Search Results (39)

Kiwifruit is a high-value subtropical crop with significant nutritional and economic importance, but its cultivation faces growing challenges due to climate change, particularly in Caucasus. This study aims to study the impact of abiotic stressors such as temperature extremes, drought, and frost on the yield of the ‘Hayward’ cultivar over a 20-year period (from 2003 to 2022). Using a combination of agroclimatic data analysis, measurements of soluble solid content, and soil moisture assessments, this research identified key factors which limit kiwifruit cultivation productivity. The results revealed a high yield variability—68%, with the mean value declining by 16.6% every five years due to increasing aridity and heat stress. Extreme temperature rises of up to 30 °C caused yield losses of 79–89%, and the presence of frost led to declines of 71–94%. In addition, it is objectively proven that the vulnerability of kiwifruit is subject to climate-driven water imbalances. This highlights the need for adaptive strategy formation in the area of optimized irrigation for the sustainable cultivation of fruit in the subtropics. One of the study’s limitations was that it was organized around a single variety of kiwifruit (‘Hayward’). In view of the fact that there are significant differences in growth characteristics among kiwifruit varieties, future research should focus on overcoming this shortcoming. Full article

Kiwifruits are highly valued for their nutritional and health-related benefits as well as for their economic importance, since they significantly contribute to the economy of many countries that cultivate them. However, kiwifruits are very sensitive to diseases that may substantially impact their final quantity and quality. Computer vision (CV) has been extensively employed for disease recognition in the agricultural sector within the last decade; yet there are limited works dealing with kiwifruit disease recognition, and there is an obvious lack of open datasets to promote relevant research, especially when compared to research on other cultivations, e.g., grapes. To this end, this study introduces the first-reported open dataset for kiwifruit leaf disease recognition, including Alternaria, Nematodes and Phytophthora, while image datasets of Nematodes have not been previously reported. The proposed dataset, named AgriVision-Kiwi Dataset, has been used first for leaf detection with You Only Look Once version 11 (YOLOv11), reporting a bounding box loss of 0.053, and then to train various deep learning models for kiwifruit diseases recognition, reporting accuracies of 98.80% ± 0.5, e.g., 98.30% to 99.30%, after 10-fold cross-validation. The introduced dataset aims to encourage the development of CV applications towards the timely prevention of diseases’ spreading. Full article

Kiwifruit, with its unique flavor, nutritional value, and economic benefits, has gained significant attention in agriculture production. Kiwifruit plants have traditionally been propagated without grafting, but recently, grafting has become a more common practice. A new and complex disease called Kiwifruit Vine Decline Syndrome (KVDS) has emerged in different kiwifruit-growing areas. The syndrome was first recognized in Italy, although similar symptoms had been observed in New Zealand during the 1990s before subsequently spreading worldwide. While kiwifruit was not initially grafted in commercial orchards, the expansion of cultivation into regions with heavy soils or other challenging environmental conditions may make grafting selected kiwifruit cultivars onto KVDS-resistant or -tolerant rootstocks essential for the future of this crop. Grafting is a common horticultural practice, widely used to propagate several commercially important fruit crops, including kiwifruits, apples, grapes, citrus, peaches, apricots, and vegetables. Grafting methods and genetic compatibility have a crucial impact on fruit quality, yield, environmental adaptability, and disease resistance. Achieving successful compatibility involves a series of steps. During grafting, some scion/rootstock combinations exhibit poor graft compatibility, preventing the formation of a successful graft union. Identifying symptoms of graft incompatibility can be challenging, as they are not always evident in the first year after grafting. The causes of graft incompatibility are still largely unknown, especially in the case of kiwifruit. This review aims to examine the mechanisms of graft compatibility and incompatibility across different fruit crops. This review’s goal is to identify potential markers and techniques that could enhance grafting success and boost the commercial production of kiwifruit. Full article

