Walnut Research Articles

‘Where the Wild Things Are’: The Medieval Augustinian Order’s Perception of Nature between Tree Lore and Environmental History

Abstract This article examines how medieval woodlands around Augustinian convents could convey messages of power. In the thirteenth century, the papacy threatened the Augustinian friars with suppression on the grounds of their ‘lack of antiquity’. Previous scholarship showed that, in reaction to this, the friars developed a fictive past in which they claimed to have been founded by St Augustine. This article shifts attention away from human agencies to the environment. It argues that natural landscapes, most prominently woodlands, were key resources which could be used as powerful assets when asserting the antiquity of the Order. The two cornerstones of this investigation are a cluster of hermitages around Siena with a sacred ilex forest, the claimed dwelling place of the eremitical predecessors of the Augustinian friars, and the convent of Santa Maria del Popolo in Rome, erected on the locus of an ‘evil walnut tree’ above the tomb of Nero. This study examines how these key spiritual centres used woodlands to display antiquity and prestige. Further attention is paid to convents on the shores of the Tyrrhenian Sea to show how the sea could be perceived as equivalent to the forest. A close analysis reveals that Augustinian convents were often situated in a liminal position framed between the urban fabric and natural landscapes, such as the forest and the sea. This article thus illuminates how, in a similar way to secular rulers and their palaces, the Augustinian friars used the natural environment in strategic ways to enhance the power of their convents.

Spatio-temporal Analysis of Agroforestry Systems in Hotan Using Multi-source Remote Sensing and Deep Learning

In the Hotan region of Xinjiang, where arable land is scarce, an agroforestry system integrating walnut trees with crops has been implemented to maximize land-use efficiency. While this dense planting enhances land use, it also limits the availability of light to the understory crops, potentially impacting their yield and quality. To address this issue and enhance the system's sustainability and productivity, precise delineation of the planting structure is critical. This study proposes a novel framework that leverages multi-source remote sensing data combined with advanced deep learning techniques to analyze the agroforestry planting structure. The methodological approach consists of three key phases. First, an instance segmentation model was employed to extract farmland parcels from high-resolution imagery, providing a basis for vegetation classification. Next, a time series model using irregular satellite image time series (irSITS) tracked the growth dynamics of the vegetation. Finally, the spatial planting structure of the walnut trees was quantified using the D-LinkNet model, integrated with a template filling algorithm.The results demonstrated a classification accuracy of 97.85% in extracting parcel-level planting structures, identifying 42,955 farmland parcels, including 21,153 intercropped parcels. The temporal and spatial characteristics of the agroforestry system were then analyzed, leading to a grading of canopy cover and walnut tree density within the intercropped areas. This comprehensive spatiotemporal planting structure offers a valuable foundation for informed local agricultural policy adjustments. In conclusion, this approach advances the understanding of complex agroforestry systems and provides a robust scientific basis for optimizing intercropping practices, contributing to sustainable agricultural development in arid regions.

Tree Nut Crop Response to Simulated Florpyrauxifen-benzyl and Triclopyr Herbicide Drift

