Search Results (79)

Soil contamination by heavy metals (HMs) threatens crop productivity, food safety, and ecosystem health, especially in intensively cultivated Mediterranean regions. This study investigated the influence of soil HM contamination on nutrient uptake, photosynthetic traits, and metal bioaccumulation in avocado (Persea americana Mill.) orchards. Twenty orchard sites were sampled, collecting paired soil and mature leaf samples. Soil physicochemical properties and HM concentrations were determined, while leaves were analyzed for macro- and micronutrients, photosynthetic pigments, and metal contents. Bioaccumulation Factors (BAFs) were computed, and multivariate analyses (Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Linear Discriminant Analysis (LDA), and Partial Least Squares Regression (PLSR)) were applied to assess soil–plant relationships, complemented by Monte Carlo simulations to quantify probabilistic contamination risks. Results revealed substantial inter-site variability, with leaf Cd and Pb concentrations reaching 0.92 and 3.54 mg/kg, and BAF values exceeding 1 in several orchards. PLSR models effectively predicted leaf Cd (R² = 0.789) and Pb (R² = 0.772) from soil parameters. Monte Carlo simulations indicated 15–25% exceedance of FAO/WHO safety limits for Cd and Pb. These findings demonstrate that soil metal accumulation substantially alters avocado nutrient balance and photosynthetic efficiency, highlighting the urgent need for site-specific soil monitoring and sustainable remediation strategies in contaminated orchards. Full article

Avocado cultivation is expanding rapidly in East Africa, driven by growing market demand, yet planning often relies on farmers’ experience rather than systematic spatial analysis, raising risks of inefficient land and resource use. Therefore, this study applied four species distribution models (SDMs), Generalized Additive Models (GAM), Boosted Regression Trees (BRT), Maximum Entropy (MaxEnt), and Random Forest (RF), along with an ensemble model to map potential avocado suitability in Tanzania. The models were calibrated using 199 Variance Inflation Factor (VIF)-depurated occurrence records from which climatic, edaphic, and topographic predictor variables were extracted. BRT and RF had the best predictive abilities, with AUC values ranging from 0.77 ± 0.20 to 0.81 ± 0.13. The individual models identified Njombe, Iringa, Songwe, Kigoma, Rukwa, Kagera, and Morogoro as regions with high suitability, with more than 30% of each region’s total area predicted to be suitable for avocado production. Moderate suitability (15% to ≤30% of the regional area) was recorded for Kilimanjaro, Arusha, Dodoma, Manyara, Mara, Mbeya, Ruvuma, Tanga, and Katavi, whereas negligible suitability was forecasted for most of the remaining regions by the majority of the models. These findings suggest that heavy investments in avocado production and value chain additions should be directed primarily to regions with high suitability in order to use resources efficiently and minimize investment risks. More targeted, site-specific management should be encouraged in moderately suitable regions, with a focus on helping farmers identify and manage the best avocado sites rather than promoting broad expansion across the country. The findings generated by the ensemble model could be incorporated in the Tanzania Agriculture Climate Adaptation Technology Deployment Programme (TACATDP) to enhance sustainable crop investment, lower production risks, and strengthen the resilience of the avocado sector in the country. Full article

Dengue is a mosquito-borne viral disease transmitted by Aedes aegypti, the main vector in the Americas. The lack of effective antiviral treatments, limited vaccine coverage, and the increasing resistance of mosquitoes to conventional insecticides emphasize the need for alternative vector control strategies. Plant-derived larvicides represent a promising and eco-friendly approach. This study characterized the phytochemical profile of Persea americana Mill. (var. Lorena) and evaluated its larvicidal activity against Ae. aegypti (Rockefeller strain). The phytochemical profile was assessed through qualitative screening, UV-Vis spectrophotometry, and UHPLC analysis. Larvicidal activity was evaluated against third-instar larvae of Ae. aegypti (Rockefeller strain) and the median lethal concentration (LC₅₀) values were determined. Preliminary screening of ethanolic extracts revealed the presence of various secondary metabolites of pharmacological relevance, including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes/sterols, and quinones. UV-Vis spectra displayed distinct absorption patterns, with a prominent peak near 260 nm, consistent with the presence of aromatic compounds. UHPLC profiling revealed high chemical diversity across different plant parts, with 70, 98, 71, and 52 peaks (above 1 × 10⁵ intensity) detected in seed, flower, pulp, and leaf extracts, respectively. Larvicidal bioassays showed significant activity, particularly in the seed extract, with LC₅₀ values (µg/mL) of 3.8 (3.3–4.1) for seeds, 22.4 (21.8–23.9) for flowers, 23.0 (21.5–24.6) for pulp, and 29.7 (28.1–31.2) for leaves. This study highlights the larvicidal potential of ethanolic extracts from P. americana (var. Lorena), with the seed extract exhibiting the highest chemical diversity and bioactivity against Ae. aegypti larvae. The detection of key secondary metabolites, including flavonoids, alkaloids, and saponins, supports the development of an effective, plant-based larvicide for sustainable vector control strategies. Full article

