Promoting tourism resources are important issue for local governments. In this study, Akima Bairin, or Akima plum grove, which is famous for its plum blossoms, in Annaka City, Gunma Prefecture, was selected as a study site. We created a 53-second tourism PR video including 3D models using aerial photos and videos taken by a small drone, which have become increasingly popular in recent years. 3D reconstruction software was used to build 3D models and also create animations. Then, we investigated the advantages of this method. Aerial video captured by a small drone enabled a dynamic expression which was different from the viewpoint from the ground. Also, by using 3D models, the viewpoint movement which was not actually recorded in situ can be simulated. The methods presented in this study can be used to create PR videos promoting local natural tourism resources.

This study evaluated the characteristics of 3D point cloud generation for estimating leaf area in floricultural crops using a smartphone-based scanning method. Focusing on stock (Matthiola incana (L.) R. Br.), a key winter-season flower cultivated in Namie Town, Fukushima Prefecture, we investigated the influence of scanning conditions, specifically the distance between the camera and the plant, and the number of scanning laps, on the accuracy of leaf area estimation. An iPhone 12 Pro with the Scaniverse application was used to acquire 3D data of a single stock plant grown under controlled greenhouse conditions. Multiple 3D models were generated by varying the camera-to-subject distance (5-40 cm) and scanning laps (1-7), and these were compared against a reference model obtained through extensive scanning. To evaluate model quality, the generated point clouds were registered to the reference model. Individual leaves were segmented, meshed, and their surface areas calculated. Absolute Percentage Error (APE) and Mean APE (MAPE) were used as accuracy metrics for individual and total leaf area estimation, respectively. Results showed that increasing the scanning distance (up to 40 cm) and using a moderate number of laps (up to 5) reduced missing parts on point clouds and improved leaf area estimation accuracy. Although shorter distances yielded denser point clouds overall, the narrower field of view resulted in incomplete capture of outer leaves, leading to reduced accuracy. These findings highlight the importance of optimizing scanning distance and lap number to minimize point cloud loss and enhance estimation performance. This approach offers a practical and non-destructive solution for plant phenotyping using widely accessible smartphone devices.

Gluten-free rice flour is used in food processing. The quality of the product during storage may be influenced by intrinsic properties and environmental factors such as temperature, humidity, and oxygen exposure. Indica rice, mainly grown in the tropics, is long, slender, and high in amylose than other varieties. In this study, we investigated the changes in the physicochemical properties of Indica rice flour under varying hermetic conditions; ambient, vacuum, CO₂-filled, and bagged during storage at 30°C for 3 months, aiming to identify an economically viable storage approach for tropical regions. The moisture content decreased over the observed period. The apparent amylose content remained relatively unchanged. The water absorption index, water solubility index, and swelling power index exhibited a rapid increase in the initial month and then steadied with slight upward fluctuations. Catalase activity and pH, showed that stored flour deteriorated gradually over time. The storage conditions significantly affected the moisture content and pH values but storage time had a greater influence on all measured parameters. The ambient storage condition effectively minimized moisture loss and pH decline over three months, offering a cost-effective storage solution ideal for low-income farmers in the tropics.

Although previous research has explored the use of saline water or biogas digestate for irrigation in closed systems, the effects of varying salinity levels on water transfer and harvest rates under different leaf area index (LAI) conditions have not been fully investigated. This study assessed the potential of saline water desalination by examining water transfer (evapotranspiration) and harvest rates across three distinct salinity levels and four LAI conditions in a closed lettuce culture system. Simultaneously, water quality parameters, including electrical conductivity (EC) and hydrogen ion concentration (pH), of the harvested water were analyzed. Water transfer and harvest rates increased with increasing LAI, independent of salinity level, despite a reduced water vapor pressure deficit (VPD) within the closed system. Simulations indicated that these rates would be significantly higher if the VPD level remained constant (e.g., 1 kPa). The water harvest rate was approximately 80% of the water transfer rate, with the difference between water transfer and harvest rates attributed to system ventilation. To achieve higher water harvest rates, a more airtight system is necessary, along with maintaining CO₂ concentrations at or exceeding atmospheric levels (approximately 500 μmol mol^-1) to prevent growth inhibition at higher LAI conditions. In addition, the EC and pH of the harvested water were significantly lower than those of the irrigated saline water, indicating the potential of using plants for water desalination in a closed system. The results provide fundamental quantitative data for harvesting freshwater and plants from saline water in closed plant culture systems.