California is the nation’s primary producer of almonds, pistachios, and walnuts, and an important producer of rice. Because of California’s diverse cropping systems, off-target herbicide drift can be a considerable problem, particularly from aerial applications that are commonly used in flooded rice production systems. Triclopyr is an auxin-mimic type herbicide that has been commonly used in rice for many years for control of broadleaf weeds and the industry is familiar with symptoms of off-target triclopyr drift. Florpyrauxifen-benzyl is a newly registered auxin-mimic herbicide in California rice with activity on key weeds and is being rapidly adopted. Although symptoms typically are similar among auxinic herbicides, it is important to understand subtle differences and risks among these herbicides as stewardship for newly registered products. This research was conducted in 2020 and 2021 to determine the relative sensitivity of almond, pistachio, and walnut trees to simulated drift rates of florpyrauxifen-benzyl and triclopyr as well as characterize and compare symptoms caused by these two herbicides. The fractional herbicide rates tested were 1/200X, 1/100X, 1/33X, and 1/10X of the florpyrauxifen-benzyl use rate of 29.4 g·ha−1 a.i. and 1/200X, 1/100X, and 1/33X of the triclopyr use rate of 420.3 g·ha−1 a.e. Florpyrauxifen-benzyl and triclopyr herbicides were applied directly to one side of the canopy of 1- to 2-year-old almond, pistachio, and walnut trees. The general symptoms of florpyrauxifen-benzyl and triclopyr were chlorosis, chlorotic spots, leaf curling, leaf narrowing, leaf distortion, leaf malformation, leaf crinkling, shoot curling, stem coloring, stunting, terminal bud death, and twisting. The florpyrauxifen-benzyl and triclopyr injury symptoms were compared at the same fractional rates and found to be similar to each other. The herbicide injury was observed on the entire pistachio canopy, particularly on developing leaves and terminal buds. In contrast, injury symptoms on almond and walnut were more apparent on the side of the canopy to which the herbicides were applied. Symptom severity peaked at 14 days after treatment with the 1/10X florpyrauxifen-benzyl rate, when the visible injury was 16%, 48%, and 78% on almond, walnut, and pistachio, respectively. Although almond and walnut symptoms from the 1/10X florpyrauxifen-benzyl rate remained visible longer than all other treatments, all trees gradually recovered throughout the growing season. In contrast, pistachio trees did not recover fully and had injury symptoms that persisted for the remainder of the treatment year and at leaf-out the following spring. When drift occurs, it is typically at rates below 1/100X up to 1/33X of herbicide use rates. This research suggested that proper herbicide drift management practices and application precautions are likely to minimize the risk of significant injury from florpyrauxifen-benzyl drift to almond and walnut because of low injury symptoms at the typical drift rates. However, extra precautions may be needed if there are nearby pistachio orchards.

Traumatic spinal cord injuries due to falls from trees in a tertiary rehabilitation center: a retrospective analysis of causes and outcomes

Aims: Falls from heights are a major cause of spinal cord injury. In developing countries such as Turkey, where fruit picking from trees is an important part of the agricultural economy, falls from trees are common. This study aims to comprehensively analyze the causes and consequences of spinal cord injuries due to falls from trees. Methods: This retrospective study reviewed cases of spinal cord injury resulting from falls from trees, treated at a tertiary rehabilitation center between March 2020 and November 2023. Data encompassed demographics (age, gender, occupation, education), spinal injury specifics (level, severity), additional injuries, tree fall details (type of tree, height of fall, cause of fall, safety precautions), and treatment details (surgery need, hospital stay duration). The patients who fell from trees were divided into two groups: those who fell from walnut trees and those who fell from other trees, and statistical analyses were performed accordingly. Results: Among the 49 patients falling from trees, the mean age was 52.3 ± 13.4 years, with 73.5% being male, 32 patients (%65.3) had graduated from primary or secondary school. No safety precautions were taken by any participants. Paraplegia (%87.8) and complete spinal cord injuries (57.1%) were common. Additional injuries occurred in %61.2 of cases. In terms of fall causes, the most common was branch breakage (%57.1), while walnut trees accounted for %44.9 of falls. There was a significant difference in education levels between the group that fell from walnut trees and the group that fell from other trees (p:0.028). Falls from walnut trees resulted in higher fall heights, complete injury rates, and longer hospital stays (p:0.003, p:0.047, p: 0.010). Conclusion: This study found that spinal cord injuries from falls often lead to additional injuries, with none of the patients taking safety precautions. This study found that walnut trees were the most common cause of spinal cord injury from falling trees. This study highlights the need for improved safety precautions and educational interventions.

Drought and heat stress interactions: Unveiling the molecular and physiological responses of Persian walnut

