Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This article provides a valuable and up-to-date systematic review on integrated management of blueberries (Vaccinium spp.), covering plant physiology, fertilization, water management, production technology, harvesting, and postharvest processes. The authors rigorously applied the PRISMA 2020 guidelines, which increases the transparency and reliability of the methodology. The broad scope of the literature (1987–2025) captures the evolution of knowledge and technology in the blueberry sector, and the interdisciplinary nature of the review is a distinct strength.

The article particularly highlights the synergies between physiological regulation, environmental control, precision fertigation, and the use of digital technologies and automation. The article presents advances in sensory science, modeling, decision support systems, and non-thermal technologies in postharvest in an accessible and well-structured manner. The analyses presented reflect global trends in precision agriculture and the growing importance of artificial intelligence and automation tools.

Another valuable element of the work is its demonstration of the role of the circular economy in blueberry production, particularly in the areas of water reuse, renewable energy, waste biorefining, and environmental footprint assessment. The conclusions are consistent and clearly summarize the most important areas of technological and environmental integration.

Despite its numerous strengths, the article has some areas requiring refinement. The most significant is the lack of a quantitative data synthesis—even a limited meta-analysis (e.g., on yield, quality, or irrigation efficiency) would significantly enhance the evidence. Furthermore, a more detailed discussion of regional differences and economic barriers to implementing modern technologies would be worthwhile. It would also be useful to introduce a framework integrating the main elements of the production system to enhance the clarity of the proposed holistic approach.

Recommendations for authors

1. Consider conducting a limited meta-analysis where data allow.
2. Include a clear section addressing the limitations of the review, including method heterogeneity.
3. Add economic and regional aspects of technology adoption to the analysis.
4. Introduce a graphical model integrating the main components of crop management.
5. Refine practical recommendations to enhance the usefulness of the review for producers and advisors.

Comments on the Quality of English Language

Minor correction recommended

Author Response

January 15 2026.

Reviwer 1.

We sincerely thank the reviewer for their constructive and insightful suggestions. These comments have been carefully considered and have significantly contributed to strengthening the scientific rigor, clarity, and applied relevance of the manuscript. The reviewer’s recommendations were fully integrated into both the conceptual and practical dimensions of the review, resulting in a more robust and coherent synthesis of the evidence. All corresponding modifications are detailed in the present response letter and have been incorporated into the revised version of the manuscript, where they are highlighted in yellow for ease of identification.

Suggest.

Consider conducting a limited meta-analysis where data allow.

Reply. We appreciate the reviewer’s suggestion to consider a limited meta-analysis and carefully evaluated this possibility during the methodological revision of the manuscript. However, we concluded that conducting a meta-analysis is not methodologically appropriate for the overall scope of this review, which integrates multiple components of the blueberry production system, including harvest, physiology, sanitary and phytosanitary management, plant material and propagation, modeling and use of technologies, greenhouse production, and sustainability. Across most of these areas, the available studies exhibit substantial heterogeneity in experimental designs, spatial and temporal scales, cultivars, environmental conditions, management practices, and response variables, which precludes the calculation of comparable effect sizes and a statistically robust quantitative synthesis. We acknowledge that postharvest management is the only domain in which some studies may show partial methodological similarity, particularly regarding fruit quality, storage conditions, and shelf-life-related variables. Nevertheless, even within this area, data remain fragmented and inconsistently reported, limiting their suitability for a reliable meta-analytical approach. Moreover, postharvest processes are currently being addressed in a separate, dedicated manuscript specifically designed to enable a more focused and coherent quantitative analysis. Including a partial meta-analysis of postharvest studies in the present review would have duplicated efforts and detracted from the primary objective of this manuscript, which is to provide a comprehensive and integrative synthesis of the blueberry production system. Finally, performing a meta-analysis restricted to one or two subtopics while the remaining sections are addressed qualitatively could introduce interpretative bias and overemphasize specific components without adequately representing the multidimensional nature of blueberry production. For these reasons, we opted for a structured narrative synthesis, which allows for the integration of experimental, technological, and production-oriented evidence, facilitates cross-topic comparison, and enables the identification of knowledge gaps and future research priorities with greater conceptual consistency and practical relevance.

 

Include a clear section addressing the limitations of the review, including method heterogeneity.

