Search Results (647)

Vertical farming (VF) is a critical solution for sustainable urban agriculture; however, its economic viability remains constrained by high labour and energy costs. The integration of Artificial Intelligence (AI) and Computer Vision (CV) offers opportunities to automate monitoring and optimize environmental control. This systematic review synthesizes peer-reviewed research published between 2015 and 2026 on Deep Learning (DL) applications for lettuce (Lactuca sativa) cultivated in Controlled Environment Agriculture (CEA). Literature was retrieved from Google Scholar, Scopus, PubMed, Semantic Scholar, OpenAlex, and Web of Science, resulting in 34 eligible studies selected from an initial pool of 893 records. The analysis indicates that Convolutional Neural Networks (CNNs) and You Only Look Once (YOLO)-based object detection models are the most widely adopted architectures for non-invasive growth monitoring and disease detection, frequently reporting accuracy metrics exceeding 90%. In parallel, hybrid approaches that integrate AI with biophysical constraints are gaining attention for yield estimation and nutrient prediction tasks. Nevertheless, significant challenges remain, particularly concerning data availability and reproducibility, as 87% of the reviewed studies rely on private datasets. Overall, the findings underscore the need for standardized benchmarking datasets and computationally efficient, edge-deployable architectures to facilitate the transition from experimental prototypes to scalable commercial applications. Full article

Phosphate ($\mathrm{P}{\mathrm{O}}_4^{3-}$) discharge from municipal wastewater is a major contributor to eutrophication, highlighting the need for efficient treatment technologies that enable both phosphorus (P) removal and potential reuse. In this study, tin (Sn)- and calcium (Ca)-based coagulants, and their composites with chitosan (CS) (CS@Sn, CS@Ca, CS@Sn/Ca), were developed and evaluated for $\mathrm{P}{\mathrm{O}}_4^{3-}$ removal and tentative recovery from both aqueous solutions and municipal wastewater. Among the tested materials, ${\mathrm{SnCl}}_4$ exhibited the highest performance, achieving 97.2–100% $\mathrm{P}{\mathrm{O}}_4^{3-}$ removal over a wide pH range and at low dosages, demonstrating its high affinity toward $\mathrm{P}{\mathrm{O}}_4^{3-}$. The CS@Sn composite material demonstrated satisfactory efficiency, while the Ca-based coagulants exhibited lower efficiency and greater sensitivity to solution chemistry. CaO achieved maximum phosphate removal of 89% under neutral to alkaline conditions, but its efficiency decreased significantly under acidic conditions. CS@Ca and CS@Sn/Ca composites exhibited only moderate removal efficiencies under all experimental conditions tested. SEM and FTIR analyses indicated that $\mathrm{P}{\mathrm{O}}_4^{3-}$ removal occurred through interactions with hydrolyzed Sn(IV) species. The recovered phosphate-rich residues were subsequently subjected to a preliminary pot experiment using lettuce (Lactuca sativa) to explore their potential for agricultural reuse. The results provided an initial indication that some recovered residues may support early plant growth, although further agronomic evaluation under controlled conditions is required. Therefore, ${\mathrm{S}\mathrm{n}\mathrm{C}\mathrm{l}}_4$ represents a promising approach for simultaneous phosphate removal and potential recovery, while the preliminary plant cultivation results indicate potential for agricultural reuse of the recovered residues, warranting further investigation. Full article

