On the cover

The cover image highlights the effectiveness of hot water dipping (HWD) followed by ethanolic shellac–modified coconut oil (ES-MCO) coating in alleviating internal browning and reducing fruit rot in gamma-irradiated ‘Pattavia’ pineapple (Ananas comosus L. Merr.) during storage.　Pineapple is an economically important tropical fruit, but its export is constrained by postharvest losses, particularly internal browning (IB), fruit rot, and physiological deterioration. Although gamma irradiation is an effective phytosanitary treatment for controlling quarantine insect pests, it can accelerate IB development and adversely affect fruit quality. Previous studies demonstrated that ES-MCO coating and HWD individually improved postharvest quality in pineapples; however, their combined application as pre-treatments before gamma irradiation have not been investigated. In this study, pre-treatment with HWD (46.5°C for 30 min) followed by ES-MCO coating effectively alleviated internal browning, reduced fruit rot severity, and maintained the postharvest quality of gamma-irradiated ‘Pattavia’ pineapple. Compared with untreated irradiated fruit, HWD + ES-MCO markedly reduced browning and fungal decay while maintaining peel and pulp quality. This resulted in fresher, higher-quality fruit after storage. These findings demonstrate that the combination of HWD and ES-MCO coating is a promising, environmentally friendly approach for preserving fruit quality and extending the storage life of gamma-irradiated pineapple.

(Provided by P. Jitareerat: King Mongkut’s University of Technology Thonburi)

Japanese apricot, which is a traditional fruit and ornamental tree species in Japan, blooms from late January to early March, depending on the year, site, and cultivar. The blooming time of temperate deciduous trees is determined by the following two genotype-specific flower bud temperature requirements: a chilling requirement (endodormancy release) and a heat requirement (ecodormancy release). Both temperature requirements have been analyzed using several temperature accumulation-based models, including the chill hour, chill unit, chill portion, and growing degree hours. However, the development rate (DVR) model, in which the amount of dormancy release per unit time is expressed as a numerical value, was recently proposed for Japanese apricot, as well as other fruit tree species. This model, which is useful for predicting blooming times, sequentially accumulates DVRs for endodormancy and ecodormancy release in accordance with external temperatures. Models for predicting Japanese apricot blooming times suggest that the heat response for ecodormancy release is initiated before the chilling requirement of flower buds is fulfilled. Moreover, differences in the blooming times of the primary cultivar ‘Nanko’ and its pollinizer cultivars are expected to increase because of global warming. Additionally, the physiological and genetic mechanisms regulating temperature requirements have recently been clarified. In terms of fluctuations in plant hormone levels, the antagonism between abscisic acid and gibberellic acid, as well as the catabolism of these hormones, are related to dormancy depth. Furthermore, recent genetic and transcriptomic studies showed that interactions between DORMANCY-ASSOCIATED MADS-box genes regulate the synthesis and catabolism of hormones, affecting the induction of bud dormancy and the maintenance of bud growth cessation during chilling accumulation and prolonged exposure to chilling stress. However, crucial factors that define the genotype-dependent temperature requirements of Japanese apricot flower buds remain to be identified. To comprehensively characterize how blooming time is controlled, more accurate phases of chilling and heat response must be distinguished.