This study highlights the growing concern over copper resistance in Pseudomonas syringae pv. actinidiae (Psa), a significant pathogen threatening kiwifruit cultivation globally. Copper-based treatments, widely used for their broad-spectrum bactericidal properties, have become less effective over time due to the emergence of copper-resistant strains. This study found that 22 strains of Psa, collected from Greek kiwifruit orchards, exhibited significant copper resistance. All strains were capable of growing in copper concentrations of at least 200 µg/mL (0.8 mM), and two strains (9.1%) survived even at higher concentrations of 400 µg/mL (1.6 mM). Additionally, resistant bacterial colonies were observed in four strains (18.2%), suggesting the presence of resistant subpopulations within the broader bacterial community. In addition to studying copper resistance, the research evaluated the effectiveness of several products in controlling Psa through field experiments. The copper products IONIC CONCENTRATED COPPER, MAGNA BLUE, and COPROFIX ULTRA were tested due to their historical effectiveness in managing bacterial diseases in plants. However, these copper products were unable to fully control Psa in this study, likely due to the observed resistance. In addition, the plant defense activator products MICONIC and NUTRI BIOCLEAN, NUTRI BIOCLEAN, BAR, and BION were evaluated and showed promising results in reducing the intensity of symptoms associated with Psa, suggesting that these formulations may enhance the plant’s natural defenses against the pathogen. While these products did not completely eliminate the disease, they significantly reduced symptom severity. The findings highlight the need for alternative strategies to combat Psa, particularly in areas where copper resistance has developed. Full article

Returning pruned branches into the field is a key procedure in kiwifruit cultivation. It utilizes discarded branches and aids in orchard management. Shearing and bending behaviors dominate the mechanized process of branch return; however, current research lacks appropriate modeling methods for these processes. In this study, we developed a discrete element method (DEM) model to simulate the shearing and bending behaviors of kiwifruit branches. Initially, laboratory experiments determined the shear strength and elastic modulus of branch samples to be 31.38 MPa and 1.21 GPa, respectively. An annular kiwifruit branch DEM model was constructed. A Plackett–Burman design test identified significant influencing factors: effective modulus of bond, bond cohesion, effective modulus between ball and wall, and the normal-to-shear stiffness ratio. Utilizing the response surface method, we derived relationships between DEM parameters and mechanical responses. Optimal parameter combinations were found: an effective modulus of bond at 2.2 × 10⁹ Pa, bond cohesion at 2.56 × 10⁸ Pa, effective modulus between ball and wall at 1.27 × 10⁸ Pa, and a normal-to-shear stiffness ratio of 1.16. Finally, simulations of the shearing and bending processes were conducted. The optimal parameter combination was verified with a relative error of 4.5%. Displacement–force curves showed general consistency, indicating reliability in the modeling approach. Full article

The kiwifruit (Actinidia) is an important nutritional and economic fruit crop. However, the short edible window period of kiwifruit has seriously affected its market value. 1-Methylcyclopropene (1-MCP), as a novel ethylene inhibitor, is widely applied to delay fruit ripening and senescence. To our knowledge, there are limited studies on the effects of 1-MCP on fruit quality and metabolism of different kiwifruit varieties. Three kiwifruit cultivars (i.e., ‘Xuxiang’, ‘Huayou’, and ‘Hayward’) widely cultivated in China were chosen as our research objects. The variations of storage quality and metabolic characteristics of kiwifruits treated with various 1-MCP concentration (0 μL/L, 0.5 μL/L, and 1.0 μL/L) were systematically investigated. The results showed that 1-MCP treatment significantly improved the quality of kiwifruit during storage. Among them, for ‘Xuxiang’ and ‘Hayward’ varieties, 1.0 μL/L 1-MCP treatment could delay the decrease in fruit firmness, the increase in maturity index and cellulase activity, and inhibit the decrease in ascorbic acid (AsA) level. However, the 0.5 μL/L 1-MCP had a great influence on the chlorophyll content and maturity index of the ‘Huayou’ cultivar, and the preservation effect was satisfactory. In addition, gas chromatography–mass spectrometry (GC–MS) based metabolomics studies revealed that 1-MCP treatment affected carbohydrates metabolism, fatty acids metabolism, and amino acids metabolism in different kiwifruit varieties. Correlation analysis indicated that sugars metabolism has the closest relationship with postharvest physiological quality. This research indicated that the effectiveness of 1-MCP treatments was dependent on fruit variety and treatment concentration. Furthermore, these findings provide a theoretical foundation for extending the shelf life of different kiwifruit varieties. Full article

