 7: 8%, 20 ng/L; 37%, 200 ng/L). The expression of heat shock protein (HSP) 70 and 90 in symbiotic dinoflagellates was upregulated after 7 days exposure to both Irgarol concentrations, whereas HSP90 in coral was not upregulated. The findings of the present study suggest that the threshold of chlorophyll fluorescence and HSP expression in symbiotic dinoflagellates is lower than 20 ng/L, which is around ecologically relevant concentrations in tropical to subtropical waters.

DOI： 10.1016/j.marpolbul.2019.110734

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Insight Society  

High-quality fruits can be produced by controlling the environmental factors, i.e. temperature, relative humidity, carbon dioxide, and light intensity. The tomato (Solanum lycopersicum) variety ‘Rinka 409', was grown hydroponically with a high-wire system in high technology greenhouse, Ehime University, Japan. The water stress treatment using visual monitoring system was used to produce the high soluble solids tomato fruits. Moreover, a high lycopene content of tomato can be produced by controlling the storage condition. Non-destructive measurement has been known to provide a fast and accurate quality measurement of fruits and vegetables. The objectives of this study were to develop a precise position for the non-destructive measurement of the lycopene content in high soluble solids stored tomato using Vis/NIR spectroscopy and evaluate its performance. In this study, the high soluble solids of tomato fruits were grown under water stress treatment and stored after harvesting at 25°C in a cool incubator for 7 days. The tomato spectra were measured using Vis/NIR spectroscopy with the wavelength 500-1010 nm. The estimation of the lycopene content was based on the statistical model using multivariate analysis. From this study, it is concluded that the measurement of lycopene content in high soluble solids of tomato fruits after storage by using the top part of the tomato, was better than if it is compared to the side part. It was best determined using PLS analysis with Visible/Near-infrared Spectroscopy non-destructively, with the R 0.98 and RMSE 0.80.

DOI： 10.18517/ijaseit.10.6.9478

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

© 2019 The Authors The circadian rhythm varies among species, and the distribution of common circadian rhythm-related genes in plants is not yet clearly understood. In this study, we analyzed the transcriptome data from plants of three different species (Solanum lycopersicum, Arabidopsis thaliana, and Lactuca sativa) and their circadian rhythms. Homology of the gene sequences was analyzed. Thirty genes containing time information were found to be common among the three species studied and were used to measure the circadian rhythm. Because 22 of these 30 genes were associated with photosynthesis, we suggest that light control could be used to regulate the circadian rhythm. Currently, a high-cost transcriptome analysis is required for the measurement of circadian rhythm; however, our results showed that it was possible to reduce the number of target genes to 30 and, hence, to reduce the cost of the analysis. Our findings will enable easier estimation of circadian time, which, in turn, will facilitate environmental control for plant growth through better control of circadian time, thus facilitating better crop management practice.

DOI： 10.1016/j.cpb.2019.100118

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Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

DOI： 10.2525/ecb.56.127

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Society of Eco-Engineering  

 To increase the annual yield of greenhouses, CO₂enrichment has been increasing in popularity in Japan. For appropriate use of the instrumentation, scientific knowledge of the environmental response of canopy photosynthesis is required. However, a lack of such knowledge by growers and instructors, e.g. agricultural extension workers and farming instructors, has resulted in scientifically inappropriate usage of such instrumentation in commercial greenhouses. To solve this problem, an adequate learning tool for growers and instructors to obtain enough knowledge of the environmental response of canopy photosynthesis is required. In this study, we developed an MS Excel based annual yield estimation tool for greenhouse tomato production. This tool is composed of 10 spreadsheets. Each spreadsheet has a particular function; an equation for leaf area estimation (Sheet 1), a model for vertical leaf area distribution (Sheet 2), a model for vertical light distribution (Sheet 3), a model for photosynthetic light (and CO₂) response of leaves (Sheet 4), a model for dry matter distribution within a plant body (Sheet 5), specifics of greenhouse structure and parameter settings for greenhouse environmental control (Sheet 6), data on solar radiation and air temperature at intervals of 1 hour (Sheet 7), estimation of total photosynthesis of tomato canopy without CO₂ enrichment (Sheet 8), estimation of total photosynthesis of tomato canopy with CO₂ enrichment (Sheet 9), and estimation of expected annual tomato yield (Sheet 10). By using the developed tool, we investigated the effect of CO₂ enrichment in a greenhouse located in Matsuyama City (Ehime Prefecture, Japan) and demonstrated that CO₂ enrichment at 8.0 kg 10 a ^-1h^-1 increased the annual tomato yield at 38.9% but further CO₂ enrichment above 10 kg 10 a ^-1h^-1 was not effective to improve annual tomato yield.

DOI： 10.11450/seitaikogaku.30.47

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2525/ecb.56.157

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Colour change in Acropora tenuis, a representative species of Indo-Pacific hard coral, in response to low concentrations of Irgarol 1051 was examined in the laboratory. Branches of A. tenuis were exposed to 0, 1, and 10 mu g Irgaro11051/L for 14 days, and photographed daily using digital camera. These Irgarol 1051 concentrations were similar to those recorded at a number of sea ports. Red, green and blue (RGB) coral colour values were quantified from the photographs, with black represented by R = G = B = 0 and white as R = G = B = 255. Exposure to Irgarol 1051 caused RGB values to increase, moving towards the 'white' end of the spectrum as Irgarol 1051 concentration increased. These results suggest that the ambient levels of Irgarol 1051 recorded from port environments could be implicated in coral bleaching, if concentrations over nearby reef ecosystems are similar.

DOI： 10.1016/j.marpolbul.2017.05.027

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Society of Eco-Engineering  

<p>&ensp;&ensp;To achieve higher production in greenhouses, maximization of crop net photosynthesis is required; hence, CO₂ enrichment and supplemental lighting equipment has been installed in many commercial greenhouses. In practice, appropriate profitability analysis should be performed before such installations. Crop growth and yield simulation models based on the environmental response of leaf photosynthesis are useful to evaluate the increase in profitability derived from the new equipment. Therefore, accurate and compatible data on the environmental response of leaf photosynthesis are necessary. In this study, we proposed a general protocol for the measurement of leaf photosynthesis environmental response, i.e., light response curve and CO₂ response curve, that can be widely applied to the crops grown in greenhouses. Furthermore, the effects of stomatal opening/closure and phosphate limitation on the photosynthesis of tomato leaves through the proposed measurement protocol were investigated. The results demonstrated that the effects of stomatal opening/closure on the photosynthetic rate during light response curve measurement are small, particularly under high CO₂ concentrations; however, the stomata tended to be closed when the measurement was performed on a cloudy day. Moreover, in the measurement of CO₂ response curve, the stomatal response to CO₂ concentration differs depending on PPFDs, i.e., stomata tended to close under high CO₂ concentrations (> 400 μmol mol^-1) at a PPFD of 500 μmol m^-2s^-1, but not at PPFDs of 1000 and 1500 μmol m^-2s^-1. Furthermore, a slight but significant decrease in photosynthetic rate, which might be caused by phosphate limitation, was observed at high PPFD and high CO₂ concentration.</p>