In recent years, the use of biostimulants, which include substances and/or microorganisms that enhance plant physiological functions, has gained increasing attention in agriculture. A biostimulant composed primarily of naturally occurring rare fatty acids is currently used as a growth promoter in some plant production systems. This study investigated the effects of foliar application of LEAFENERGY^® by comparing changes in the photosynthetic rate, transpiration rate, and stomatal conductance of mature greenhouse-grown tomato leaves. The upper leaf surfaces were sprayed with 600 μL of a 600-fold dilution of LEAFENERGY^®. solution, and control leaves were sprayed in the same manner with an equivalent volume of water. The photosynthetic rate and stomatal conductance were greater in the biostimulant-treated leaves than in the control leaves, suggesting that treatment with the biostimulant promoted photosynthesis by opening the stomata and increasing gas exchange. The sugar content of the biostimulant-treated leaves also increased, likely due to the promotion of photosynthesis.

In recent years, space agencies including NASA, academia, non-profit organizations, and private companies have been considering potential human settlement sites on Mars. The First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars was conducted in the United States in 2015. At the workshop, 47 teams analyzed separate exploration zones under the same rubric and criteria to identify potential landing sites, areas of scientific interest, and areas of resource interest. Most of the studies focused primarily on scientific exploration, and did not analyze from a perspective of settlement. In this paper, Mars Society Japan compared the same 47 exploration sites from four main perspectives: "local water resource usage," "atmospheric thickness corresponding to altitude," and "latitudes with sufficient sunlight for agriculture," to determine settlements capable of accommodating up to 10,000 people. In total, four locations were selected as candidates. Two of the locations coincided with potential settlement sites selected by SpaceX for city construction.

I have been studying material circulation in closed systems, including CELSS (Closed/Controlled Ecological Life Support System), from an engineering standpoint. This paper reviewed our research. First, we applied autonomous decentralized control to the CELSS material circulation system. Next, I constructed a mathematical model of a microcosm, the smallest ecosystem, and explored the causes of its stability. Around the same time, I helped to develop a method for creating operating procedures for material circulation systems using an automatic scheduling method. Based on these experiences, I proposed a hierarchical control method. As an additional function to this method, I added a function to automatically determine the order in which to repair multiple faulty machines.

We investigated the soil nutrient conditions of commercial broccoli fields and evaluated them for fertilization improvement using Low-PK fertilizers (those fertilizers which contain lower P and K than N) over two years in field experiments. Continuous cropping of broccoli may result in higher phosphate and potassium content and a disruption of the base balance, and potentially cause environmental pollution. Therefore, the relationship between excessive soil nutrients and the use of Low-PK compound fertilizers was investigated to evaluate the appropriate method and conditions for improved plant growth. The results suggest that we can improve the excessive accumulation of nutrients and base balance using a combined Low-PK fertilizer and drip irrigation in broccoli fields. This fertilization method may help address the nutrient environment for optimal broccoli growth while also being effective for high-quality vegetable management and improvement in soil nutrient conditions for broccoli cultivation.

Insect pollination is one of the most widely used methods in greenhouse horticulture. An efficient pollination service minimising external energy input is essential to realise carbon-neutral and self-sufficient greenhouse system. In this study, we developed a preliminary model for simulating the dynamics of pollination process to contribute to the future establishment of energy-efficient pollination services for sustainable practices in greenhouse cultivation. The model assumes that pollinators are attracted by the VOCs emitted from pollen grains and that pollen are consumed by the pollinators. Our results demonstrate significant variations in pollination efficiency based on the distribution of plant species within a field. Further research on pollinator behaviour and the dynamics of attractants from plants is necessary to refine the model.