Proper substrate moisture management is essential for producing high-quality seedlings in nurseries. This study aimed to evaluate the morphological and physiological quality of lettuce (Lactuca sativa L.) and tomato (Solanum lycopersicum L.) seedlings subjected to different substrate moisture levels, monitored by weighing lysimetry under protected environment conditions. Four experiments were conducted over two growing seasons (2019 and 2020) using six irrigation treatments corresponding to 80, 70, 60, 50, and 40% of the substrate water-holding capacity, in addition to the conventional irrigation management adopted by the grower (Control). Water consumption, morphological traits, root architecture, gas exchange, chlorophyll fluorescence, and photosynthetic pigments were assessed. Cumulative irrigation water applied ranged from 77 to 92 mm in lettuce and from 91 to 132 mm in tomato. Reducing substrate moisture to 40% negatively affected seedling growth, root development, and physiological performance in both species. In tomato, stomatal conductance decreased by up to 90%, accompanied by a decline in Fv/Fm from 0.78 to 0.70. Both lettuce and tomato tolerated moderate reductions in substrate moisture (60–70% holding capacity) without significant losses in growth or gas exchange performance. However, the highest seedling quality was achieved under the grower-managed Control and the 80% substrate moisture treatment, although the traits contributing to this response differed between species. In lettuce, favorable performance was associated with growth, pigment-related traits, and photochemical efficiency, whereas in tomato superior seedling quality was linked to shoot growth, root development, and gas exchange characteristics. These findings support the use of species-specific irrigation strategies to improve seedling quality in nursery production. Full article

Fungal pathogens cause severe yield losses in lettuce production worldwide. We developed transgenic lettuce lines overexpressing the ch5B chitinase gene from Phaseolus vulgaris (bean) under the regulation of the rbcS1 (ribulose-1,5-bisphosphate carboxylase small subunit) promoter. Molecular characterization confirmed stable transgene integration and expression across the selected lines. In vitro assays demonstrated that transgenic leaf extracts significantly inhibited Rhizoctonia solani mycelial growth. Furthermore, inoculation assays in both seedlings and adult plants in the greenhouse showed a significant reduction in lesion areas compared to non-transgenic (NT) controls. Finally, two lines were evaluated in field trials, both showing agronomic substantial equivalence to the NT, satisfying international biosafety frameworks for commercial development. Among them, the ch5B 3-4 line appears to be the most promising candidate for further studies, as it showed slightly higher fresh weight compared to the NT under field conditions.: Full article

Lettuce (Lactuca sativa L.) is a widely consumed leafy vegetable cultivated globally, particularly under soilless systems to enable intensive and high-efficiency production. In these systems, precise nutrient solution management is essential, especially regarding calcium, an indispensable macronutrient involved in cell wall stabilization, membrane integrity, root development, and physiological responses to stress. This study evaluated the morphological and nutritional performance of crisp lettuce cultivars Mônica SF 31 and Veneranda grown using a nutrient film technique (NFT) system, using Calcário, Lithocal^®, and LT Supra^® as alternative calcium sources, alongside a control treatment. The experiment followed a randomized block design in a 4 × 2 factorial arrangement. Measured variables included root, leaf, and stem dry mass; stem length and diameter; and nutrient accumulation and gas exchange parameters. Data were subjected to analysis of variance and means were compared using Scott-knott test. Calcium supplementation significantly increased plant growth, with leaf fresh mass rising by 37% and root fresh mass by 56% compared to the control. Foliar calcium and magnesium concentrations were effectively enhanced by the treatments. Calcário, Lithocal^®, and LT Supra^® demonstrated effectiveness as calcium sources in soilless lettuce cultivation, promoting improved nutrient accumulation—particularly calcium and magnesium—and substantial gains in fresh biomass and root system development. Calcium supplementation is therefore recommended as a strategy to enhance productivity and crop quality in intensive soilless systems. Full article