While numerous studies explored the response of walnut plants to drought stress (DS), there remains a significant gap in the knowledge regarding the impact of heat stress (HS) and the combined effects of DS and HS on the recovery capacity of walnut trees. This study aimed to investigate the mechanism of Persian walnut (cv. Chandler) response to the combined DS and HS, focusing on various aspects including photosynthesis, water relations, and osmotic regulation. The treatments involved subjecting plants to DS (through a withholding method for 24 d), HS (gradually up to 40 °C for 8 d), and a combined DS and HS, which were compared to a control group (no stress) during the stress and recovery phases. The results showed that DS had significantly more negative effects on chlorophyll content, relative water content (RWC), leaf water potential (WP), osmotic potential (OP) compared to HS. Involvement of osmoregulation mechanism was detected more in DS and HS plants through the accumulation of proline, glycine Betaine and total soluble carbohydrates. The functionality of photosynthesis was significantly impacted by both HS and DS, respectively. While the HS accelerated the change of the abovementioned physiological processes in drought-stressed seedlings. Consistently, more pronounced damage was found in leaves under the combined stress, alongside the decrease RWC, chlorophyll content and fluorescence ratios. Based on the analysis of the linear mixed-effect model, the effects of combined stress and HS on photosynthesis parameters were detected in the early stages of stress compared to DS. Within a range of stresses, the abovementioned physiological processes of individual and combined-stressed plants recovered to levels comparable to those of the control. Our results also showed a substantial reduction in the expression of the photosynthetic genes (Fd, Cyt b6f, and PsbB) in Persian walnut saplings under abiotic stress conditions indicating significant damage to their photosynthetic apparatus. This study highlights that, under scenarios of aggravating drought occurring with heat, walnut seedlings could face a high risk of damage to physiological structures in relation to the synergistically increased hydraulic and thermal impairments.

Evaluation and prediction of synergistic antioxidant effects of green walnut hulls, potato peel, and date pulp extracts on the stability of sunflower oil by deep neural networks

Evaluation and prediction of synergistic antioxidant effects of green walnut hulls, potato peel, and date pulp extracts on the stability of sunflower oil by deep neural networks

Distribution characteristics of photoassimilates in walnut leaves to different organs

The understanding of photoassimilate distribution serves as the fundamental basis for scientific regulation of fruit quality. Currently, there is a scarcity of research on whole-plant scale photoassimilate distribution in walnut. In order to clarify the characteristics of leaf photoassimilates translocation to various organs in 5-year-old 'Wen185' (J. regia 'Wen185') walnut during the growing season, this study used the 13C isotope pulse labeling technique to label the whole plant of walnut trees in the growing season, temporal variations of 13C abundance (δ13C), 13C partition rate (R13C), leaf source strength and fruit sink strength were analyzed in various organs at different days after tree flowering. The findings indicated that during the periods of 30–70 days and 90–110 days after flowering, there was a higher distribution of 13C in fruits and vegetative branches. However, at 110–130 days after flowering, the predominant allocation of 13C shifted towards main trunk and roots. In-depth study of source leaves and sink fruits showed that chlorophyll content in leaves increased significantly 30–50 days after anthesis, indicating that they gradually became mature functional leaves. The increase of net photosynthetic rate led to increase of source strength, and the retention of photoassimilates in leaves was higher at this time. From 30 to 70 days after flowering, the fresh weight and volume of fruit increased rapidly, which increased the capacity of the sink and enhanced the competition ability against photoassimilates. The recovery of photosynthetic capacity of leaves from 90 to 110 days promoted the output of photoassimilates. At this time, walnut entered the oil conversion period, and the demand for photoassimilates increased. All these factors jointly promoted the unloading of photoassimilates in fruit. In summary, maintaining adequate material conditions and optimizing tree structure at 30-70d and 90-110d after anthesis are important for more efficient distribution of photoassimilates to fruit.

Effect of walnut tannin on wood surface hardness: A study on pine and walnut samples

The hardness of the wood surface determines its wear resistance and resistance to mechanical damage. This study aimed to determine the effect of walnut tannin used in wood preservation on the surface properties of wood. For this purpose, Scots pine (Pinus sylvestris L.) and walnut (Juglans regia L.) wood test specimens were treated with walnut tannin with a brush. The specimens then were coated with water-based and polyurethane varnishes. After drying, the surface hardness was measured. As a result of the research, it was determined that the highest surface hardness was in the control samples without tannin application and the highest value was in walnut wood.

New Ophiostoma species associated with Dryocoetes himalayensis and decline of Juglans regia in Czechia

AbstractA new ophiostomatoid fungus involved in the decline of walnuts was discovered in Czechia. The fungus was isolated from necrotic wood surrounding the larval galleries of Dryocoetes himalayensis, the alien bark beetle attacking walnut trees. This insect species is rather unique within hardwood-associated bark beetle species for its aggressiveness and ability to attack apparently healthy trees. The isolated fungus, associated with an exotic insect vector is described as a new species, Ophiostoma juglandis sp. nov., based on its unique morphology and phylogenetic position. The pathogenicity tests confirmed the aggressiveness of the species to both Juglans regia and J. nigra plants, manifested by formation of extensive bleeding and necrotic lesions. The symbiotic relationship between O. juglandis and D. himalayensis is expected due to massive presence of the fungal spores on surface of adult beetles in pits forming the elytral striae. In the case of hardwood-associated ophiostomatoid fungal species, phytopathogenicity is very rarely observed. The described species is exceptional in this ability, which corresponds to the aggressive behaviour of its vector. The role of the fungus in walnut tree mortality caused by D. himalayensis is discussed.

