Search Results (1,012)

Contemporary nurseries of fruit trees and ornamental plants constitute a key component in the production of high-quality planting material. At present, conventional technology dominates in nurseries in Poland and throughout the European Union. It is based on universal agricultural tractors working with numerous specialized machines—typically underutilized—including sprayers, inter-row cultivation equipment, fertilizer spreaders, and tree lifters. This concept entails several limitations and high investment costs. Because of the considerable size and turning radius of such machinery, a dense network of service roads (every 15–18 m) and wide headlands must be maintained. These areas, which constitute approximately 20% of the total surface, are effectively wasted yet require continuous agronomic maintenance. An alternative concept employs a set of implements mounted on a high-clearance portal tractor (1.6–1.8 m), forming a specialized unit capable of moving above the rows of nursery crops. The study objective of the research was to evaluate the air distribution generated by an air-jet system installed on a crop-spray boom mounted on a portal sprayer, and to assess spray deposition during treatments in nursery trees. Such a configuration enables the mechanization of a broader range of nursery operations than currently possible, while reducing investment costs compared with conventional technology. One still underutilized technology consists of sprayers with an auxiliary airflow (AA) generated by air sleeves. Mean air velocity was measured in three vertical planes, and they showed lower air velocity between 1.0 m and 5.5 m. Spray deposition on apple nursery trees was assessed using a fluorescent tracer. The experimental design consists of a comparative field experiment with and without air flow support, spraying at two standard working rates (200 and 400 L·ha⁻¹) and determining the application of the liquid to plants in the nursery. The results demonstrated a positive effect of the AA system on deposition. At a travel speed of 6.0 km·h⁻¹ and an application rate of 200 L·ha⁻¹, deposition on the upper leaf surface was 68% higher with the fan engaged. For a 400 L·ha⁻¹ rate, deposition increased by 47%, with both differences statistically significant. The study showed that the nursery sprayer mounted on a high-clearance portal tractor and equipped with an AA system achieved an increase of 58% in spray deposition on the upper leaf surface when the fan was operating at 200 L·ha⁻¹ and 28% at 400 L·ha⁻¹. Substantial differences were found between deposition on the upper and lower leaf surfaces, with the former being 20–30 times greater. Given the complexity of nursery production technology, sprayers that ensure the highest possible biological efficacy and high quality of nursery material will play a pivotal role in its development. At the current stage, AA technology fulfils these requirements. Full article

Vegetation in residential areas plays a crucial role in biodiverse and sustainable cities as it enhances biological diversity, environmental quality, and the human well-being of city residents. However, the distribution of vegetation among these areas is often unequal, leading to disparities in access to its benefits. To promote a more biodiverse and environmentally just city, we investigated how woody plants (trees, shrubs and vines) vary with socioeconomic level in residential streetscapes of Santiago de Chile. Across the city, we sampled woody plants in 120 plots (11 m radius) located in residential streetscapes of three socioeconomic levels: low, medium, and high. A total of 557 woody plants were identified and measured. Of these, only 9.7% corresponded to native species, whereas 90.3% were introduced species. Wealthier residential areas had higher species richness and abundance of woody plants, as well as plants with greater structural size (revealed by height and crown area). In addition, we found that the composition of woody plants differed among socioeconomic levels: Liquidambar styraciflua, Platanus x hispanica, and Pittosporum tobira were more abundant in high socioeconomic areas; Prunus cerasifera, Citrus limon, and Ailanthus altissima were more abundant in medium socioeconomic areas; Robinia pseudoacacia, Acer negundo, and Schinus areira were more abundant in low socioeconomic areas. Our research highlights that woody plant diversity, abundance, structure, and composition vary with socioeconomic level in residential streetscapes. Key insights for reducing these inequalities and achieve a more environmentally just city include: (a) governance and equity-based investment; (b) prioritizing local native species; (c) promoting the use of non-tree woody plants; and (d) empowering communities through capacity building and stewardship. Full article