Reply. Following the reviewer's recommendation, we have included the following section:

Study Limitations

Despite the methodological rigor applied under the PRISMA 2020 guidelines, this review presents several limitations inherent to its scope and design. First, the literature search relied exclusively on the Scopus database, selected for its broad multidisciplinary coverage and rigorous editorial standards. While this approach ensured the inclusion of high-quality peer-reviewed studies, it may have excluded relevant contributions indexed in other databases or available as grey literature (theses, technical reports, institutional documents). As a result, some region-specific or practice-oriented evidence may be underrepresented, potentially affecting the global representativeness of the synthesis.

Second, a major limitation of this review arises from the high methodological heterogeneity of the included studies, which ultimately precluded the application of a quantitative meta-analysis and favored a structured narrative synthesis. Heterogeneity was evident across experimental designs, temporal and spatial scales, cultivars, environmental conditions, management practices, and the diversity of response variables evaluated. In addition, limited standardization was observed in experimental protocols and outcome reporting, particularly for physiological indicators, postharvest quality attributes, sustainability metrics, and technology performance indicators. In many cases, incomplete reporting of variance measures further constrained quantitative comparability across studies, limiting the aggregation of effect sizes and cross-study synthesis.

Beyond heterogeneity, the feasibility of meta-analytical approaches was further constrained by structural inconsistencies in data availability and reporting, including the use of non-uniform measurement units, divergent baseline definitions, variable control treatments, and inconsistent statistical summaries (means reported without dispersion metrics or effect estimates). Moreover, several studies reported results at different biological or operational levels (plant, organ, fruit, plot, or system scale), complicating data harmonization and violating key assumptions required for quantitative pooling. Under these conditions, any attempt to conduct a limited meta-analysis would risk producing biased or misleading estimates, rather than strengthening the robustness of the evidence synthesis.

Finally, although the review prioritizes recent and high-quality studies, the rapid pace of technological development in areas such as artificial intelligence, precision agriculture, biotechnology, and controlled-environment production systems means that parts of the evidence base may become outdated relatively quickly. These dynamic highlights the importance of periodic updates or living reviews to capture emerging advances. Furthermore, the predominance of studies conducted in temperate regions limits the direct applicability of findings to tropical and subtropical production systems, where climatic conditions, resource constraints, and management strategies differ substantially. Strengthening comparative, region-specific research particularly in Latin America and other emerging production regions is therefore essential to support the development of locally adapted, resilient, and technologically inclusive blueberry production systems.

 

Add economic and regional aspects of technology adoption to the analysis.

Reply. Following the reviewer's recommendation, the following section is included:

Economic and Regional Aspects of Technology Adoption in Blueberry Production

The adoption of agricultural technologies in blueberry (Vaccinium spp.) production is increasingly shaped by economic feasibility and regional market dynamics, particularly under a global scenario of rapid supply expansion [114]. Historically, blueberries have maintained relatively high and stable prices compared to other fruit crops, largely due to a sustained growth in global demand that outpaced production increases [249]. However, medium-term market outlooks indicate that this balance is likely to become more fragile toward 2030 as global blueberry production continues to expand rapidly, increasing the risk of market saturation and value erosion. In this context, technological adoption is no longer driven solely by yield enhancement, but by the capacity to deliver consistent quality, precise harvest timing, and market differentiation, as fruit that fails to meet these standards is increasingly excluded from premium supply chains regardless of price [250].

This evolving economic pressure is closely linked to a transformation of the global blueberry production map. While the Americas remain a central pillar of global supply, their relative contribution has declined below 50% of total world production [251]. Peru has emerged as a dominant actor due to its “flattened production curve” strategy, enabled by advanced varietal genetics, irrigation management, and data-driven scheduling, allowing year-round or extended supply windows and improved price stability [252]. However, this leadership faces growing constraints related to water availability, social pressures, and environmental sustainability [253]. In contrast, Chile confronts structural challenges associated with aging orchards and declining competitiveness in both price and quality, while Mexico must improve production efficiency and reduce its heavy dependence on the U.S. market to sustain profitability.

Economic incentives for technology adoption vary markedly across regions and market orientations. In export-driven systems supplying North America, Europe, and increasingly Asia, investments in precision irrigation, fertigation control, postharvest monitoring, and cold-chain technologies are often economically justified by the need to meet strict quality, shelf-life, and traceability requirements [254–256]. Conversely, in domestic or regional markets, particularly in emerging producing countries, growers tend to favor incremental, low-cost innovations such as improved irrigation scheduling or passive greenhouse structures over capital-intensive digital or automated systems [257,258]. This divergence aligns with broader evidence showing that the economic returns of digital and precision agriculture are highly context-dependent, influenced by scale, access to credit, and growers’ ability to integrate new technologies into existing management systems.

