Search Results (305)

Soil compaction alters soil structure and hydrology by increasing bulk density and penetration resistance, disrupting aggregates, reducing porosity and infiltration capacity, and enhancing shear strength. These changes can impede seedling establishment, particularly by restricting root development. The objective of this study was to evaluate the effects of a controlled soil penetration resistance (SPR) gradient on velvet maple (Acer velutinum Boiss.) seedling growth, morphology, and architecture under nursery conditions in northern Iran’s Hyrcanian forests. We hypothesized that increasing compaction would reduce seedling size and total biomass while altering the pattern of biomass partitioning between above- and belowground organs. Seven compaction levels were induced using a 4.736 kg hammer dropped from 45.7 cm, applying 0 (control), 1, 2, 4, 6, 8, or 10 blows per layer across 35 pots (5 replicates per level). After the 227-day growing period, seedlings were carefully excavated; root systems were gently washed, and all morphological indicators (main root length, lateral root length, and stem length) were measured manually using a ruler. Soil compaction resulted in a marked increase in soil penetration resistance (SPR), rising from 0.32 ± 0.03 MPa in the control treatment to 2.09 ± 0.08 MPa at the highest compaction level (p ≤ 0.01). Elevated SPR elicited significant polynomial responses in seedling morphological traits, including stem and root dimensions, as well as in biomass accumulation (total, shoot, and root). Notably, the main root biomass exhibited a significant decline with increasing compaction intensity, whereas lateral root length increased correspondingly, despite a reduction in lateral root biomass. These findings indicate that, in loam to clay-loam soils under optimal moisture conditions, total seedling biomass increased with moderate compaction, peaking near 1.5 MPa, whereas significant root growth reduction occurred above approximately 1.2 MPa. Above this level, compensatory lateral root elongation and a shift in biomass partitioning toward shoots were observed, but severe compaction (>1.5 MPa) ultimately suppressed whole-plant productivity. The study identifies a novel root architectural trade-off characterized by a 198% increase in specific root length and a tripling of the lateral-to-main root length ratio under severe compaction, providing species-specific thresholds and early-warning indicators for nursery soil management. These findings provide valuable insights into adaptive seedling responses to soil compaction and contribute to the development of sustainable forest nursery practices. Improving seedling quality under compacted soil conditions can enhance plantation success, soil conservation, and the long-term sustainability of forest restoration programs. Full article

Ganoderma boninense, a soil-borne pathogenic fungus causing basal stem rot (BSR) disease in oil palm, is the major threat to cultivation in Southeast Asia, with the potential to reduce oil production by up to 80% in severely affected plantations. With a view to marker-assisted selection (MAS) of resistant planting material, we combined genetics and transcriptomics approaches to investigate the defense mechanisms of oil palm against infection by G. boninense. We first performed quantitative trait locus (QTL) mapping of BSR resistance using a multi-locus Bayesian variable selection approach applied to more than 10 years of data collected during pre-nursery tests of Deli and La Mé breeding populations. We found 6 and 5 BSR resistance loci segregating in Deli and La Mé respectively, with no overlap between them. Then we performed an RNA-sequencing approach on libraries of roots and bole of oil palm seedlings inoculated or not with G. boninense, focusing on Deli × La Mé crosses with contrasted BSR resistance. A Bayesian variable selection on predictors obtained by tracing the resistance loci haplotypes in profiled individuals identified 195 differentially expressed genes (DEGs) for the G. boninense inoculation × QTL interaction, among the 551 DEGs found for inoculation effects. The DEGs were located both in cis and trans positions compared to the segregating QTL intervals, enabling the prioritization of candidate genes and resistance mechanisms associated. Focusing on a strong effect QTL region on chromosome 4 in the Deli genetic background, we identified three candidate genes in cis positions that exhibited differential expression both in response to G. boninense inoculation and between resistant and susceptible haplotypes. Our study is the first combining QTL and RNA-seq approaches in oil palm based on genetically connected experimental setup, providing valuable information on the underlying mechanisms and paving the way for MAS of BSR resistant planting material. Full article