With the aim of effectively utilizing north sea urchins removed from the sea-urchin barren grounds and reducing food waste, the feeding value of discarded fried chicken and rice balls from a convenience store for north sea urchins was examined. After 56 days of rearing, a comparison of gonad index, gonad coloration, taste, and free amino acid content in north sea urchins revealed that when fed with diets adjusted from fried chicken, their gonads exhibited a relatively bright yellow coloration, but were accompanied by a higher content of valine and methionine, resulting in a pronounced bitterness. In contrast, when fed with diets adjusted from rice balls, although the gonad indexes were smaller in size, the gonads had a sweet taste without bitterness, and there was a minimal amount of remaining food. When fed diets comprising equal amounts of rice balls and fried chicken, the north sea urchins exhibited higher gonad indexes, mitigating color and taste shortcomings observed when each diet was provided individually. Based on the above results, it is considered that these two types of food waste can be potentially utilized as suitable feed for north sea urchins by either mixing them or, if mixing is not feasible, providing fried chicken to enhance gonad indexes, followed by rice balls to improve taste. This approach may enhance the utilization of north sea urchins by either mixing them or, if mixing is not feasible, providing fried chicken to enhance gonad indexes, followed by rice balls to improve taste. Such approaches may contribute to optimizing the utilization of north sea urchins with waste as an advantageous feed source.

The influences of quercetin on the productions of lipid peroxides, anisidine-reactive compounds and ozone in autoxidation of α-linolenic acid were investigated. Lipid peroxide concentration, anisidine value and ozone concentration significantly increased in the autoxidation of α-linolenic acid for 5 days. On the other hand, the addition of quercetin as a natural antioxidant agent efficiently suppressed the increases in the generations of these peroxidation products. The increase in ozone concentration was correlated with the increase in anisidine value, but not the lipid peroxide concentration. The oxidative cleavage of double bonds in α-linolenic acid and lipid peroxides by ozone generated in the autoxidation seems to be involved in the productions of anisidine-reactive compounds. Quercetin inhibited the process of productions of anisidine-reactive compounds by inhibiting the generation of ozone from lipid peroxides. Next, the direct effect of autoxidized α-linolenic acid on λDNA was evaluated. The autoxidized α-Linolenic acid degraded λDNA dependently upon the increase in anisidine-reactive compounds. On the other hand, the addition of quercetin during the autoxidation of α-linolenic acid significantly inhibited the degradation of λDNA. 2,4-Heptadienal and trans-2-pentenal efficiently degraded λDNA, suggesting that the DNA-degrading compounds in autoxidized α-linolenic acid might be these aldehydes.

Recovery of plant nutrients from food residue is one of the most effective methods for resource recycling. To use food residue for hydroponics, the organic matters have to be mineralized and the nutrients have to be dissolved. Anaerobic digestion, biological oxidation, anaerobic digestion followed by biological oxidation, and wet oxidation are treatments to break down organic matter. The decomposition products of these processes are in liquid form and would be used as liquid fertilizer. The authors investigated the difference in the behaviour of nitrogen, potassium, and phosphorus in each treatment. Nitrogen was converted to ammonium by anaerobic digestion and wet oxidation, and to nitrate by biological oxidation. Potassium did not change significantly with treatment. The percentage of dissolved phosphorus in all treatments, especially in the microbial treatment, was smaller than in food residue. This is probably due to phosphorus binding to other ions and uptake by microorganisms during the treatment process.

Green onions (Allium fistulosum L.) are an essential flavoring vegetable in Asian cuisine with high nutritional value. To ensure their stable future production, efficiently cultivating them in plant factories is necessary. In this study, we investigated the effects of spectral photon flux density and lighting position and direction for green onion production using two cultivars (ʻWhite Starʼ and ʻFukuichi-Negiʼ). First, we investigated the effects of four types of light-emitting diode (LED) lamps with or without far-red light and different red/blue (R/B) ratios on the growth of the green onion cultivars. ʻWhite Starʼ had the highest shoot fresh weight when grown under low blue-light ratio LED lamps with far-red light, while ʻFukuichi-Negiʼ had the highest shoot fresh weight under medium blue-light ratio LED lamps. The R/B ratio and far-red light affected green onion growth, with the effect varying among the varieties. Furthermore, we investigated a light irradiation method to increase the production efficiency of green onions. We compared the growth of the two green onion varieties by irradiating the top of the plants (conventional method) or their sheath base from the lateral direction (sideward irradiation). The results showed that the shoot fresh weight of ʻWhite Starʼ and ʻFukuichi-Negiʼ grown under sideward irradiation were 1.5- and 1.3-fold higher than those under the conventional method, respectively.