Understanding how climatic variability shapes the reproductive behavior of perennial crops is essential for improving their adaptation to tropical mountain environments. This study examined the influence of altitudinal and thermal gradients on flowering synchrony in ‘Hass’ avocado (Persea americana Mill.) cultivated across the tropical Andes of Colombia. Climatic variables and phenological stages were monitored across three elevations (2056, 2212, and 2338 m.a.s.l.) during two production cycles. Principal component, confirmatory factor, and circular statistical analyses were applied to integrate multivariate climatic structure with temporal flowering patterns. Results revealed that temperature was the main climatic driver of phenological variability, with significant differences among altitudes. The study revealed an altitudinal thermal–hydric gradient structuring distinct microclimates between 2050 and 2350 m.a.s.l., which determine the synchrony and rate of ‘Hass’ avocado phenological processes. Anthesis was the most environmentally sensitive phase, showing greater stability at intermediate elevations (~2200 m). Multivariate (PCA, CFA, ANOVA) and circular analyses confirmed that accumulated temperature (GDD) effectively predicts phenological progression, defining an optimal altitudinal range for synchrony and productivity in high Andean temperate zones. Full article

The transition towards a circular bioeconomy drives the search for sustainable valorization routes for agricultural waste streams. In this context, lignocellulosic residues from avocado tree prunings (Persea americana Mill.), with a reported high extractives content, represent a promising resource for pyrolytic valorization; however, their thermal behavior remains scarcely studied. This work characterized the chemical composition of whole branches (including bark) by FTIR and evaluated thermal degradation by thermogravimetric analysis (TGA) at five heating rates (10–30 °C/min) in an inert atmosphere. Kinetic analysis of the TGA data employed Friedman, FWO, KAS, Coats–Redfern, and Kissinger models. The Avrami model determined a reaction order of n ≈ 0.28. Among the methods, Coats–Redfern, applied with this n, provided the most consistent description, achieving the best average fit (R² ≈ 0.9878) and the narrowest range of pre-exponential factors (10¹²–10¹⁶ s⁻¹). The Friedman model showed greater dispersion (10¹²–10²² s⁻¹). Average activation energies ranged from 185 to 210 kJ/mol (Kissinger: 171.3 kJ/mol). The thermodynamic parameters confirmed a non-spontaneous, endothermic process (ΔH = 166.4–205.9 kJ/mol; ΔG = 178.8–179.8 kJ/mol). The entropy change (ΔS from –33.8 to 194.1 J/mol·K) reflects the complex solid-to-volatiles transition during pyrolysis. This study establishes a tailored kinetic framework for avocado branch pyrolysis, providing a reliable kinetic description for this biomass and identifying the Avrami–Coats–Redfern method as the most suitable for its accurate modeling. Full article

Avocado (Persea americana Mill.) is cultivated in a wide range of environments, from tropical and semitropical to subtropical regions. Its fruit, of high nutritional value, is increasingly demanded worldwide. Spain is the main European producer, but avocado cultivation in certain areas, such as the Canary Islands, requires the genetic identification of West-Indian rootstocks because they often show tolerance to low-quality water and soil salinization. In the present study, eight novel Retrotransposon-Based Insertion Polymorphism assays, derived from previously characterized inter-Primer Binding Site markers, have been developed and evaluated by multiplex PCR across 58 P. americana cultivars. The results showed 100% specificity and sensitivity in detecting the West-Indian genomic component, both in pure and hybrid avocado cultivars. This cost-effective and fast molecular tool provides a valuable resource for characterization and selection programs of avocado cultivars genetically related to the West-Indian horticultural race. Full article