DOI： 10.11450/seitaikogaku.29.73

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Language：English   Publisher：WILEY  

DOI： 10.1111/pbi.12546

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

DOI： 10.1371/journal.pone.0150788

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PubMed

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Language：Japanese   Publisher：Japan Science Support Foundation  

DOI： 10.5363/tits.21.10_94

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Society of Eco-Engineering  

Effects of low nighttime air temperature (LNT) and high electrical conductivity (HEC) of a nutrient solution on the growth and yield of sweet pepper (Capsicum annuum L.) were investigated during winter (Oct 25, 2014 to Feb 28, 2015) in an experimental Venlo-type greenhouse in Kochi Prefecture. A "pre-night temperature drop," which is a quick drop in the air temperature early in the nighttime, is often used in large-scale greenhouses. In this study, the length of the pre-night temperature drop was extended from 3 h (control) to 9 h (LNT), and the electrical conductivity of the nutrient solution supplied to the plants was increased from 2–3 dS m-1 (control) to 3–4 dS m-1 (HEC). The effects of LNT and HEC on the growth of sweet pepper differed between the periods before and after the winter solstice. Before the winter solstice, LNT significantly reduced the rates of stem elongation and node formation by 34% and 32%, respectively, whereas after the winter solstice, HEC became the key factor influencing the reduction in the rate of stem elongation, but neither LNT nor HEC affected the rate of node formation. Neither LNT nor HEC affected the leaf photosynthetic ability, or the number or dry weight of fruits, but HEC did reduce the total yield by inhibiting leaf expansion and fruit enlargement.

DOI： 10.11450/seitaikogaku.28.29

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Other Link： https://jlc.jst.go.jp/DN/JLC/20022476843?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PUBLIC LIBRARY SCIENCE  

In plant factories, measurements of plant conditions are necessary at an early stage of growth to predict harvest times of high value-added crops. Moreover, harvest qualities depend largely on environmental stresses that elicit plant hormone responses. However, the complexities of plant hormone networks have not been characterized under nonstress conditions. In the present study, we determined temporal expression profiles of all genes and then focused on plant hormone pathways using RNA-Seq analyses of gene expression in tomato leaves every 2 h for 48 h. In these experiments, temporally expressed genes were found in the hormone synthesis pathways for salicylic acid, abscisic acid, ethylene, and jasmonic acid. The timing of CAB expression 1 (TOC1) and abscisic acid insensitive 1 (ABA1) and open stomata 1 (OST1) control gating stomata. In this study, compare with tomato and Arabidopsis thaliana, expression patterns of TOC1 have similarity. In contrast, expression patterns of tomato ABI1 and OST1 had expression peak at different time. These findings suggest that the regulation of gating stomata does not depend predominantly on TOC1 and significantly reflects the extracellular environment. The present data provide new insights into relationships between temporally expressed plant hormone-related genes and clock genes under normal sunlight conditions.

DOI： 10.1371/journal.pone.0143412

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

Heme activator protein (HAP), also known as nuclear factor Y or CCAAT binding factor (HAP/NF-Y/CBF), has important functions in regulating plant growth, development and stress responses. The expression of rice HAP gene (OsHAP2E) was induced by probenazole (PBZ), a chemical inducer of disease resistance. To characterize the gene, the chimeric gene (OsHAP2E::GUS) engineered to carry the structural gene encoding -glucuronidase (GUS) driven by the promoter from OsHAP2E was introduced into rice. The transgenic lines of OsHAP2Ein::GUS with the intron showed high GUS activity in the wounds and surrounding tissues. When treated by salicylic acid (SA), isonicotinic acid (INA), abscisic acid (ABA) and hydrogen peroxide (H2O2), the lines showed GUS activity exclusively in vascular tissues and mesophyll cells. This activity was enhanced after inoculation with Magnaporthe oryzae or Xanthomonas oryzae pv. oryzae. The OsHAP2E expression level was also induced after inoculation of rice with M. oryzae and X. oryzae pv. oryzae and after treatment with SA, INA, ABA and H2O2, respectively. We further produced transgenic rice overexpressing OsHAP2E. These lines conferred resistance to M. oryzae or X. oryzae pv. oryzae and to salinity and drought. Furthermore, they showed a higher photosynthetic rate and an increased number of tillers. Microarray analysis showed up-regulation of defence-related genes. These results suggest that this gene could contribute to conferring biotic and abiotic resistances and increasing photosynthesis and tiller numbers.

DOI： 10.1111/pbi.12239

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Society of Eco-Engineering  

The effects of low long-term vapor pressure deficit (VPD) conditions on leaf morphology, photosynthetic functions, and yield of sweet pepper (<i>Capsicum annuum</i> L.) grown in a Venlo-type greenhouse were investigated. The relative humidity in a greenhouse with a fogging system (Fog) was maintained at >70%, which was approximately 10% higher than that in a greenhouse without a fogging system (Control). In Fog, VPD was approximately 0.7 kPa during daytime throughout the experimental period (September 20, 2013 to January 31, 2014). In the low VPD condition, the water uptake decreased by 18% and the leaf area increased by 6% (upper leaf) to 20% (lower leaf). The maximum photosynthetic rate, total chlorophyll (Chl) content, and Chl <i>a</i>/<i>b</i> ratio of the lower leaves in Fog decreased compared with those in Control. These results suggested that the low water uptake in Fog because of the lower VPD probably decreased the nutrient uptake and resulted in the low total Chl content of the leaves. In addition, the lower VPD in Fog may have allowed leaf expansion and resulted in a higher leaf area index and acclimation of the lower leaves to the low light condition. However, there was no obvious difference in the yields between Fog and Control.