In this study, three-year-old seed-derived seedlings of Horsfieldia hainanensis Merr. were subjected to 0%, 25%, 50%, and 75% shade treatments in a nursery shade-net experiment from October 2025 to June 2026. Each treatment included three replicates, with three seedlings per replicate. The results showed that the light environment significantly affected growth. Seedlings under 0% shade showed severe wilting and mortality; therefore, this treatment was treated as a mortality outcome and excluded from subsequent statistical comparisons, which were conducted among the 25%, 50%, and 75% shade treatments. Within this range, plant height, ground diameter, crown width, leaf traits, and above- and belowground biomass increased with shade level, with the highest values observed under 75% shade. The 75% shade treatment was associated with higher maximum net photosynthetic rate (Pmax), apparent quantum yield (AQY), initial carboxylation efficiency (α), and CO₂-saturated net photosynthetic rate (Amax), together with lower light compensation point (LCP) and carbon dioxide compensation point (CDCP), indicating improved light- and CO₂-response performance within the tested shade range. Leaf thickness, epidermal thickness, and palisade and spongy parenchyma thicknesses increased with shade level, whereas variation in stomatal traits was mainly reflected in stomatal density. Chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids increased under stronger shading, showing clear variation in pigment accumulation along the shade gradient. Growth, biomass, photosynthetic capacity, leaf anatomical traits, and pigment contents were positively correlated, whereas the light saturation point (LSP), LCP, carbon dioxide saturation point (CDSP), and CDCP were generally negatively associated with these traits. Among the surviving treatments tested, the 75% shade treatment produced the best seedling performance and may be suitable for nursery cultivation, although further validation at different sites and in different seasons is needed. These findings provide practical guidance for artificial propagation, seedling production, plantation establishment, and light-environment management of this species. Full article

The white peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) (Hemiptera: Diaspididae), is a highly polyphagous insect pest of global phytosanitary relevance affecting fruit trees, perennial crops, and ornamental plants in temperate and subtropical regions. Its invasive success is largely driven by high thermal tolerance, a wide host range, and strong survival capacity under postharvest handling and cold-chain storage, which greatly enhances its potential for long-distance dispersal through international trade of fresh fruit and plant material. A systematic review and meta-synthesis of 105 scientific studies published between 1958 and 2026 identified key research areas, including geographic distribution and invasion pathways, host plants and varietal susceptibility, temperature-dependent life history, agricultural impact and quarantine risk, chemical and biological control strategies, and the development of phenology-based monitoring and prediction tools using thermal models and pheromones. Although recent official reports do not confirm the presence of P. pentagona in Ecuador, climate suitability modeling and evidence of long-term survival during cold storage indicate a high risk of introduction and establishment, particularly in inter-Andean valleys. Consequently, preventive phytosanitary surveillance and integrated pest management strategies tailored to Ecuadorian Andean fruit production are proposed, emphasizing phenological monitoring, nursery and agro-urban inspections, and the conservation of natural enemies as a foundation for sustainable management of this emerging pest. Full article

Water scarcity is a major constraint to sustainable horticultural production, particularly in arid and semi-arid regions. This study evaluated the effectiveness of two natural foliar biostimulants, chitosan and Spirulina extract, in improving water productivity, growth performance, biomass production, and drought tolerance of passion fruit (Passiflora edulis Sims) seedlings under deficit irrigation. A factorial experiment was conducted using three irrigation regimes (100%, 85%, and 70% of field capacity, FC) combined with three foliar spray treatments: distilled water (control), chitosan (1 g L⁻¹), and Spirulina extract (1 g L⁻¹). Deficit irrigation significantly reduced chlorophyll content, vegetative growth, biomass production, and water productivity, with the greatest reductions observed at 70% FC. Foliar application of both biostimulants effectively alleviated these adverse effects by enhancing plant growth, biomass production, chlorophyll retention, and water productivity under water-limited conditions. Chitosan consistently outperformed Spirulina, particularly under moderate water deficit, by reducing irrigation water requirements while maintaining seedling growth and physiological performance comparable to those under full irrigation. Multivariate analyses, including Pearson correlation, principal component analysis, and response surface methodology, revealed strong positive relationships among biomass production, chlorophyll content, vegetative growth traits, and water productivity. Among all treatments, foliar application of chitosan at 1 g L⁻¹ combined with 85% FC was identified as the optimum strategy, providing substantial irrigation water savings while maintaining vigorous seedling growth, high biomass production, and superior water productivity. These findings demonstrate that integrating moderate deficit irrigation with chitosan application is an effective and sustainable strategy for improving passion fruit nursery production under conditions of limited water availability. Full article

