Search Results (346)

Date palms, a vital Moroccan crop that typically flowers once a year, displayed a rare double flowering phenomenon in the summer of 2023. This study investigated the occurrence of this phenomenon across three small oases in the Zagora region of southeastern Morocco. Field surveys revealed that 60% of spring-blooming palms also produced a second bloom in July, affecting trees of all ages, sexes, and varieties. This secondary flowering cycle featured a compressed development period, leading to limited fruit enlargement and a failure of most fruit to reach maturity. Analysis suggests that climatic fluctuations, specifically a delayed temperature rise during the normal spring cycle and relatively cooler shifts in July 2023, likely disrupted the palms’ reproductive schedule, triggering the anomaly. Despite the failed second harvest, the phenomenon did not have a negative impact on the palms’ productivity for the subsequent year, confirming that double flowering is a complex, climate-influenced event that requires further research to understand its full implications for local date production. Full article

Phytoplasmas are obligate bacterial pathogens transmitted by phloem-feeding insects and responsible for severe diseases in numerous crops worldwide. In Iran, insect-associated phytoplasma transmission pathways remain poorly resolved, particularly at fine phylogenetic and vector-specific scales. Here, we investigated phytoplasma strains detected in four plant species, grapevine (Vitis vinifera), soybean (Glycine max), barberry (Berberis vulgaris), and the weed Conyza canadensis, and in three potential insect vectors (Tropidocephala prasina, Eysarcoris ventralis, and Nysius graminicola) collected from distinct agroecosystems across Iran. Phytoplasmas were characterized by using nearly full-length 16S rRNA gene sequences and a multilocus dataset of protein-coding genes obtained through a targeted next-generation sequencing approach. Five phytoplasma strains belonging to ribosomal groups 16SrI, 16SrVI, 16SrIX, and 16SrXII were identified, including two novel ribosomal subgroups, 16SrI-AS and 16SrIX-K. Several previously unreported plant–phytoplasma and insect–phytoplasma associations were documented. Comparative phylogenetic analyses revealed that ribosomal and multilocus markers capture complementary evolutionary signals, with protein-coding genes providing additional resolution beyond 16S-based classification. These findings highlight the potential role of diverse hosts and polyphagous insects, not yet confirmed as vectors, in phytoplasma circulation and underscore how high-throughput next-generation sequencing and multilocus approaches advance our understanding of phytoplasma diversity and evolution. Full article

The Acrocomia aculeata is a promising palm tree for biofuel production, but it faces challenges related to propagation, especially due to seed dormancy. This article presents an integrative review, supported by bibliometrics, of the sexual and asexual propagation methods of the species, conducted through searches in Scopus, SciELO, and Web of Science databases. The results indicate that sexual propagation is the predominant approach in the literature, although it faces significant challenges due to seed dormancy, such as the physical resistance to embryo protrusion imposed by the operculum. Asexual propagation demonstrates great potential through micropropagation techniques, which allow obtaining genetically uniform plants in relatively short periods. The non-deep physic dormancy exhibited by the seeds interferes with germination by constraining embryo growth potential and postponing the metabolic reactivation essential for successful germination. Despite the existence of promising methods for overcoming dormancy, additional studies are needed to understand the mechanisms involved in this process. This review maps the scientific literature to highlight areas of proven research success, identify critical gaps and underexplored topics, and indicate how future investigations can support the development of efficient propagation protocols and the establishment of commercial plantations. Full article

The probability that female bagworms (Lepidoptera: Psychidae) are in mating time-in (live pheromone calling) was recorded in three bagworm species: Oiketicus kirbyi in a Costa Rican oil palm plantation in 1993–1994; Metisa plana in Malaysian oil palm plantations during five consecutive generations of bagworms in 1996; and Thyridopteryx ephemeraeformis on ornamental trees in the Midwest United States. Because females entirely reproduce within their bag (mate attraction, copulation, and oviposition), it is possible to assess the mating success of time-out females (dead individuals from an ongoing generation that either mated or died as a lifelong virgin) and incidence of calling females that may or may not mate before death. Synchronous larval development and discrete (non-overlapping) generations imply a declining proportion of live calling females over time in all three bagworm species: ‘young’ calling females prevail in the early season as opposed to a majority of time-out (post-reproductive) females in the late season. Calling females are long-lived relative to males (one-day lifespan) and thus expected to mate as adults when abundance of males is high and/or female longevity exceeds three days. A low mating success of calling females is associated with extreme protogyny (early season male shortage; O. kirbyi in 1994) or late adult emergence in populations at the edge of the distribution range (T. ephemeraeformis at latitudes > 41° N in 2019). Full article