A process-based developmental model was developed to predict leaf appearance and expansion in romaine lettuce (Lactuca sativa L. var. longifolia) using hourly air temperature and daily light integral as environmental inputs. The model consisted of two linked modules representing leaf appearance and individual leaf expansion as distinct biological processes. The leaf appearance module calculated the hourly leaf tip appearance rate as the product of a beta-type nonlinear temperature response function and a developmental stage weighting function based on growing degree days accumulated above a base temperature of 4 °C. The leaf expansion module estimated individual leaf expansion using photothermal age, a Gompertz growth function, and a leaf length–area allometric relationship, with potential leaf length determined by the mean growing temperature and leaf rank. The optimum temperatures for leaf appearance rate and potential leaf length differed by approximately 6 °C (26.7 °C vs. 20.4 °C), indicating distinct temperature response patterns between the two developmental processes. Model calibration was performed using datasets (n = 437) collected from a temperature-gradient greenhouse with a nutrient film technique hydroponic system across the spring, summer, and autumn growing seasons, yielding an overall model efficiency (EF) of 0.92 and a root mean square error (RMSE) of 4.26 leaves for leaf appearance, and an EF of 0.80 and an RMSE of 448.1 cm² for leaf expansion. Independent model evaluation was also performed using datasets (n = 132) obtained from a commercial greenhouse with either a deep flow technique hydroponic system or a perlite-based substrate system across the same three growing seasons, yielding an EF of 0.96 and an RMSE of 2.24 leaves for leaf appearance, and an EF of 0.92 and an RMSE of 216.8 cm² for leaf expansion. These results demonstrate that the model effectively described leaf appearance and expansion in romaine lettuce across the tested soilless culture systems under greenhouse conditions, highlighting its potential as a leaf development module for integration into canopy photosynthesis and biomass production models. Full article

Hydroponic and soilless systems are increasingly adopted as low-cost, sustainable solutions for global food production, yet they remain highly susceptible to contamination by potential toxic elements (PTEs), particularly arsenic. While biochar is widely recognized as an effective amendment for mitigating PTE contamination in soil-based systems, its ability to alleviate PTE stress in hydroponic environments has been largely overlooked. The gap reveals a critical and underexplored frontier in controlled-environment agriculture, where extending biochar-based mitigation strategies could yield substantial benefits. Here, we evaluated whether Acacia auriculiformis wood biochar could alleviate arsenic (As) toxicity in lettuce (Lactuca sativa) grown in a continuous-flow hydroponic system. Using a completely randomized factorial design (arsenic species × dose × biochar) with three independent replicates per treatment, we tested biochar under 0.2 and 0.8 mg/L of As(III) and As(V). Arsenic significantly (p < 0.05) reduced lettuce growth, with As(III) being more toxic than As(V). Biochar significantly (p < 0.05) improved morphological traits (2.4–103%), cell membrane stability (5.5–12%), photosynthetic pigments (3–73%), and stress indicators proline (8–11%) and malondialdehyde (8–14%). Arsenic accumulated mainly in roots (1.7–2.63 mg/kg) and shoots (0.76–1.36 mg/kg), but biochar reduced accumulation by 28–47% in roots and 33–48% in shoots. Additionally, biochar enhanced nutrient uptake (K, P, Ca, Mg, B, Zn, Cu, S, Mn) at both arsenic levels. Overall, the results indicate that Acacia biochar can substantially reduce arsenic toxicity and improve plant physiological responses in continuous-flow hydroponics, highlighting its promise as a viable and scalable mitigation tool for safeguarding soilless food production systems against PTE contamination. Full article

Phenolic acids are considered important allelochemicals that can restrict nutrient uptake and inhibit plant growth. Most existing studies have focused on growth phenotypes and single nutrient changes under phenolic acid stress, while the coupled C:N:P balance responses of plant–soil systems remain poorly characterized. Ecological stoichiometry offers a holistic perspective to reveal the nutrient supply–demand mismatch underlying allelopathic inhibition by analyzing elemental ratio dynamics, thus deepening the mechanistic understanding of allelopathy beyond traditional single-indicator observations. Using lettuce (Lactuca sativa L.) as the test plant, this study investigated the effects of cinnamic acid (CA) and p-hydroxybenzoic acid (PHA) stress, combined with nitrogen (N), phosphorus (P), and their combined application (NP) on plant growth and plant C, N, and P stoichiometric characteristics. Soil C, N, and P contents and stoichiometric characteristics were further analyzed as supplementary indicators. The results showed that phenolic acid stress significantly reduced lettuce biomass: PHA decreased aboveground biomass by 40.11% and belowground biomass by 44.14%, with a stronger inhibitory effect than CA. Both phenolic acids induced marked stoichiometric imbalance, characterized primarily by a sharp decline in leaf nitrogen content; N content dropped by 49.80% under CA and 70.75% under PHA, corresponding to a 64.43% and 162.79% increase in leaf C:N ratio, and a 37.63% and 63.19% decrease in leaf N:P ratio, respectively. Nutrient addition alleviated these responses to varying degrees: N addition mainly promoted biomass recovery and elevated plant N status, P addition optimized elemental ratios, and combined NP application yielded the strongest overall recovery. Correlation and redundancy analyses indicated that soil C, N, and P stoichiometric characteristics were closely associated with plant growth, with soil organic carbon and total phosphorus identified as major explanatory variables associated with plant growth. Overall, phenolic acid stress altered plant stoichiometric characteristics and growth, as well as soil C, N, and P stoichiometric characteristics, while nutrient addition partially alleviated these responses. These findings provide a stoichiometric perspective for understanding allelopathic stress and may offer a theoretical basis for nutrient management under continuous cropping conditions. Full article