Africa and Asia are increasingly shaping the future geography of blueberry production and technology adoption [259]. According to assessments released by the International Blueberry Organization (IBO), Africa has emerged as the fastest-growing blueberry production frontier globally over the last decade, with a rapid expansion of cultivated areas across multiple countries. Countries such as Morocco exemplify this shift, combining high yields, proximity to European markets, efficient logistics, and rapid adoption of advanced genetics [260]. Neighboring countries including Zimbabwe, Zambia, Kenya, and Namibia represent a new wave of expansion, benefiting from land availability and competitive labor costs, yet facing critical challenges related to water planning, infrastructure development, and strategic market positioning. In Asia, and particularly in China, the dual role as both a major producer and a rapidly expanding consumer market reinforces the need for technologies that ensure uniform quality, efficient logistics, and brand differentiation [261,262].

Infrastructure and climate constitute additional bottlenecks that condition technology adoption. As global blueberry volumes increase, pressure on postharvest infrastructure intensifies, given the crop’s high perishability and dependence on uninterrupted cold chains and efficient logistics [263]. Regions that fail to invest in postharvest handling, storage, and transport technologies risk losing competitiveness despite agronomic potential. At the same time, climate change is reshaping production zones, enabling successful cultivation in new high-altitude or temperate regions while increasing climatic risks elsewhere. These shifts further reinforce the importance of adaptive technologies, including controlled-environment systems, improved water-use efficiency, and climate-resilient production models.

Controlled-environment agriculture illustrates the strong interaction between economics and regional context in blueberry systems. While high-tech greenhouses with active climate control can substantially reduce environmental variability and enhance fruit quality, their high capital and energy costs limit adoption to regions with favorable market access, energy prices, or policy support [264]. In contrast, low-cost passive greenhouses and tunnel systems, which dominate blueberry production in many countries, offer a more accessible pathway to technological intensification [3]. These systems provide partial microclimate regulation and water-use efficiency improvements at significantly lower investment levels, making them particularly relevant for small- and medium-scale producers in emerging regions [265].

Genetic innovation and data-driven technologies represent the structural backbone of long-term competitiveness in the blueberry industry. The widespread adoption of new cultivars with low chilling requirements, improved firmness, enhanced flavor, and extended postharvest life has been central to global expansion. Today, varietal renewal is no longer optional but a prerequisite for economic survival. Simultaneously, the sector is transitioning toward a data-intensive model, incorporating artificial intelligence, sensor networks, optical sorters, and emerging robotic harvesting solutions [266,267]. These technologies underpin the concept of the “smart orchard,” increasingly positioning blueberries among the most technologically advanced fruit crops. Ultimately, successful adoption will depend on aligning technological sophistication with economic viability, regional infrastructure, and evolving consumer expectations for quality, sustainability, and traceability.

 

Introduce a graphical model integrating the main components of crop management.

Reply. Following the reviewer's recommendation, the following section is included:

Conceptual Framework for Integrated Blueberry Production Systems  

Figure 3 presents a conceptual framework that integrates the main dimensions governing contemporary blueberry (Vaccinium spp.) production, synthesizing the evidence generated across the six analytical axes addressed in this review. Rather than representing isolated management domains, the model conceptualizes blueberry production as a dynamic system in which environmental and climatic conditions, genetic and plant material, agronomic management, enabling technologies, postharvest logistics, and economic and market drivers interact continuously. This systemic perspective reflects the diversity of approaches identified in the reviewed studies and provides a unifying structure to interpret how advances in individual components contribute positively or negatively to overall system performance.

 

 

Figure 3. Conceptual framework integrating the main components of modern blueberry (Vaccinium spp.) production systems.

A central feature of the framework is the transversal role of enabling technologies, which act as a functional bridge between biological processes, management decisions, and market requirements. Precision irrigation and fertigation systems, sensor networks, artificial intelligence tools, and spectral or imaging technologies support real-time monitoring, predictive decision-making, and resource-use optimization. As shown across multiple studies reviewed in this work, the effectiveness of these technologies depends on their alignment with cultivar characteristics, environmental constraints, and production objectives. Consequently, the framework highlights that technological innovation alone does not guarantee improved outcomes unless it is embedded within a coordinated agronomic and physiological management strategy.

