Controlled Environment Agriculture Research Articles

The Impact of Genotype and Controlled Environment Cultivation Parameters on Tomato-Leaf-Derived Exosome-like Nanoparticle Yield and Properties

Horticultural plant material offers several advantages for isolating exosomes and other natural plant-derived exosome-like nanoparticles (PDENs) due to the accessibility and affordability of plant material for widespread applications. This study aims to explore the impacts of the tomato genotype (‘Admiro’, ‘Roma’, ‘Brooklyn’, ‘Marmande’ and ‘Betalux’) and the main cultivation parameters in controlled environment agriculture on the yield and properties of their PDENs for pharmaceutical and cosmeceutical applications. The PDEN yield, size distribution, and antioxidative properties of young tomato seedlings were evaluated. The ‘Betalux’ tomato was distinguished by a remarkably higher nanoparticle concentration and a uniform size distribution and was selected for further experiments. The impact of cultivation temperature (18, 22, and 26 °C), nitrogen nutrition (0, 250, and 500 mg L−1), and the lighting photosynthetic photon flux density (PPFD; 150, 250, and 450 µmol m−2 s−1) on nanoparticle properties was investigated. Optimal conditions consisting of a temperature of 22 °C, 250 mg L−1 nitrogen nutrition, and 250 µmol m−2 s−1 lighting PPFD were used as a reference. Optimal temperature, nitrogen nutrition, and lighting intensity resulted in the highest nanoparticle yield, the most uniform particle distribution, and the highest impact of PDEN preparations on keratinocyte metabolic activity. Deviation from optimal cultivation conditions reduced the tomato biomass and the PDEN protein and yield.

Propagation Light Intensity Influences Yield, Morphology, and Phytochemistry of Purple-Leaf Butterhead Lettuce (Lactuca sativa)

Lettuce (Lactuca sativa) is an economically important leafy green produced in controlled environment agriculture (CEA). Optimization of lighting conditions is a crucial factor for sustainable production of high-quality lettuce in CEA systems. This study aimed to determine the effects of propagation light intensity (60, 100, 200, 400, and 600 μmol∙m-2∙s-1, 24-h photoperiod) on harvestable yield, morphology, carotenoids, chlorophylls, and anthocyanins of purple-leaf butterhead ´Teodore´ lettuce at transplant (14 days after showing) and harvest (21 days after transplanting in a greenhouse environment). We observed a 275% increase in shoot fresh mass in seedlings grown under 600 μmol∙m-2∙s-1 compared to those under 60 μmol∙m-2∙s-1, and a 163% improvement persisted through harvest. The HPLC quantification demonstrated that all carotenoids, including violaxanthin, neoxanthin, zeaxanthin, antheraxanthin, lutein, α-carotene, and total carotenoid content and/or concentration increased in lettuce seedlings as light intensities increased from 60 to 400 or 600 μmol∙m-2∙s-1 (5.4 to 35.9 or 52.7 mol∙m-2∙d-1 DLI). A similar increasing trend was also observed for chlorophyll accumulation. Anthocyanin concentration and content increased with increasing propagation light intensity, but no differences persisted through harvest. Overall, differences in most phytonutrient concentrations and contents persisted through harvest; carotenoid content trends were similar to those at transplant, but carotenoid and chlorophyll concentration trends were somewhat opposite with quadratic decreases as light intensity increased. The results indicate that propagation light intensity could be used as an effective and sustainable strategy to improve the harvestable yield and nutritional quality of lettuce grown in CEA.

Low–carbon regulation method for greenhouse light environment based on multi–objective optimization