This research aimed to conduct a bibliometric review on Acrocomia aculeata (Jacq.) Lodd. ex Mart., popularly known as “macaúba”, a palm tree of the Arecaceae family with great potential to promote sustainable practices. The review focused on the applications associated with the oil, pulp, and almonds of the fruit, products that can be used in industries such as food, cosmetics, and bioenergy, contributing to the development of more ecological production chains with less environmental impact. Data were collected from the Scopus, Web of Science, and ScienceDirect databases for publications related to phytochemical and bioactive aspects, while only Web of Science was used for data on energy aspects. The documents found were analyzed in the VOSviewer software (version 1.6.20), allowing the creation of bibliometric networks (clusters) and tables on scientific production. The analyses included authors, co-authors, countries, institutions, journal sources, and keywords. For phytochemical and bioactive aspects, the search resulted in 1026 articles, of which 261 were selected after applying the exclusion criteria. For energy aspects, 99 publications were found. Based on the data, it was possible to analyze the existing research on A. aculeata, identifying the state of the research and possible gaps in studies related to this oilseed. The results highlight the importance of macaúba as a sustainable alternative for diversifying agricultural and bioindustrial products, promoting the bioeconomy and contributing to the mitigation of environmental impacts. In addition, the research allowed us to identify the universities and researchers most dedicated to this species, their main results and the areas that still require investment to advance research. Thus, A. aculeata emerges as a relevant option to strengthen sustainable practices in key sectors, integrating economic, social, and environmental benefits. Full article

Reliable estimation of oil palm carbon stock is essential for climate mitigation, concession management, and sustainability certification. While satellite-based approaches offer scalable solutions, redundancy among spectral indices and inter-sensor variability complicate model development. This study evaluates machine learning regressors for predicting oil palm carbon stock at tree (CO_tree, kg C tree⁻¹) and hectare (CO_ha, Mg C ha⁻¹) scales using spectral indices derived from Landsat-8, Landsat-9, and Sentinel-2. Fourteen vegetation indices were screened for multicollinearity, resulting in a lean feature set dominated by NDMI, EVI, MSI, NDWI, and sensor-specific indices such as NBR2 and ARVI. Ten regression algorithms were benchmarked through cross-validation. Ensemble models, particularly Random Forest, Gradient Boosting, and XGBoost, outperformed linear and kernel methods, achieving R² values of 0.86–0.88 and RMSE of 59–64 kg tree⁻¹ or 8–9 Mg ha⁻¹. Feature importance analysis consistently identified NDMI as the strongest predictor of standing carbon. Spatial predictions showed stable carbon patterns across sensors, with CO_tree ranging from 200–500 kg C tree⁻¹ and CO_ha from 20–70 Mg C ha⁻¹, consistent with published values for mature plantations. The study demonstrates that ensemble learning with sensor-specific index sets provides accurate, dual-scale carbon monitoring for oil palm. Limitations include geographic scope, dependence on allometric equations, and omission of belowground carbon. Future work should integrate age dynamics, multi-year composites, and deep learning approaches for operational carbon accounting. Full article

Deep learning has become a powerful tool for diagnosing pests and plant diseases, although conventional convolutional neural networks (CNNs) generally suffer from limited interpretability and suboptimal focus on important image features. This study examines the integration of attention mechanisms into two prevalent CNN architectures—ResNet50 and MobileNetV2—to improve the interpretability and classification of diseases impacting date palm trees. Four attention modules—Squeeze-and-Excitation (SE), Efficient Channel Attention (ECA), Soft Attention, and the Convolutional Block Attention Module (CBAM)—were systematically integrated into ResNet50 and MobileNetV2 and assessed on the Palm Leaves dataset. Using transfer learning, the models were trained and evaluated through accuracy, F1-score, Grad-CAM visualizations, and quantitative metrics such as entropy and Attention Focus Scores. Analysis was also performed on the model’s complexity, including parameters and FLOPs. To confirm generalization, we tested the improved models on field data that was not part of the dataset used for learning. The experimental results demonstrated that the integration of attention mechanisms substantially improved both predictive accuracy and interpretability across all evaluated architectures. For MobileNetV2, the best performance and the most compact attention maps were obtained with SE and ECA (reaching 91%), while Soft Attention improved accuracy but produced broader, less concentrated activation patterns. For ResNet50, SE achieved the most focused and symptom-specific heatmaps, whereas CBAM reached the highest classification accuracy (up to 90.4%) but generated more spatially diffuse Grad-CAM activations. Overall, these findings demonstrate that attention-enhanced CNNs can provide accurate, interpretable, and robust detection of palm tree diseases and pests under real-world agricultural conditions. Full article