DOI： 10.11450/seitaikogaku.27.91

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：INT SOC HORTICULTURAL SCIENCE  

Tomato fruit color is the most important marketing factor that is often used for the purchase decision of customer. Since tomato fruit color is varied with the harvesting time and the ripening in tomato fruit is affected by storage temperature, it is difficult to achieve an even tomato color at the shipping time. In this study, the effects of storage duration and temperatures on the tomato fruit color change and quality with different maturity stages were investigated. In addition, tomato fruit color change at different maturity stages after storage was estimated using a multiple regression analysis. Tomatoes were grown hydroponically in greenhouse. Tomato fruit samples with pink to red were stored in cool incubator for 48 h. The storage temperature was adjusted at 10, 15, 20, 25, and 30 degrees C, respectively. The maturity stage of tomato fruit was evaluated with chromaticity using image analysis. Our results showed that increase in tomato fruit color was the highest for pink tomato fruit stored at 25 degrees C. Sweetness, acidity, firmness, and fresh weight of tomato fruit were slightly decreased after storage. Actually, in some cases (25 degrees C, maturity stage 10), sweetness was increased after storage. Tomato fruit color change after storage was estimated with variables of tomato fruit color before storage, storage duration and temperatures by multiple regression (R-2=0.88). Our results suggested that tomato fruit color estimation technique can be contributed to control the tomato fruit color with storage.

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Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：INT SOC HORTICULTURAL SCIENCE  

The Speaking Plant Approach (SPA) is regarded as a desirable and indispensable concept for environmental control in highly sophisticated greenhouses. The SPA is based on the paradigm that the optimization of crop cultivation conditions should be based on measurements of the plant physiological status. The weekly monitoring of stem diameter and stem elongation rate is the most traditional and fundamental SPA in year-round tomato production. In general, the stem diameter and stem elongation rate of the specified 6-10 plants selected from 25,000-75,000 plants grown in 1-2 ha cultivation area are measured. Based on these values, growers judge whether or not the plant's growth is balanced. However, the distributions of stem diameter and stem elongation rate in a commercial large-scale greenhouse have never discussed. In this study, the stem diameter and stem elongation rate of more than 1,000 tomato plants selected from 30,000 plants in a 1.3 ha cultivation area were measured and the distribution of these parameters across the cultivation area was investigated. The maps of stem diameter and stem elongation rate revealed that the plant with a thick stem showed a shorter stem elongation. Furthermore, an additional investigation of night air temperature distribution demonstrated that the plants with thicker and shorter stems were located in the lower air temperature areas.

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

Long-lived shade leaves of avocado had extremely low rates of photosynthesis. Gas exchange measurements of photosynthesis were of limited use, so we resorted to Chl fluorescence imaging (CFI) and spot measurements to evaluate photosynthetic electron transport rates (ETRs) and non-photochemical quenching (NPQ). Imaging revealed a remarkable transient heterogeneity of NPQ during photosynthetic induction in these hypostomatous, heterobaric leaves, but was adequately integrated by spot measurements, despite long-lasting artifacts from repeated saturating flashes during assays. Major veins (mid-vein, first- and second-order veins) defined areas of more static large-scale heterogeneous NPQ, with more dynamic small-scale heterogeneity most strongly expressed in mesophyll cells between third- and fouth-order veins. Both responded to external CO2 concentration ([CO2]), occlusion of stomata with Vaseline (TM), leaf dehydration and relative humidity (RH). We interpreted these responses in terms of independent behavior of stomata in adjacent areoles that was largely expressed through CO2-limited photosynthesis. Heterogeneity was most pronounced and prolonged in the absence of net CO2 fixation in 100 p.p.m. [CO2] when respiratory and photorespiratory CO2 cycling constrained the inferred ETR to similar to 75% of values in 400 or 700 p.p.m. [CO2]. Likewise, sustained higher NPQ under Vaseline (TM), after dehydration or at low RH, also restricted ETR to similar to 75% of control values. Low NPQ in chloroplast-containing cells adjacent to major veins but remote from stomata suggested internal sources of high [CO2] in these tissues.

DOI： 10.1093/pcp/pct128

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Roof greening in warehouse is expected not only to improve the environment but also to reduce the heat island effects by evapotranspiration from the soil and plants. Effects of roof greening on room air temperature in warehouse and cooling load in summer were investigated using simulation model. In this study, two types of roof greening were assumed, roof greening with soil (greening type 1) and without soil (greening type 2). Our results showed that room air temperature in warehouse was decreased by 18.1°C for greening type 1 and 9.5°C for greening type 2 compared with no roof greening. In greening type 1, the room air temperature was decreased with increasing the coefficient of transpiration from the plants. The maximum room air temperature was decreased with increasing the light interception ratio and decrease in room air temperature with increasing light interception ratio in greening type 2 was larger than that in greening type 1. Daily cooling load with greening type 1 was lower than that with greening type 2. Electricity cost for air-conditioning in summer was reduced by 135 yen for greening type 1 and 63 yen for greening type 2 compared with that for no greening when set temperature for cooling was 26°C. These results suggested that roof greening with soil can maintain lower air temperature in warehouse and save more cooling load than that without soil due to the latent heat with evaporative cooling from the soil.

DOI： 10.2525/ecb.51.99

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

Measurement of volatile organic compounds (VOCs) emitted by plants allows us to monitor plant health status without touching the plant. To bring this technique a step further towards a practical plant diagnosis technique for greenhouse crop production, we have defined a numerical index named "Emission index" to evaluate VOC emissions from tomato plants isolated from ambient greenhouse air using an open-bottom chamber. The emission index of a VOC is a ratio of the concentration of the VOC in the air inside the chamber to that in the ambient greenhouse air and the index should be larger than one if the VOC is emitted by the plants in the chamber. Measurement of the emission indices of representative tomato VOCs proved that non-stressed tomato plants in a greenhouse emit n-hexanal, 2-carene, beta-phellandrene, alpha-copaene, beta-caryophyllene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), do not emit (Z)-3-hexenol, and might absorb and/or adsorb n-hexanol. Another experiment proved that a routine crop maintenance operation, i.e. removal of old leaves from the lower part of plants and removal of side shoots, enhances the emissions of n-hexanal, (E)-2-hexenal, (Z)-3-hexenol, but does not enhance the emissions of alpha-copaene, methyl salicylate (MeSA) and TMTT. The results suggest that the measurement of emission index with the open-bottom chamber is a useful technique for monitoring VOC emissions by plants in a greenhouse under practical conditions. (C) 2012 IAgrE. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biosystemseng.2012.08.004

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

Measurement of the slow phase (the P-S-M-T phase) of the chlorophyll fluorescence induction (CFI) phenomenon is a prospective candidate for plant diagnosis in greenhouses. We applied a methodology, the consecutive measurements of photochemical efficiency of photosystem (PS) II (Ψ_PSII) and non-photochemical quenching (<i>NPQ</i>) during a CFI phenomenon, to clarify the contributions of photochemical and non-photochemical quenching to the slow phase of CFI curves in mature tomato leaves grown in a semi-commercial greenhouse. The Ψ_PSII increased significantly between the inflection points of P and S and decreased between the inflection points of S and M. On the other hand, the <i>NPQ</i> remained at low values during the inflections of P, S and M, but then increased exponentially. These results prove that the shape of the CFI curve during the inflections of P, S and M is predominantly determined by the changes in the status of the photosynthetic electron transport chain, and the shape of the CFI curve after the inflection of M is strongly regulated by non-photochemical quenching, especially of the xanthophyll cycle. Furthermore, the two CFI measurements conducted at an interval of nine days proved that the slight changes in the photosynthetic functions, i.e. decreases in the capacities of the photosynthetic electron transport and the xanthophyll cycle, are detectable by measuring the slow phase of the CFI phenomenon.