This study investigated the effects of chitosomes, sweet basil oil, and sweet basil oil-chitosomes on oxidative stress and disease resistance in ‘Nam Dok Mai No. 4’ mangoes stored at room temperature (27 ± 2°C) for 8 days. Untreated fruits developed disease rapidly, with incidence reaching 100% by day 6, while all treatments delayed symptom development. Notably, sweet basil oil-chitosomes completely suppressed disease throughout storage. Hydrogen peroxide (H₂O₂) levels increased sharply in control and chitosome-treated fruits, while sweet basil oil and its encapsulated form significantly reduced H₂O₂ accumulation, with the encapsulated treatment maintaining the lowest levels in both peel and pulp. Both treatments slowed a decline in total phenolic content and ascorbic acid, with sweet basil oil-chitosomes offering the most effective preservation. Antioxidant enzyme activities (catalase and ascorbate peroxidase) were lowest in controls, moderately increased by chitosomes, and strongly enhanced by sweet basil oil. The encapsulated treatment showed the highest enzyme activities, with 4.02- and 8.02-fold increases in peel, and 10.8- and 4.96-fold increases in pulp. Pearson’s correlation indicated that sweet basil oil-chitosomes most effectively stabilized the antioxidant network and minimized oxidative stress, followed by chitosomes and free basil oil, while the control exhibited the weakest defense, consistent with its higher anthracnose susceptibility. Principal component analysis further confirmed that sweet basil oil-chitosomes offered the greatest protection by sustaining both enzymatic and non-enzymatic antioxidants. These results demonstrate that sweet basil oil-chitosomes, as an innovative nanocarrier delivery system, offer a promising natural strategy for enhanced postharvest disease management and quality preservation in mangoes.

Anthracnose, caused by Colletotrichum sp., is one of the major postharvest diseases affecting ‘Nam Dok Mai Sithong’ mangoes. This study explored the efficacy of Zinc oxide nanoparticles (ZnO NPs) and ozone (O₃), both individually and in combination, in controlling anthracnose while preserving fruit quality. Two ZnO NPs types (P10 and P20) were evaluated at 0.5, 1.0, and 2.0 g·L⁻¹ using the poisoned food technique. ZnO NPs inhibited Colletotrichum colony growth in an isolate-dependent manner; P20 (~20 nm) showed greater inhibition at 1.0 g·L⁻¹ (27.8–55.6%), whereas P10 (~10 nm) showed no significant additional inhibition at 2.0 g·L⁻¹ (32.1–53.7%) compared with P20 across three isolates. O₃ treatment at 40 mg·L⁻¹ resulted in complete suppression of spore germination that was observed after 30 and 90 min of exposure, but prolonged exposure damaged the fruit lenticel. O₃ treatment at 40 mg·L⁻¹ caused only minimal inhibition of C. siamense colony growth (≤ 3% compared with the control). However, a 10-min exposure significantly reduced disease incidence to 22.2% and reduced lesion diameter to 4.4 mm in inoculated mangoes. The combination of ZnO NPs (P10, 2.5 g·L⁻¹) and O₃ (40 mg·L⁻¹ for 10 min) exhibited significant colony growth inhibition of C. siamense (72.4%), comparable to ZnO NPs alone (69.4%), but markedly greater than O₃ alone (20.0%). Both P10 alone (1.5–2.5 g·L⁻¹) and the sequential application of P10 followed by O₃ fumigation (40 mg·L⁻¹, 10 min) completely suppressed anthracnose, resulting in 0% disease incidence and no lesion development in all treated fruit. Fruit quality was evaluated using non-inoculated mangoes treated with P10, O₃, and their combination; results showed preserved fruit firmness, increased total soluble solids, and maintained visual quality. Zinc residue analysis was conducted at 1.5 and 2.5 g·L⁻¹ to represent the lower and upper application rates. No detectable residues were found in fruit treated at 1.5 g·L⁻¹ P10, and only a very low level (1.37 mg·kg⁻¹) was detected at 2.5 g·L⁻¹. Even at the highest concentration, ZnO NPs residues remained minimal. These results highlighted the combination of ZnO (2.0 g·L⁻¹) and O₃ (40 mg·L⁻¹ for 10 min) as a promising postharvest strategy for managing anthracnose, while preserving mango quality and ensuring residue levels remain within safe limits.