The incorporation of economic and market drivers into the conceptual model emphasizes their feedback role in shaping production systems and technology adoption pathways. Market access, quality standards, postharvest requirements, and cost structures influence decisions related to cultivar selection, investment in infrastructure, and adoption of advanced management tools. At the same time, environmental sustainability considerations such as water-use efficiency, energy consumption, and carbon footprint interact with economic viability, reinforcing the need for integrated assessments. In this sense, the proposed framework provides a practical interpretative lens for understanding how productivity, quality, sustainability, and profitability converge in climate-smart blueberry production systems.

 

Refine practical recommendations to enhance the usefulness of the review for producers and advisors.

Reply. Following the reviewer's recommendation, the following section is included:

Practical use of evidence-based recommendations

To enhance the applicability of this review for producers, consultants, and decision-makers, the following table synthesizes the main scientific findings into operational recommendations linked to specific management goals. Rather than presenting exhaustive protocols, the table prioritizes decision-oriented guidance, allowing users to identify which interventions are most relevant according to their production system (open field, protected cultivation, container systems), market destination (fresh vs. processing), and prevailing constraints (water availability, labor cost, climate risk).

The Table should be used as a diagnostic and prioritization tool, not as a prescriptive recipe. Each recommendation is associated with its expected agronomic or economic impact, an indicative cost/complexity level, and the strength of supporting evidence. Advisors are encouraged to adapt these guidelines to local conditions, cultivar behavior, and regulatory frameworks, and to validate critical thresholds (irrigation deficit levels, shading intensity, postharvest treatments) through pilot-scale trials before full implementation.

 

Table. Evidence-based practical recommendations for blueberry producers and advisors

Management objective	Recommended action	Production context	Expected benefit	Cost / complexity	Evidence strength*
Improve establishment and uniformity	Use certified, pathogen-free plant material; validate micropropagated clones locally	All systems	Lower mortality; reduced disease risk; uniform growth	Medium	High
Adapt phenology to market window	Select cultivar + chill requirement matched to climate; use tunnels or dormancy regulators where justified	Protected / warm regions	Earlier or synchronized harvest; price premium	Medium–High	High
Optimize root-zone conditions	Use peat/coir-based substrates; avoid excessive bark; ensure drainage	Containers / greenhouses	Improved nutrient uptake; reduced stress	Medium	High
Reduce water use	Pulse irrigation with soil/substrate moisture sensors	All systems (esp. sandy soils)	−30–45% water use; lower leaching	Medium	High
Improve fruit firmness	Preharvest Ca applications + optimal irrigation scheduling	Protected & open field	Higher firmness; longer shelf life	Low–Medium	High
Enhance fruit quality (°Brix, phenolics)	Moderate deficit irrigation (validated locally)	Water-limited regions	Higher soluble solids; increased antioxidants	Low	Medium
Reduce disease pressure	Resistant/tolerant cultivars + drainage + sanitation pruning	High disease-risk areas	Lower incidence of Phytophthora, cankers	Medium	High
Protect beneficial organisms	Use selective inputs compatible with IPM	Protected systems	Stable biological control	Low	High
Reduce labor dependency	Assisted or partial mechanized harvest with soft-catch systems	Labor-limited regions	Higher picking efficiency; lower fatigue	High	Medium
Minimize mechanical damage	Reduce drop height; use padded contact surfaces	Mechanized harvest	Less bruising; higher pack-out	Medium	High
Improve harvest timing	Use optical/spectral maturity tools	Fresh market	Reduced unripe fruit; uniform quality	Medium	High
Extend shelf life	Strict cold chain + rapid cooling	All systems	Major decay reduction; quality retention	Medium	Very high
Reduce postharvest decay	Pulsed light / HPP / cold plasma (cultivar-calibrated)	Fresh & processed	Lower microbial load; bioactive retention	High	Medium–High
Reduce environmental footprint	Replace plastics with biopolymers; improve energy efficiency	All systems	Lower GHG emissions; compliance	Medium	High
Valorize residues	Use pomace for extracts, powders, or active packaging	Processing chains	Added value; circularity	Medium	Medium

*Evidence strength refers to consistency and replication of results across studies reviewed (High = multi-study consensus; Medium = promising but context-dependent).