Avocado trees (Persea americana Mill.) grown in Mediterranean conditions are exposed to high temperatures and intense solar radiation during summer, factors that can severely compromise plant water status and key physiological processes. To minimize these stressful conditions, the use of shade nets is an agronomical technique that permits the creation of an optimal microclimate for crop development. Thus, the aim was to evaluate the effects of shade netting on the physiological response of young avocado trees commercially grown under Mediterranean climatic conditions. The main results showed similar circadian rhythms of plant water status under both crop systems (open-air and shaded) in both seasons. However, the use of shading nets altered the circadian rhythm of leaf gas exchange. In summer, stomatal conductance (g_s) remained significantly more open after midday in shaded trees, allowing higher leaf transpiration (E_leaf) and cooler leaf temperature (T_leaf). A similar daily pattern was observed in chlorophyll a fluorescence parameters, including the effective quantum yield of photosystem II (ΦPSII) and the electron transport rate (ETR), with the lowest values occurring at midday. In shaded plants, ΦPSII and ETR remained higher after midday than in open-air, suggesting a lower photochemical inhibition of photosynthesis caused by heat stress and photoinhibition. Thus, the use of shade nets represents an agronomic alternative technique for cultivating avocados in Mediterranean climate conditions. Full article

Avocado (Persea americana Mill.) is one of the most widely consumed fruits worldwide. The tree species is traditionally classified into three botanical races: Mexican, Guatemalan, and West Indian (with a potentially distinct Colombian genepool). However, previous studies using molecular markers, such as AFLPs, microsatellites (SSRs), and GBS-derived SNP markers, have only partially resolved this racial divergence, especially in the hyper agrobiodiverse region of northwest South America. Therefore, in order to confirm genetic identity and origin of “criollo” avocado cultivars in the region, as well as to improve their traceability as rootstocks for the Hass variety, we performed low-coverage whole genome resequencing (lcWGS) on 205 ex situ conserved tree samples, comprising 42 commercial varieties and 163 “criollo” trees from various provinces in Colombia. This characterization yielded a total of 64,310,961 SNPs at an average coverage of 4.69×. Population structure analysis using principal component analysis (PCA) and ADMIXTURE retrieved at least five genetic clusters (K = 5), partly confirmed by Bayesian phylogenetic inference. Three clusters matched the recognized Mesoamerican botanical races (Mexican, Guatemalan, and West Indian), and two clusters reinforced the distinctness of two novel Andean and Caribbean Colombian genetic groups. Finally, in order to retrieve high-quality SNP markers for racial screening, a second genomic dataset was filtered, consisting of 68 avocado tree samples exhibiting more than 80% ancestry to a given racial cluster, and 9826 SNPs with a minimum allele frequency (maf) of 5%, a minimum sequencing depth (SD) of 10× per position, and missing data per variant not exceeding 20% (i.e., variants with genotypes present in at least 80% of the samples). This racially segregating high-quality subset was analyzed against the racial substructure using linear mixed models (LMMs), enabling the identification of 254 SNP markers associated with the five avocado genetic races. The previous candidate SNPs may be leveraged by nurseries and producers through a high-throughput SNP screening system for the racial traceability of seedling donor trees, saplings, and rootstocks. These genomic resources will support the selection of regionally adapted elite rootstocks and represent a landmark in Colombian horticulture as the first large-scale lcWGS-based characterization of a local avocado germplasm collection. Full article

Understanding the diversity of avocado production systems is crucial for developing effective agricultural policies and extension strategies. This study examined the Colombian avocado variety “Lorena” in the Colombian lowlands of Casanare through spatial typology analysis to inform sustainable agricultural development strategies. We employed spatial autoregressive modeling and clustering techniques to analyze data from 45 production systems, revealing heterogeneity despite small-scale operations with productivity (2.9 ton ha⁻¹) below regional (8 ton ha⁻¹) and national averages (11.03 ton ha⁻¹). Five distinct typologies emerged: transitional traditional (n = 15), intensive technical management (n = 4), experience-based traditional (n = 5), balanced management (n = 10), and comprehensive technical systems (n = 11). In contrast to conventional assumptions about economies of scale, productivity was not primarily determined by farm size, as smaller intensive technical management systems achieved the highest yields (3375 kg) despite having the smallest size (162.50 trees), followed by experience-based traditional systems (3280 kg). The spatial autoregressive model effectively captured spatial dependence in yield patterns, demonstrating the importance of geographic context in agricultural system analysis. Technology/practice adoption patterns varied markedly, with high adoption of established practices (>90%) but low foliar analysis adoption (17.78%). High organic fertilization adoption (93.33%) reflected a commitment to environmental sustainability but may partially explain productivity gaps, highlighting trade-offs between sustainability and short-term yield optimization. Socioeconomic analysis revealed characteristics of part-time farming systems, with 91.11% of producers having additional income sources and 95.56% using hired labor, suggesting evolved livelihood strategies that may enhance resilience. These findings challenge one-size-fits-all development approaches and demonstrate the need for tailored, spatially targeted interventions that account for specific production system characteristics, multiple pathways to sustainable intensification, and the complex interactions between productivity, sustainability, and socioeconomic factors in smallholder agriculture. Full article