Gamma irradiation is widely used for the disinfestation of insect pests in fruits under plant quarantine. However, its application can negatively impact on fruit quality. In pineapple, irradiation has been reported to accelerate internal browning (IB) and increase susceptibility to rot disease during storage. This study investigated the effects of pre-treatment with ethanolic shellac-modified coconut oil (ES-MCO) coating and hot water dip (HWD) on reducing IB and fruit rot disease in gamma-irradiated pineapple cv. Pattavia. Pineapples were subjected to the following pre-treatments: (1) ES-MCO coating solution (8% shellac + 2% modified coconut oil), (2) HWD at 46.5°C for 30 min, (3) HWD followed by ES-MCO coating, and (4) 500 ppm fungicidal prochloraz. After pre-treatment, fruits were irradiated with gamma rays at a dose of 400 ± 10 Gy. Additionally, (5) gamma-irradiated (GI) and (6) non-irradiated pineapples without pre-treatment served as controls. All fruit samples were stored at 13°C for 21 days and then transferred to 25°C for 2 days to stimulate shelf-life conditions. The results showed that GI induced IB, and pre-treatment with HWD accelerated IB in GI-treated fruit. Pre-treatments with ES-MCO alone and HWD + ES-MCO effectively alleviated IB symptoms, suppressed polyphenol oxidase (PPO) activity, total phenolic content accumulation, and quinone formation in GI-treated fruit. Quality analysis revealed that HWD + ES-MCO pre-treatments delayed peel and pulp color changes, reduced the respiration rate and ethylene production, maintained total soluble solids and ascorbic acid content, and slowed the increase in titratable acidity in GI-treated fruit. Moreover, HWD + ES-MCO pre-treatments significantly reduced fruit rot severity, with efficacy comparable to prochloraz. Overall, the findings suggest that HWD + ES-MCO is a promising pre-treatment for alleviating IB severity, preserving fruit quality, and reducing rot disease in gamma-irradiated pineapples.

Uncontrolled lighting, occlusion, and variations in viewing angles make it difficult to perform high-frequency, non-destructive monitoring of grape (Vitis vinifera L.) berry growth in the field. Instead of tracking absolute millimeter-level size, a biology-informed pipeline based on YOLOv8 to track relative growth trends is presented. A biology-informed, monotonicity-constrained smoothing step (F-smoothed) is integrated into a workflow that also includes object detection, pixel-to-centimeter conversion using an in-frame 1-cm ruler, preliminary smoothing (outlier removal, interpolation, moving average), and double-sigmoid fitting to summarize phase timing. Images of the ‘Kerner’ and ‘Zweigelt’ clusters in Yoichi, Hokkaido (2024 season; 10 clusters; 1–3-day intervals) were examined as a field case study. On a hold-out validation set, the trained YOLOv8s model demonstrated stable identification (mAP50 = 0.931; mAP50–95 = 0.704; Precision = 0.906; Recall = 0.875). In an independent laboratory validation using detached berries from the 2025 season imaged on a white background, image-derived diameters closely agreed with manual caliper measurements over a range of approximately 0.3–2.3 cm (n = 89; mean absolute error = 0.08 cm; root mean square error = 0.09 cm; mean absolute percentage error = 7.2%; bias = +0.07 cm; R² = 0.97). Biologically credible trajectories were obtained by applying F-smoothed, averaged cultivar curves followed a double-sigmoid pattern with clear timing features. Such relative temporal indicators are directly relevant for viticultural decisions such as scheduling field inspections and harvest windows and for designing sampling strategies for berry composition and quality. Although destructive sampling of the 2024 field clusters was not undertaken, the combination of a validated measurement module and biology-informed smoothing provides reliable phase timing and relative trend tracking in real-world scenarios. With only a handheld camera and conventional computing, this approach offers a practical methodology for non-destructive growth monitoring that emphasizes temporal dynamics while retaining interpretable links to physical berry size.