Despite the increasing interest in Silene compacta Fisch. as a landscape plant, its greenhouse cultivation protocols remain poorly explored, leaving a critical gap in optimizing seedling production duration and efficiency. Therefore, this study aimed to compare the growth characteristics, growing medium properties, and leaf nutrient contents of S. compacta seedlings grown for two different periods (2.5 and 4.5 months) under standardized nursery conditions using a single pot type, a uniform growing medium, and a fixed fertilization program. Seedlings were grown simultaneously under greenhouse conditions, and final measurements were made at the end of each assigned growing period. Differences between the two growing periods were evaluated using independent samples t-tests based on replicate means. Several growth traits, including leaf number, leaf area, root number, stem diameter, and root and shoot biomass, were significantly higher at 4.5 months than at 2.5 months, whereas plant height, plant width, lateral branching traits, leaf dimensions, and root length did not differ significantly between the two periods. In the growing medium, pH was higher at 4.5 months, whereas total nitrogen and several micronutrients were higher at 2.5 months. Leaf N, P, K, Mn, and Cu concentrations were also higher at 2.5 months, whereas leaf Ca concentration was higher at 4.5 months. Overall, the results indicate that the 2.5-month growing period provided sufficient seedling development within a shorter production time and may offer significant economic and practical advantages in terms of compact appearance, lower input requirement, and earlier saleable seedling production under the nursery conditions tested. Full article

The early post-weaning period in piglets is characterized by physiological and environmental stress that can impair intestinal function and growth performance. Plant-derived feed additives have gained interest as a nutritional strategy to support gut integrity and productivity. Extracts from Cynara scolymus stimulate bile secretion and exhibit antioxidant properties, whereas inulin may promote beneficial microbial populations and intestinal functionality through prebiotic activity. This study evaluated the biological activity of a feed additive containing Cynara scolymus extract and inulin on intestinal functional indicators and productive performance of post-weaned piglets under intensive production conditions. Four hundred and eight piglets were randomly assigned to two groups: a control group (CON) that was fed a basal diet, and a treatment group (CSI) that was supplemented with the additive (5% Cynara scolymus extract and 14% inulin) at 300 g/ton of feed. Plasma cortisol and citrulline concentrations were measured during the first 15 days post-weaning. On day 16 post-weaning, intestinal parameters were evaluated, including gastrointestinal pH; enterobacteria and lactic acid bacteria counts; volatile fatty acids; bacterial adhesion to ileal mucus; disaccharidase activity; and small intestinal histomorphology. Growth performance was monitored during the 50-day nursery phase. Compared with CON piglets, CSI piglets exhibited higher plasma citrulline concentrations (72.72 ± 20.87 vs. 47.54 ± 17.05 µM; p < 0.001), indicating improved intestinal epithelial functionality. CSI supplementation also increased the villus height-to-crypt depth ratio (3.67 ± 0.75 vs. 2.68 ± 0.64; p = 0.001), suggesting enhanced intestinal epithelial integrity. Furthermore, CSI piglets showed higher average daily gain (0.53 ± 0.07 vs. 0.44 ± 0.09 kg/day; p = 0.003) and a better feed conversion ratio (1.27 ± 0.20 vs. 1.57 ± 0.57; p = 0.004). These results suggest that Cynara scolymus extract and inulin supplementation has beneficial biological effects on intestinal epithelial functionality and productive performance in post-weaning piglets under commercial conditions. Full article