Water scarcity and environmental degradation have emerged as critical challenges threatening sustainable agricultural development worldwide. This study hypothesized that organic substitution buffers the physiological stress of deficit irrigation on lettuce (Lactuca sativa L.), and that this buffering effect of organic substitution can be quantified using AquaCrop to optimize irrigation schedules. Field experiments were conducted to evaluate the interactive effects of irrigation levels and organic/urea fertilizer rates on soil moisture, lettuce growth and yield during two growing seasons (April to May and September to October 2024) in Songjiang, Shanghai. Six treatments combining two irrigation levels (full irrigation at 100% of crop evapotranspiration (ETc) and deficit irrigation at 60% ETc) with three fertilization levels (300 kg/ha urea, 150 kg/ha urea + 15 t/ha organic fertilizer, and 150 kg/ha urea) were conducted. AquaCrop was calibrated and validated using field observations. The results demonstrated that organic substitution under deficit irrigation preserved soil moisture, canopy development, and fresh yield at levels comparable to full irrigation and nitrogen fertilization, whereas 50% nitrogen alone caused substantial yield reduction. AquaCrop showed satisfactory performance in simulating lettuce growth under organic substitution, with normalized root mean square error (NRMSE) values of 3.07%~21.42%, 5.02%~20.11%, and 8.22%~20.95% for soil water content, canopy cover, and fresh yield, respectively. Using the validated model, scenario analysis across the different precipitation years revealed that lettuce yield was most responsive to irrigation during the seedling stage, followed by the rosette stage and cupping stage. Specifically, 100% ETc during the seedling and rosette stages was suggested for dry years; 100% ETc at the seedling stage combined with 80% to 100% ETc at the rosette stage for normal years; and more flexible strategies (60% to 100% ETc at the seedling stage) for wet years based on model predictions. These irrigation strategies, combined with organic substitution, can achieve above 90% of the potential yield of the full irrigation and nitrogen treatment. These findings offer preliminary guidance for irrigation and fertilization management of lettuce under the experimental climate and soil conditions, while further validation across diverse cultivars and environments is needed before broader application. Full article