Behavioral, Physiological, and Molecular Mechanisms Underlying the Adaptation of Helicoverpa armigera to the Fruits of a Marginal Host: Walnut (Juglans regia).

In northwest China, changes in cultivation patterns and the scarcity of preferred hosts have forced Helicoverpa armigera to feed on the marginal host walnut (Juglans regia). However, the mechanisms allowing this adaptation remain poorly understood. Here, we investigated the behavioral, physiological, and molecular mechanisms underlying the local adaptation of this pest to walnut fruits. The green husk and shell generally contained higher levels of phytochemicals than the kernel. Bioassays revealed that the phytochemical-rich green husk and shell were less preferred, reduced larval fitness and growth, and elevated the activity of detoxification enzymes compared to the nutrient-rich kernel, which were further supported by a larger number of upregulated detoxification genes in insects fed green husks or shells based on transcriptome sequencing. Together, these data suggest that P450 genes (LOC110371778) may be crucial to H. armigera adaptation to the phytochemicals of walnuts. Our findings provide significant insight into the adaptation of H. armigera to walnut, an alternative host of lower quality. Meanwhile, our study provides a theoretical basis for managing resistance to H. armigera larvae in walnut trees and is instrumental in developing comprehensive integrated pest management strategies for this pest in walnut orchards and other agricultural systems.

EFFICACY OF A RANGE OF FUNGICIDES AGAINST FUNGAL DISEASES OF WALNUT IN THE SOUTHERN FRUIT-GROWING ZONE OF KAZAKHSTAN

The most widespread and effective method of protecting walnut trees from diseases is through chemical treatments. With the increasing variety of fungal pathogens affecting walnut trees in the southern zone of fruit production in Kazakhstan, there is a need to study the effectiveness of fungicides against these pathogens. Therefore, laboratory and field studies were carried out to evaluate the effectiveness of several fungicides against the most common diseases of walnut trees caused by Fusarium and Alternaria fungi. The effectiveness of fungicides with different mechanisms of action was studied for the first time. The fungicides evaluated were Score (difenoconazole, 250 g/l), Horus (cyprodinil, 750 g/kg), Stroby (kresoxim-methyl, 500 g/kg), Luna Tranquility (fluopyram, 125 g/l + pyrimethanil, 375 g/l) against walnut diseases in the southern zone of fruit cultivation in Kazakhstan. The results of both laboratory and field experiments showed that the most effective fungicide against fungal pathogens on walnut was Score (difenoconazole, 250 g/l). Stroby (kresoxim-methyl, 500 g/kg) also demonstrated over 80% biological efficacy against Alternaria alternata. The results of this study will assist local growers in managing various fungal diseases in walnut plantations.

Foliar application of biostimulants improves nutritional and bioactive quality of walnuts.

Owing to their health benefits, walnuts are attracting interest as a good option for nutritious meals, thereby promoting their production. Furthermore, the adoption of ecologically and environmentally friendly agriculture strengthens biostimulant use as a sustainable complement to traditional fertilizers. This study evaluated the effects of different foliar-applied biostimulants in walnut tree orchards, in northeastern Portugal, on walnuts' chemical composition and bioactivity. Walnut samples were rich in fat (particularly the polyunsaturated linoleic acid), dietary fiber and protein. Sucrose was the most prevalent soluble sugar, followed by glucose and fructose. Studied samples also showed an antioxidant activity comparable (or superior) to that of Trolox. Some plant biostimulants (e.g. Sprint Plus®) had a positive impact on the nutritional composition of walnuts, more specifically by boosting tocopherol levels, besides improving the bioactivity of walnut extracts against specific bacteria. Overall, this research demonstrated that important quality traits of walnuts can be improved using sustainable agricultural bioproducts and practices. © 2024 Society of Chemical Industry.