In container-grown ornamental shrub production, limited substrate volume can rapidly alter plant water status and affect leaf-level physiological performance. A randomized block experiment was conducted to evaluate the effects of three foliar-applied biostimulants, BiStep, Kelpak, and Yeald Plus, compared with an untreated control in container-grown Forsythia × intermedia ‘Beatrix Farrand’. Each treatment comprised 25 plants distributed across five blocks. Stomatal density, stomatal length, leaf transpiration, net photosynthesis, total chlorophyll content, and gravimetrically determined daily water loss were measured. Compared with the control, BiStep significantly increased stomatal density, whereas Yeald Plus significantly decreased it. Kelpak and Yeald Plus significantly increased stomatal length compared with the control. Leaf transpiration was significantly lower under Kelpak and Yeald Plus than in the control, while Kelpak and BiStep had significantly higher net photosynthetic rates than Yeald Plus, whereas the control did not differ significantly from any treatment. Total chlorophyll content did not differ significantly among treatments. Whole-plant daily water loss was higher in all biostimulant-treated plants than in the control, with the highest values recorded under BiStep. These results show that the tested biostimulants induced treatment-specific physiological changes rather than a uniform response. Kelpak provided the most favorable leaf-level balance by reducing instantaneous transpiration while maintaining high photosynthetic activity, whereas BiStep promoted a more water-demanding physiological profile. Based on these outcomes, Kelpak may be recommended where improved leaf-level physiological efficiency is required under container-grown nursery conditions, while BiStep should be applied only with adequate irrigation management. Full article

Apple replant disease (ARD) is a significant problem in regions with intensive fruit production. ARD deteriorates the production properties of soil, reduces yield, and results in lower fruit quality. The effects of ARD can be mitigated with organic amendments applied to soil to improve its productivity. Our experiment was conducted on a farm in western Poland. Biochar was added to replanted soil at 5%, 10%, and 20% by volume and its effect on the physicochemical and biological properties of the soil, the growth vigour, and the quality of strawberries was analysed. Strawberry plants were planted in soil which either had been used for nursery production (replanted soil) or had never been used for this purpose (agricultural soil). The results of our study confirmed earlier reports on the negative consequences of ARD. The replanted soil was more saline and contained less organic matter than the agricultural soil. The plants growing on the replanted soil developed worse. When biochar was added to the replanted soil, depending on its percentage content, the organic matter content and soil respiration rate almost doubled, whereas the count of bacterial taxonomic units increased. As a result of these changes, the root mass of the plants growing in the replanted soil increased by nearly 50%, whereas the root collar mass of shrubs and their leaf area increased by 25 to 30%. The average fruit weight also increased by about 40%. The optimal biochar content in the replanted soil was 10%. The biochar content of 20% did not cause significant changes in most of the parameters under analysis. Full article

Walnut multiplication technology for obtaining high-quality planting material consists of grafting, followed by forcing bionts in protected spaces under controlled microclimatic conditions, and completed by acclimatization under field conditions. The present research substantiates the hypothesis that the use of protected spaces (polyethylene tunnels) enables rigorous control of limiting factors. The main objectives of the paper are the comparative evaluation of two grafting methods (chip and patch budding) on the grafting success of eight native genotypes (‘Anica’, ‘Grădinar’, ‘Miroslava’, and ‘Velnița’, ‘Bălțăți’, ‘Belcești’, ‘Săbăuani’, and ‘Șorogari’) grafted on ‘Bălțați’ local biotype, determining the optimal moment of grafting by identifying the time window (April vs. August) that maximizes the success rate of the grafting association. The study, carried out from 2022 to 2024, evaluated the performance of chip and patch budding executed under high-tunnel conditions, quantifying the scion/rootstock growth, callus formation, and anatomical symbiont similarity through cross-sectional microscopy and image analysis software to measure vessel number, density, and diameter; the results are presented as the mean values of three annual repetitions across the experimental period. Preliminary results indicate a superior efficiency of the chip budding method, with a 51.3% success rate compared to 32.9% for the patch budding method. Another objective of the study was the ranking of the experimental variants. Thus, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), a multi-criteria decision analysis method, ranked the experimental variants and identified the chip budding performed in April (variant a1/b2) as the optimal solution across all analyzed physiological and morphological parameters. These findings are highly significant for the nursery sector, as they demonstrate that transitioning from unpredictable field conditions to controlled high-tunnel conditions stabilizes production outcomes. By establishing a clear methodological hierarchy and a precise chronological window, this study provides actionable guidelines to standardize walnut multiplication, mitigate seasonal climate risks, and substantially increase the output of high-quality certified planting material. Full article