 

Taken together, these recommendations translate a highly diverse and multidisciplinary body of evidence into actionable guidance that supports informed decision-making at the farm and advisory levels. By linking management interventions with expected agronomic, quality, economic, and environmental outcomes, the table facilitates the prioritization of strategies according to local constraints and production objectives. Importantly, while the proposed actions are grounded in peer-reviewed evidence, their successful implementation depends on adaptive calibration to cultivar, climate, and market context. In this sense, the recommendations should be viewed as a flexible decision-support framework that bridges scientific knowledge and practical application, strengthening the role of this review as a tool for advancing sustainable, efficient, and climate-resilient blueberry production systems.

 

Regards

Authors.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Review Comments

this review was to synthesize scientific and technological advances related to the integrated management of blueberry cultivation, and it is concluded that integrating physiology, technology, and sustainability within a unified management framework is essential to consolidate a resilient, low carbon, and technologically advanced fruit-growing system.

 

Minor points:

Blueberry species such as highbush blueberry (V. corymbosum L.), lowbush blueberry (V. chamaebuxus C.Y.Wu), and rabbiteye blueberry (V. virgatum Ait.) are cultivated.

In the results and discussions in the manuscript, highbush blueberries (V. corymbosum L.) are generally used. In fact, some cultivars such as Line 240 'Alix Blue ', Line 315 and Line 359 'Climax' are rabbieye blueberries (V. virgatum Ait.) . It is recommended to add their Latin names. Or do not specifically indicate the Latin word  (V. corymbosum L.) for  blueberries in the subheading.

The term Vaccinium in the manuscript should be italicized or abbreviated as V. in many places, including references.

For commercial production, most fruit trees are grafted and replanted to renew species. The rootstock can affect the water use efficiency, scion nutrition, and fruit quality of grafted  trees. The research progress in blueberry grafting can also be reviewed, with references such as Zhu et al. A better fruit quality of grafted blueberry than own-rooted blueberry is linked to its anatomy. Plants, 2024

Explain the tables within the narrative of Sections 3.7, 3.9…. For example, explicitly state which technology from Table 2 is most promising for specific goals like anthocyanin retention or microbial safety.

Section 5 (Future Perspectives) outlines important general directions. Its impact would be greater by directly connecting these to the specific gaps identified in the review and proposing more concrete research pathways.

 

 

 

Author Response

January 15 2026.

Reviewer 2.

We sincerely thank the reviewer for the careful evaluation of our manuscript and for the insightful and constructive suggestions provided. All comments were thoroughly addressed, and the manuscript was revised accordingly. The revisions have improved the clarity, structure, and practical interpretability of the review, particularly through the explicit integration of tables into the narrative, the strengthening of future research directions, and the refinement of taxonomic and methodological consistency. All changes made in response to the reviewer’s comments are highlighted in green in the revised manuscript to facilitate their identification and evaluation.

 

Suggest.

Blueberry species such as highbush blueberry (V. corymbosum L.), lowbush blueberry (V. chamaebuxus C.Y.Wu), and rabbiteye blueberry (V. virgatum Ait.) are cultivated. In the results and discussions in the manuscript, highbush blueberries (V. corymbosum L.) are generally used. In fact, some cultivars such as Line 240 'Alix Blue ', Line 315 and Line 359 'Climax' are rabbieye blueberries (V. virgatum Ait.) . It is recommended to add their Latin names. Or do not specifically indicate the Latin word  (V. corymbosum L.) for  blueberries in the subheading. The term Vaccinium in the manuscript should be italicized or abbreviated as V. in many places, including references.

Reply. We thank the reviewer for this valuable and constructive comment regarding taxonomic consistency and scientific nomenclature. As this manuscript is a systematic review that integrates evidence from multiple blueberry species (including highbush, rabbiteye, and lowbush blueberries), the scope of the study is appropriately addressed at the genus level. Therefore, all section headings and general references have been revised to use Vaccinium spp. instead of specifying a single species (e.g., Vaccinium corymbosum L.), in order to accurately reflect the diversity of species and cultivars discussed throughout the manuscript. In addition, the manuscript has been carefully revised to ensure that: All scientific names of Vaccinium species are consistently italicized,

For commercial production, most fruit trees are grafted and replanted to renew species. The rootstock can affect the water use efficiency, scion nutrition, and fruit quality of grafted  trees. The research progress in blueberry grafting can also be reviewed, with references such as Zhu et al. A better fruit quality of grafted blueberry than own-rooted blueberry is linked to its anatomy. Plants, 2024.

Reply. We thank the reviewer for this insightful comment and for drawing attention to recent advances in blueberry grafting research.