Evaluation of Pyroxasulfone Crop Safety and Weed Control for California Tree Nut Orchards

Pyroxasulfone is a very long chain fatty acid (VLCFA) inhibitor (group 15) with potential for preemergence weed control in orchard crops and would be beneficial for reducing selection pressure for resistance to more commonly used herbicides, such as glyphosate. Pyroxasulfone is registered and widely used in corn and soybeans in the United States as a solo product and in several premix formulations. However, there is limited published information on the performance and safety of pyroxasulfone in tree nut orchard systems. To assess the potential fit for pyroxasulfone in this crop sector, a series of crop safety and weed control efficacy experiments were carried out in key California orchard crops and in fallow fields with common orchard weeds. The non-crop studies were conducted near Davis, CA, to evaluate winter annual weed control with pyroxasulfone in comparison with pendimethalin and indaziflam. In addition, an irrigation incorporation experiment was conducted in summer to evaluate the effects of incorporation timing on pyroxasulfone, pendimethalin, and indaziflam efficacy as a measure of relative stability. Orchard weed control experiments were conducted in spring in an almond orchard near Arbuckle, CA, and a walnut orchard near Davis, CA. The orchard experiments included pyroxasulfone, pendimethalin, and indaziflam in various rate combinations with glufosinate. To evaluate crop safety, 2-year experiments were conducted to evaluate repeated applications of above-label rates of pyroxasulfone at 1199 g·ha−1 and S-metolachlor at 14,010 g·ha−1 on 1- to 2-year-old almond, pistachio, and walnut trees near Davis. Pyroxasulfone performed similarly to commercial standards with up to 95% control of broadleaf and grass weeds with pyroxasulfone and indaziflam providing 96% to 100% control of annual bluegrass, and pyroxasulfone (293 g·ha−1) being the only herbicide to suppress (>70%) common lambsquarters at 60 days after treatment (DAT). Other weeds controlled by pyroxasulfone include swinecress, redroot pigweed, yellow nutsedge, and Italian ryegrass. No differences were found among treatments in the incorporation timing study indicating adequate stability on the soil surface under summer conditions. Crop injury was not observed in the established orchards or the young orchard studies and there were no treatment effects on tree trunk diameter of almond, pistachio, and walnut in the 2-year crop safety experiments. These results indicate a potential for pyroxasulfone in California tree nut orchard systems that would be an additional site of action and beneficial for management of herbicide-resistant weeds in these crops.

Influence of Soil Properties on the Growth and Yield of Walnut Trees in the Hawraman Area, Sulaymaniyah-Iraq.

Influence of Soil Properties on the Growth and Yield of Walnut Trees in the Hawraman Area, Sulaymaniyah-Iraq.

Study of vibration patterns and response transfer relationships in walnut tree trunks

Fruit tree trunk is the support structure of the whole tree, carrying the task of vibration transmission to all levels of branches, fruit tree trunk vibration response to the design and optimization of the vibration harvesting device to provide guiding value. In this paper, the vibration response and harvesting test was carried out for four walnut fruit trees with different morphology and size, and the vibration transmission relationship between the excitation device and the fruit tree as well as inside the fruit tree was analyzed and studied according to the acceleration response curves at each position point under different frequencies. At the same time, the theoretical vibration pattern of the fruit tree and the measured spatial three-dimensional vibration pattern were constructed, and the response transfer law between each point of the fruit tree was further analyzed in terms of the vibration pattern and direction of each position point on the tree. The results show that the excitation response acceleration is basically no attenuation inside the device, but there is some attenuation in the clamping part due to the presence of damping pads. The vibration response in the fruit tree trunk is greater in amplitude farther from the excitation point. The phase relationship between each position point is basically the same in the theoretical vibration mode and the measured vibration mode, but there is damping in the actual fruit tree, which leads to the accumulation of phase hysteresis in the transmission of excitation parameters. The actual response trajectory is a narrow ellipse, and the different position points show different rotational relationships along the ellipse trajectory due to the growth of the fruit tree.