Controlled environment agriculture is uniquely positioned to contribute to the decarbonization of cities due to its low carbon emissions and high energy efficiency in the food supply process. The energy consumed by the horticultural industry to suppplemental lighting is enormous, but improvements in the light environment of greenhouse plants are essential. To make light regulation compatible with low carbon and environmentally friendly while improving photosynthetic production, experiments on tomato plant measurements with nested light intensity, spectra, carbon dioxide concentration and temperature were carried out in a solar greenhouse based on an infrared gas analyzer and machine learning. Based on the photosynthetic response to the photosynthetic photon flux density and red–blue ratio under multi–environmental conditions, the photosynthesis prediction model was developed using the least squares support vector regression, and model hyperparameter optimization was achieved by genetic algorithm nested cross–validation. A calculation method of carbon emissions from suppplemental lighting was proposed, and the low–carbon light regulation was abstracted into multi–objective optimization for the solution. Based on the comprehensive objective evaluation method, low–carbon targets for light regulation were obtained through decision–making. The results showed that the developed prediction model with root mean square error of 1.069 and determination coefficient of 0.976, which is both accurate and fast, realizes the description and expression of the net photosynthetic rate in response to the environments. The optimal targets contain two–dimensional information of light intensity and spectra, and reduces carbon emissions by a maximum of 14.85% compared to the light saturation objective based on single–objective optimization at 95.49 % of the net photosynthetic rate. The method is energy efficient and suitable for supporting multi–spectral light environment regulation applications and guiding the greenhouse environment management under the demand of carbon reduction.

Amber LEDs outperform red, blue, and red-blue-amber LEDs for lettuce

ABSTRACT Debate persists on light in controlled environment agriculture. To dissect the effects of conventionally used wavelengths on a crop and provide new information to this expanding food production sector, this study investigated the effects of monochromatic and combined red, blue, and amber light on lettuce growth with increasing light intensities (up to 1300 µmol·m−2·sec−1) for 18 days with a 16 h·d−1. Under amber light at PPFDs ranging from 500 to 700 µmol·m−2·sec−1, fresh mass displayed a 33.3% greater yield when compared to red light at the same PPFD. Suppressed growth was observed with either red or amber alone at high PPFD (>800 µmol·m−2·sec−1). Blue light was the least productive of the four treatments, yet lettuce plant growth was not suppressed at high intensities. No growth suppression was observed for lettuce plants grown under combined red-blue-amber light at high intensities, and these plants exhibited greater biomass yield than blue light alone. Varied degrees of pigmentation occurred under each light treatment, yet bleaching was only observed in plants grown under amber light alone at PPFD above 1000 µmol·m−2·sec−1. Findings present novel plant responses to high intensity light, setting precedence for future experiments aimed at expanding the use of LEDs in horticulture.

Light emitting diode effect of red, blue, and amber light on photosynthesis and plant growth parameters

The visible light spectrum (400–700 nm) powers plant photosynthesis and innumerable other biological processes. Photosynthesis curves plotted by pioneering photobiologists show that amber light (590–620 nm) induces the highest photosynthetic rates in this spectrum. Yet, both red and blue light are viewed superior in their influence over plant growth. Here we report two approaches for quantifying how light wavelength photosynthesis and plant growth using light emitting diodes (LEDs). Resolved quantum yield spectra of tomato and lettuce plants resemble those acquired earlier, showing high quantum utilization efficiencies in the 420–430 nm and 590–620 nm regions. Tomato plants grown under blue (445 nm), amber (595 nm), red (635 nm), and combined red-blue-amber light for 14 days show that amber light yields higher fresh and dry mass, by at least 20%. Principle component analysis shows that amber light has a more pronounced and direct effect on fresh mass, whereas red light has a major effect on dry mass. These data clarify amber light's primary role in photosynthesis and suggest that bandwidth determines plant growth and productivity under sole amber lighting. Findings set precedence for future work aimed at maximizing plant productivity, with widespread implications for controlled environment agriculture.

Assessing sensory attributes and quality of lettuce from open field, greenhouse, and controlled environment production systems

