Greenhouses In Japan Research Articles

Practical use of Deep Learning-Based Daily Stem Elongation Measurement of Tomato Plants in Two Commercial Greenhouses

Skilled farmers generally evaluate the growth of a crop by observing the crop's appearance. However, with the increasing digitalization of agricultural practices, a numerical index representing the crop's growth status is strongly needed. For this purpose, the speaking plant approach (SPA), a sophisticated strategy for environmental control in greenhouses, has attracted a lot of attention. The first and most important step in SPA is to obtain physiological information from a plant and then judge whether the plant is healthy. The daily measurement of plant growth is therefore important in SPA, particularly for environmental control. Various imaging techniques have been studied for this purpose. A robotized chlorophyll fluorescence (CF) imaging system that evaluates daily changes in the photosynthetic function of a tomato canopy was developed in our previous study and later commercialized. In this study, for the measurement of the daily stem elongation of tomato plants, we developed a deep learning model that detects a tomato plant's shoot apex in a CF image. YOLOv3, a representative object detection algorithm, was used for the shoot apex detection model. Images captured at Ehime University were used for training and validating the model. The developed shoot apex detection model was applied to two different commercial greenhouses (Asai Nursery and Agrimind; largest greenhouses in Japan) to measure the daily stem elongation of tomato plants. The developed model detected the shoot apexes with an average F-measure of 0.97 for the greenhouse from which the training dataset was derived (Ehime University test dataset) and with average F-measures of 0.69 and 0.82 for the two commercial greenhouses (Asai Nursery and Agrimind test datasets). Then, the 19 days and 26 days consecutively measurements were conducted, and the daily stem elongation of tomato plants was measured. The obtained results indicate that the developed deep learning model is effective for measuring the daily stem elongation of tomato plants in commercial greenhouses.

Augmentative biological control in greenhouses in Japan

Abstract In Japan, augmentative biological control is mainly implemented in greenhouses using arthropod natural enemies. Two imported natural enemy species, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) against spider mites and Encarsia formosa Gahan (Hymenoptera: Aphelinidae) against the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), were first commercialised in greenhouses in 1995, followed by the commercialisation of other exotic species. Exotic arthropod natural enemies are used to control both exotic and indigenous pests in greenhouses. Currently, the most popular exotic natural enemy species are predatory mites such as P. persimilis and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). Recently, there has been a shift from using exotic to using indigenous natural enemies in greenhouses. Currently, the importation of generalist predators for augmentative biological control is very difficult in Japan. Several collaborative studies have been conducted in Japan to develop biological control using indigenous natural enemies. These studies developed innovative technologies, such as new banker plant systems based on combinations of two natural enemies or flightless Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Indigenous natural enemies have been commercialised following the registration of Orius strigicollis (Poppius) (Hemiptera: Anthocoridae). Biological control can be achieved using an indigenous strain of Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) with a banker plant system, on which the bug can reproduce without alternative prey. Research and development of biological control using indigenous natural enemies should be continued in Japan.

Design and development of a simulation-based decision support tool to improve the production process at large-scale greenhouses in Japan

Design and development of a simulation-based decision support tool to improve the production process at large-scale greenhouses in Japan

Can Japan enhance its 2030 greenhouse gas emission reduction targets? Assessment of economic and energy-related assumptions in Japan's NDC

This study investigates the stringency of Japan's greenhouse gas emissions reduction target for 2030 (nationally determined contribution: NDC), focusing on the macroeconomic assumptions of Kaya indicators and others previously overlooked, e.g. GDP per working-age population. It also conducts a decomposition analysis in light of historic political and economic events.We find that the real GDP growth assumption underlying the NDC target is unrealistic. Namely, the real GDP per working-age population, which is an indicator of productivity, needs to be improved annually by 2.5% on average for 15 years, a high level that has not been observed since the collapse of the economic bubble in the early 1990s.Based on these findings and the data from mitigation scenarios, we conclude that Japan can achieve the NDC target (26% below 2013 levels by 2030) with existing mitigation measures and by resuming operations only at those nuclear power plants that come under the conformity assessment, assuming realistic GDP assumptions. If the government enhances mitigation measures promoting low-carbon technologies that are politically affordable in terms of costs with realistic GDP assumptions, then it would be possible to achieve 27–42% of GHG emissions reduction compared to the 2013 level, including the “no nuclear” scenarios.