DOI： 10.2525/ecb.50.181

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Language：English   Publishing type：Research paper (scientific journal)  

The transgenic lettuce expressing double repeated Stx2eB (2 × Stx2eB) is considered to be an edible vaccine candidate against swine edema disease. For the efficient vaccine protein production in transgenic lettuce grown in a plant factory, the effects of air flow on vaccine protein production in transgenic lettuce were investigated. Plants were grown hydroponically in a closed-type plant factory for 21 days with four airflow patterns: 1) air flow from the side to leaves at 2.0 m s -1
2) air flow from the top to the inner developing leaves with flexible transparent tubing at 1.0 m s -1
3) air flow from the bottom to leaves with transparent tubing at 1.0 m s -1
and 4) no air flow. Our results showed that the total leaf number in air flow from the top and the bottom to leaves was significantly increased compared with that in no air flow. While lettuce growth with inner air flow and bottom air flow was enhanced, tipburn at the developing leaves were eliminated by air flow. 2 × Stx2eB per plant in bottom air flow to leaves was the highest of the four air flow patterns. These results suggest that bottom air flow to the leaves can enhance vaccine protein productivity in transgenic lettuce.

DOI： 10.2525/ecb.50.135

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：American Society of Agricultural and Biological Engineers  

Air temperature in greenhouse is high for tomato plants in summer. It is important to maintain optimum temperature in greenhouse for yield. The cost of whole cooling in greenhouse is so expensive that local temperature control is suggested. Our previous research showed tomato plants with root cooling at 25°C increased yields compared with those with no cooling. The chilled water can be used for root cooling system in greenhouse. The objective of this research was to evaluate the root cooling system using cold water for growing tomato plants in summer. Tomato plants were grown hydroponically in greenhouse. The cooling water flows into PVC pipe which is installed under cultivation bed. Water temperature was maintained at 12°C. Inlet and outlet water in pipe and rockwool temperatures were measured. Our results showed that the rockwool temperature was maintained around 22°C with high air temperature (30°C) using root cooling system.

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

The chlorophyll fluorescence measurement technique can be used for evaluating photosynthetic functions of plants without actually sampling the plants. In this study, we applied two types of chlorophyll fluorescence measurement techniques: pulse amplitude modulation (PAM) chlorophyll fluorescence measurement (MINI-PAM) and chlorophyll fluorescence imaging (CF Imager), to evaluate the health of grafted tomato seedlings. We monitored changes in F_v/F_m of seedlings incubated under different light conditions: Light-treated (10 h/14 h [light/dark]) and Dark-treated (continuous dark), for 10 days. Dark-treated seedlings showed slight wilting on day 10. Total chlorophyll content of Dark-treated leaves slightly decreased during the 10-day treatment, but Light-treated and Dark-treated leaves did not differ significantly. F_v/F_m measured with MINI-PAM was almost constant for 10 days in Lighttreated leaves, although F_v/F_m in Dark-treated leaves significantly decreased. Similar results were obtained with CF Imager. Absolute values of F_v/F_m measured with MINI-PAM were significantly higher than corresponding F_v/F_m values measured with CF Imager throughout the experiment. This result was probably due to CF Imager underestimating F_v/F_m because the imager's saturation pulse light intensity was not strong enough to saturate the plant's photosynthetic electron transport reaction. And the decrease in F_v/F_m of Dark-treated leaves was larger with CF Imager (60%) than with MINI-PAM (6%). Part of this difference could be attributed to changes in leaf angles caused by wilting. The results suggest that F_v/F_m imaging does not provide accurate F_v/F_m values but has greater sensitivity than MINI-PAM F_v/F_m measurement for detecting subtle changes in health of grafted tomato seedlings.

DOI： 10.2525/shita.23.101

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Other Link： http://agriknowledge.affrc.go.jp/RN/2010814138

Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

The chlorophyll fluorescence imaging technique is useful for evaluating photosynthetic functions of plants without actually touching the plant. In our previous study, we developed a chlorophyll fluorescence imaging system for tomato plants cultivated in greenhouses. This imaging system measures the chlorophyll fluorescence induction phenomenon, a dynamic change in chlorophyll fluorescence intensity induced by illuminating a dark-adapted leaf with a stable intensity excitation light, and analyzes the shape of the induction curve, i.e., the temporal course of chlorophyll fluorescence intensity during this phenomenon. The shape of the induction curve is characterized by an initial maximum peak (P), subsequent transient dip (S), and secondary small peak (M). We defined an index, the photosynthetic function index (PFI
fluorescence intensity of P divided by the average fluorescence intensity from S to M), to evaluate the shape of the induction curve. In this study, we applied this system to detect drought stress in tomato plants cultivated in a semi-commercial greenhouse. PFI was clearly lower in stressed plants than in healthy plants. The decreased PFI in stressed plants is probably attributable to photosynthetic dysfunction in these plants. © 2011 IFAC.

DOI： 10.3182/20110828-6-IT-1002.01490

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：INT SOC HORTICULTURAL SCIENCE  

The chlorophyll fluorescence imaging technique is useful to evaluate the photosynthetic functions of living plants. In our previous study, we developed a chlorophyll fluorescence imaging system for full-size tomato plants in a greenhouse. This system images the chlorophyll fluorescence induction phenomenon, a dynamic change in chlorophyll fluorescence intensity induced by an excitation light under dark condition and analyzes the shape of the induction curve, i.e., the time course of the chlorophyll fluorescence intensity during this phenomenon. The shape of the induction curve is characterized with the initial maximum peak (P), the following transient dip (S) and secondary small peak (M). We defined a photosynthetic function index (PFI; the fluorescence intensity of P divided by the average fluorescence intensity from S to M) to evaluate the shape of the induction curve. In this study, we applied this system to evaluate the photosynthetic functions of tomato plants grown under different night air temperatures during winter and to detect the difference in photosynthetic functions of two tomato cultivars, i.e., 'Reika' and 'Tomimaru', in a greenhouse. The PFI of the plants grown under relatively low night air temperature (11 degrees C) was significantly lower than that of the plants grown under normal night air temperature (15 degrees C). The PFI of 'Tomimaru' was significantly higher than that of 'Reika'. The differences in PFIs would be partly due to the differences in the chlorophyll pigments compositions.