Lettuce is a popular, low-calorie, nutrient-rich leafy vegetable known for its health benefits and bioactive compounds. The transition from open-field to controlled-environment agriculture has revolutionized lettuce production, enabled year-round cultivation while provided advantages such as enhanced environmental management, diminished pest challenges, and improved crop quality. This study assessed the consumers’ perception of quality attributes of Eden lettuce from three production systems: open field, greenhouse, and controlled environment. Sensory evaluation encompassed the assessment of attributes such as colour, flavour, texture, and nutrition, with panellists evaluating lettuce samples from each production system, and the Kruskal-Wallis H test was used to analyse the data. Controlled environment cultivation showed the highest texture intensity, with significant variations in sweetness, sourness, bitterness, and astringency among production systems. Aroma and aftertaste remained relatively consistent across different systems. Acceptability levels of sensory attributes varied among lettuce samples from different production systems. Controlled environment lettuce received the highest acceptability ratings for texture, flavour, and colour, while notable variations were observed in colour acceptability among production systems. Taste attributes varied among production systems, with open field lettuce displaying diverse taste profiles, greenhouse lettuce leaning towards bitterness, and controlled environment lettuce emphasizing sweetness. Texture attributes also differed, with open field exhibiting balanced profiles, greenhouse yielding firmer textures, and controlled environments emphasizing moderate firmness. In conclusion, the choice of production system has a substantial impact on lettuce quality and sensory attributes. Controlled environment cultivation consistently yielded lettuce with superior attributes, while greenhouse cultivation led to firmer textures and specific taste profiles. On the other hand, open field cultivation exhibited a broader range of taste attributes. These findings provide valuable insights for agricultural practices, resource management, and quality control in lettuce cultivation, offering opportunities for growers and consumers to make informed choices based on their preferences and requirements.

Paradise by the far-red light: Far-red and red:blue ratios independently affect yield, pigments, and carbohydrate production in lettuce, Lactuca sativa.

In controlled environment agriculture, customized light treatments using light-emitting diodes are crucial to improving crop yield and quality. Red (R; 600-700 nm) and blue light (B; 400-500 nm) are two major parts of photosynthetically active radiation (PAR), often preferred in crop production. Far-red radiation (FR; 700-800 nm), although not part of PAR, can also affect photosynthesis and can have profound effects on a range of morphological and physiological processes. However, interactions between different red and blue light ratios (R:B) and FR on promoting yield and nutritionally relevant compounds in crops remain unknown. Here, lettuce was grown at 200 µmol m-2 s-1 PAR under three different R:B ratios: R:B87.5:12.5 (12.5% blue), R:B75:25 (25% blue), and R:B60:40 (40% blue) without FR. Each treatment was also performed with supplementary FR (50 µmol m-2 s-1; R:B87.5:12.5+FR, R:B75:25+FR, and R:B60:40+FR). White light with and without FR (W and W+FR) were used as control treatments comprising of 72.5% red, 19% green, and 8.5% blue light. Increasing the R:B ratio from R:B87.5:12.5 to R:B60:40, there was a decrease in fresh weight (20%) and carbohydrate concentration (48% reduction in both sugars and starch), whereas pigment concentrations (anthocyanins, chlorophyll, and carotenoids), phenolic compounds, and various minerals all increased. These results contrasted the effects of FR supplementation in the growth spectra; when supplementing FR to different R:B backgrounds, we found a significant increase in plant fresh weight, dry weight, total soluble sugars, and starch. Additionally, FR decreased concentrations of anthocyanins, phenolic compounds, and various minerals. Although blue light and FR effects appear to directly contrast, blue and FR light did not have interactive effects together when considering plant growth, morphology, and nutritional content. Therefore, the individual benefits of increased blue light fraction and supplementary FR radiation can be combined and used cooperatively to produce crops of desired quality: adding FR increases growth and carbohydrate concentration while increasing the blue fraction increases nutritional value.

Opportunities for membrane technology in controlled environment agriculture

Controlled environment agriculture has the potential to enhance agriculture sustainability, a United Nations sustainable development goal. Enclosed agricultural facilities can be used in locations that cannot support field agriculture while reducing water usage and increasing productivity relative to open field agriculture. The primary challenges with operation arise from energy consumption to maintain the proper growth conditions. Membrane processes can reduce energy consumption by controlling temperature, humidity, and carbon dioxide concentration. Membrane processes also can minimize water consumption by enabling the use of non-conventional water resources and reducing wastewater production. The literature describing these applications is reviewed and opportunities for future innovation are discussed.