Tree fruit and nut crops are a critical component of the global economy, producing at least 400 million tonnes of produce in 2022 and nourishing a growing population of approximately 8 billion humans every year. Improved cultivars and growing practices depend upon an understanding of the molecular basis of tree traits and physiology. Over the past 20 years, the proliferation of reference genomes for tree fruit and nut crop species has transformed the study of genetics in these crops, providing a platform for resequencing analyses of large populations, enabling comparative genomic analyses between distant plant species, and allowing the development of molecular markers for use in breeding. However, reference bias and poor transferability of markers limit widespread applicability in many instances. As third-generation sequencing has become more accurate and accessible, a greater number of reference genomes have become available, enabling higher-quality assemblies and wider sampling of genomic diversity. To facilitate the effective use of multiple closely related genomes to create a reference and comparative genomics platform, tools have been developed for the creation of pangenome graphs, a data structure using nodes connected by edges to represent multiple genomes and their sequence variations. Pangenome graphs allow for singular representations of diversity within a species or even a wider genus. Pangenomic analyses at the genus-scale (e.g., Malus, Citrus) have been conducted for Malus and Citrus, and more tree fruit and nut species are likely to follow. As the number of genome sequences and pangenome resources increases, the importance of generating great quantities of transcriptomic and phenomic data will increase as well. This data is essential in the drive to connect genes to traits and overcome traditional breeding bottlenecks, which is needed to develop improved tree fruit and nut crops, which can satisfy global demand. Full article

Understanding soil respiration (Rs) dynamics in Mediterranean olive groves is crucial for quantifying carbon fluxes under climate change. Soil respiration represents the combined CO₂ efflux from root metabolic activity and microbial decomposition of soil organic matter, processes strongly controlled by soil moisture, temperature, and the quantity and quality of organic matter inputs in semi-arid Mediterranean environments. This study quantified the seasonal and spatial variability of Rs in a traditional rainfed olive orchard planted at a spacing of 11 m between rows and 9 m between trees (≈101 trees ha⁻¹). Continuous measurements were conducted in two contrasting zones, under-canopy (UC) and inter-row (IR), using automated soil CO₂ flux chambers. Annual Rs reached 3.68 Mg CO₂ ha⁻¹ y⁻¹ in UC and 2.21 Mg CO₂ ha⁻¹ y⁻¹ in IR, with substantially higher emissions per unit area beneath the canopy. However, due to its larger surface proportion, the IR zone contributed more to the orchard scale CO₂ budget. Soil water content emerged as the dominant environmental driver of Rs, moderating or suppressing the temperature response during dry periods. These findings highlight the importance of explicitly considering microsite heterogeneity when assessing soil CO₂ efflux and designing sustainable carbon-management strategies in Mediterranean olive agroecosystems. Full article

Scots pine (Pinus sylvestris L.) is a key species in boreal forests, valued both economically and ecologically, in part due to its associations with foliar fungi. These fungi influence plant health, nutrient cycling, and resistance induction. To investigate these interactions, we collected 1367 needle and shoot samples across 12 plus tree genotypes grown in 4 progeny trials in Estonia. Amplifying the ITS1-5.8S-ITS2 gene region, we obtained over 1.3 million high-quality sequences and identified 1261 fungal OTUs at the 98% species hypothesis level. Among the identified OTUs, 24.6% were classified as saprotrophic and 18.2% as pathogenic fungi. Fungal diversity varied significantly between tree tissue types, progeny trial locations, and plus tree origins. Fungal community composition varied across tissue types, with older needles tending to harbor more complex communities. Plus trees 593 and 267-1 progenies stood out for their high phyllosphere fungal richness, and genotype-specific correlations indicated associations between fungal diversity and tree height or needle retention, suggesting potential genotype-dependent effects on tree performance. Heritability of fungal diversity between ramets in seed orchard and progeny trees was found for saprotrophic fungi but was negligible for total fungi and pathogens, indicating strong influence of microclimate conditions. These findings underscore the potential value of integrating fungal community traits into Scots pine breeding programs. Considering microbial associations alongside traditional growth traits may help identify genotypes better suited for future forestry needs under changing environmental conditions. Additionally, Setomelanomma holmii is reported here as a new fungal pathogen on Scots pine shoots in Estonia. Full article