DOI： 10.17660/ActaHortic.2011.907.55

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

This paper describes a model to calculate the concentrations of (Z)-3-hexenol, alpha-pinene, alpha-terpinene, beta-caryophyllene, and methyl salicylate in a greenhouse on the basis of their source and sink behaviour. The model was used to determine whether these volatile organic compounds (VOCs) can be used to indicate Botrytis cinerea infection in a large-scale tomato production greenhouse with a volume of 5 x 10(4) m(3) containing 2.2 x 10(4) plants. Seven experiments were done to parameterise the model for these VOCs. Based on model predictions, the B. cinerea-induced increase in concentration of methyl salicylate is detectable in a large-scale tomato production greenhouse when: (a) windows are fully opened, and (b) the increase continues for at least 1 h, and (c) 5% of the plants are infected. The B. cinerea-induced increase in concentration of methyl salicylate is also detectable when: (a) windows are closed, and (b) the increase continues for at least 6 h, and (c) 5% of the plants are infected. The B. cinerea-induced increase in concentration of (Z)-3-hexenol is detectable under all conditions studied. However, it is expected that besides infected plants, many additional sources of (Z)-3-hexenol exist including plant debris and nearby field crops especially upon harvest or stress. The B. cinerea-induced increases in concentration of alpha-pinene, alpha-terpinene and beta-caryophyllene are probably undetectable in a large-scale tomato production greenhouse. Therefore, it is recommended to focus on the detection of methyl salicylate to indicate B. cinerea infections in large-scale tomato production greenhouses. (C) 2010 IAgrE. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biosystemseng.2010.01.009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

Chlorophyll fluorescence is red light emitted from chlorophyll <i>a</i> pigment and hence accurate measurement of this emission allows us to assess photosynthetic functions of the plant. The chlorophyll fluorescence induction imaging measures a chlorophyll fluorescence induction phenomenon. This phenomenon is a dynamic change in chlorophyll fluorescence intensity induced by illuminating plant body with an excitation light at a stable intensity under dark condition. The time course of the chlorophyll fluorescence intensity during this phenomenon is called induction curve. In this study, we developed a chlorophyll fluorescence induction imagining system for whole tomato plants as a first prototype for plant diagnosis in greenhouse. By using this system, we assessed the effects of sunlight exposure treatment, i.e. PPFD 1500 μmol m⁻²s⁻¹ for 2.5 h, on the photosynthetic functions of a whole tomato plant of 1.1 m high. A substantial transformation of induction curve was observed between before and just after the treatment, but it was recovered in 6 h under dark condition. During the recovery process, the inflection points of P and M, which are the characteristic inflections of an induction curve, showed different behaviour. The M kept lower values for 1.5 h after the sunlight exposure treatment even though the P had been almost recovered. This result suggests that the chlorophyll fluorescence induction imaging, especially concurrent monitoring of the images of P and M inflection points, is useful to detect invisible photosynthetic dysfunctions at whole plant level.

DOI： 10.2525/ecb.48.151

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

We previously characterized the vertical distribution of photosynthetic functions within a tomato plant canopy in a large-scale commercial greenhouse. Here we present a more detailed characterization of the spatial distribution of photosynthetic function within a tomato plant canopy. The leaves of the canopy were divided into spatial groups oriented laterally with respect to the path (path-side and inside, which is adjacent to another row of tomato plants) and vertically (upper, middle and lower). Photosynthetic-light response curves, chlorophyll content, chlorophyll fluorescence parameters, and the SPAD values were measured for each leaf group, and we discuss the relationships between these parameters and the light environment. Maximum photosynthetic rates of the leaves in both lower layer and inside/middle leaf groups were approximately half those of both upper layer and path-side/middle leaf groups. The chlorophyll <i>a</i>/<i>b</i> ratios of both lower layer and inside/middle leaf groups were significantly lower than in both upper layer and path-side/middle leaf groups. The lower chlorophyll <i>a</i>/<i>b</i> ratios for both lower layer and inside/middle leaf groups suggests that these leaf groups had become acclimated to low-light conditions. Conversely, the chlorophyll content and fluorescence parameters (i.e., F_v/F_m) of both lower layer and the inside/middle leaf groups were relatively higher than those of both upper layer and path-side/middle leaf groups. These findings imply that the photosynthetic rates of leaves in both lower layer and inside/middle leaf groups, which are associated with low maximum photosynthetic rates, would increase if the light environment was improved.

DOI： 10.2525/shita.22.175

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Other Link： http://agriknowledge.affrc.go.jp/RN/2010810031

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Society of Eco-Engineering  

Chlorophyll fluorescence imaging is a useful tool to assess photosynthetic ability of plant leaf without contact. By applying an actinic light of stable intensity to dark adapted leaf, a dynamic change in chlorophyll fluorescence intensity can be induced. This dynamic change in chlorophyll fluorescence intensity is called &ldquo;Induction phenomenon&rdquo;. &ldquo;Induction method&rdquo; is a representative way to detect photosynthetic dysfunction in plant leaf by analyzing the induction phenomenon. In this study, we investigated whether imaging of chlorophyll fluorescence induction phenomenon induced by weak actinic light at a PPFD of 10 &mu;mol m<SUP>-2</SUP>s<SUP>-1</SUP> can detect photoinhibition, which is caused by strong light irradiation treatments at PPFDs of 500, 1000 and 2000 &mu;mol m<SUP>-2</SUP>s<SUP>-1</SUP> for 1 hour. As a result, the photoinhibition in individual tomato leaves caused by the strong light irradiation treatments could be detected by measuring chlorophyll fluorescence induction phenomena that were induced by the weak actinic light. Furthermore, continuous measurement of chlorophyll fluorescence induction phenomena during a relaxation of photoinhibition under dark condition for 24 hours proved that P value, i.e. maximum chlorophyll fluorescence intensity in chlorophyll fluorescence induction phenomenon, can be used as an index of photoinhibition.