Gunung Omeh mandarin (Citrus reticulata Blanco var. ‘Gunung Omeh’) is a promising local citrus cultivar from Indonesia, valued for its sweet flavor, distinct aroma, and good postharvest storability. However, its production is constrained by pest and disease pressures, including fruit flies, scale insects, and citrus vein phloem degeneration (CVPD), along with limited availability of high-quality culturing material. Somatic embryogenesis offers an effective strategy for mass propagation and as a long-term platform for genetic improvement. This study aimed to develop a somatic embryogenesis protocol using nucellar Gunung Omeh mandarin explants through three experimental stages: induction, proliferation, and maturation. Nucellar embryos isolated from 60–70 days after anthesis (DAA) fruits were cultured on MS medium supplemented with various auxins (2,4-D, NAA, Picloram) at concentrations of 10, 20, and 30 μM. The highest rate of embryogenic callus formation (76%) and largest callus size (13.1 mm) were achieved using 20 μM 2,4-D. The proliferated calli were then subcultured onto media with 0–0.6 g·L⁻¹ malt extract, and the highest globular embryo formation (80%) occurred at 0.5 g·L⁻¹. Maturation was induced on MS medium with 20–60 g·L⁻¹ sucrose plus 7 μM ABA, where 50 g·L⁻¹ sucrose resulted in the highest number of cotyledon-stage embryos (3.55) and 100% maturation efficiency. This study establishes a stepwise protocol for embryogenesis in Gunung Omeh mandarin, with optimal concentrations of 20 μM 2,4-D for induction, 0.5 g·L⁻¹ malt extract for proliferation, and 47–50 g·L⁻¹ sucrose for maturation. The developed protocol can serve as a foundation for future breeding programs, mass propagation, and genetic transformation of this elite cultivar.

Four soil substrates—a mixture of peat moss and Kanuma soil (mixed soil), peat moss alone, Rockwool, and coir—were tested for their suitability for producing low-potassium southern highbush blueberries (Vaccinium corymbosum L. interspecific hybrid) (SHB). The characteristics of the substrates were first analyzed: peat moss and Rockwool had low cation exchange capacities, Rockwool had a high pH, and coir had high potassium content. SHB ‘Misty’ plants were transplanted into each substrate and grown under potassium-restricted conditions for 5 or 12 weeks. The 5-week restriction did not reduce the fruit potassium content, whereas the 12-week restriction reduced it by 30–45%. Although fruit quality did not differ significantly among substrates, leaf chlorosis was observed with Rockwool, and both mixed soil and coir resulted in lower yields or fewer fruits. These results suggest that peat moss is the most suitable substrate for low-potassium SHB production as it minimizes adverse effects on plant growth and fruit quality.

Accurate identification of apple cultivars is critical to enhance their economic value and market positioning throughout production and distribution. However, due to the complex genetic backgrounds and highly similar external traits of different apple cultivars, traditional manual identification methods are costly and fail to meet the requirements for efficient and precise classification. To address this challenge, we developed an enhanced detection model, YOLO-APPLE, built upon the YOLOv7 framework. The model integrates attention mechanisms and more efficient convolutional operations to improve accuracy, and further investigates the impact of incorporating the Focal loss mechanism on overall model performance. To evaluate the proposed approach, we conducted experiments on a dataset comprising 363 images under both stable and variable lighting conditions. Experimental results indicated that YOLO-APPLE can accurately identify various apple cultivars and demonstrates excellent generalization capability. On the test set, the model achieved a precision (P) of 0.908, recall (R) of 0.968, mAP@0.5 of 0.973, mAP@0.5:0.95 of 0.933, and an F1-score of 0.937. Compared to the baseline YOLOv7 model, the proposed model achieved improvements of 0.5%, 7.4%, 1.5%, 0.4%, and 3.9% in P, R, mAP@0.5, mAP@0.5:0.95, and F1-score, respectively. These findings suggest that YOLO-APPLE offers a high-performance solution for rapid and accurate apple cultivar detection, providing valuable technical support for fruit production and supply chain management.