Grape (Vitis vinifera spp.) accessions exhibit rich diversity, and understanding their genetic variation and evolutionary relationships is crucial for cultivar selection and utilization. A highly representative SNP marker set was developed in this study based on re-sequencing data analysis, to clarify the phylogenetic relationships among 96 grape accessions and to evaluate the genetic resolution of core markers. Using PN40024 as the reference genome, high-quality SNP loci were screened from resequencing data of the 96 accessions. A phylogenetic tree was constructed, and genetic diversity was analyzed using PCA and population structure analysis. The results showed that the 96 accessions were mainly divided into four groups: European (‘Merlot’, ‘Chardonnay’), American (‘Beta’, ‘Concord’), Euro-American hybrids (‘Vidal’, ‘Miguang’), and wild populations along with their hybrid progeny (‘Zuoyouhong’, ‘Huajia 8’). PCA and ADMIXTURE validated population differentiation, revealing clear separation between wild and cultivated accessions. Through screening of core SNP markers, 384,304 candidate SNPs suitable for probe design were identified. Further refinement yielded 2000 and 10,000 SNP markers. Detailed analysis of core marker characteristics showed that their minor allele frequency (MAF) was predominantly between 0.1 and 0.3, with the majority distributed in CDS (38.65%), intronic (30.2%), and intergenic regions. The most common mutation types were [A/G] (35%) and [C/T] (34%) transitions. The 2000 core SNPs were associated with 1220 functional genes and were significantly enriched in pathways such as protein binding, RNA transport, and plant–pathogen interaction. These findings provide an efficient tool for grape genetic diversity analysis, cultivar identification, and molecular breeding, laying the groundwork for the precise utilization of grape germplasm resources. Full article

Sweet cherry (Prunus avium L.) is a tree species cultivated worldwide with high economic value. During its growth, it is frequently threatened by pathogenic fungi, leading to reduced yield and deteriorated quality. However, in sweet cherry, the disease-resistant cultivars against brown spot disease (BSD) caused by Alternaria alternata, as well as the associated disease-resistant metabolic pathways and metabolites, remain limited. In this study, we investigated the disease-resistant germplasm and associated metabolic pathways of sweet cherries using field disease resistance screening, physiological analyses, and metabolomics. The results showed that sweet cherry cultivar Q8 exhibited relatively strong resistance to BSD, while cultivar Q9 demonstrated the weakest resistance. Physiological experiments revealed that the changes in relative electrical conductivity (REC), malondialdehyde (MDA) content, and relative water content (RWC) of the disease-resistant cultivar Q8 were smaller than those of Q9 within 9 days under A. alternata infection. At 9 days post-infection (dpi), the relative electrical conductivity (REC) of Q9 (57.78%) was significantly (p < 0.05) higher than that of Q8 (49.01%), whereas the relative water content (RWC) of Q8 (78.29%) was significantly (p < 0.05) greater than that of Q9 (67.88%). For malondialdehyde (MDA) levels, Q8 reached its peak value (27.81 nmol/g) at 3 dpi, while Q9 attained its maximum (27.80 nmol/g) at 9 dpi. At 3 dpi and 9 dpi, Q8 consistently maintained a significantly (p < 0.05) higher RWC than Q9. Linolenic acid metabolism and unsaturated fatty acids were found to be involved in the disease resistance process, and Pinellic acid might be a bioactive metabolite conferring disease resistance. The disease-resistant metabolic pathways and bioactive metabolites identified in this study may be conserved in plants beyond sweet cherry, providing a theoretical basis for disease-resistant breeding of sweet cherry. Full article