In response, a new paragraph has been incorporated into the section “Innovations in propagation, plant material acquisition, and genetic improvement”, addressing grafting as an emerging and complementary propagation strategy in blueberry cultivation. To maintain taxonomic consistency with the scope of this systematic review—which integrates evidence across multiple blueberry specie the discussion is presented at the genus level (Vaccinium spp.), without emphasizing species-specific nomenclature in the main text. The revised manuscript now cites Zhu et al. (Plants, 2024) as representative evidence showing that different blueberry rootstocks can significantly influence fruit quality, mineral nutrition, gas exchange, anatomical traits, and drought resistance in grafted plants. These additions strengthen the propagation section and acknowledge grafting as a promising, although still limited, approach for improving blueberry performance under specific agronomic and environmental conditions.

Explain the tables within the narrative of Sections 3.7, 3.9…. For example, explicitly state which technology from Table 2 is most promising for specific goals like anthocyanin retention or microbial safety.

We thank the reviewer for this constructive suggestion. In response, the manuscript was revised to explicitly interpret all summary tables (Tables 1–5) within the narrative, clearly linking each table to specific technological, quality, safety, or sustainability objectives, rather than leaving interpretation implicit.

Specifically:

Section 3.7 (Table 1) was revised to explicitly state that assisted harvesting with controlled vibration and soft-catch systems currently offers the best compromise between labor efficiency and fruit quality preservation, while impact-reduction strategies are the most effective for minimizing mechanical damage, and optical selection technologies provide the highest reliability for ripeness uniformity and harvest timing.

Section 3.8 (Table 2) now explicitly indicates that high hydrostatic pressure (HHP/HPP) and manothermosonication are the most promising technologies for anthocyanin retention, whereas HHP/HPP provides the most robust microbial safety, with cold atmospheric plasma and pulsed light being particularly effective for surface decontamination of fresh fruit, and PEF/MPEF being best suited for liquid matrices and continuous processing.

Section 3.8 (Table 3) was revised to clarify that HHP combined with gallic acid and chitosan–κ-carrageenan nanocomplexes provide the highest anthocyanin retention and color stability, while alginate–pectin hydrogels are most effective for extending pigment half-life and photostability, and copigmentation with CaCl₂ and thermosonication remain flexible options when full encapsulation is not feasible.

Section 3.8 (Table 4) now explicitly highlights that chitosan- and natural gum–based antimicrobial coatings are the most immediately transferable strategies for extending shelf life of fresh blueberries, anthocyanin-based sensorial films are most suitable for real-time freshness monitoring, and active microcapsules and protein–polyphenol carriers are especially promising for processed products and functional ingredients within a circular-economy framework.

Section 3.9 (Table 5) was revised to explicitly identify that the most cost-effective sustainability strategies target plastics, energy use, and fertilizer management, with biopolymer substitution, energy efficiency, renewable energy integration, and nutrient-use optimization emerging as the highest-impact mitigation measures when aligned with system-specific environmental hotspots.

These revisions ensure that each table is directly interpreted within the main text, guiding the reader toward decision-oriented conclusions and fully addressing the reviewer’s request.

The sections are as follows:

Subsection. 3.7.

Harvest represents one of the most critical stages in the production chain of blue-berries (Vaccinium spp.), due to its high labor demand and its direct impact on posthar-vest physiology and commercial fruit quality. Recent literature converges toward partial or assisted mechanization, seeking to reduce labor costs without compromising firm-ness, anthocyanin content, or cellular integrity of the berries. In tunnel-based systems, assisted harvesting using portable electric shakers and soft capture surfaces increased the picking rate to 81.3 berries·min⁻¹, although with 30.6% unripe fruits. Adjusting the detachment speed to 900 rpm for 1.2 seconds improved overall efficiency to 80.7%, demonstrating the potential of this method to balance productivity and selectivity [110]. This hybrid approach combines the operator’s perceptual precision with the controlled force of the device, reducing physical strain and improving consistency in handling factors that directly influence the preservation of cell turgor and cuticle integrity. As shown in Table 1, electrical assistance and soft-capture mechanisms enable progress toward intermediate mechanization with minimal quality loss, while impact reduction strategies and optical sorting contribute to maintaining the structural integrity and ripeness uniformity of the fruit key elements for standardizing the harvesting system.

From an applied perspective, Table 1 highlights that assisted harvesting with con-trolled vibration and soft-catch systems currently offers the best compromise between labor efficiency and fruit quality preservation. For mechanical damage mitigation, im-pact-reduction strategies (reduced drop height and padded contact surfaces) are the most effective, whereas optical selection technologies provide the highest reliability for ripeness uniformity and harvest timing in fresh-market blueberries.