The quarantine pathogen Phytophthora ramorum has a high potential for dispersal due to its airborne inoculum, its wide range of hosts, and its ability to spread through the trade of nursery plants. For these reasons, it represents a serious threat to ornamental nursery production and, consequently, to urban, natural and semi-natural ecosystems. This oomycete pathogen (EU1 lineage, A1 mating type) has been detected on Viburnum tinus in a commercial nursery located in the Pistoia nursery district (PND) (Tuscany, central Italy), one of the main nursery areas for the production of ornamentals in Europe. Artificial inoculations were carried out in the laboratory under controlled conditions, following a standard detached-leaf assay protocol, on leaves of 16 ornamental shrub species commonly marketed by the PND. Disease severity was assessed, and susceptibility categories (high, moderate, low, and non-susceptible) were defined based on data collected at 7 and 14 days post-inoculation and validated through statistical analysis. Inoculated species exhibited variable levels of disease severity. The results confirmed the pathogen’s high virulence on Viburnum tinus and Rhododendron hybrid ‘Madame Masson’. The following species were also found to be highly susceptible: Ilex aquifolium, Loropetalum chinense, Magnolia stellata, Osmanthus fragrans, and Trachelospermum jasminoides. Camellia japonica, Nerium oleander, Osmanthus heterophyllus, Prunus laurocerasus, and Rhododendron obtusum showed moderate susceptibility. Arbutus unedo, Laurus nobilis, Photinia fraseri and Syringa vulgaris exhibited low susceptibility. At the end of the trial, no infected species fell into the non-susceptible categories. The oomycete proved particularly aggressive on Ilex aquifolium, the most susceptible host among those tested. This high susceptibility is a new finding that could have significant epidemiological implications. Our findings emphasize the need for rigorous phytosanitary surveillance in nursery systems, based on constant monitoring and the adoption of high-throughput diagnostic protocols, in order to implement effective and rapid control measures. Full article

Sweet basil (Ocimum basilicum L.) is a member of the Lamiaceae family, which includes a wide variety of medicinal and aromatic herbs cultivated for their essential oils and bioactive compounds. However, prolonged drought stress can significantly impair growth and essential oil content. In this study, a two-season pot experiment was conducted under open-field conditions. The study was carried out at the Floricultural Nursery, Faculty of Agriculture and Natural Resources, Aswan University, Egypt, during 2024 and 2025, with the aim of assessing how foliar applications of silicon (Si) and zinc (Zn) impact the morphological, physiological, and biochemical responses of sweet basil under different soil water capacity (SWC) levels (80%, 60%, and 40% SWC). Drought stress markedly reduced plant height, branch number, leaf area, biomass, photosynthetic pigments, macronutrient content, and essential oil content, while increasing levels of proline and secondary metabolites such as phenolics, flavonoids, and ascorbic acid. Growth and productivity were highest under 80% SWC, followed by 60%, and lowest under 40%. Under drought stress (40% SWC), Si₂₀₀ increased plant dry biomass by approximately 12%, chlorophyll content by 53%, and essential oil content by 46% compared with untreated plants. Silicon application proved more effective at ameliorating the negative consequences of drought than Zn, with Si₂₀₀ combined with 80% SWC yielding the best results in terms of plant performance and essential oil percentage and content. Meanwhile, Si₂₀₀ under 40% SWC induced the highest accumulation of secondary metabolites. These results highlight the potential of silicon foliar application as a practical strategy to reduce drought stress in sweet basil, enhancing both yield and phytochemical quality, and offering valuable guidance for sustainable cultivation under water-limited conditions. Full article