Vegetable Production in PFALs: Control of Micro-Environmental Factors, Principal Components and Automated Systems

Plant factories with artificial lighting (PFALs) are indoor crop production systems aiming at the growth of high-value products in terms of yield and quality, while maximizing resource use efficiency. The emergence of PFALs opened a new world for crop production and offered an option to tackle problems related to climate change, land availability, and urban/peri-urban farming. This was made possible upon major technological advancements and extensive research in the field of controlled environment agriculture, which paved the way for the establishment of such cost-efficient and climate-unaffected modules of vegetable and other crops’ production. In the present review, we have examined the recent research achievements regarding the micro-environmental factors, the principal components, as well as the automated systems used for plant production in PFALs. Ultimately, we provide the reader with a number of future perspectives that can be considered for indoors cultivation in the following years.

Energy-saving effect assessment of various factors in container plant factories: A data-driven random forest approach

Plant factory is one of the controlled environment agriculture forms with huge potential to alleviate food crisis, but the high energy cost restricts its widespread adoption. Numerous researches have explored various factors for energy-saving in plant factories in their settings, but there is a lack of analysis of the importance of these factors in energy saving. In this work, the energy-saving effect assessment of various factors in the container plant factory is investigated. Four cities (Harbin, Taiyuan, Shanghai, and Guangzhou), three plant densities (cultivation area: floor area=100 %, 150 %, and 200 %), and two temperature/humidity setpoints (20/22 ℃, 60/70 %, and 16/22 ℃, 50/95 %) are selected as operating conditions to cover different weather conditions and plant heat loads. The energy-saving effect of each factor is calculated using a random forest algorithm based on large amounts of energy simulation data. We identify that envelope overall heat transfer coefficient (U), air conditioner coefficient of performance (COP), and light efficacy (Efficacy) are three factors that have the largest impact on energy-saving in plant factories, in which light efficacy is the most important factor. Simultaneous optimization of these three factors could possibly reduce electricity consumption by ∼50 % compared to the base case. Finally, employing weight-light intensity correlation, the minimum specific energy consumption is approximately 4.76 kWh/kg lettuce fresh weight. This study utilizes advanced machine learning methods to sort out important factors and shows that significant energy reduction may be achieved by optimizing dominant factors, which gives a general guidance for future designers to build energy-efficient plant factories.

Investigating the Impacts of Wastewaters on Lettuce (Lactuca sativa) Seed Germination and Growth

There is an opportunity for agriculture to utilize the many different waste streams in our world and capitalize on what would otherwise be viewed as waste products. Hydrothermal liquefaction (HTL) is an emerging technology for converting wet biomass to bio-crude oil, while aquaponics is a practice tracing back to indigenous communities around the world; both technologies have the potential to sustainably provide the necessary nutrients for crop growth. Food systems worldwide are actively transitioning to address the many challenges of climate change in a sustainable and efficient manner. Urban agriculture (UA) has the potential to generate localized crops in densely populated areas year-round, but has its challenges, involving high capital requirements, especially for vertical farming and controlled-environment agriculture, and being energy intensive due to artificial lighting and fossil fuel-based synthetic fertilizers. This study investigated the potential for aquaponic and HTL effluents to be used in hydroponic systems through a seed germination screening experiment. Buttercrunch lettuce (Lactuca sativa L.) seeds were placed in Ziploc plastic bags on paper towels saturated with the wastewater treatments for 10 days while their total length of growth was routinely measured from the tip of the root to the tip of the cotyledons. The Chicago High School for Agricultural Sciences (CHSAS) aquaponic effluent with a 5.8× times higher nitrate concentration and 4.25× higher ammonia concentration outperformed the Bevier aquaponic effluent and improved any other source water it was combined with. Results also showed that seed germination was not inhibited in the presence of 2–8% solutions of hydrothermal liquefaction aqueous phase (HTL-AP), which performed on par with standard hydroponic fertilizer; solutions of a higher percentage, though, may lead to inhibitory effects in plants, and those of a lower percentage may not provide enough nutrients in the proper forms to sustain plant growth. However, the nutrient analyses revealed that there is still much to investigate regarding the combination of wastewaters to provide a complete, well-rounded, and sustainable source for hydroponic crop production.

Effect of Far-Red Light on Biomass Accumulation, Plant Morphology, and Phytonutrient Composition of Ruby Streaks Mustard at Microgreen, Baby Leaf, and Flowering Stages.