DOI： 10.11450/seitaikogaku.21.69

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE  

The energy-balance equation was used to estimate evapotranspiration in a greenhouse, and an instrument was developed to collect data for this purpose. The values estimated by this method were in good agreement with the measured data. It was shown that the net solar radiation term was the largest and cannot be neglected, and that long-wave radiation exchange had a relatively small effect. As usual, soil heat flux can be neglected but the sensible heat transfer term cannot be neglected since the maximum of the possible range of values is large and significant.
It was concluded that the method used was simple and suitable for irrigation control in greenhouses. It was also concluded that normal radiation sensor measurements on a horizontal surface are not adequate for measuring radiation received by a plant canopy in a single-span greenhouse. (C) 2009 IAgrE. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biosystemseng.2008.12.004

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE  

Early detection of physiological dysfunctions in plants caused by biotic or abiotic stresses is very important for the greenhouse management. The objective of this study is to investigate the availability of PRI measurement technique for early detection of water stress induced photosynthetic dysfunction in tomato plant leaf. Physiological (or Photochemical) Reflectance Index (PRI) has been used as a useful parameter that indicates the status of plant leaf stress in various research fields in recent years. PRI is calculated with the reflectance at 531 nm and 570 nm, PRI=(R531-R570)/(R531+R570), and several previous studies reported that the changes in the reflectance at 531nm were correlated with the changes in de-epoxidation state of the xanthophyll cycle, which regulates the activation of heat dissipation of excessive light energy absorbed by chloroplasts. Hence, PRI provides information on leaf photosynthetic activity, e.g.. PRI shows linear or curvilinear relationships with chlorophyll fluorescence parameters such as non-photochemical quenching (NPQ) and photosynthetic efficiency (Phi(PSII)), however, which is depending on plant species. In this study, we simultaneously measured PRI, chlorophyll fluorescence parameters (NPQ) and (Phi(PSII)), photosynthetic rate and stomatal conductance of an attached tomato plant leaf during water stress treatment induced by cutting the petiole of the leaf in the air. Then, the relationships between those parameters were analyzed. Photosynthetic rate and stomatal conductance promptly decreased after the petiole cutting and reached to their lowest levels within 60 min. This showed that the severe water stress was induced by the petiole cutting treatment. During the water stress treatment, Phi(PSII) decreased slowly, though NPQ and PRI decreased immediately. The results imply that the changes in PRI observed here reflected the changes in NPQ, i.e. activation of the heat dissipation process in leaf, and PRI measurement technique is useful for early detection of photosynthetic dysfunctions in plants.

DOI： 10.17660/ActaHortic.2008.801.148

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

DOI： 10.2525/ecb.45.39

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Biotron Institute  

In the present research, the psychological state of elderly people in the process of raising plants from seedlings and bulbs was analyzed by means of brain waves and the semantic differential technique. Subjects were ten elderly individuals and ten young individuals. Each subject raised four kinds of plants (hyacinth, pansy, Italian parsley and candelabra cactus) for ten weeks in his or her house. Subjects raised the hyacinth from bulbs and the pansy from seedlings. At the starting, second, sixth, and tenth weeks of the experiment, the psychological state of the subjects upon seeing their plants in front of them was evaluated. The ratio of alpha waves to beta waves was calculated as an index of the degree of calmness of psychological state. In the elderly subjects, the differences in the ratios of alpha waves to beta waves between the evaluated plants became smaller over time. The influence of the bloom of the pansy on the elderly subjects' psychological state was observed. An increase in the second factor score of the pansy evaluated by the elderly subjects was also observed and this indicated that the elderly people's psychological state was changed by the blooming process of the plants.

DOI： 10.2525/ecb.45.143

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.2525/shita.18.277

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Language：English   Publishing type：Research paper (international conference proceedings)  

A simple heat balance equation for the plant canopy model from which the Penman- Monteith equation was derived is used to estimate é vapotranspiration from a plant canopy. Incoming radiation downward and upward, air temperature and wind speed above the canopy are the only four factors to be measured. Estimated évapotranspiration is in good agreement with the values measured by an accurate scale in wet and dry conditions. This method was proven to be simpler and more accurate than that based on the Penman-Monteith equation.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.2480/agrmet.1179

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

DOI： 10.1093/pcp/pcg165

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Language：English   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

Using a developed chlorophyll (Chl) fluorescence imaging system, the photosynthetic effects of a commercially available soil-application type urea herbicide on attached Cucumis sativus L. leaves were analyzed.<BR>Decreases in the stomatal conductance and the assimilation rate caused by the herbicide were detected with diffusion porometer measurements. However, a decrease in stomatal conductance was smaller than that in assimilation rate.<BR>Photosynthetic injuries caused by the herbicide were detected with the Chl fluorescence imaging system. The inhibitions of primary electron transport in injured areas were detected from Chl fluorescence induction (CFI) images (Changes in intensity of Chl fluorescence during dark-light transition) taken by the CFI method. NPQ (non-photochemical quenching) and Yield (photosystem II photochemical efficiency) images were calculated from fluorescence images taken by the saturation pulse method. NPQ was reduced greatly in injured areas and NPQ images were useful to quantify the photosynthetic injuries. However, Yield was not reduced as much as the decrease in assimilation rate. This showed that Yield images were not suitable for diagnosis of the photosynthetic injuries of attached plant leaves caused by the herbicide.

DOI： 10.2525/jshita.13.247

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE SOCIETY OF AGRICULTURAL, BIOLOGICAL AND ENVIRONMENTAL ENGINEERS AND SCIENTISTS  

We have developed a new image analysis system, capable of quantitative analysis of two aspects of chlorophyll a fluorescence ; i) the changes in intensity of chlorophyll fluorescence during dark-light transitions by the induction method, and ii) the chlorophyll fluorescence quenching by the saturation pulse method. With this system we analyzed the effects of an herbicide on the photosynthetic activity of <I>Phaseolus vulgaris</I> L. leaves. Furthermore, stomatal conductance and assimilation rate were measured with a diffusion porometer.<BR>Results showed that the photosynthetic injuries caused by the herbicide were detected by both fluorescence measurement methods. These injuries were also detected with the porometer as a decrease in stomatal conductance and assimilation rate. Information obtained by the induction method was effective for determining the site in the electron transport system which was damaged by the herbicide. The saturation pulse method could analyze the photosynthetic injuries more quantitatively than the induction method. However, the saturation pulse method required an evenly distributed high level of photosynthetic active radiation (PAR), which makes it difficult to apply to a large leaf area. In contrast, the induction method did not require such a high level of PAR for measurements, and was easier to use for a large leaf area. Consequently, simultaneous use of the saturation pulse method and the induction method enables detailed diagnosis of injuries of the photosynthetic system.