Xylem sap flow is critical for grapevine dormancy release and early spring growth. However, the dynamic metabolic shifts within the sap during this transition are not fully understood. In this study, we employed untargeted liquid chromatography-mass spectrometry (LC-MS) to profile the xylem sap metabolome of grapevine across key developmental stages in early spring. We detected 585 and 407 metabolites in positive and negative ion modes, respectively. Our time-resolved analysis revealed a highly orchestrated, three-phase metabolic reprogramming to prepare the vine for budburst. The initial stage was marked by the activation of amino acid metabolism, exemplified by a significant increase in glutamic acid, indicating the mobilization of foundational nitrogenous resources. This was followed by a broad upregulation of biosynthetic pathways for secondary metabolites and phenylpropanoids, likely priming the plant for defense and structural development. The final stage was characterized by a decisive shift towards purine metabolism, essential for producing energy (ATP) and nucleic acids to fuel imminent cell division. Concurrently, a strategic reallocation of resources was observed, with a dramatic decrease in dormancy-associated defense compounds like resveratrol. Collectively, these findings provide the first detailed metabolic map of this transition, revealing a coordinated biochemical strategy for dormancy release and identifying potential biomarkers for assessing vine readiness for spring growth.

In terms of the sensory characteristics of tomato, fruit texture is important for consumer acceptance. The fruit texture can be measured with instruments like texture profile analyzers or through sensory evaluation, and depends on several factors, including salt stress and cultivar. Additionally, alterations in pectin composition and metabolizing enzymes contributes to changes in fruit texture. However, cultivar differences regarding pectin content and pectin-metabolizing enzymes, the effect of salt stress on fruit texture and their relationships are often overlooked. This study tested whether the effect of salt stress on consumers’ evaluation of hardness, fruit texture, and pectin metabolism varied between three tomato cultivars; a cherry-type ‘cf Kosuzu’, a large-type ‘cf Momotaro Fight’, and a medium-large type ‘Celeb Sweet’. Salt stress was applied by adding 100 mM NaCl to the nutrient solution. The salt-induced changes in consumer evaluations of hardness and fruit texture depending on the cultivar; the evaluation of the large tomato type was higher than that of the cherry and medium-large types. Salt-stressed fruits of the large type exhibited increased pectin content and pectin-metabolizing enzymes, including pectin methylesterase (PME) and polygalacturonase (PG), compared to the cherry and medium-large types. Additionally, in a correlation network, PME and PG were connected by the consumers’ evaluations of hardness. Our results indicate that consumers’ evaluation of hardness, texture profile, and pectin metabolism varied across the three tomato cultivars. We infer that salt stress had a greater impact on the texture attributes of large-type fruits. Furthermore, pectin metabolism may contribute to cultivar variations in the effects of salt stress on fruit texture and the sensory evaluation of hardness.

Optimizing both the fresh weight of the bulb and the overall yield is crucial to achieve profitable onion production. This study aimed to examine the effects of cultivar, plant density, and the amount of light interception on bulb weight and total yield. Two yellow onion cultivars, ‘Momiji No. 3’ and ‘Totana’, were grown at plant densities ranging from 10.4 to 31.2 plants per m² (with plant spacings of 24, 16, 12, and 8 cm at a fixed row spacing of 24 cm) over two years. Bulb fresh weight increased as plant spacing widened, whereas total yield per unit area increased with plant density. This shows a trade-off between individual bulb size and yield. ‘Totana’ consistently produced larger bulbs and higher yield than ‘Momiji No. 3’ at each plant density. For both cultivars, regardless of plant density, the amount of integrated light interception post-transplantation strongly correlated with bulb fresh weight and dry matter production. High light interception is driven primarily by a greater leaf area index (LAI) and canopy development. Among tested conditions, plant densities of 10.4–20.8 plants per m², with plant spacings of 24, 16, and 12 cm, in ‘Totana’ provided the optimal balance between bulb weight and yield, with bulbs exceeding 300 g per plant and total yields surpassing 4.0 kg·m⁻². For ‘Momiji No. 3’, wider plant spacing (16–24 cm) increased bulb weight, and bulbs exceeding 300 g may be achieved under favorable environmental conditions. The results of this study suggest that optimizing the combination of cultivar selection and plant density, while considering light interception capacity, can simultaneously improve bulb size and yield under field conditions.