A sustainable method of improving soil fertility and developing climate-resilient cropping systems is vermicomposting agricultural waste. This study hypothesized that vermicompost derived from mixed organic agricultural wastes would significantly improve soil fertility, crop productivity, and drought resilience compared to single-substrate treatments and the unamended control. The effects of vermicompost generated from mixed organic wastes using Eisenia fetida on soil quality, crop performance, and drought resilience of lettuce (Lactuca sativa, Eden variety) were evaluated in this study using a randomized complete block design. Crop performance indicators included germination, growth characteristics, biomass, SPAD chlorophyll content, and yield, while soil physicochemical properties, including pH, organic carbon, total nitrogen, available phosphorus, exchangeable potassium, electrical conductivity (EC), and cation exchange capacity (CEC), were assessed both before and after amendment application. The effects of drought stress were evaluated using leaf surface temperature, wilting score, recovery time, and survival rate. The results demonstrated that vermicompost application significantly improved soil fertility and crop performance relative to the control treatment (p < 0.05). The best-performing treatment (T2) increased soil organic carbon by approximately 22–28%, total nitrogen by 18–24%, available phosphorus by 20–27%, and exchangeable potassium by 16–21% compared with the control. Fresh biomass increased by approximately 14–17%, marketable yield improved by 16–24%, and SPAD chlorophyll values increased by nearly 20%, indicating enhanced photosynthetic efficiency and nutrient uptake. T2 showed the most resilience under drought stress, with ~94.9% survival rate, reduced wilting severity, shortened recovery time and sustained stable leaf temperature (~27.8 °C), whereas low-performing treatments and the control recorded survival rates of only ~70–78%. Mixed organic waste substrates consistently outperformed single-substrate treatments, demonstrating synergistic effects on nutrient cycling, microbial activity, soil structural quality, and drought tolerance. These findings provide quantitative evidence that vermicomposting can simultaneously enhance soil fertility, crop productivity, and drought resilience, highlighting its strong potential as a scalable climate-smart strategy for sustainable agriculture, circular bioeconomy development, and organic waste valorization in smallholder farming systems. Full article

Supplemental light-emitting diode (LED) lighting is essential for greenhouse crop production when solar radiation is insufficient, but it also contributes substantially to operating costs. Conventional strategies based on fixed photosynthetic photon flux density (PPFD) do not accurately reflect plant photosynthetic status, often leading to inefficient use of light energy. A chlorophyll fluorescence (CF)-based biofeedback system offers a plant-driven approach that dynamically adjusts light output to maintain target photosynthetic parameters. This system has been successfully tested in growth chambers with controlled environmental conditions, but no research has been conducted in greenhouses yet. This study developed and tested a greenhouse-compatible biofeedback lighting system using ‘Casey’ lettuce (Lactuca sativa) to evaluate its performance compared with conventional light controls. Two biofeedback control logics were applied: electron transport rate (ETR)-based (target ETR of 85 or 120 µmol·m⁻²·s⁻¹) and quantum yield of photosystem II (Φ_PSII)-based control (target Φ_PSII of 0.735), with constant PPFD- and timer-based lighting as reference treatments. Both biofeedback logics maintained their target values, confirming stable performance under dynamic greenhouse conditions. Despite successful real-time light regulation in greenhouse conditions, shoot biomass and energy-use efficiency did not differ among treatments under moderate greenhouse conditions (p > 0.05). This study establishes a functional prototype of a real-time physiological biofeedback system for greenhouse supplemental lighting control. Full article

The seedling production stage of lettuce (Lactuca sativa L.) is crucial for crop success, as it determines the initial quality of the plants. The use of seeds with rapid and uniform germination is essential to ensure proper seedling establishment. Among sustainable alternatives for water management, irrigation with ozonated water stands out due to its disinfectant potential and its ability to stimulate plant physiology. This study evaluated the effects of irrigation with ozonated water on the production and development of lettuce seedlings. The experiment was conducted in a completely randomized design (CRD) arranged in a 2 × 2 factorial scheme, with four replications. Two lettuce cultivars were tested: one with smooth leaves and another with crisp leaves. The variables analyzed included germination parameters (final percentage, germination index and mean germination rate, uniformity, and time to reach 10, 50, and 90% germination), as well as initial growth parameters (total height, shoot and root height, and dry matter content). Analyses were performed on 20 seedlings per cultivar. Irrigation with ozonated water promoted significant growth (p < 0.05) of the shoot and root growth, with increases of 16.90 and 4.99% for the smooth-leaf cultivar, and 24.27 and 9.26% for the crisp-leaf cultivar, compared to the control. Ozone application did not alter the microbiological, physical, or chemical parameters of the water. These growth-promoting effects are likely associated with increased oxygenation of the root zone, enhanced oxidation of organic matter in the substrate, and improved nutrient availability promoted by ozone-derived radicals, which may also optimise root respiration and reduce pathogenic pressure. The applied concentration of 5 mg L⁻¹ O₃ over a 25-day seedling production cycle proved effective and did not cause phytotoxic effects. Irrigation with ozonated water is an efficient and environmentally safe alternative for producing vigorous lettuce seedlings. Full article