Detection of Paecilomyces formosus associated with declining urban forests and beetles in Iran

Urban forest trees are vital components of urban ecosystems, offering a range of benefits that are essential for improving the livability and sustainability of cities, providing numerous advantages for both the environment and public health. They enhance air quality by filtering pollutants, assist in regulating urban temperatures, and alleviate the urban heat island effect, which can result in substantial energy savings. Trees are often vulnerable to pathogens and pests that can cause significant damage. A survey of different trees in five provinces of Iran revealed a severe decline and dieback disease on woody plants. The affected trees included ailanthus, cedrus, cypress, ash, haloxylon, walnut, magnolia, black mulberry, paulownia, pine, oriental plane, apricot, wild pear, and elm trees. Samples of symptomatic branches and trunks were collected, and the causal fungal pathogen was isolated on potato dextrose agar (PDA) media. A total of 90 fungal isolates were obtained from trees (60 isolates) and insects (30 isolates) and then morphological investigations were done for all isolates. Molecular identification was confirmed through sequencing of the ITS and tub2 regions. This study reports 14 new hosts for Paecilomyces formosus in Iran and worldwide. Pathogenicity tests were conducted on detached branches of apricot, ailanthus, cypress, pine, sycamore, and walnut trees. The study showed that most isolates were pathogenic to six woody plants, and some isolates were associated with disease for eight woody plant species. Additionally, potential vectors and reservoirs for P. formosus were assessed in different beetles, including Aeolesthes sarta, Scolytus kirschii, and Orthotomicus erusus in Tehran, Alborz, Qazvin, Lorestan, and Zanjan Provinces. The results confirmed the potential of beetles for the transmission and maintenance of P. formosus.

Transcription combined metabolic analysis reveals the mechanism of potassium phosphate enhances resistance to walnut anthracnose (Colletotrichum gloeosporioides)

Given the increasingly serious diseases [anthracnose mainly caused by Colletotrichum gloeosporioides (C. gloeosporioides)] of walnut plants in recent years and the environmental pollution caused by chemical pesticides, phosphites had been shown to be new environmental friendly chemical agents for plants. In this study, seven-year-old ‘Xiangling’ and ‘Xifu 4’ walnut trees were treated with different concentrations of potassium phosphite foliar fertilizer. The treatments were T1 (1500-fold dilution fluid of potassium phosphite), T2 (1000-fold dilution fluid of potassium phosphite) and CK (water). The results showed that the disease incidence rates of fruit treated with potassium phosphite were lower than CK. Moreover, the diseased fruit rates of ‘Xiangling’ (4) and ‘Xifu 4’ (14) in T2, lower than they (28 and 38) in CK. Metabolome and transcriptome further analysis revealed that potassium phosphite significantly increased the expression level of genes in the photosynthesis pathway and accumulated terpeniods, phenolic, salicylic acid and other secondary metabolic pathways. In addition, as salicylic acid content significantly increased, the expression level of the gene encoding the disease resistance-related protein (PR1) showed a corresponding trend. In vitro antibacterial tests of six related metabolites on C. gloeosporioides showed that hederagenin, 23-hydroxybetulinic acid, ursolic acid, eriodictyol, and salicylic acid had effect on C. gloeosporioides spores, among which salicylic acid and ursolic acid significantly inhibited the growth of C. gloeosporioides. Further experiments revealed that the minimum inhibitory concentrations of salicylic acid and ursolic acid were 2 and 5 g L−1, respectively. In addition, potassium phosphite could directly inhibit the growth of C. gloeosporioides spores in vitro tests. In conclusion, potassium phosphite enhanced walnut fruit disease resistance through up-regulated the genes related to photosynthetic performance and abundant in secondary metabolites, such as salicylic acid, terpenoids and phenolics, which were antibacterial effects on C. gloeosporioides.

A new approach for artificial pollination in walnut trees: AirPoll

Pollination is the first step in the plant's fruit development. Therefore, fruit setting does not occur without pollination. Some problems encountered in natural pollination cause pollination not to be achieved as desired and cause significant losses in yield and fruit quality. Artificial pollination applications with drones are the best way to solve these problems. In this study, the AirPoll artificial pollination machine, which performs artificial pollination through the air using drone technology, was developed and the operating success of the machine was tested in walnut gardens. In the experiment gardens, female flowers on 18 branches of 5 trees each in the artificially pollinated area with a drone and in the control area were marked with colored strings. Control trees were selected from a distance that would not be possible to transport pollen with a drone. As a result of the study carried out in 2020 and 2021, the average fruit setting rate in trees pollinated by drone was determined as 94.61%. In control trees, 32.33% fruit setting was achieved. Thus, it was determined that the productivity increase in artificial pollination with AirPoll was 62.28%. In addition, in the study, Computational Fluid Dynamics (CFD) simulation analysis was performed using ANSYS Fluent 2024 R1 software to predict the downward air flow and pollen distribution in the walnut tree crown. The analysis was carried out in 680 iterations using drone propellers at a rotation speed of 4500 rpm, 4 m/s airflow and a k-w viscous model. In the analysis, it was observed that the pollen was distributed homogeneously with the determined height and the created artificial pollination environment. Based on the results obtained from the simulations, a convergence criterion of 5e−3 for continuity and 1e−6 for speed, k, w was determined. Considering all the results, the ease of use of the developed AirPoll artificial pollination machine and the successful results obtained in field trials reveal the effectiveness of the AirPoll artificial pollination machine.