In Japan, wholesale prices of strawberries fluctuate markedly, making the timing of peak harvest with periods of high market value a critical issue. Consequently, there is a strong demand for technologies that enable harvest control. We aimed to achieve harvest control with fruit maturation management using environmental control. Harvest control requires accurate prediction of fruit yield, which predicts fruit size and harvest date. In this study, we focused on predicting fruit size. To construct an early prediction model of fruit size as the foundation for harvest control decisions, we attempted predictions using only floral and environmental parameters available at the time of flowering. From the collected parameters, variable selection based on the variance inflation factor was performed to mitigate the effects of multicollinearity. To avoid overfitting, a 4-fold cross-validation was applied, and a multiple regression model was constructed to predict fruit weight. As a result of variable selection, six parameters were selected as explanatory variables: flowering order within the inflorescence, receptacle area, pedicel diameter, flowering day, average air temperature, and direction of inflorescence. The multiple regression model achieved an R² of 0.775. Additionally, the feasibility of substituting future temperature data with historical data or target set-point temperatures was demonstrated. Furthermore, a flower thinning experiment showed that the influence of post-flowering source–sink balance on fruit size was minimal, indicating that it does not need to be incorporated into the model. These results demonstrate that fruit size can be predicted with reasonable accuracy using data available at flowering, and will play an important role in early yield prediction systems that will be developed in the future.

The domestication of chili peppers (Capsicum spp.) across diverse environments has generated a wide range of cultivars that constitute valuable reservoirs of allelic diversity. Single nucleotide polymorphism (SNPs) markers are particularly useful for characterizing this diversity due to their high abundance in plants and environmental stability. However, the latest methods such as multiplexed inter-simple sequence repeats genotyping by sequencing (MIG-seq) and genotyping by sequencing (GBS) face limitations in terms of efficiency and costs, respectively. To address these challenges, we applied the novel, cost-effective, degenerate oligonucleotide primer MIG-seq (dpMIG-seq) method to assess genetic diversity in 65 Capsicum accessions from South America and Asia, representing C. annuum, C. chinense, C. frutescens, and C. baccatum. Sequencing generated a total of 78,673 SNPs, of which 11,557 high-quality markers were retained. Principal component analysis and neighbor-joining phylogenetic method resolved two major genetic pools corresponding to C. annuum and C. baccatum complexes, further dividing the collection into four clusters. C. baccatum formed a distinct branch, while C. chinense and C. frutescens occupied intermediate positions, suggesting their potential role as genetic bridges between C. annuum and C. baccatum. Population structure analysis (K = 5) confirmed species-level clustering and revealed admixture among C. frutescens and C. chinense for unclassified Capsicum spp. accessions. Because of the overall low interspecific gene flow, it is necessary to incorporate novel alleles into breeding programs. Using dpMIG-seq for SNP discovery and genetic analysis in Capsicum expands the study of phylogenetic relationships, germplasm characterization, and breeding strategies for crop improvement and biodiversity conservation.

Hokkaido is located in a subarctic area of Japan, where attempts have been made to produce leafy vegetables with high Brix values in winter under cold-stress conditions. Kale has recently become popular due to its high nutritional value. ‘Winterbor’, a cold-tolerant cultivar of borecole, a type of kale, grows without any cold stress damage in unheated plastic greenhouses at temperatures as low as −7°C. In this study, it was found that the growth rate of ‘Winterbor’ in winter was less than that of the collard kale cultivar ‘Hi-Crop’ and had a higher dry matter ratio and Brix value. The air temperature within the greenhouse was lowered by approximately 2°C by removing some of the insulation layer on the greenhouse under the winter cultivation. As a result, neither leaf emergence nor overall plant weight was affected. As the air temperature continued to fall with the approach of winter, the dry matter ratio, Brix value, and sucrose content increased in ‘Winterbor’ leaves. The dry matter ratio, Brix value, and combined content of fructose, glucose, and sucrose tended to be higher under cold management (less insulation) than under standard management. Statistical analysis based on the air temperature conditions during the cultivation period indicated that leaf emergence and plant weight reached constant values at approximately 5°C and 3°C daily mean air temperature, respectively. However, the dry matter ratio, Brix value and total soluble sugar content (three soluble sugars) increased by 1.1%, 1.1, and 7.3 mg·g⁻¹ fresh weight (FW) with every 1°C drop from the average daily minimum air temperature for 10 days before harvest, starting at approximately 6°C. These results suggest the possibility of estimating and controlling borecole plant growth and quality parameters and could contribute to the systematic production and distribution of highly valuable borecoles grown in unheated plastic greenhouses in winter in Hokkaido.