Kiwifruit (Actinidia chinensis) cultivation is expanding worldwide, with China, New Zealand, and Italy being the major producing countries. Halyomorpha halys, the brown marmorated stink bug, is raising serious concerns to kiwifruit cultivation both in China and Italy. This study aimed at improving the chemical control efficacy against this pest by comparing two insecticide spray techniques (a conventional ray atomizer and a trumpet-modified atomizer adapted for localized spray application) in kiwifruit. In fact, kiwifruit is often grown with a ‘pergola’ training system, which may reduce the effectiveness of insecticide penetration into the canopy. Experiments were performed in naturally infested orchards of both Actinidia chinensis var. chinensis ‘Jintao’ and A. chinensis var. deliciosa ‘Hayward’. Furthermore, mesh cages containing H. halys adults were deployed within orchards to assess the insects’ mortality at 1, 3, 7, and 10 days after an insecticide application with two spray techniques during two consecutive seasons. In the cultivar ‘Jintao’, the two systems performed similarly, while in the cultivar ‘Hayward’, an overall significantly higher insect mortality was recorded with the trumpet atomizer (94–100%) compared to the conventional atomizer (59–78%). Crop damage was also evaluated on both cultivars, simulating the grower insecticide applications with the two spray techniques. At harvest, no difference emerged between the spray techniques, which provided a significantly better protection compared to the untreated control (12–17% compared to 33–47% of injured fruits). Further investigations in this direction are needed also considering the restriction of insecticidal active substances ongoing in the European Union and the need to maximize the efficacy of the available tools. Full article

Climate change, a pressing global concern, poses significant challenges to agricultural systems worldwide. Among the myriad impacts of climate change, the cultivation of kiwifruit trees (Actinidia spp.) faces multifaceted challenges. In this review, we delve into the intricate effects of climate change on kiwifruit production, which span phenological shifts, distributional changes, physiological responses, and ecological interactions. Understanding these complexities is crucial for devising effective adaptation and mitigation strategies to safeguard kiwifruit production amidst climate variability. This review scrutinizes the influence of rising global temperatures, altered precipitation patterns, and a heightened frequency of extreme weather events on the regions where kiwifruits are cultivated. Additionally, it delves into the ramifications of changing climatic conditions on kiwifruit tree physiology, phenology, and susceptibility to pests and diseases. The economic and social repercussions of climate change on kiwifruit production, including yield losses, livelihood impacts, and market dynamics, are thoroughly examined. In response to these challenges, this review proposes tailored adaptation and mitigation strategies for kiwifruit cultivation. This includes breeding climate-resilient kiwifruit cultivars of the Actinidia species that could withstand drought and high temperatures. Additional measures would involve implementing sustainable farming practices like irrigation, mulching, rain shelters, and shade management, as well as conserving soil and water resources. Through an examination of the literature, this review showcases the existing innovative approaches for climate change adaptation in kiwifruit farming. It concludes with recommendations for future research directions aimed at promoting the sustainability and resilience of fruit production, particularly in the context of kiwifruit cultivation, amid a changing climate. Full article

The commercial value of kiwifruit is determined mostly by its nutritional composition and antioxidant content. The enrichment of these traits in an era where climate change affects kiwi growth conditions is worth investigating via the application of biostimulants that enhance plant growth. In this work, we evaluated the effects of three commercial biostimulants on the metabolism and growth characteristics of the Actinidia deliciosa cultivar ‘Hayward’: (I) a humic and fulvic-based biostimulant, (II) a glycine–betaine–proline-based biostimulant, and (III) a vegetal amino acid-based biostimulant. A biostimulant-free treatment was used as a control. In the two-year experiment (2022 and 2023), the growth characteristics of kiwi trees were measured, such as stem length, the number of leaves, leaf area, and fresh and dry biomass at the end of each growing season. The leaves’ total chlorophyll, total phenolics, and proline content were detected during the two seasons in order to obtain more insights into plant metabolism. Κiwifruit qualities and antioxidant traits, such as total soluble solids, titratable acidity, firmness, fresh and dry biomass, DPPH, and ascorbic acid (vitamin C), were recorded during the postharvest life for each season. Data analysis illustrated the beneficial impact of some biostimulants on several of the previously mentioned parameters, such as antioxidant kiwifruit traits, especially in the case of glycine–betaine–proline-based acid-based biostimulants. Full article