This study provides important knowledge for improving the efficiency of green onion production in plant factories using LEDs.

Seed-propagated strawberry ‘Yotsuboshi’ is capable of flower bud differentiation under short-day and low-temperature conditions, which promotes flower bud differentiation in June-bearing varieties, as well as under 24-hour light period. In this study, we hypothesized that overnight supplemental lighting during the nursery period could induce flowering and promote growth of ‘Yotsuboshi’. We investigated the effects of photosynthetic photon flux density (PPFD) and light quality of overnight supplemental lighting on growth and flowering of ‘Yotsuboshi’. Blue, green, and red light-emitting diodes (BGR_LED) or blue, red, and far-red LEDs (BRFR_LED) were used as supplemental light sources. Overnight supplemental lighting was conducted from 18 : 00 to 6 : 00 hours at 100, 200, and 300 μmol m^-2 s^-1 PPFDs on the canopy of seedlings for 30 days during the summer season in Japan. At 15 and 30 days after initiating treatment, the dry weights of plants in all treatments with supplemental lighting were >1.5-times higher than those in the control without supplemental lighting. There was no significant difference in the total dry weight between the different supplemental light sources at each PPFD. The number of days from the start of the treatment to flowering was less than 50 for plants that received supplemental lighting with BRFR_LED than those for plants without supplemental lighting (control). Therefore, overnight supplemental lighting should include far-red light to promote flowering in ‘Yotsuboshi’.

To investigate effects of CO₂ concentration, light intensity, and nutrient solution strength on the growth of wasabi (Eutrema japonicum (Miq.) Koidz.) seedlings, they were grown in environmentally controlled chambers. In the first experiment, single effect of CO₂ concentration on growth of wasabi cultivar ʻIzumaʼ was investigated. The dry weight of the whole seedling was increased more under enriched CO₂ concentrations (1000 and 2000 ppm (v/v)) than under ambient CO₂ concentration (400 ppm). However, the CO₂ effect to raise photosynthesis was weakened in the latter half of the experiment. To sustain the effect of the enriched CO₂ throughout the whole seedling cultivation period and maximize the wasabi seedling growth, the wasabi seedlings were grown under different light intensities and different nutrient solution strengths in the second experiment. Two wasabi cultivars ʻIzumaʼ and ʻFujimidoriʼ were used. ʻFujimidoriʼ is a newly developed cultivar that is more tolerant to high temperatures. The results revealed that ʻFujimidoriʼ had the highest whole dry weight under enriched CO₂ concentration (1000 ppm), higher light intensity (200 µmol m^-2 s^-1), and higher concentration of the nutrient solution. Contrary, the whole dry weight of ʻIzumaʼ under such environmental conditions was almost the same as that of ʻIzumaʼ grown under a lower concentration of nutrient solution but enriched CO₂ concentration and higher light intensity, and under lower light intensity but enriched CO₂ concentration and higher concentration of nutrient solution. This suggests that a combination of a higher concentration of the nutrient solution and higher light intensity cannot amplify the CO₂ effect on ʻIzumaʼ growth. The difference in the environmental response between the two cultivars seemed to be partially caused by the different temperature tolerances.

To evaluate the effectivity of ʻCoral gravel agricultureʼ on cherry tomato, we examined the effects of silicon and calcium included in solid medium on growth, yield and photosynthesis. Total fruit yield and total number of fruits were increased by silicon material in solid medium. Simultaneously, net photosynthetic rate at later growth stage was increased by silicon material. However, the yield and photosynthesis parameters were no affected by foliar spray of silicon. These effects indicate that the silicon thorough root was the important on yield and dry matter production of cherry tomato. Moreover, the calcium material in solid medium increased the total fruit yield in cherry tomato. The photosynthetic rate was slightly increased by calcium material, but the effects was not significant. Therefore, the calcium through root was the important factor in cherry tomato, but the importance of calcium was smaller than silicon. These results indicated that silicon and calcium in Coral gravel promoted the growth and photosynthesis, and consequently increased the yield of cherry tomato.