Next-generation sequencing technology was employed to read and assemble the complete plastid genome of the ‘Mejhoul’ date palm cultivar (Phoenix dactylifera L.). The genome consisted of 158,436 base pairs (bp) with a GC content of 37.24%, and it included 95 protein-coding genes, 44 tRNA genes, and eight rRNA genes. The plastome of five ‘Mejhoul’ genotypes from Jordan was compared with three genotypes from the USA, Morocco, and the UAE. It revealed 91 single-nucleotide polymorphisms (SNPs) and 23 insertions–deletions (InDels); the majority of them (62%) were located in intergenic regions, while the remaining variants were located in intragenic regions, including tRNA and rRNA genes. When the plastomes of all eight ‘Mejhoul’ genotypes were aligned, along with major cultivars ‘Barhee’ and ‘Khalas’, 24 SNPs and 23 InDels could be found. This would enable the development of a cultivar-specific fingerprint test for authentication. The phylogenetic tree was constructed using seventeen date palm cultivars. The phylogenetic analysis places ‘Mejhoul’ as a lineage derived within Clade I rather than as an early-diverging cultivar, suggesting it shares a more recent common ancestor with ‘Deglet Noor’ and ‘Barhee’. Full article

Estuaries provide numerous ecosystem services, including fisheries, coastal community livelihoods, and resistance to saltwater intrusion. Despite this knowledge, estuaries worldwide are threatened by decreasing and/or aseasonal freshwater inflows, which negatively affect ecosystem structure and function. Sound estuarine management requires an understanding of the natural freshwater inflow regime and knowledge of the salinity tolerances of local plant and animal communities—data that are completely lacking in most estuaries. This paper describes a 2-week field survey of mangrove zonation in the Ruvu River estuary carried out during the wet–dry season transition to obtain a multi-decadal proxy for the salinity regime within the estuary. Salinity conditions arising from the mixing of freshwater inflows and sea tides influence the species composition of mangroves. The mouth of the estuary (highest salinity −35 ppt) had monospecific stands of Sonneratia alba—the mangrove with the highest salinity tolerance. Salinity decreased going upriver, from 30 ppt to 5 ppt over 13 km, with 7 other mangrove species progressively appearing in the riverbank forests, ultimately transitioning to palms and other trees intolerant of salinity (<5 ppt). The resulting map relating mangrove zonation with salinity can then be used to calibrate estuary salinity mixing models for calculating minimum freshwater inflows necessary to maintain the estuarine ecosystem. Such periodic surveys and maps can also serve to calibrate/validate remote sensing products for continued coastal vegetation monitoring. The study also reviews available information on climate and land use relating to river flow in the Ruvu basin to summarize the hydrologic vulnerability of the Ruvu estuary to climate change, land use change, and river water demands in the Basin. Full article

Carnauba (Copernicia spp.) is a palm tree native to the Brazilian semi-arid region, valued for its significant economic, social, and environmental importance. This resilient species possesses adaptive mechanisms that enable it to endure prolonged periods of soil water scarcity and conditions of flooding and salinity. However, despite its relevance, there is a notable lack of scientometric data on this species in the literature, representing a significant research gap. This study aimed to analyze the state of research on carnauba palm from 2007 to 2022. Datasets were collected from the Web of Science central database, totaling 658 publications related to the terms “carnauba” or “copernicia”. The bibliometric software VOSviewer was used to create visual maps of keyword co-occurrence networks, providing deeper insights into the progress and research trends on the topic. Since 2014, the number of publications on carnauba has steadily increased, peaking between 2019 and 2021. The most prominent focus in these articles is on carnauba wax, with extensive research on its properties and applications in the food production chain. This significance is also reflected in the keyword co-occurrence networks. However, studies combining carnauba with soil sciences remain underexplored. Given carnauba’s importance in environmental and soil conservation, future research linking these areas could become a key avenue for advancing knowledge on the subject. Full article