The kiwifruit, Actinidia genus, has emerged as a nutritionally rich and economically significant crop with a history rooted in China. This review paper examines the global journey of the kiwifruit, its genetic diversity, and the role of advanced breeding techniques in its cultivation and improvement. The expansion of kiwifruit cultivation from China to New Zealand, Italy, Chile and beyond, driven by the development of new cultivars and improved agricultural practices, is discussed, highlighting the fruit’s high content of vitamins C, E, and K. The genetic resources within the Actinidia genus are reviewed, with emphasis on the potential of this diversity in breeding programs. The review provides extensive coverage to the application of modern omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, which have revolutionized the understanding of the biology of kiwifruit and facilitated targeted breeding efforts. It examines both conventional breeding methods and modern approaches, like marker-assisted selection, genomic selection, mutation breeding, and the potential of CRISPR-Cas9 technology for precise trait enhancement. Special attention is paid to interspecific hybridization and cisgenesis as strategies for incorporating beneficial traits and developing superior kiwifruit varieties. This comprehensive synthesis not only sheds light on the current state of kiwifruit research and breeding, but also outlines the future directions and challenges in the field, underscoring the importance of integrating traditional and omics-based approaches to meet the demands of a changing global climate and market preferences. Full article

Actinidia latifolia, with the highest vitamin C content in its genus, is a unique wild relative of kiwifruit that could be important for genetic breeding research. Climate change significantly influences the distribution range of wild plants. Accurately assessing the potential distribution of wild kiwifruit and its response to climate change is crucial for the effective protection and sustainable utilization of its germplasm resources. In this study, we utilized the optimized MaxEnt model to predict the potential habitats of A. latifolia in China, employing the jackknife test to assess the importance of environmental variables in our modeling process. The results showed that annual precipitation (Bio12) and temperature annual range (Bio7) emerged as the most influential environmental variables affecting the distribution of this kiwifruit wild relative. As radiative forcing and time increase, the potential habitats of A. latifolia in China are projected to shrink southward, thereby exacerbating habitat fragmentation. This research offers significant scientific references for the investigation, protection, cultivation, and application of wild relatives of the kiwifruit. Full article

Kiwifruit decline syndrome (KiDS) has affected kiwifruit orchards for more than ten years in the Mediterranean area, severely compromising productivity and causing extensive uprooting. The affected plants go through an irreversible and fast wilting process. The problem has not been solved yet, and a single cause has not been identified. In this work, we carried out a survey on ten five-year-old healthy kiwifruit cv. Hayward plants cultivated in an area strongly affected by KiDS and characterised by a rising temperature and vapor pressure deficit (VPD). Five plants were located in a KiDS-affected orchard. Our goal was to assess the hydraulic conductance of asymptomatic plants in a KiDS-affected area where rising climate change stress is underway. Our hypothesis was that a rising temperature and VPD could impair xylem functionality, leading the plants to develop strategies of tolerance, such as vessel narrowing, or stress symptoms, such as cavitation or implosion, inducing a higher risk of KiDS onset. Hydraulic conductance was investigated using a physiological and morphological approach to detect trunk sap flow, trunk growth and daily diameter variations, leaf gas exchanges and temperature, stem water potential, and the root xylem vessel diameter and vulnerability to cavitation. A strong xylem vessel narrowing was observed in all plants, with the highest frequency in the 30–45 µm diameter class, which is an indicator of long-term adaptation to a rising VPD. In some plants, cavitation and implosion were also observed, which are indicative of a short-term stress response; this behaviour was detected in the plants in the KiDS-affected orchard, where a high leaf temperature (>39 °C), low stomatal conductance (<0.20 mol H₂O m⁻² s⁻¹) and transpiration (<3 mmol H₂O m⁻² s⁻¹), low stem water potential (<−1 MPa), high vulnerability to cavitation (3.7 μm mm⁻²), low trunk sap flow and high daily stem diameter variation confirmed the water stress status. The concurrence of climate stress and agronomic management in predisposing conditions favourable to KiDS onset are discussed, evidencing the role of soil preparation, propagation material and previous crop. Full article