Performance of residential fuel-cell-combined heat and power systems for various household types in Japan

A residential fuel-cell-combined heat and power (FC-CHP) system is considered a promising low-carbon technology that can reduce residential energy consumption and thus, achieve Japan's greenhouse gas (GHG) emissions reduction targets. However, to consider future directions for the systems' research and development, it is critical to understand the relationships between the performances of FC-CHP systems and residential energy demand profiles, which vary by household characteristic. This study evaluates the effects of applying city gas-fueled FC-CHP systems to Japanese households with different attributes. We compare total costs and GHG emissions for residential energy use between the FC-CHP systems and a conventional system. The economic performance results suggest that the basic PEMFC-CHP systems have an economic advantage only for four-person families with teenage children and further development efforts for low-output FC-CHP systems are required to enable various households save energy costs. The environmental evaluation results show that SOFC-CHP systems can drastically reduce GHG emissions from particularly small-sized households.

Development of a production area and long-term harvesting of red raspberries using plastic greenhouses in Japan

The demand for raspberries (Rubus idaeus) has increased in Japan since 1999. Almost all of the raspberry supply is imported, and domestic raspberry production is limited. The Japanese market for raspberries is represented by the supply of imported raspberries. A raspberry production area has been developed by a joint research program involving the industry, academia, and the local government in Akita since 2008. Akita is located in the northwestern part of the northeast region of Japan called the Tohoku region. Most farmers in this area mainly cultivate rice and have introduced raspberry production for crop diversification. The market for fresh fruit imports in Japan has expanded with the year-round supply; however, domestically produced fresh fruits are not being supplied. To expand domestic production, it may be necessary to promote the production of fresh fruits, assuming that they are available over a long term. There is an off-season for raspberries cultivated outdoors in Akita, between fruits from floricanes of 'Chilcotin' and those from primocanes of 'Heritage'. Accordingly, to manipulate the fruit harvest from primocanes in 'Heritage', we cultivated them in a plastic greenhouse. The date of budding of primocanes from the soil surface and the date of initiation of harvesting were forced. We demonstrated that long-term harvesting in Akita is possible by the continuous cultivation of floricane fruits under outdoor culture, primocane fruits using forcing culture under plastic greenhouses, and primocane fruits under outdoor culture.

Current Usage of Air Circulators in Greenhouses in Japan

Current Usage of Air Circulators in Greenhouses in Japan

Evaluations on the Japan's Greenhouse Gas Emission Reduction Target for 2030

Evaluations on the Japan's Greenhouse Gas Emission Reduction Target for 2030

Host species-dependent and size-dependent ecological characteristics of Ephedrus nacheri (Hymenoptera: Braconidae)

Banker-plant systems with Aphidius species have been used to control pest aphids in greenhouses in Japan. However, the occurrence of secondary parasitoids, which lead to aphid-control failures, and of minor aphid species, are problematic. In this work the ecological characteristics of Ephedrus nacheri Quilis (Hymenoptera: Braconidae), an alternative biological control agent to Aphidius species against the pest aphids Aphis gossypii and Myzus persicae, were examined under laboratory conditions at 25 °C. Attack rate, success of parasitization, and offspring sex ratio were highly dependent on aphid species and instar stage. Development time and offspring body size depended on aphid species. Because of insufficient honeydew production, survival of the female wasp decreased when the host density was low; as a result, a type III functional response curve was observed for the two aphid species in most stage combinations. The intrinsic rate of natural increase estimated by use of the bootstrap method ranged from 0.128 to 0.258, depending on the larval mortality, host species, and stage. These values were insufficient to support inoculative use of E. nacheri for aphid control. In future work we will conduct a survey to discover a better combination of banker plant and host aphid which maintains a sufficient population and offspring sex-ratio, and decide the scale of the banker-plant system in the greenhouse that will supply a sufficient wasp population.