Far-red (FR) light influences plant development significantly through shade avoidance response and photosynthetic modulation, but there is limited knowledge on how FR treatments influence the growth and nutrition of vegetables at different maturity stages in controlled environment agriculture (CEA). Here, we comprehensively investigated the impacts of FR on the yield, morphology, and phytonutrients of ruby streaks mustard (RS) at microgreen, baby leaf, and flowering stages. Treatments including white control, white with supplementary FR, white followed by singularly applied FR, and enhanced white (WE) matching the extended daily light integral (eDLI) of FR were designed for separating the effects of light intensity and quality. Results showed that singular and supplemental FR affected plant development and nutrition similarly throughout the growth cycle, with light intensity and quality playing varying roles at different stages. Specifically, FR did not affect the fresh and dry weight of microgreens but increased those values for baby leaves, although not as effectively as WE. Meanwhile, FR caused significant morphological change and accelerated the development of leaves, flowers, and seedpods more dramatically than WE. With regard to phytonutrients, light treatments affected the metabolomic profiles for baby leaves more dramatically than microgreens and flowers. FR decreased the glucosinolate and anthocyanin contents in microgreens and baby leaves, while WE increased the contents of those compounds in baby leaves. This study illustrates the complex impacts of FR on RS and provides valuable information for selecting optimal lighting conditions in CEA.

IoT-enabled Greenhouse Systems: Optimizing Plant Growth and Efficiency

Greenhouses have long been important in the advancement of agricultural operations because they provide regulated settings for optimal plant growth. With the introduction of real-time monitoring and automation capabilities, the Internet of Things (IoT) integration into greenhouse systems represents a revolutionary change. This abstract delves into the wider field of greenhouse technology, highlighting the role that IoT plays in improving agricultural in controlled environments. Conventional greenhouses provide plants with a protected environment, but they might not be as accurate or flexible. Intelligent control of environmental conditions is made possible by the introduction of IoT-enabled greenhouses, which utilize data exchange protocols, actuators, and sensors that are networked. The project aims to elevate traditional greenhouse models by integrating Node-RED and MQTT technologies. Transitioning from a Blynk-based prototype showcases the system's versatility. Other key components, including NodeMCU, sensors for real-time data, and LED lighting, collaborate to redefine controlled environment agriculture. The Raspberry Pi serves as a central hub, facilitating seamless communication through Node-RED and MQTT. This advanced greenhouse system harmonizes cutting-edge technologies, showcasing a commitment to sophistication and adaptability in agricultural practices.

The Short Inflorescence Mutation in Diploid Strawberry Fragaria vesca Affects Inflorescence Architecture and Runner Elongation

Mutants are useful for determining the genes that underlie a given trait. This information is highly useful for developing molecular markers for breeding and is the foundational knowledge required for future genomic crop improvements. The dessert strawberry, Fragaria ×ananassa, is a valuable crop with high potential for increased use in controlled environment agriculture. The genome of the woodland strawberry Fragaria vesca is the dominant genome of the four diploid strawberry subgenomes that contribute to the octoploid F. ×ananassa genome. F. vesca is therefore a useful reference system for determining gene function and should be a useful source of gene diversity for breeding of F. ×ananassa. Chemical mutagenesis of the inbred F. vesca line H4 F7-3 resulted in one M2 line with a smaller stature overall and which produces flowers on very short peduncles close to the crown. This line was named short inflorescence (sin). The sin phenotype results from a single gene recessive mutation that is pleiotropic in that the mutation also affects internode lengths of runners as well as petiole elongation of sin plants. Microscopic characterization revealed that sin peduncles are most likely short because of a failure of cells to elongate. Inflorescences, runners, and petioles of sin plants were found to elongate in response to exogenous gibberellin, indicating that sin could be a gibberellin biosynthesis or transport mutant. A brief characterization of sin plants is presented to facilitate collaborative studies of the line.