Extraction of phenolic compounds from Juglans regia L. leaves using aqueous solutions of eutectic solvents

The leaves of Juglans regia L. (walnut tree) are a rich source of bioactive phenolic compounds, particularly flavonoids and phenolic acids, which can be used in cosmetic applications due to their antioxidant properties. Conventionally, these compounds are extracted using volatile organic solvents. This study focuses on a more sustainable approach by designing a heat-assisted extraction process using aqueous solutions of eutectic solvents (ES) composed of cosmetic-compatible ingredients aiming for direct incorporation into cream formulations. In this context, aqueous solutions of the ES betaine + urea and betaine + 1,3-propanediol (PPD) were selected, considering their potential as cosmetic ingredients. The screening process targeted the maximum extraction yield of phenolic compounds (phenolic acids and flavonoids), quantified by HPLC-DAD. The selected variables were water content (25, 50 and 75 % in weight) and the molar proportion of the ES components. For comparison purposes, pure water was used as a reference solvent.The total phenolic content ranged between 5.5 and 14.6 mg/g of dry plant. Betaine:urea (2:1), betaine:PPD (1:2), betaine, and PPD, all with 50 % water mass percentage, were among those resulting in higher extraction yields and were further selected for bioactivity analysis. The system containing betaine presented the best antioxidant capacity, analysed through ferric reducing power, DPPH radical scavenging, and TBARS assays. The extracts obtained with PPD presented the highest antimicrobial activity against gram-positive and gram-negative bacteria, and yeast. The results show the potential of using binary aqueous mixtures of betaine, or 1,3-propanediol, which are simple ingredients in cosmetics formulations, to efficiently extract phenolic compounds from a natural matrix. Moreover, the bioactivity results, particularly in the antioxidant dimension, support using J. regia leaves as a source of natural antioxidants.

Phytochemical Analysis and Biological Activities of Different Extracts of Walnut (Juglans regia Linn.) Kernels

The walnut tree (Juglans regia Linn.) is a valuable medicinal plant. Almost all parts of this plant have significant nutritional and curative properties. The walnut fruit has been claimed to possess antioxidant, anti-inflammatory, anti-hypertensive, antimicrobial properties and high nutritional value. The present work is focused on the phytochemical screening and study of antioxidant and antimicrobial properties of Juglans regia kernels extracted from four different solvents; methanol, ethyl acetate, chloroform, and hexane. The highest yield of extract was obtained with methanol. The phytochemical screening showed the presence of alkaloids, flavonoids, tannins, phenolic compounds, glycosides, terpenoids, quinones, reducing sugars, and saponins in methanol extract. The total phenolic content was higher in methanolic extract. Methanolic and chloroform extracts possessed more flavonoid content than ethyl acetate and hexane extracts. The DPPH radical scavenging assay showed that the IC50 value of methanolic extract was 78.77 μg/mL with TPC 67.65 mg GAE/g and TFC 391.00 mg QE/g. The IC50 value obtained for ethyl acetate extract was 135.28 μg/mL with TPC 36.56 mg GAE/g and TFC 212.00 mg QE/g. The IC50 value for chloroform extract was 313.72 μg/mL with TPC 13.08 mg GAE/g and TFC 393.73 mg QE/g. The IC50 value of hexane extract was 898.99 μg/mL with TPC 6.26 mg GAE/g and TFC 77.82 mg QE/g. Only methanolic extract showed the antimicrobial activity against Proteus vulgaris, Pseudomonas aeruginosa, and Staphylococcus aureus.