Table 2.

Non-thermal technologies and hybrid preservation methods represent the core of post-harvest innovation in blueberries. Table 2 summarizes the main treatments de-veloped, their operating parameters, matrices, and validation scales, highlighting the trend toward gentle physical processes with high retention of bioactive compounds and energy efficiency. From an applied perspective, Table 2 indicates that the suitability of non-thermal technologies strongly depends on the dominant postharvest objective and the product format. For anthocyanin retention and preservation of bioactive com-pounds, high hydrostatic pressure (HHP/HPP) and manothermosonication emerge as the most promising approaches, as they consistently maintain or enhance anthocyanin levels while limiting enzymatic degradation. For microbial safety, HHP/HPP provides the most robust and broad-spectrum inactivation, while cold atmospheric plasma (CAPP) and pulsed light (PL) are particularly effective for surface decontamination of fresh fruit when dose–cultivar interactions are properly managed. In contrast, PEF/MPEF technologies are best suited for liquid matrices where continuous processing and nutrient retention are prioritized. Overall, Table 2 highlights the need to align technology selection with specific quality and safety goals rather than adopting a single universal postharvest solution.

Table 3.

From an applied and comparative perspective, Table 3 indicates that the most effective strategies for maximizing anthocyanin retention and long-term color stability are those that combine structural protection with enzymatic inhibition. In particular, HHP combined with gallic acid and chitosan–κ-carrageenan nanocomplexes show the highest anthocyanin preservation (>90%) while simultaneously limiting polyphenol oxidase activity, making them especially suitable for high-value beverages and semi-liquid matrices. For applications where photostability and extended shelf life are the primary objectives, alginate–pectin hydrogels provide the most robust protection by markedly increasing anthocyanin half-life. In contrast, phenolic copigmentation with CaCl₂ and thermosonication offer flexible, process-compatible solutions for enhancing color in-tensity and antioxidant retention when full encapsulation is not technically or eco-nomically feasible. Overall, Table 3 highlights that optimal pigment stabilization depends on aligning the physicochemical strategy with the target matrix, processing in-tensity, and desired storage performance rather than relying on a single universal approach.

Table 4.

These strategies establish circular loops in which residues, ingredients, and packaging improvements contribute to enhanced product stability and safety. Within the context of functional packaging and coatings, biopolymeric and protein-based solutions have been developed with antioxidant, antimicrobial, and indicator properties designed to extend fruit shelf life and integrate freshness monitoring within the cold chain. Table 4 highlights the diversification of emerging strategies in active and intelligent packag-ing: antimicrobial coatings based on chitosan and natural gums, sensorial films with anthocyanins as ammonia indicators, biodegradable microcapsules with antioxidant activity, and protein matrices that enhance phenolic compound stability. These inno-vations strengthen the link between quality preservation and smart packaging within the circular-economy paradigm.

From an applied perspective, Table 4 indicates that the most mature and immedi-ately transferable strategies for extending shelf life of fresh blueberries are antimicrobial biopolymer coatings based on chitosan and natural gums, which consistently reduce decay and weight loss while remaining compatible with existing cold-chain logistics. For applications requiring real-time freshness monitoring, anthocyanin-based sensorial films offer the greatest potential due to their high antioxidant activity and reliable response to ammonia as a spoilage indicator. In contrast, active microcapsules and protein–polyphenol carriers are especially promising for processed products and functional ingredients, where controlled release, antioxidant stability, and biodegradability are prioritized over immediate antimicrobial action. Overall, Table 4 highlights that successful by-product valorization and active packaging design depend on matching material functionality with the intended product form and supply-chain requirements rather than adopting a single universal packaging solution.

Subsection 3.9.