Analysis of light recipe, seeding density, and fertilization effects on secondary metabolite accumulation and growth-defense responses in Brassicaceae microgreens

Although there have been large improvements to crop yield over time, this has not been accompanied by an increase in human nutritional wellbeing. In fact, there are worsening health crises associated with over- and under-consumption of particular food groups, resulting in negative human health outcomes. One solution to this is to utilize controlled environment agriculture to produce microgreens that have a high density of valuable Secondary Metabolites (SMs) such as antioxidants, phenolics, or pigment molecules that are associated with positive human health outcomes. However, optimal growth recipes to produce microgreens and their valuable nutritional compounds are not well known due to much species-specific variation, as well as biological tradeoffs between biomass and SM production. This is known as the growth defense hypothesis which describes how plants have a finite carbon budget from which to allocate to growth, or defensive, processes. To further research in this regard, this project used climate chambers to grow three species of Brassicaceae microgreens (kohlrabi, mustard, and radish) in highly controlled environmental conditions, where we used five Light Recipes, two fertilization levels, and two seeding density treatments. Our results showed that there were significant differences in SM production of these microgreens due to changes in incident light, as well as significant interactions between Fertilizer and Light Recipe for all SMs except Anthocyanins. For example, for all three species, the High Far-Red Light Recipe had the significantly highest Phenolic concentration, but with lower values of the other four SMs. The low-intensity 24-volt high efficiency LEDs had the significantly highest Trolox Equivalent Antioxidant Capacity (TEAC) concentrations, while the High Red recipe had the highest Ferric Reducing Antioxidant Power (FRAP) and Flavonoid concentrations. For Anthocyanins, there were less clear patterns, with the No Green or High Red recipes having generally higher concentrations, but not always significantly. We did find some evidence supporting the growth-defense hypothesis, where our higher biomass values were negatively correlated with SM concentrations. We also found significant differences between the concentrations of SMs in leaves and stems for kohlrabi and mustard microgreens. Finally, we found some significant relationships between increasing Fertilizer dosage and SMs, for instance that Flavonoids and FRAP concentrations increased with Fertilizer application, while Anthocyanin decreased, and Phenolic and TEAC had little effect. In conclusion, we found that there were significant relationships for Light Recipe and Fertilizer, and oftentimes their interaction, for the accumulation of SMs in Brassicaceae microgreens, which can inform microgreen production environments.

Evaluating Organic Fertilizers and Microbial Inoculation for Soilless and Hydroponic Crop Production

Because hydroponic operations in the United States can be certified as organic, and because the price of chemical fertilizers has increased, there is an increasing interest in using organic fertilizers and beneficial microorganisms for controlled-environment agriculture. However, there is a scarcity of information regarding their effectiveness and application methodologies. We investigated the effects of inoculating Azospirillum brasilense and Rhizophagus intraradices and using organic fertilizers on growing lettuce (Lactuca sativa ‘Cherokee’) and tomato (Solanum lycopersicum ‘Red Robin’) young plants in an indoor vertical farm. Seeds were sown in rockwool substrate, with A. brasilense (1.05 × 108 colony-forming units⋅L−1) or R. intraradices (580 propagules⋅L−1) applied weekly via subirrigation. Seedlings received chemical fertilizer, organic fertilizer derived from corn steep liquor and fermented fish by-products, and food waste-derived organic fertilizer at 100 ppm total nitrogen every 2 or 3 days. They were grown indoors at 23 °C under light-emitting diode lighting at a photosynthetic photon flux density of 200 μmol⋅m−2⋅s−1 with an 18-hour photoperiod. Lettuce under organic fertilizers had 75% lower shoot fresh mass and 64% less shoot dry mass compared with lettuce under chemical fertilizer. Similarly, tomato seedlings with organic fertilizers had fewer leaves, 75% less shoot fresh mass, and 67% less shoot dry mass. In both lettuce and tomato, the macronutrient and micronutrient concentrations in plant tissues were generally similar regardless of fertilizer treatments, but nitrogen use efficiency and nitrogen uptake efficiency were lower under organic fertilizers compared with those under chemical fertilizer. The inoculation of A. brasilense or R. intraradices showed limited effects on plant nutrient uptake, nutrient concentrations, and seedling growth in both lettuce and tomato. Further research is necessary to optimize application methods for organic fertilizers and beneficial microorganisms to fully harness the benefits of sustainable alternative fertilizers in soilless and hydroponic crop production.

Protein plant factories: production and resource use efficiency of soybean proteins in vertical farming.