Historic districts, as important spatial units that carry urban cultural memory and everyday social life, play a crucial role in shaping residents’ spatial identity, emotional attachment, and perceptual experience. Although quantitative research on built environments and perception has advanced considerably in recent years, the mechanisms through which perception is formed in historic districts, particularly the nonlinear threshold effects and perceptual trade-off patterns that arise under conditions of high-density and mixed land use, remain insufficiently examined. To address this gap, this study develops an analytical framework that integrates spatial attributes with multidimensional subjective perceptions. Focusing on six historic districts in central Shanghai, the study combines micro-scale environmental indicators extracted from street-view imagery, POI data, and public perceptual evaluations and employs an XGBoost model to identify the nonlinear response patterns, threshold effects, and perceptual trade-offs across seven perceptual dimensions. The results show that natural elements such as visual greenery and sky openness generate significant threshold-based enhancement effects, and once reaching a certain level of visibility, they substantially increase positive perceptions including beauty, safety, and cleanliness. By contrast, commercial and traffic-related facilities exhibit dual and competing perceptual influences. Moderate densities enhance liveliness, whereas high concentrations tend to induce perceptual fatigue and intensify negative emotional responses. Overall, perceptual quality in historic districts does not arise from linear accumulation but is shaped by dynamic perceptual trade-offs among natural features, functional elements, and cultural symbolism. Overall, the study reveals the coupling mechanism between spatial renewal and perceptual experience amid the pressures of urban modernization. It also demonstrates that increasing visible greenery (e.g., planting street trees, incorporating micro-green spaces, improving façade greening), enhancing street openness (e.g., optimizing view corridors, reducing visual obstruction, implementing moderate setback adjustments), guiding a moderate mix and spatial distribution of commercial and service functions, and strengthening the perceptibility of cultural landscape elements (e.g., façade restoration, streetscape coordination, and improved signage systems) are concrete and effective planning and design actions for improving landscape quality and enhancing the experiential quality of historic districts. Full article

Apple (Malus domestica) is a deciduous perennial tree that belongs to the family “Rosaceae”. Due to the highly suitable agro-climatic conditions for apple cultivation, it is among the widely cultivated fruits in Gilgit-Baltistan (GB). This study aims to evaluate elite apple genotypes in GB based on morphological and biochemical traits. Five- to six-year-old plants were selected for this study. The research employed a completely randomized design (CRD) with three replications, and mean differences were analyzed using the LSD test. In this study, five genotypes were assessed based on morphological (fruit weight, fruit length, fruit width, and firmness) and biochemical attributes (TSS, TA, ascorbic acid, total phenolic content, and flavonoid content). The results revealed significant variation among apple cultivars in both phytochemical and fruit quality attributes. The cultivar ‘Red Delicious’ exhibited the highest fruit weight (146.18 g), total soluble solids (TSS) (15.4 °Brix), and flavonoid content (105.75 mg 100 g⁻¹ FW). In contrast, ‘Red Full Star’ demonstrated superior firmness (7.19 kg cm⁻²), along with the highest total phenolic content (TPC) (4.00 mg GAE g⁻¹ FW) and ascorbic acid content (26.45 mg 100 g⁻¹ FW). Although the indigenous variety ‘Nus Khushu’ exhibited lower values in commercial traits, it holds substantial potential for conservation due to its unique local adaptation. The findings indicate that the “Red Delicious” and “Red Full Star” cultivars cultivated in GB are enriched with a variety of bioactive compounds that offer notable health benefits and may be utilized for future crop enhancement and breeding initiatives. Full article

Sustaining irrigated agriculture under drought conditions with alternative water sources such as saline groundwater requires understanding their effects on salt-tolerant crops like pistachio. During recent California droughts, pistachio trees planted in 2002, 2009, and 2011 were irrigated with high-saline water containing traces of boron (B) and selenium (Se). In 2018, irrigation was divided so that half of the trees received low-saline water, while the others continued under high-saline irrigation. Three years later, nuts were harvested to evaluate how irrigation quality affected seed coats, the main storage site of phenolic antioxidants. Sixty seed coat extracts from both irrigation treatments were analyzed for antioxidant capacity (ABTS, DPPH, FRAP and Folin–Ciocalteu assays). Nuts from the oldest trees (planted in 2002) had the highest antioxidant capacity. High-performance liquid chromatography (HPLC) identified gallic acid and nine flavonoids. Catechin, procyanidin B1, cyanidin-3-O-galactoside, and eriodictyol were most abundant in the oldest trees. Irrigation salinity significantly affected gallic acid, quercetin, and isoquercetin, with higher concentrations detected in seed coats from trees receiving continued high-saline irrigation. These compound-specific shifts, together with strong age-dependent patterns, provide insight into how long-term salinity exposure influences phenolic composition in pistachio seed coats. Full article