This study investigated the efficacy of fruit peel-derived fertilizers from banana (Musa), orange (Citrus × sinensis), and mixed fruit peels in promoting lettuce (Lactuca sativa) growth in a hydroponic system as a sustainable alternative to synthetic nutrient solutions. The research determined the optimal concentration and application through trials, comparing effectiveness across concentrations and light exposure conditions within the first 1–2 weeks of cultivation. Findings revealed that optimal concentrations of 400–1000 g of peels per liter of water and a 3-L fertilizer combination yielded favorable outcomes under direct sunlight. The study concludes that banana and mixed peel fertilizers supported robust lettuce growth, with banana being the most effective. Full article

The use of sophisticated software for greenhouse microclimate analysis often requires advanced modelling expertise and significant computational effort, which may not always be available to greenhouse designers. This study proposes an integrated and modular workflow aimed at supporting greenhouse design through coupled thermal and evapotranspiration simulations. The design methodology is based on three steps. In the initial phase, the greenhouse environmental conditions are evaluated through the implementation of a dynamic thermal analysis, which is conducted by the DesignBuilder software (version 4.2). Subsequently, a plant evapotranspiration model is employed in MATLAB/Simulink (version R2025b) to evaluate crop transpiration, moisture production, and irrigation water consumption. In the final phase, the simulated moisture production is used to estimate the required ventilation rates and to support the sizing of greenhouse systems, including irrigation and HVAC components. Plant moisture production is a crucial factor in determining the sizing of greenhouse subsystems, such as the irrigation system, the ventilation rate, and the HVAC system. Nonetheless, the implementation of the evapotranspiration model necessitates a bespoke calibration to a case study. Indeed, the proposed models are more generally applicable and must be adapted to real-world applications. The methodology was applied to a small greenhouse used for the cultivation of aeroponic lettuce (Lactuca sativa cv. Romana) in a Mediterranean environment. The aim of the study was to explore the potential of the proposed integrated modelling framework to estimate annual irrigation water demand and the minimum ventilation rate required to mitigate excess moisture production, using a coupled MATLAB/Simulink implementation. The proposed approach should be interpreted as an exploratory design-support methodology rather than a fully validated predictive model, intended to investigate system behaviour under the specific conditions of the case study. Full article

Developing sustainable strategies for natural resource management and conservation under shifting climatic scenarios is increasingly necessary due to exacerbated abiotic stresses, such as salinity. Under salt stress, several negative effects are observed in plants, particularly in leafy vegetables such as lettuce (Lactuca sativa L.). To mitigate the effects of saline stress from brackish water, several strategies have been adopted, including hydroponic cultivation. Therefore, this study aimed to determine the effects of variations in nutrient solution concentration and volume per lettuce plant cultivated in a nutrient film technique (NFT) hydroponic system using brackish water. The experiment was conducted using a randomized complete block design in a 2 × 2 × 2 factorial scheme, combining two levels of water electrical conductivity (ECw of 0.3 and 5.0 dS m⁻¹), two nutrient solution concentrations (NSC of 50 and 100%), and two nutrient solution volumes (NSV of 1 and 2 L plant⁻¹), with four replications. Growth, production, and water productivity variables were evaluated at 20 and 25 days following the imposition of treatments. The responses of the variables to saline stress varied according to the evaluation period (20 and 25 days), depending on the NSC and NSV levels. At the end of the 25-day cycle, it can be concluded that for lettuce cultivation using brackish water, the NSC can be reduced to 50% and provide an NSV of 2 L plant⁻¹. Under these growing conditions, leaf fresh matter production loss was approximately 40% lower than under cultivation without saline stress, which yielded 144.11 g plant⁻¹ under 100% NSC and an NSV of 2 L plant⁻¹. In contrast, water productivity of fresh matter was similar, at 78.68 and 76.55 g L⁻¹, respectively. Full article