Avocado (Persea americana), originally from Mesoamerica, has emerged as a focus of intense scientific and industrial interest due to its unique combination of nutritional richness, bioactive potential, and technological versatility. Its pulp, widely consumed across the globe, is notably abundant in monounsaturated fatty acids, especially oleic acid, which can comprise over two-thirds of its lipid content. In addition, it provides significant levels of dietary fiber, fat-soluble vitamins such as A, D, E and K, carotenoids, tocopherols, and phytosterols like β-sitosterol. These constituents are consistently associated with antioxidant, anti-inflammatory, glycemic regulatory, and cardioprotective effects, supported by a growing body of experimental and clinical evidence. This review offers a comprehensive and critical synthesis of the chemical composition and functional properties of avocado, with particular emphasis on its lipid profile, phenolic compounds, and phytosterols. It also explores recent advances in environmentally sustainable extraction techniques, including ultrasound-assisted and microwave-assisted processes, as well as the application of natural deep eutectic solvents. These technologies have demonstrated improved efficiency in recovering bioactives while aligning with the principles of green chemistry. The use of avocado-derived ingredients in nanostructured delivery systems and their incorporation into functional foods, cosmetics, and health-promoting formulations is discussed in detail. Additionally, the potential of native cultivars and the application of precision nutrition strategies are identified as promising avenues for future innovation. Taken together, the findings underscore the avocado’s relevance as a high-value matrix for sustainable development. Future research should focus on optimizing extraction protocols, clarifying pharmacokinetic behavior, and ensuring long-term safety in diverse applications. Full article

In vitro propagation of avocado faces several limitations. To optimize the establishment phase, we evaluated three plant material types: etiolated shoots, 30-day covered field shoots, and uncovered field shoots, collected at two time points. Biochemical and anatomical analyses were conducted to understand material performance during establishment. Across both collection times, etiolated shoots exhibited minimal oxidation, enhanced bud sprouting, reduced malondialdehyde (MDA) and reactive oxygen species (ROS) levels, increased peroxidase (POD) activity, and improved xylem development, consistently outperforming field-derived materials. Using etiolated shoots, we optimized disinfection and in vitro multiplication protocols. Pre-disinfection with 3 mL L⁻¹ Phyton 27^® and 2% sodium hypochlorite yielded the highest survival rates. In multiplication experiments, varying concentrations of 6-benzylaminopurine (BAP) and meta-topolin (MT), supplemented with gibberellic acid (GA₃), did not significantly affect growth variation. However, 8.88 µM BAP with 0.29 µM GA₃ resulted in the greatest number of sprouted buds. Full article

The production of fruit crops plays a vital role in the agricultural sector, contributing significantly to the social and economic development of rural communities. In Brazil, fruit production is diverse due to favorable edaphoclimatic conditions, with avocado (Persea americana Mill.) emerging as an important crop. Its production continues to expand in both cultivated areas and yield, making it a key export to non-producing countries. However, despite its importance, nutritional management information, crucial for achieving high yields, remains limited. Current guidelines on nutrition monitoring are outdated, general, and based on data from other countries with different edaphoclimatic conditions, making them not directly applicable to Brazilian orchards. Furthermore, outdated nutritional information becomes less reliable over time, as climate change alters soil conditions and crop nutrient concentrations and requirements, reinforcing the need for the establishment of up-to-date and specific nutritional information. This study aimed to establish nutritional standards for ‘Hass’ avocado production using the Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND) methodologies, and to define sufficiency ranges (SRs) and Critical Levels (CLs) for both macronutrients (N, P, K, Ca, Mg, and S) and micronutrients (B, Cu, Fe, Mn, and Zn). The analyses were based on yield (t ha⁻¹) and leaf nutrient content data from commercial orchards, with datasets divided into younger (4–9 years) and older (10–26 years) plant groups. The DRIS effectively established nutritional standards for younger plants, explaining 11% of yield variation through nutritional balance. CND, in turn, was effective for both groups, accounting for 14% of yield variation and outperforming DRIS in associating nutritional status with productivity. SRs and CLs for ‘Hass’ avocado production were defined using both DRIS and CND. Together, these indices and diagnostic parameters offer valuable tools for enhancing nutritional monitoring and fertilization strategies in Brazil. Notably, SRs and CLs varied according to plant age. Full article