We investigated the grain thickness distribution of flavorful rice (Oryza sativa L. cv. Koshihikari) in Japan. A total of 150 samples were collected from three Special A rice cultivation areas (with high ratings for taste quality) and compared with 30 samples collected from other rice growing areas. We found that the flavorful rice samples tended to have greater grain thickness than the control samples. There were multiple differences in the physicochemical properties of rice samples with different thicknesses. In general, the thicker rice grains had higher amylose contents and lower protein contents. Higher amylose and lower protein contents were correlated with higher taste values and cooking qualities. The results suggested that we can improve the taste quality of rice by selecting grains with greater thickness. We can also sort rice with different protein and amylose contents by fractionation based on thickness. This fractionation method could help address the increasing demand for high quality rice.

The freshness of leafy vegetables is one of the most essential requirements that plant factories need to meet in order to attract consumers. The farmbox^® developed by Farmship, Inc. is an in-store plant cultivation system. It can be placed on the floor of a supermarket where it can be used to grow aromatic herbs with lighting and irrigation equipment. This system allows consumers to purchase extremely fresh vegetables by harvesting the aromatic herbs by themselves and minimizes the time lag between the time of harvest and purchase, which is a major factor affecting freshness. In addition, the flavor/smell, which is attributed to volatile organic compounds (VOCs) that are emitted by plants, is also one of the most important factors affecting freshness, especially for aromatic herbs. In this study, we investigated the effect of in-store cultivation using a farmbox^® on VOC emissions from sweet basil (Ocimum basilicum) leaves. In the standard commercial production process, control plants were grown under a PPFD (Photosynthetic Photon Flux Density) of 300 μmol m^-2s^-1 for 16 hours a day for 23 days (16L:8D). Then, for the light treatment, plants were maintained in the farmbox^® and subjected to lighting with a PPFD of 130 μmol m^-2s^-1 for 4 hours a day for an additional 7 days (4L:20D). For the dark treatment, plants were maintained in the farmbox^® under continuous dark conditions for an additional 7 days. VOCs emitted from whole and shredded leaves were collected using a closed chamber system and analyzed by GC-MS (Gas Chromatograph Mass Spectrometer) with a thermal desorption system. The emission of typical VOCs from sweet basil, such as eugenol, cineole, linalool, (Z)-3-hexenal, and (Z)-3-hexenol, was observed. In the case of the whole leaves, the emission of cineole during the dark treatment was significantly higher than that from the from the control and the light treatments. Conversely, in the case of the shredded leaves, the emission of (Z)-3-hexenal from both the light and the dark treatments was significantly lower than that from the control treatment. Furthermore, the emissions of linalool and (Z)-3-hexenol from shredded leaves of plants maintained under dark conditions were lower than those of the control. The results suggest that lighting conditions during the preservative cultivation period in the farmbox^® affect the VOC emission profile of sweet basil leaves, and that these conditions can be used to modify the flavor/smell profile of this herb.

To investigate effects of environmental factors in nurseries on growth of Wasabi (Eutrema japonicum (Miq.) Koidz.) seedlings, they were grown in four different sites in Shizuoka and one site in Yamanashi during summer season in 2021 and 2022. At the end of experiment, ratio of shippable seedlings among the seedlings used for experiment was highest (= 80%) at Yamanashi site, followed by Fujinomiya highland site. At the site of Fujinomiya lowland, no shippable seedlings were obtained. Environmental factors affecting the shippable ratio at individual sites seemed to be different, i.e. air temperature, vapor pressure deficit, or light intensity. A multiple regression analysis was applied to clarify the significant factors affecting the shippable ratio. Accumulated air temperature over 30°C, diurnal range of air temperature, light intensity, and yearly-different growing setup have been revealed to be affecting factors. Using the relationship, suitable sites for Wasabi seedling cultivation during summer season were estimated among 55 sites where meteorological data were provided by Japan Meteorological Agency. The number of the suitable sites were 1, 3, and 20 in Shizuoka, Yamanashi, and Nagano prefectures, respectively. Assuming that air temperature was 1°C higher than average of those during 2021 and 2022, the number of the suitable sites was decreased, but Yamanakako village was left, to which our experimental site in Yamanashi was adjacent.