Population dynamics of iris yellow spot virus in onion fields and lisianthus greenhouses in Japan

Iris yellow spot virus (IYSV, genus Tospovirus) mainly occurs on onion and lisianthus plants (Eustoma grandiflorum) in Japan. The virus is genetically diverse and is classified based on its nucleocapsid protein sequence into two genotypes, IYSVNL (NL) and IYSVBR (BR), first isolated in the Netherlands and Brazil, respectively. Both genotypes are present in Japan, and they are sometimes found in the same field. Furthermore, the two genotypes are occasionally detected in a single necrotic lesion of an infected plant (designated as a ‘mosaic’ genotype). In this study, the population structures of these two genotypes and their dynamics in onion fields and lisianthus greenhouses from 2004 to 2006 were analysed using reverse transcription-PCR-restriction length polymorphism analysis (RT-PCR-RFLP). In onion fields the two genotypes were detected in all three years, and the BR genotype predominated within a year. On the other hand, both genotypes were detected at the first outbreak each year in almost all lisianthus greenhouses; however, the BR genotype was more widespread than the NL genotype. These results suggest that the incidence of IYSV disease in lisianthus during each year was triggered by the invasion of viruliferous Thrips tabaci that have acquired one or both genotypes from nearby onion fields. Although the BR genotype predominated in the last stages of cultivation, IYSV disease might be expanded by monocyclic patterns but may occasionally spread secondarily in lisianthus greenhouses.

Development of a New Energy-Saving Pipe-Framed Greenhouse

We summarize the basic techniques used to save energy in a greenhouse and discuss the development of a new energy-saving pipe-framed greenhouse, similar to the type used on most small-scale farms in Japan. To enhance the thermal insulation performance of a pipe-framed greenhouse, a multi-layered thermal curtain was installed. As a result of our experiments, both the heating load and the heating oil consumption in the greenhouse with a multi-layered thermal curtain (M-house) were approximately 40% lower than those in the control greenhouse with a conventional thermal cover (C-house). Furthermore, the heating oil consumption was also reduced by approximately 60% in the M-house equipped with water heat storage, which stored solar energy in daytime and released heat to the greenhouse at night. This multi-layered thermal curtain is expected to gain recognition as the most effective energysaving material available and immediate widespread use nationwide is expected. Another experiment was performed concerning the structural reinforcement of pipe-framed greenhouses. Pipe-framed greenhouses are usually constructed with single-arch pipes in Japan and there has been a recent increase in greenhouses collapsing due to strong winds. Accordingly, techniques to reinforce the structure of pipe-framed greenhouses were also developed. Discipline: Horticulture Additional key words: heating load, heat transmission, multi-layered thermal curtain *Corresponding author: e-mail hirokik@affrc.go.jp Received 31 March 2014; accepted 24 December 2014. Introduction In Japan, greenhouses used for protected horticulture take up an area of approximately 50,000 ha, about 40% are equipped with a heating system and more than 90% depend on fossil fuel. In Japan, protected horticulture is responsible for 45% of all carbon dioxide emissions (about 611 million tons) derived from fossil fuels used for agriculture, forestry and fisheries (Hayashi 2008). Most fossil fuels are used in protected horticulture for heating oil and the amount of fuel consumed for this purpose increased about 2.2 times from 1990 to 2005. Energy costs have also been steadily increasing, which has become an important factor influencing the management of farms. Accordingly, it has become necessary to develop energy-saving techniques for protected horticulture. In Japan, approximately 80% of all greenhouses are high-tunnel and high tunnel-like greenhouses; these are referred to as pipe-framed greenhouses, where the frames are constructed from steel pipes. The high tunnel, where sidewalls are not round like a hooped house, has no electrical service, automated ventilation or heating system (Lambert 2009). This review focuses on pipe-framed greenhouses in Japan with a heating system and other environmental control equipment. Basic energy-saving techniques for greenhouses have been classified into three groups: 1) reducing heating load, 2) introducing a high-efficiency heating system and 3) temperature management, namely, varying night temperature control, local air heating, the usage of cultivars for low-temperature tolerance and so on (Hayashi 2008). These techniques are usually used in combination. The key energy-saving technique in greenhouses involves reducing heating load or loss by installing a fixed or movable covering, an air-inflated covering, etc. (Naito 1981). Overnight, heat loss from greenhouses occurs due to overall heat transmission through coverings and structures. It is also caused by air infiltration and heat flux of the inside-air to the soil, although this is reversed in some cases. Heat transmission accounts for a large part of the total heat loss from a greenhouse, followed by heat transfer due to air

Testing the Polarization Model for TANSO-FTS on GOSAT Against Clear-Sky Observations of Sun Glint Over the Ocean

A model is developed to relate the polarized signals measured by the thermal and near infrared sensor for carbon observations-Fourier transform spectrometer (TANSO-FTS) on Japan's Greenhouse Gases Observing Satellite to Stokes' vector for radiation leaving the target. The model requires the position and velocity of the satellite, the yaw angle between TANSO-FTS and the satellite bus, the reflectance and phase shift properties of the pointing mirror of TANSO-FTS, and the radiometric calibration coefficients. The accuracy of the polarization model is tested by comparing the degree of polarization observed in clear sky over sun glint on the ocean against the value predicted by Fresnel reflection from a rough sea surface. Observations from April 2009 to December 2011 suggest that the polarization characteristics of TANSO-FTS have remained stable.