Reliable nursery production is essential for producing ex situ planting stock of the locally threatened mangrove Lumnitzera littorea in Can Gio, Vietnam. We evaluated 12-month seedling performance using two nursery substrates—CTI (topsoil) and CTII (mixed substrate)—and salinity-structured irrigation regimes: C, a dynamic river/tidal water plus freshwater reference regime and seven fixed-salinity treatments (E1–E7: 0, 10, 15, 20, 25, 30, and 35‰). Each substrate–regime combination comprised three replicate cells of 40 seedlings (N = 1920). The primary endpoints were month 12 survival (SR12), seedling height among survivors (H12), and root collar diameter among survivors (Do12). Statistical inference was confined to E1–E7; C was retained as a descriptive operational reference. For E1–E7, substrate and regime significantly affected SR12 and H12, whereas Do12 varied by regime but not by substrate; no substrate × regime interaction was detected. SR12 declined sharply at 30–35‰, especially under CTI, and the high-salinity H12 and Do12 estimates were based on few survivors. CTII outperformed topsoil alone, particularly for survival and survivor-conditioned height. The findings support conservative nursery guidance for Can Gio: use a mixed substrate and avoid sustained high fixed-salinity irrigation, without extending the inference to a species-wide salinity optimum or post-planting field performance. Full article

Apple (Malus domestica Borkh.) rootstocks play a key role in modern intensive orchard systems, where their accurate identification is essential for breeding, nursery production, and certification of planting material. This is particularly important in Kazakhstan, a recognized center of origin of cultivated apple, where local germplasm remains insufficiently characterized at the molecular level. In this study, we integrated simple sequence repeat (SSR) genotyping and morphological trait analysis to develop a reliable approach for the identification of clonal apple rootstocks cultivated in Kazakhstan. Five widely used rootstocks (Zhetysu 5, ARM-18, B-7-35, M9, and B9) were analyzed using 17 polymorphic SSR markers and 30 vegetative traits. SSR analysis revealed moderate genetic polymorphism (PIC = 0.28–0.54; He = 0.35–0.58) and enabled clear discrimination among all studied genotypes. Cluster analysis based on genetic distances grouped rootstocks according to their genetic similarity, reflecting their origin and differentiation. Morphological evaluation demonstrated significant phenotypic variability and identified correlations among key vegetative traits related to plant vigor and leaf development. The integration of molecular and morphological data allowed the development of comprehensive genotype profiles (“molecular–morphological passports”) for each rootstock, ensuring their reliable identification. The proposed approach provides a practical framework for the certification of planting material and the management of apple genetic resources in Kazakhstan. It can be applied to improve nursery systems, support breeding programs, and ensure the production of true-to-type planting material in modern horticulture. Full article

The global citrus industry is under severe threat from devastating diseases, including Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), and Citrus tristeza disease, caused by Citrus tristeza virus (CTV). Establishing efficient pathogen elimination techniques is crucial for developing virus-free citrus nursery systems and helps facilitate the prevention and control of devastating diseases. This study systematically evaluated the multiple effects of hot water treatment and plant growth regulator application on bud germination, pathogen elimination, antioxidant enzyme activities, and CsWUS expression in citrus scion. The results showed that moderate hot-water treatment at 40 °C for 5 min promoted bud germination, while higher temperatures or extended durations were inhibitory. Both 6-benzylaminopurine (6-BA) and melatonin (MT) significantly enhanced germination, with 50 mg/L 6-BA and 100 μM MT being most effective. All treatments significantly enhanced pathogen elimination and increased the activities of antioxidant enzymes SOD, POD, and CAT, with melatonin concentrations of 100 μM and above reducing CLas and CTV titers by over 93.64% and 96.07%. Furthermore, hot-water treatment and MT, but not 6-BA, upregulated the expression of the virus-resistance-related gene CsWUS. A combined treatment of hot water and MT did not yield synergistic benefits. In conclusion, melatonin treatment, particularly at 100 μM, optimally balances high bud germination with effective pathogen elimination, likely through activating antioxidant defenses and CsWUS-mediated immunity. This study provides a practical and efficient strategy for citrus pathogen-free seedling production. Full article