In the cherry-growing area of Apulia (Italy), sweet cherry (Prunus avium L.) cultivars are commonly grafted onto Prunus mahaleb L. rootstock. This study investigated the influence of the scion on the fruit quality of the rootstock, an aspect that remains largely underexplored in studies of stionic interactions. In an old sweet cherry orchard in the Bari area, several ‘Ferrovia’ trees grafted onto P. mahaleb L. rootstock were observed, where some rootstock individuals had developed fruiting branches below the grafting point. We collected fruits from those mahaleb rootstocks and compared them with fruits produced by non-grafted P. mahaleb L. trees growing in the same orchard. Extracts of grafted and non-grafted mahaleb cherries was analyzed by HPLC-DAD and ¹H-NMR. Anthocyanins, coumaric acid derivatives, organic acids, and reducing sugars were identified in both extracts. Non-grafted mahaleb fruits were characterized by a higher relative content of malic acid, fructose, dihydro-coumaric acid derivatives, and anthocyanins and lower content of α/β glucose and sorbitol, with respect to the grafted mahaleb. The metabolic differences observed between fruits from grafted and non-grafted P. mahaleb L. were further supported by our preliminary NMR-based analysis conducted on fruit juice over two consecutive years. The results suggest that grafting may induce some physiological changes not only in the scion, but also in the rootstock, even in its vegetative (above-ground) organs, if developed. This work represents a novel finding and reinforces the broader understanding that grafting impacts physiological processes in plants. Full article

The yield and quality of rubber tree latex are affected by environmental stresses and plant hormone stimulation. Heat shock protein 90 (HSP90) is widely involved in various developmental processes and stress responses in plants, especially in drought stress. In this study, we cloned the HbHSP90.3 gene and characterized its expression pattern in different tissues and mechanical wounding treatments of the rubber tree and found that it is highly expressed in latex and responds to mechanical wounding treatment. To reveal the roles of plant hormones and HSP90.3 protein in the drought resistance process of rubber trees. Treatment with the specific HSP90 protein inhibitor geldanamycin (GDA) and yeast expression experiments demonstrated that HbHSP90.3 has a relieving effect on water deficit in rubber trees. The expression pattern showed that the HbHSP90.3 gene was closely related to hormone signaling, especially for Indole acid (IAA) and Zeatin (ZT) induction under different plant hormone treatments. Protein interaction analysis showed that HbHSP90.3 interacted with the suppressor of the G2 allele of skp1 (HbSGT1b). Taken together, HbHSP90.3 interacts with HbSGT1b in the nucleus and plays a key role in water deficit. Full article