Development and reproduction of a potential biological control agent, Aphelinus varipes (Hymenoptera: Aphelinidae), at different temperatures

The development and reproductive potential of an indigenous parasitoid, Aphelinus varipes (Forster), was studied at 15, 17, 20, 25, and 30 °C. Developmental durations decreased with increasing temperatures. The emergence rate was higher than 90 % at 15, 17, and 20 °C. Offspring sex ratios were 0.69, 0.54, and 0.70 at 17, 20, and 25 °C, respectively, but were 0.14 at 15 °C and 0.38 at 30 °C. Developmental zeros of females and males were calculated as 9.9 and 9.6 °C, respectively. The effective accumulative temperature (K) was 204.1 degree-days in both sexes. Fecundity peaked in early age after emergence, then gradually decreased in a fluctuating manner at 20 and 25 °C. Host feeding continued constantly during the life of female adults at two temperatures. Single female parasitoids produced 218.5 and 203.1 mummies at 20 and 25 °C, respectively, during their lifespans. Aphids killed by parasitoid host feeding numbered 79.1 at 20 °C and 63.8 at 25 °C. Longevities were 27.0 days at 20 °C and 20.6 days at 25 °C. Moreover, intrinsic rates of natural increase (r m) were estimated as 0.151 at 20 °C and 0.227 at 25 °C. We discuss the potential of A. varipes as biological control agents by comparing them with Aphidius colemani Viereck, which has been introduced to horticultural crops in greenhouses in Japan.

Vicarious Calibration of the GOSAT Sensors Using the Railroad Valley Desert Playa

Japan's Greenhouse Gases Observing Satellite (GOSAT) was successfully launched into a sun-synchronous orbit on January 23, 2009 to monitor global distributions of carbon dioxide <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$( \hbox{CO}_{2})$</tex></formula> and methane <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(\hbox{CH}_{4})$</tex></formula> . GOSAT carries two instruments. The Thermal And Near-infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) measures reflected radiances in the 0.76 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$ </tex></formula> oxygen band and in the weak and strong <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{CO}_{2}$</tex> </formula> bands at 1.6 and 2.0 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$</tex></formula> . The TANSO Cloud and Aerosol Imager (TANSO-CAI) uses four spectral bands at 0.380, 0.674, 0.870, and 1.60 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$</tex></formula> to identify clear soundings and to provide cloud and aerosol optical properties. Vicarious calibration was performed at Railroad Valley, Nevada, in the summer of 2009. The site was chosen for its flat surface and high spectral reflectance. In situ measurements of geophysical parameters, such as surface reflectance, aerosol optical thickness, and profiles of temperature, pressure, and humidity, were acquired at the overpass times. Because the instantaneous field of view of TANSO-FTS is large (10.5 km at nadir), the spatially limited reflectance measurements at the field sites were extrapolated to the entire footprint using independent satellite data. During the campaign, six days of measurements were acquired from two different orbit paths. Spectral radiances at the top of the atmosphere were calculated using vector radiative transfer models coupled with ground in situ data. The agreement of the modeled radiance spectra with those measured by the TANSO-FTS is within 7%. Significant degradations in responsivity since launch have been detected in the short-wavelength bands of both TANSO-FTS and TANSO-CAI.

Lower Concentrations of Microelements in Leaves of Citrus Infected with 'Candidatus Liberibacter asiaticus'