Water resource management and agricultural practices in the Mediterranean region, characterised by the excessive use of pesticides, pose significant environmental and human health challenges. As they can be easily and inexpensively produced from various biomass sources, biochars are frequently recommended as a low-cost secondary decontamination strategy to address soil contamination problems. This study investigates the properties and sorption behaviours of biochars produced in a low-cost metallic kiln using local rosemary, giant reed, St. John’s wort, olive, cypress, and palm tree biomass residues to evaluate their potential for environmental remediation, with a special focus on the mobility and retention of contaminants. Analytical and experimental techniques were employed to characterise the biochars’ physicochemical attributes and sorptive capacities. The core analyses included measurement of basic physicochemical properties, including pH, electrical conductivity, functional group identification via Fourier transform infrared (FTIR) spectroscopy, and the molarity of ethanol droplet (MED) test to assess the surface hydrophobicity. Batch sorption experiments were conducted using methylene blue (MB) and two fluorescent tracers—uranine (UR) and sulforhodamine-B (SRB)—as proxies for organic contaminants to assess the adsorption efficiency and molecule–biochar interactions. Furthermore, the adsorption isotherms at 20 °C were fitted to different models to assess the biochars’ specific surface areas. Thermodynamic parameters were also evaluated to understand the nature and strength of the adsorption processes. The results highlight the influence of feedstock type on the resulting biochar’s properties, thus significantly affecting the mechanism of adsorption. Rosemary biochar was found to have the highest specific surface area (SSA) and cation exchange capacity (CEC), allowing it to adsorb a wide range of organic molecules. Giant reed and palm tree biochars showed similar properties. In contrast, wood-derived biochars generally showed very low SSA, moderate CEC, and low hydrophobicity. The contrasting properties of the three dyes—MB (cationic), UR (anionic), and SRB (zwitterionic)—enabled us to highlight the distinct interaction mechanisms between each dye and the surface functional groups of the different biochars. The reactivity and sorption efficiency of a biochar depend strongly on both the nature of the target molecule and the intrinsic properties of the biochar, particularly its pH. The findings of this study demonstrate the importance of matching biochar characteristics to specific contaminant types for optimised environmental applications, providing implications for the use of tailored biochars in pollutant mitigation strategies. Full article

Palm trees, referred to here as vegetation cover (VC), provide essential ecosystem services in an arid Oasis. However, because of socioeconomic transformation, the rapid urban expansion of major cities and villages at the expense of agricultural lands of the Al-Ahsa Oasis, Saudi Arabia, has placed enormous pressure on the palm-growing area and led to the loss of productive land. These challenges highlight the need for robust, integrative methods to assess their impact on the agroecosystem. Here, we analyze spatiotemporal fluctuations in vegetation cover and its effect on the agroecosystem to determine the potential influencing factors. Data from Landsat satellites, including TM (Thematic mapper of Landsat 5), ETM+ (Enhanced Thematic mapper plus of Landsat 7), and OIL (Landsat 8) and Sentinel-2A imageries were used for analysis, while GeoEye-1 satellite images as well as socioeconomic data were applied for result validation. Principal Component Analysis (PCA) was applied to extract pure endmembers, facilitating Spectral Mixture Analysis (SMA) for mapping vegetation and urban fractions. The spatiotemporal change patterns were analyzed using time- and space-oriented detection algorithms. Results indicated that vegetation fraction patterns differed significantly; pixels with high fraction values declined significantly from 1990 to 2020. The mean vegetation fraction value varied from 0.79 to 0.37. This indicates that a reduction in palm trees was quickly occurring at a decreasing rate of −14.24%. Results also suggest that vegetation fractions decreased significantly between 1990 and 2020, and this decrease had the greatest effect on the agroecosystem situation of the Oasis. We assessed urban sprawl, and our results indicated substantial variability in average urban fractions: 0.208%, 0.247%, 0.699%, and 0.807% in 1990, 2000, 2010, and 2020, respectively. Overall, the data revealed an association between changes in palm tree fractions and urban ones, supporting strategic vegetation and/or agricultural management to enhance the agroecosystem in an arid Oasis. Full article