DOI： 10.2525/jshita.13.29

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Total pages：211   Responsible for pages：168-178  

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Total pages：448   Responsible for pages：367-371   Language：Japanese  

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Total pages：576   Responsible for pages：323-327  

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Responsible for pages：207-228   Language：English  

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Total pages：399   Responsible for pages：181-183   Language：Japanese  

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Total pages：360   Responsible for pages：37-51   Language：Japanese  

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Total pages：168   Responsible for pages：22-34   Language：Japanese  

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Total pages：209   Responsible for pages：141-146 ・ 192-195   Language：Japanese  

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Total pages：1400   Responsible for pages：742-748   Language：Japanese  

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Total pages：480   Responsible for pages：287-308   Language：English  

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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J-GLOBAL

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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J-GLOBAL

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Language：Japanese   Publisher：Institute of Electrical Engineers of Japan  

CiNii Research

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Language：Japanese   Publisher：Institute of Electrical Engineers of Japan  

CiNii Research

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Language：Japanese   Publisher：電気学会  

CiNii Research

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Language：Japanese   Publisher：電気学会  

CiNii Research

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J-GLOBAL

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J-GLOBAL

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J-GLOBAL

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publisher：Institute of Electrical Engineers of Japan  

CiNii Research

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Language：Japanese   Publisher：Institute of Electrical Engineers of Japan  

CiNii Research

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Language：Japanese   Publisher：Institute of Electrical Engineers of Japan  

CiNii Research

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J-Global ID : 202102251211867469

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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CiNii Books

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (bulletin of university, research institution)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (international conference proceedings)   Publisher：日本施設園芸協会  

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CiNii Books

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Language：English   Publisher：FRONTIERS MEDIA SA  

The timing of measurement during plant growth is important because many genes are expressed periodically and orchestrate physiological events. Their periodicity is generated by environmental fluctuations as external factors and the circadian clock as the internal factor. The circadian clock orchestrates physiological events such as photosynthesis or flowering and it enables enhanced growth and herbivory resistance. These characteristics have possible applications for agriculture. In this study, we demonstrated the diurnal variation of the transcriptome in tomato (Solanum lycopersicurn) leaves through molecular timetable method in a sunlight-type plant factory. Molecular timetable methods have been developed to detect periodic genes and estimate individual internal body time from these expression profiles in mammals. We sampled tomato leaves every 2 h for 2 days and acquired time-course transcriptome data by RNA-Seq. Many genes were expressed periodically and these expressions were stable across the 1st and 2nd days of measurement. We selected 143 time-indicating genes whose expression indicated periodically, and estimated internal time in the plant from these expression profiles. The estimated internal time was generally the same as the external environment time; however, there was a difference of more than 1 h between the two for some sampling points. Furthermore, the stress-responsive genes also showed weakly periodic expression, implying that they were usually expressed periodically, regulated by light dark cycles as an external factor or the circadian clock as the internal factor, and could be particularly expressed when the plant experiences some specific stress under agricultural situations. This study suggests that circadian clock mediate the optimization for fluctuating environments in the field and it has possibilities to enhance resistibility to stress and floral induction by controlling circadian clock through light supplement and temperature control.

DOI： 10.3389/fpls.2016.00087

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Information Processing Society of Japan (IPSJ)  

The Speaking Plant Approach (SPA) is regarded as a desirable concept for environmental control in highly sophisticated greenhouses. Sensor-based plant diagnosis techniques to monitor plant physiological status are important for the SPA. Chlorophyll fluorescence imaging technique is useful to evaluate the photosynthetic functions of plant without touching. In this report, the outline of the chlorophyll fluorescence imaging robot developed in the research center for high-technology greenhouse plant production of Ehime University is introduced. In addition, the possibility of an intelligent greenhouse based on the daily measurement of plant data would be mentioned.

CiNii Books

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publisher：The Japanese Society for Quality Control  

The speaking plant approach (SPA) is becoming an indispensable concept to maximize profit of agricultural production in current greenhouses. This concept is defines the optimal plant cultivation conditions should be achieved by monitoring the physiological status of the plants. Chlorophyll fluorescence imaging technique is useful to evaluate the photosynthetic functions of plant without touching. We developed a chlorophyll fluorescence imaging robot with the features of feasible design, automated simple operation and low-cost for implementation in commercial tomato production greenhouse. This system images chlorophyll fluorescence induction phenomenon, a dynamic change in chlorophyll fluorescence intensity induced by an excitation light under dark condition and analyses the shape of the induction curve, the time course of the chlorophyll fluorescence intensity during this phenomenon. We applied this robot to grasp a spatial distribution and daily fluctuation of photosynthetic function of hydroponically-cultivated tomato plants in a semi-commercial greenhouse. In addition, this robot also provide the information on the daily changes in stem elongation rate. Such high spatial and temporal resolution information is useful for the precise management of plant growth in greenhouse. The developed chlorophyll fluorescence imaging robot is expected to be implemented in commercial tomato production greenhouse in the near future.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本植物工場学会  

CiNii Books

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Language：English   Publishing type：Research paper, summary (international conference)  

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Language：English   Publishing type：Research paper, summary (international conference)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

The speaking plant approach (SPA) is regarded as a desirable concept for environmental control in highly sophisticated greenhouses. An important feature of SPA is sensor-based plant diagnostic techniques, which are used to monitor plant physiological status. Although the concept of SPA was originally proposed approximately 30 years ago, the practical application of SPA techniques in commercial greenhouses has only recently become feasible, due to the innovation of easy-to-use devises and information and communication technologies in the present decade. In this review, two prospective plant diagnostic techniques that can be utilized for the SPA, and their applications in semi-commercial greenhouses, are introduced. The first technique is plant diagnosis based on a plant's odor. Plants emit a broad range of volatile organic compounds and a plant's emission profile changes depending on its physiological status. The second technique is chlorophyll fluorescence imaging. This technique measures the chlorophyll fluorescence induction phenomenon -a dynamic change in chlorophyll fluorescence intensity induced by illuminating a dark-adapted leaf with a stable intensity excitation light- and analyzes the shape of the induction curve. In addition, new challenges for an SPA-based mega-scale greenhouse are discussed.

DOI： 10.2525/shita.25.165

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Other Link： http://agriknowledge.affrc.go.jp/RN/2010890776

Language：English   Publishing type：Article, review, commentary, editorial, etc. (international conference proceedings)  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

To resolve the problem of declination of Japanese agriculture, plant factories with automation, quality control, robotization and speaking plant approach are necessary. The multi operation system described in this paper has running unit with automatic position sensing. Growth environment measurement unit has transpiration, photosynthesis, distance and temperature sensors to obtain plant growth information. The pest control unit uses the antiseptic effect of ozone water. The harvesting unit is used for cucumbers that grow fast; recognition of cucumbers ready to be harvested is achieved through distance information gathered by an attached distance sensors. The development of multi-operation robot is continued by developing controlling program that can change the operating pattern by sharing the contents by each controlling and operating unit.