Citrus trees affected by greening (huanglongbing, HLB) often develop symptoms that resemble those of Zn or Fe deficiency in their leaves. However, there have been few studies of mineral concentrations in infected leaves. To examine the effects of infection by ‘Candidatus Liberibacter asiaticus’ (the causal organism of the Asiatic form of HLB) on mineral nutrition, Citrus jambhiri (Lush.), C. reticulata cv. Siem, and C. depressa Hayata were patch-grafted with infected bark squares and grown in pots in greenhouses in Japan and Indonesia. In addition, leaves were collected from field-grown C. tankan Hayata and C. unshiu Marc. in Japan and C. reticulata cv. Siem in Indonesia, and their disease status was determined by PCR. Leaf samples were homogenized in 2-(N-morpholino) ethanesulfonic acid buffer and the concentrations of water-soluble Cu, Fe, Mn, and Zn in the macerate were determined using inductively coupled plasma atomic emission spectrometry (Japan) or atomic absorption spectrometry (Indonesia). In general, infected leaf samples had lower Fe and Zn. On average, the concentrations of Fe and Zn in infected plants were approximately half those in healthy plants. Cu was not significantly reduced by infection and Mn was occasionally lower. In C. unshiu, the concentrations of Fe and Zn were reduced before chlorosis appeared. These results suggested that the concentrations of particular elements (Fe and Zn) rather than element concentrations in general are reduced by infection by ‘Candidatus Liberibacter asiaticus’.

Molecular Identification and Evaluation of Orius species (Heteroptera: Anthocoridae) as Biological Control Agents

Orius strigicollis is a predatory bug that attacks small arthropods, such as thrips, and augmentative release of commercial strains has been widely conducted in greenhouses in Japan. The accurate evaluation of its effectiveness is essential for successful biological control programs. However, because Orius species occur naturally in the field, it is difficult to discriminate O. strigicollis from other Orius species. Furthermore, it is necessary to discriminate commercial strains of O. strigicollis from field populations. In this review, we introduce two types of molecular procedures: (1) a multiplex polymerase chain reaction technique to identify Japanese Orius species, and (2) microsatellite DNA markers that can be used to measure genetic diversity within populations of O. strigicollis and to discriminate field and commercial strains. The usefulness of molecular ecological approaches is also discussed.

Estimating colony number of Bombus terrestris (Hymenoptera, Apidae) queens foraging in Biratori, Hokkaido, Japan

Commercial colonies of European bumble bee, Bombus terrestris, have been widely used for pollinating tomato plants in greenhouses in Japan; however, a wild colony of the species was found in Hokkaido in 1996, after which several studies were conducted to investigate the ecological impact of the naturalization of B. terrestris to Japanese ecosystems. To quantify the status of naturalization, it is necessary to establish a method for estimating the population size of the alien bees established in the field. Locating bumble bee colonies in the field is, however, very difficult because they usually nest underground. In this study, we estimated the number of colonies using genetic data from B. terrestris queens foraging near greenhouses in Biratori, Hokkaido, Japan, applying the Shared Loci Correspondence Analysis (SLCA). Sampled 39 queens were assigned to 30 different families, which indicates that most queens came from different colonies. Based on the findings, we discuss the importance of urgent measures to prohibit B. terrestris from escaping from greenhouses and becoming naturalized in Hokkaido.

O301 我が国の作物生産用温室へのバイオマスエネルギー適用の可能性 : 第2報(セッション3:資源・導入,口頭発表)

O301 我が国の作物生産用温室へのバイオマスエネルギー適用の可能性 : 第2報(セッション3:資源・導入,口頭発表)

3-82.我が国の作物生産用温室におけるバイオマスエネルギー適用の可能性((19)評価2,Session 3 バイオマス等)

3-82.我が国の作物生産用温室におけるバイオマスエネルギー適用の可能性((19)評価2,Session 3 バイオマス等)

農作物生産用温室へのコージェネレーションシステム適用性評価

In greenhouses for crop production in Japan, large-scale/intensive management has advanced in recent years due to price competitiveness for import crops and the structural shortage of workers, and energy-conserving measures have become an important issue.The purpose of this study was to provide practical strategies for application of Combined Heat and Power, CHP in short, to effective energy conservation in greenhouses. The authors have performed energy demands measurement at existing large tomato greenhouses in Japan for 4 years, and investigated the effectiveness of CHP operated for the greenhouses. Model analysis revealed the following results.(1) The ratio of Heat to electricity in the greenhouses is zero in all time zones except the carbon dioxide Fertilization time in summer while 60 during maximum Heating time in winter, showing a particular characteristic of energy consumption in greenhouses.(2) Relatively larger-sized CHPs are useful for larger-scale greenhouses to attain the energy conservation rate of 3 to 4%.(3) From the economic aspect of tomato production, the scale of greenhouse should be 5×104m2 or more, and gas engine CHP is superior to micro gas turbine. Combined use of a boiler is necessary to satisfy heat demands and carbon dioxide fertilization.