Pinus koraiensis, as a keystone tree species, possesses immense economic and ecological value. However, the present cultivation of high-quality seedlings in Pinus koraiensis plantations remains hindered by prohibitively high costs and inadequate technological advancements. Additionally, the species’ prolonged growth cycle and low yield, when compounded by issues such as excessive harvesting, may result in supply constraints. Plant growth regulators (PGRs), a class of naturally occurring or synthetically derived chemical compounds, are capable of modulating plant development and physiology. These regulators exert notable effects by enhancing root proliferation, facilitating lignification, influencing plant architecture, and augmenting yield. Owing to their operational simplicity and relatively low cost, PGR applications hold substantial promise for cultivating Pinus koraiensis seedlings with superior traits. In this study, four-year-old Pinus koraiensis seedlings were employed to evaluate the impacts of three PGRs (paclobutrazol, chlormequat chloride, and diethyl aminoethyl hexanoate), alongside varied application methods (dosage and frequency), on the growth, physiological, and photosynthetic parameters of the seedlings. The findings revealed that treatment with 1.5 g/L paclobutrazol produced the most pronounced effects across a range of indicators. Specifically, this treatment markedly enhanced growth traits (e.g., branch diameter, new shoot length, lateral branch length, aboveground fresh and dry weights, root fresh and dry weights, lateral root dry weight, and number of second-order roots), physiological attributes (e.g., increased superoxide dismutase and peroxidase activities, elevated lignin content, and reduced relative conductivity and malondialdehyde levels), and photosynthetic metrics (e.g., elevated net photosynthetic rate, stomatal conductance, transpiration rate, and maximum net photosynthetic rate), thereby constituting the optimal treatment combination. Full article

To achieve accurate prediction of jujube tree yield and quality, this study developed a prediction model based on a backpropagation (BP) neural network. By measuring the diurnal variation of photosynthetic rate and tree structural parameters at different phenological stages, and screening input variables through correlation analysis, two prediction models were established: one for yield er plant (with an 11-10-1 network structure) and another for the rate of first-grade fruits (with a 7-8-1 structure). After optimization, both models demonstrated excellent performance, with validation set R² values reaching 0.87556 and 0.94406, respectively. SHAP (SHapley Additive exPlanations) analysis was applied to interpret key influencing factors, revealing that features X11 and X10 contributed the most to the yield-per-plant model, whereas features X7 and X8 were the most critical in the first-grade fruit rate model. Response surface analysis further identified optimal parameter intervals for high yield and quality: the yield per plant was maximized when photosynthetically active radiation in the evening during the fruiting period was between 0.7–0.8 μmol·m⁻²·s⁻¹ and tree height was 2.5–3.5 m; the rate of first-grade fruits was optimized when tree height ranged from 1 to 4 m and the number of first-grade branches was between 1 and 13. This study provides a reliable prediction tool and a theoretical foundation for precision management in jujube cultivation. Full article

In forest tree nursery production, bioactive compounds are sought to promote plant growth in response to changing environmental conditions. This study evaluated the effects of the Ecklonia maxima (Osbeck) seaweed extract and the bacterium Bacillus subtilis (Ehrenberg) and their combination on the growth and development of beech (Fagus sylvatica L.) seedlings. A two-factor experiment was conducted in 2023 at the Didactic and Research Station, Department of Ecology and Silviculture, University of Agriculture in Krakow. The nursery experiment investigated the effects of foliar applications of varying doses: Ecklonia maxima at 960 and 1920 cm³·ha⁻¹ and Bacillus subtilis at 112 and 224 g·ha⁻¹ on European beech (Fagus sylvatica L.) seedlings. The application of E maxima seaweed extract a dose of 960 cm³·ha⁻¹ promoting beech seedlings increase in the area of the root system (101.0 ± 17.8 cm²). Seedlings sprayed with B. subtilis at a dose of 112 g·ha⁻¹ were characterized by the longest root system, the largest root collar diameter, and the highest DQI (Dickson Quality Index) values (22.9 ± 3.4 cm, 6.00 ± 0.4 mm, and 0.74 ± 0.2, respectively). Applying B. subtilis at 224 g·ha⁻¹ resulted in an increased SQ (Sturdiness Quotient) value (from 6.33 ± 0.7 for the control variant to 6.62 ± 0.7) and the lowest SHI (Seedling Health Index) value (5.59 ± 0.9). Applying higher doses of Ecklonia maxima (1920 cm³·ha⁻¹) and B. subtilis (224 g·ha⁻¹) increased the SQ index value but decreased the root system area. The best DQI and SHI values were observed with the highest dose combinations of E. maxima and B. subtilis. Selecting suitable biological substances promoting growth can support the sustainable production of beech seedlings while improving the adaptability of forest tree seedlings. Full article