Controlled environment agriculture, particularly vertical farms (VF), also called plant factories, is often claimed as a solution for global food security due to its ability to produce crops unaffected by weather or pests. In principle, essential macronutrients of the human diet, like protein, could technically be produced in VF. This aspect becomes relevant in the era of protein transition, marked by an increasing consumer interest in plant-based protein and environmental challenges faced by conventional farming. However, the real question is: what does the cultivation of protein crops in VF imply in terms of resource use? To address this, a study was conducted using a VF experiment focusing on two soybean cultivars. With a variable plant density to optimize area use, and because of the ability to have more crop cycles per year, protein yield per square metre of crop was about eight times higher than in the open field. Assuming soy as the only protein source in the diet, the resources needed to get total yearly protein requirement of a reference adult would be 20 m2 of crop area, 2.4 m3 of water and 16 MWh of electricity, versus 164 m2, 111 m3 and 0.009 MWh in the field. The study's results inform the debate on protein production and the efficiency of VF compared to conventional methods. With current electricity prices, it is unlikely to justify production of simple protein crops in VF or promote it as a solution to meet global protein needs. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Period induced reflectance tuning in transparent gold metasurfaces

Gold (Au) nanodisk arrays are modeled and fabricated for tunable near infrared reflectance with high visible transmittance. Simulations are performed in the visible and near infrared regimes between 400 and 2000 nm with varying period of nanostructures. A progressive increase in period of up to three times the diameter of the nanodisks on polymer and quartz substrates is presented. As a result, an increase in visible transmittance with a decrease in near infrared reflectance peak intensity is observed. Modeling results exhibit a high average visible transmittance of 91.5% (400–700 nm) and average reflectance of 62.9% (750–2000 nm) with diameter (D) variations from D=120 nm to D=500 nm with a period (P) equal to twice the diameter, P=2D for a polymer substrate. Electric field intensities exhibit an increase with a decrease in the period between individual nanostructures for constant unit cell dimensions. Alongside simulations, electron beam lithography and evaporation processes are utilized for the patterning and fabrication. Optical characterizations including scanning electron microscopy (SEM) and atomic force microscopy (AFM) of selected metasurfaces on quartz are performed. For a specific period and diameter, the fabricated metasurfaces exhibit near infrared reflectance having a good agreement with the simulated results about plasmonic wavelengths. Such metasurfaces offer potential to be deployed for applications that require selective reflectance intensities in the near infrared range with high visible transmittance, such as controlled environment agriculture (CEA) or multi spectral near infrared sensing. With tunability over a broadband (750–2500 nm), this simple and fabrication-friendly model may be used as a theoretical guide in quantifying specific design parameters with varying light intensity configurations.

Alteration of growth, phenology, and yield of lily flowers through the synergetic effect of light spectra and endophytic bacterial priming

The production of ornamental flowers in controlled environment agriculture (CEA) has gained significant attention due to its potential for efficient cultivation. This study aimed to evaluate the influence of light quality (red, blue, red+blue, and white) after priming bulbs with Bacillus subtilis (Bs) on lily plant growth, phenology, yield, ornamental attributes, and pigmentation. Both light quality and Bs treatment significantly affected vegetative and generative organ development and overall plant growth. Bulbs primed with Bs and grown under blue light exhibited the earliest budding and flowering phases, along with an extended flowering period. The highest flower yield and productivity were achieved in Bs-primed bulbs under blue light. Regarding qualities, the best scores were obtained for Bs-primed bulbs grown under blue or red+blue light, compared to control plants grown under red light. The combined effects of Bs treatment and light quality also impacted photosynthetic pigment content in lily leaves. Throughout the growing season, the highest levels of photosynthetic pigments were detected under white light. Although the ratio between Chl a with other photosynthetic pigments were decreased during the flowering period, Bs treatment positively influenced those rations during the flowering phase when plants grown under monochromatic lights (red and blue). In summary, to achieve high-quality lily flowers in CEAs, the most promising approach involves utilizing a red+blue light spectrum in combination with Bs priming. This research highlights the importance of optimizing growing conditions and understanding the interplay between light quality and biological treatments for enhancing ornamental flower production in CEA systems.

Reporting and practices of sustainability in controlled environment agriculture: a scoping review

Reporting and practices of sustainability in controlled environment agriculture: a scoping review