A GIS-based Plant Coefficient Method (PCM), termed the Plant Coefficient Method Tool (PCMT), is presented and validated through this research. It is designed for sustainable irrigation management within arid urban environments, exemplified by Riyadh, Saudi Arabia. The study integrates remote sensing data, including Landsat 8 satellite imagery, vegetation indices (NDVI, LAI), and climatic parameters to estimate daily and seasonal plant water demand for diverse landscape species. Results demonstrate that plant-specific coefficients (${\mathrm{K}}_{\mathrm{p}\mathrm{l}}$) fluctuate seasonally, ranging from 0.1 to 1.4, with average water demand (${\mathrm{E}\mathrm{T}}_{\mathrm{p}\mathrm{l}}$) reaching up to 25 L per square meter during the summer months and decreasing to around 6 L in winter. It may be found by good management based on PCMT that average daily projected ${\mathrm{E}\mathrm{T}}_{\mathrm{p}\mathrm{l}}$ rates can be lowered to as low as 3 mm/day, resulting in a significant decrease in water needs, by around 70% to 50%, when compared to higher categories. Validation across three sites (urban trees, date palms, and turf grass), showed strong correlations (R² > 0.8) between satellite-derived vegetation indices and modeled water needs. The volumetric water demand estimates closely aligned with actual irrigation practices, albeit with some over- and under-irrigation episodes. Spatial analysis indicated that high-demand zones predominantly occur in summer, emphasizing the necessity of adaptive irrigation scheduling. Overall, the PCMT presents a scalable, accurate tool for optimizing water use, supporting sustainable landscape management aligned with Saudi Arabia’s green initiatives. Full article

The impact of biochar pyrolyzed at 450 ± 10 °C and made from date palm (D) and olive tree (O) wastes on the hydrophysical characteristics of sandy soil was assessed in this study through a laboratory column experiment. Two different application rates (wt/wt) were tested: 1% and 5%. The prepared biochars were added at 25 °C to the upper 10 cm layers of the soil columns. The outcome showed that, in comparison to O, D biochar possessed slightly less alkalinity and more salinity. The corresponding values for pH and EC in D and O biochars were 8.99 and 4.10 dS/m and 9.42 and 2.17 dS/m. Therefore, these biochars should be used cautiously as soil amendments in saline–sodic soils because of their excessive salinity, especially D biochar. On the other hand, they are safe to employ as amendments in acidic and non-saline soils. Cumulative evaporation (CE) decreased with all treatments, and the highest decrease of 10.2% (compared to control treatments after five cycles) was observed for D biochar and 5% application rate (D450, 5%). Moreover, the available water increased by 182%, 158%, 153%, and 29% for D450, 5%, D biochar and 1% application rate (D450, 1%), O biochar and 5% application rate (O450, 5%), and O biochar and 1% application rate (O450, 1%), respectively. The saturated hydraulic conductivity decreased by 94.8%, 87.0%, 76.6%, and 35.1% for D450, 5%, D450, 1%, O450, 5%, and O450, 1%, respectively. It was also found that the date palm biochar was more efficient than olive waste biochar in decreasing the cumulative infiltration and infiltration rate. Finally, this study showed the superiority of biochar prepared from date palm trees over that prepared from olive tree waste for improving the hydrophysical properties of sandy soil. Full article

Pharomachrus mocinno breeds in the cloud forests of the El Triunfo Biosphere Reserve, and migrates annually for six months to elevations of 900–1600 m. On the Gulf slope, temperate forests were identified as habitats for migration, but the forests on the Pacific slope have not been similarly described. In this study we described the emergent properties and phenological behavior of the plant communities of five sites identified as migration habitats, in order to test if the number of fruit-bearing species is related to the migration period. At each site, 10,000 m² was sampled, for which PBH (perimeter at breast height) and the height of shrubs and trees were annotated, including the number of palms and ferns included. We identified 25 orders, 41 families, 71 genera, and 94 species; 86.6% of these species produce fleshy fruits or fruits with modified structures that are eaten by Quetzals. During the migration period, 25–43% of these species have fruits. Eight woody species included 49% of the total individuals, which produce Quetzals’ feeding resources. The sites differed in vertical structure, composition and diversity levels. The rarefaction curve indicated that the upper site (1600 m) required more sampling. We identified three plant communities that were distributed either in montane rain forest or in the temperate forest. Since nearly 84% of the plant species are listed in the IUCN (International Union for Conservation of Nature), these forests have an intrinsic importance. The number of fruit-bearing species did not differ between migration and breeding seasons (X² (1, N = 76) 0.57; p = 0.32. Lauraceae did not stand out for the number of fruit-bearing species in any of the migration sites. Full article