Biostimulants (BSs) are natural materials (i.e., organic or inorganic compounds, and/or microorganisms) having beneficial effects on plant growth and productivity, and able to improve resilience/tolerance to biotic and abiotic stresses. Therefore, they represent an innovative alternative to the phyto- and agrochemicals, being environmentally friendly and a valuable tool to cope with extreme climate conditions. The objective of this study was to investigate the effects of several biomolecules (i.e., Xylanase, β-Glucosidase, Chitinase, and Tramesan), alone or in combinations, on lettuce plant growth and quality. With this aim, the influence of these biomolecules on biomass, pigment content, and antioxidant properties in treated plants were investigated. Our results showed that Xylanase and, to a lesser extent, β-Glucosidase, have potentially biostimulant activity for lettuce cultivation, positively influencing carotenoids, total polyphenols, and ascorbic acid contents; similar effects were found with respect to antioxidative properties. Furthermore, the effect of the more promising molecules (Xylanase and β-Glucosidase) was also evaluated in kiwifruit cultured cells to test their putative role as sustainable input for plant cell biofactories. The absence of phytotoxic effects of both molecules at low doses (0.1 and 0.01 µM), and the significantly enhanced cell biomass growth, indicates a positive impact on kiwifruit cells. Full article

To evaluate a new kiwifruit genotype named “Arta Kiwifruit”, a comparative analysis of fruit physical characteristics and biochemical composition in comparison to the widely cultivated Hayward cultivar took place, both at harvest and after a storage period for two successive years. The findings revealed that “Arta Kiwifruit” holds a significant advantage, as it features a larger fruit size, is approximately 34% heavier than “Hayward”, and boasts a distinct shape characterized by a bigger length. Both genotypes exhibited similar dry matter content. No significant difference was observed in protein content, or total phenolic compounds between the two genotypes, while “Hayward” exhibited a significantly higher concentration of sugars and higher sweetness index. “Hayward” demonstrated also increased levels of chlorophyll at harvest, along with higher concentrations of carotenoids. “Hayward” during the first year presented higher antioxidant activity both at harvest and after storage. On the other hand, “Arta Kiwifruit” displayed elevated amino acid concentrations compared to “Hayward”, both at harvest and after storage. Phenotypic traits, as well as the genetic analysis using inter-simple sequence repeats (ISSR) markers, further confirmed the distinct genetic profile of “Arta Kiwifruit”, highlighting its potential significance for kiwifruit breeding programs and commercial use. Full article

Actinidia chinensis ‘Hongyang’, also known as red yangtao (red heart kiwifruit), is a vine fruit tree native to China possessing significant nutritional and economic value. However, information on its genetic diversity and phylogeny is still very limited. The first chloroplast (cp) genome of A. chinensis ‘Hongyang’ cultivated in China was sequenced using de novo technology in this study. A. chinensis ‘Hongyang’ possesses a cp genome that spans 156,267 base pairs (bp), exhibiting an overall GC content of 37.20%. There were 132 genes that were annotated, with 85 of them being protein-coding genes, 39 transfer RNA (tRNA) genes, and 8 ribosomal RNA (rRNA) genes. A total of 49 microsatellite sequences (SSRs) were detected, mainly single nucleotide repeats, mostly consisting of A or T base repeats. Compared with 14 other species, the cp genomes of A. chinensis ‘Hongyang’ were biased towards the use of codons containing A/U, and the non-protein coding regions in the A. chinensis ‘Hongyang’ cpDNA showed greater variation than the coding regions. The nucleotide polymorphism analysis (Pi) yielded nine highly variable region hotspots, most in the large single copy (LSC) region. The cp genome boundary analysis revealed a conservative order of gene arrangement in the inverted repeats (IRs) region of the cp genomes of 15 Actinidia plants, with small expansions and contractions of the boundaries. Furthermore, phylogenetic tree indicated that A. chinensis ‘Hongyang’ was the closest relative to A. indochinensis. This research provides a useful basis for future genetic and evolutionary studies of A. chinensis ‘Hongyang’, and enriches the biological information of Actinidia species. Full article