In summary, Table 5 shows that the greatest environmental impacts are concentrated in plastic use, fertilizers, and energy during cultivation, postharvest, and processing stages. Strategies such as substituting plastics with biopolymers, improving energy efficiency, and valorizing by-products emerge as cost-effective solutions to re-duce the carbon footprint, while logistical efficiency and renewable energy use con-solidate a comprehensive sustainability approach. From a comparative and decision-oriented perspective, Table 5 indicates that the most broadly applicable and cost-effective strategies for reducing the environmental footprint of blueberry production are those targeting plastics, energy use, and fertilizer management. Across production contexts, substitution of conventional plastics with biopolymers and improved recycling schemes emerges as the most immediate mitigation option, particularly at the postharvest stage. In parallel, energy efficiency improvements and the integration of renewable energy sources consistently reduce emissions in cultivation, cold storage, and transport, often delivering net economic benefits. In production systems where fertilizer inputs dominate the carbon footprint, as observed in organic orchards, nutrient-use optimization and cover cropping provide the highest mitigation potential. At the processing level, Table 5 shows that energy-intensive operations such as osmotic dehydration can be environmentally viable when offset by efficiency gains and high value addition. Overall, the table highlights that sustainability gains are maximized when mitigation strategies are prioritized according to system-specific hotspots rather than applied uniformly across the value chain.

Section 5 (Future Perspectives) outlines important general directions. Its impact would be greater by directly connecting these to the specific gaps identified in the review and proposing more concrete research pathways.

The section was improved by incorporating suggestions; the section now reads as follows:

The technological and scientific advancement of blueberry (Vaccinium spp.) cultivation demands an integrative vision that transcends traditional approaches and establishes a coherent, reproducible, and sustainability-oriented methodological framework. This review identified several persistent gaps, including strong methodological heterogeneity among studies, limited multi-year and multi-site validation, weak integration between experimental and commercial scales, and insufficient linkage between technological innovation, economic feasibility, and environmental performance. Addressing these gaps is essential to consolidate evidence-based, climate-smart blueberry production systems. Based on the findings of this review, four priority research pathways are proposed.

Experimental Standardization and International Cooperative Networks: A major limitation identified across propagation, nutrition, irrigation, and postharvest studies is the lack of standardized experimental protocols and comparable response variables, which hinders meta-analytical synthesis and cross-regional extrapolation. Future re-search should prioritize multi-site and multi-year experiments using harmonized methodologies, enabling robust comparison across agroclimatic zones and production systems. A minimum core set of interoperable indicators should be adopted, including physiological (gs, Aₙ, Ψ, PSII efficiency), quality (°Brix, titratable acidity, firmness, shelf life), safety (pathogen log reduction), productivity (kg·plant⁻¹, t·ha⁻¹), and sustainability metrics (water and energy use efficiency, LCA, CF). Establishing international cooperative networks around these indicators would significantly improve data comparability and accelerate technology transfer.

Integration of Digital Tools and Intelligent Modeling: Although numerous studies demonstrate the potential of artificial intelligence, computer vision, and sensor-based systems, this review revealed that most applications remain fragmented, cultivar-specific, or limited to short-term trials. Future research should move toward integrated digital platforms and crop digital twins that combine IoT sensors, phenomics, ecophysiological models, and real-time decision support. Priority should be given to validating these tools under commercial conditions and assessing their robustness across cultivars and environments, using standardized performance metrics (R², RMSE, MAPE) and transparent data governance frameworks to ensure scalability and reproducibility.

Sustainability and Technological Circularity: The review highlighted that environmental impacts are consistently concentrated in plastics, fertilizer inputs, energy use, and postharvest operations, yet relatively few studies evaluate mitigation strategies in an integrated manner. Future research should explicitly link Life Cycle Assessment (LCA) and Carbon Footprint (CF) analysis with agronomic and technological interventions, such as water reuse systems (electrodialysis–forward osmosis), biodegradable coatings and packaging, renewable energy integration, and by-product valorization within agricultural biorefineries. Long-term assessments that jointly evaluate environmental performance, energy balance, and economic viability are needed to support the transition toward circular and climate-neutral blueberry production systems.

Technology Transfer and Capacity Building: A recurrent gap identified in this re-view is the weak connection between experimental innovation and adoption at the farm and industry levels, particularly in emerging production regions. Future research and development efforts should therefore be coupled with technology transfer programs, focusing on breeding for mechanization and climate resilience, incentives for sustainable certification, and targeted training in automation, data management, energy efficiency, and environmental control. These initiatives should be aligned with national bioeconomy strategies and the Sustainable Development Goals (SDGs) to ensure that technological advances translate into practical, inclusive, and economically viable solutions.

Together, these research pathways provide a concrete and gap-driven roadmap for advancing blueberry cultivation toward intelligent, sustainable, and climate-adaptive systems, reinforcing the role of this crop as a model for technologically advanced and environmentally responsible fruit production.

 

 

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Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The correct answer completely satisfies me. The work is suitable for publication.

Comments on the Quality of English Language

Minor correction recommended