CiNii Books

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：Japanese   Publisher：日本施設園芸協会  

CiNii Books

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：CSIRO PUBLISHING  

Recognising that plant leaves are the fundamental productive units of terrestrial vegetation and the complexity of different environments in which they must function, this review considers a few of the ways in which these functions may be measured and potentially scaled to the canopy. Although canopy photosynthetic productivity is clearly the sum of all leaves in the canopy, we focus on the quest for 'economical insights' from measurements that might facilitate integration of leaf photosynthetic activities into canopy performance, to better inform modelling based on the 'insights of economics'. It is focussed on the reversible downregulation of photosynthetic efficiency in response to light environment and stress and summarises various xanthophyll-independent and dependent forms of photoprotection within the inner and outer canopy of woody plants. Two main themes are developed. First, we review experiments showing the retention of leaves that grow old in the shade may involve more than the 'payback times' required to recover the costs of their construction and maintenance. In some cases at least, retention of these leaves may reflect selection for distinctive properties that contribute to canopy photosynthesis through utilisation of sun flecks or provide 'back up' capacity following damage to the outer canopy. Second, we report experiments offering hope that remote sensing of photosynthetic properties in the outer canopy (using chlorophyll fluorescence and spectral reflectance technologies) may overcome problems of access and provide integrated measurements of these properties in the canopy as a whole. Finding appropriate tools to scale photosynthesis from the leaf to the landscape still presents a challenge but this synthesis identifies some measurements and criteria in the laboratory and the field that improve our understanding of inner and outer canopy processes.

DOI： 10.1071/FP11255

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (international conference proceedings)  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

The autonomous driving unit using the regression reflective type laser sensor and the laser range sensor has been developed aiming at automation and robotization of various work in the intelligent greenhouse (harvesting and pest control) and plant diagnosis information measurement. Some study cases of on-board equipped system of harvesting, pest control and plant diagnosis information measurement are reported.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：養賢堂  

CiNii Books

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

For establishment and the spread of the intelligent greenhouse which stably enabled farming, the high quality and the stable supply are essential tasks. Moreover, the environmental control and delicate cultivation management are necessary for implementation. Then, we developed the autonomous travelling robot diagnosing plant growth for the tomato cultivation. This robot collects the plant diagnosis information such as the temperature of the leaf and the photosynthesis function with the self-position in the intelligent greenhouse. As a result, this study showed that the growth diagnosing robot was a promising technique for monitoring of the health condition of the tomato crops in the intelligent greenhouse.

CiNii Books

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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Language：English   Publishing type：Book review, literature introduction, etc.   Publisher：Biotron Institute  

This review focuses on the monitoring of crop health status at greenhouse scale, based on the measurement of volatile organic compounds (VOCs) emitted from the plants. The review includes the most important factors that affect the emission of these VOCs from greenhouse crops. Since both, stress factors as well as non-stress factors have an effect on. the emission, they are covered separately. The review provides an overview of processes that affect the gas balance of plant VOCs in the greenhouse including the loss processes. These processes are considered as important since they contribute to the time-dynamic concentration profiles of plant-emitted VOCs. In addition, we review the most popular techniques currently in use to measure volatiles emitted from plants with, emphasis on greenhouse application. Dynamic sampling in combination with gas chromatography coupled to mass spectrometry is considered as most appropriate method for application at greenhouse scale. It is recommended to evaluate the state-of-the-art in the fields concerned with this method and to explore the development of a new instrument based, on the specific needs for application in greenhouse practice. However, to apply such an instrument at greenhouse-scale remains a challenge, mainly due to the high costs associated with it.

DOI： 10.2525/ecb.47.87

Scopus

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Language：English   Publishing type：Book review, literature introduction, etc.   Publisher：Biotron Institute  

Chlorophyll fluorescence imaging is useful as a non-destructive method for evaluating photosynthetic function of plants. A dynamic change in. chlorophyll fluorescence intensity, known as the chlorophyll fluorescence induction phenomenon, can be observed by illuminating a darkadapted green leaf with a stable intensity excitation light. The time course of the chlorophyll fluorescence intensity during this phenomenon, presented as an induction curve, varies depending on the health of the plant. Imaging of the chlorophyll fluorescence induction phenomenon may be used to monitor the health status of plants. In this review, we introduce studies on our chlorophyll fluorescence imaging system, for plant health monitoring of tomato crops grown in a greenhouse. We first developed a prototype of the imaging system to confirm performance on detection of artificially induced light stress in a single leaf and whole plant. Based on the successful detection of photosynthetic dysfunction caused by light stress using the prototype, we applied our chlorophyll fluorescence imaging system to measurements of the chlorophyll fluorescence induction curves of tomato crops grown in a semi-commercial greenhouse. Upon comparing the induction curves of 20 tomato crops planted on a north-south lane in the greenhouse, we found two plants with unique induction curve patterns. One of these two plants showed visible symptoms of physiological dysfunction 7 days after measurement. Thus, our chlorophyll fluorescence imaging system appears to be a useful tool for plant health monitoring in horticultural production.

DOI： 10.2525/ecb.47.101

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：SPRINGER  

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Language：English   Publishing type：Book review, literature introduction, etc.   Publisher：Biotron Institute  

Early detection of water stress in tomato plants is required for the precise irrigation control to produce high-brix tomato fruits. For this purpose, we have developed a new water stress detection technique based on the projected plant area calculated from digital color images captured by a commercially available, inexpensive, digital still camera. As a first step, the effectiveness of using the projected plant area of tomato plants as a water stress index was confirmed by measuring the projected plant area along with other plant physiological information, e.g. leaf temperature, water potential, transpiration rate, and photosynthetic rate. Next, an image processing algorithm for the automated calculation of the projected plant area from digital color images was established using the discriminant analysis method. Furthermore, the most effective measurement angle of the projected plant area for the early detection of water stress was examined and measurement at an angle of 90° was proved to be the most sensitive to water stress in the tomato plant, i.e. wilting. The features of this technique are the stability of the projected plant area as an index of water stress, the low cost of the measurement equipment, and easy installation of the system.. These features suggest that this technique can be introduced to commercial greenhouses to detect water stress in tomato plants and to be used for irrigation control for the production of high-brix tomatoes.

DOI： 10.2525/ecb.45.241

Scopus

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Publisher：農業電化協会  

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