Many rapidly expanding food crops, including avocado (Persea americana Mill.), are dependent on animal pollination but there is a growing shortfall in global pollinator supply. Avocado flowers are insect-pollinated and yields of the main cultivar, ‘Hass’, are often pollen-limited, especially in the middle of single-cultivar orchard blocks, where there is limited deposition of cross-pollen from another cultivar. We analysed two avocado cultivars of alternate flowering types, ‘Maluma’ (Type A) and ‘Shepard’ (Type B), using SNP-based DNA markers to identify the pollen parent of fruit at different distances from the other cultivar. We aimed to determine whether the numbers of cross-fertilised fruit and tree yields decline at increasing distances from a cross-pollen source, and whether cross-fertilised fruit are larger than self-fertilised fruit. We found that the number of cross-fertilised fruit produced by each tree declined in the middle of the blocks of each cultivar. Trees in the middle of the ‘Maluma’ block compensated for low levels of cross-pollination by producing more self-fertilised fruit, and their yields did not appear to be pollen-limited. However, yields in the middle of the ‘Shepard’ block declined by 25% as a direct result of a 43% reduction in the number of cross-fertilised fruit produced by each tree. ‘Shepard’ trees did not compensate for poor cross-pollination by producing more self-fertilised fruit. Cross-fertilisation of ‘Maluma’ by ‘Shepard’ increased fruit mass by 8% and cross-fertilisation of ‘Shepard’ by ‘Hass’ increased fruit mass by 5%, compared with self-fertilisation. Our results confirm that yields of avocado trees are sometimes, but not always, pollen-limited. Low levels of both self-pollination and cross-pollination resulted in pollen limitation of yield in the middle of the ‘Shepard’ block, but high levels of self-pollination were sufficient to generate high yields in the middle of the ‘Maluma’ block. Closer interplanting of Type A and Type B avocado cultivars increases the opportunities for cross-pollination, which can often increase tree yield and fruit size, and improve the financial returns for growers. Improving the pollination efficiency of foraging insects by providing them with the optimal pollen genotypes is increasingly important as we experience a growing demand for managed pollinators and a declining abundance of wild pollinators. Full article

The root system of clonal rootstocks has been poorly studied, despite its crucial importance. Roots not only provide support and nutrition to the plant but also contribute to tolerance to pests, diseases and environmental stresses, in addition to optimizing yields. Although the initial cost of clonal rootstocks is higher, the investment is offset by the reduction in phytosanitary treatments, greater longevity of the trees and a lower mortality rate. The aim of this research was to quantify the root system growth of five clonally propagated dwarf and normal avocado genotypes evaluated in rhizotrons, with the perspective of identifying distinctive characteristics suitable for their possible use in container culture. The avocado clonal plants to be evaluated were placed in rhizotrons and evaluated for six months, where 35 growth variables were evaluated with the aid of a root analyzer program. A randomized complete block design with five treatments (genotypes) and three replications was used under greenhouse conditions. Analysis of variance, variable purge and multivariate analysis were performed. It was found that ‘Duke 7’ and ‘San Martín’ were statistically different for most of variables, with ‘San Martín’ showing less root growth and ‘Duke 7’ showing remarkable lateral growth. The adventitious root system’s growth depends on the genotype, and the use of rhizotrons allows its study, which proved to be a useful methodology for this type of evaluation since it allows the visualization and adequate quantification of root growth. Genotypes with less root growth may be suitable for use in container culture, and roots with extensive lateral growth may be useful in shallow soils. Full article

Aging is a process characterized by tissue degeneration, increased susceptibility to chronic degenerative diseases, infections, and the appearance of neoplasms, which leads to disability and a reduction in the length and quality of life. This phenomenon is the result of the convergence of multiple processes, including mitochondrial dysfunction, fibrosis, inflammation, dysregulation of cell death processes, and immunosenescence. These processes have as their point of convergence an increase in the production of ROS. Avocado oil (Persea americana Mill.) contains a diverse array of bioactive compounds, including oleic acid, phytosterols, chlorophylls, xanthones, xanthines, and carotenoids. These bioactive compounds have the capacity to modulate the excessive production of ROS, thereby reducing the progression of age-related diseases and extending lifespan in experimental models of aging. In addition, several studies have demonstrated the efficacy of avocado oil in mitigating age-related diseases, including hypertension; insulin resistance; diabetes; non-alcoholic liver disease; and degenerative processes such as hearing loss, cognitive decline, neurodegeneration, and impaired wound healing. In light of these findings, it is hypothesized that avocado oil is a promising agent capable of promoting healthspan in later stages of life owing to its direct antioxidant actions and the activation of pathways that enhance endogenous antioxidant levels. Full article