In greenhouse tomato production, maintaining optimal environmental conditions—such as temperature and CO₂ concentration—has traditionally been considered essential for maximizing crop yield. However, this study demonstrates that the most profitable strategy does not always align with biologically “optimal” conditions. Instead, the proposed framework occasionally selects mildly stressful environments that reduce operational costs and ultimately increase net profit. We developed a simple, profit-oriented optimization framework that integrates a yield prediction model, energy cost simulation, and Bayesian optimization via the Metropolis-Hastings algorithm. The framework was calibrated using data from a research greenhouse in Tsukuba equipped with advanced environmental control systems, including heat pumps. Simulation results showed that optimized control strategies could more than double profitability. Practical validation was conducted during the autumn–winter 2024 season at agricultural research stations in Gifu and Aichi prefectures, where heat pumps were not installed. Weekly environmental settings—including CO₂ concentration, heating, and ventilation—were optimized to maximize profit rather than yield alone. Field experiments confirmed up to a 1.5-fold increase in profit, even in greenhouses without advanced equipment. Importantly, both Aichi and Gifu achieved increased yields without incurring losses, primarily due to effective CO₂ enrichment. In Aichi, although heat stress reduced overall productivity, the conventional plot also suffered yield loss, making the optimized strategy appear more favorable in relative terms. Simulated profit reductions due to heat stress were similar in both plots, indicating that the optimization mitigated—but did not eliminate—environmental impacts. The framework selected temperature settings near the threshold where yield reduction begins (daily mean ≈23°C), balancing reduced operational costs with slight yield suppression. These findings suggest that profit-oriented environmental control, which may involve a tolerable temperature, can be more effective than traditional yield-maximization approaches, especially under economic and operational constraints.

The scent of cut carnation flowers decreases rapidly after harvest. Recent research has shown that continuous treatment with 5% sucrose mitigates this decrease in the scent of Dianthus caryophyllus ‘Milky Way’. However, continuous sucrose treatment is not practical for actual shipping and transport. It is also unclear how the effect of sucrose treatment on scent is affected by preservatives commonly applied to cut carnation flowers. In this study, the effects of sucrose treatment duration and co-treatment with preservatives on scent emission from cut flowers were evaluated. Sucrose treatment for 24 or 48 h increased scent emission from cut flowers of the ‘Milky Way’ cultivar, and the longer the treatment, the longer the period of high scent emissions. Short-term sucrose treatment promoted scent increases immediately after flower opening, but not later in the anthesis period. These findings suggest that exogenous sucrose is used as a substrate for scent production and is depleted over a short period. To evaluate whether this knowledge could be applied to improve the scent of cut carnations in Japan, we conducted a demonstration experiment wherein cut flowers were treated with 5% sucrose for a 48 h period that included time spent under wet-transport conditions. Thereafter, scent-retention capacity was assessed. Sucrose treatment increased scent emission significantly in all five cultivars tested. Furthermore, in a sensory evaluation test, sucrose treatment increased the percentage of positive ratings for the intensity of cut carnation scent significantly. The combination of sucrose and conventional chemical treatments, including preservatives containing silver thiosulfate or slow-release chlorine to prevent ethylene-induced flower senescence or bacterial growth in the vase water used during transport, resulted in scent improvement, along with the expected effects of the chemical treatments. Overall, these results suggest that wet transport with sucrose is a promising technique for improving the scent of cut carnations.