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This study focuses on the genetic diversity and population structure of Prunus dulcis (almond tree), a crucial agricultural component with widespread cultivation and commercial importance, particularly in Iran, a region with a longstanding tradition of almond cultivation. The diverse almond collection in Iran encompasses many local varieties, breeding selections, rootstocks, and international cultivars. This diversity necessitates advanced genotyping techniques to gain insights into genetic diversity, population structure, and linkage disequilibrium (LD). In this paper, genotyping-by-sequencing (GBS) was employed to analyze 62 almond germplasm samples, identifying approximately 63,537 high-quality single nucleotide polymorphisms (SNPs) distributed across the eight chromosomes of the almond genome. On average, there were 30,225 SNPs per chromosome. The analysis yielded an average polymorphism information content (PIC) of 0.315 and an expected heterozygosity (He) rate of 0.28, indicating a significant level of genetic diversity within the studied almond germplasm. The LD analysis demonstrated a rapid decline, with an average LD decay spanning approximately 300 kb for an r2 value of 0.2. This suggests substantial hybridization among the sampled almond varieties. Principal Component Analysis (PCA) and structure analysis could not differentiate genotypes based on geographical origin, providing further evidence of genetic mixing among the studied almond populations. An Analysis of Molecular Variance (AMOVA) highlighted significant genetic diversity within populations but revealed minimal differences. This comprehensive study of Iran's almond genotypes offers valuable insights for future breeding and conservation efforts, emphasizing this agriculturally significant species abundant genetic diversity and intricate population structure. [ABSTRACT FROM AUTHOR]

Digital agriculture supports farmers' decision making to improve productivity and profitability. However, adoption of digital technology is uneven. Through interviews with 21 medium acreage almond growers and crop consultants in California's Central Valley, we examine barriers to adoption through the lens of technology acceptance models, Technology Acceptance Model (TAM-3) and Unified Theory of Acceptance and Use of Technology (UTAUT-2). Not surprisingly, farmers are willing to adopt technology when profitability and ease of use are shown, with economic returns (either anticipated or demonstrated) from the technology investment serving as the primary factor influencing adoption. Trust operates as a moderating factor to the desire for economic returns that influences adoption. There may be trust, or lack of trust, in technology performance or in the advisors who recommend it. Producer trust is affected by expectations of technology relevance and usefulness, and it is influenced by prior experience. Concerns about data management (e.g., governance, quality, privacy, security) take a back seat to more practical issues such as profitability, leaving producers in an imbalanced position with tech companies who have an interest in their agricultural data. We assert that producer acceptance of data management practices (despite their uncertainty in how to utilize the data being generated) implies that there is a basic level of trust in tech companies' data management practices that is consistent with models of moralistic trust behaviors for precision ag adoption. Our findings contribute to the growing research on digital agriculture that debates the benefits and downsides of digital agriculture. [ABSTRACT FROM AUTHOR]

Hyperspectral sensors provide near-continuous spectral data that can facilitate advancements in agricultural crop classification and characterization, which are important for addressing global food and water security issues. We investigated two new-generation hyperspectral sensors, Germany's Deutsches Zentrum für Luft- und Raumfahrt Earth Sensing Imaging Spectrometer (DESIS) and Italy's PRecursore IperSpettrale della Missione Applicativa (PRISMA), within California's Central Valley in August 2021 focusing on five irrigated agricultural crops (alfalfa, almonds, corn, grapes, and pistachios). With reference data from the U.S. Department of Agriculture Cropland Data Layer, we developed a spectral library of the crops and classified them using three machine learning algorithms (support vector machines [SVM], random forest [RF], and spectral angle mapper [SAM]) and two philosophies: 1. Full spectral analysis (FSA) and 2. Optimal hyperspectral narrowband (OHNB) analysis. For FSA, we used 59 DESIS four-bin product bands and 207 of 238 PRISMA bands. For OHNB analysis, 9 DESIS and 16 PRISMA nonredundant OHNBs for studying crops were selected. FSA achieved only 1% to 3% higher accuracies relative to OHNB analysis in most cases. SVM provided the best results, closely followed by RF. Using both DESIS and PRISMA image OHNBs in SVM for classification led to higher accuracy than using either image alone, with an overall accuracy of 99%, producer's accuracies of 94% to 100%, and user's accuracies of 95% to 100%. [ABSTRACT FROM AUTHOR]

This work was conducted over three-year monitoring seasons of three almond cultivars (Guara, Marta, and Lauranne) subjected to deficit irrigation in combination with cover crops in a Mediterranean semiarid area (SW, Spain). Four water–soil treatments were evaluated based on the conjunction of two irrigation strategies: fully irrigated (FI), covering 100% of the ETC, and regulated deficit irrigation (RDI), with two soil-management systems: bare soil (BS) and cover crop based on a mixture of vetch (Vicia sativa L.) and oat (Avena sativa L.) (CC). Throughout the study period in trees, the yield, the stem water potential (Ψstem), leaf nutrient content (N, P, K, Ca, Mg, Na, Fe, Zn, Mn, and Cu) in soils, organic carbon, microbial biomass, fluoresceine diacetate, and enzymatic activities (dehydrogenase, protease, β-glucosidase, and alkaline phosphatase) were determined. In addition, the dry matter and carbon fixation by plant covers were evaluated. For Guara and Lauranne, yield reductions (22 and 26%, respectively) were found for water-stressed (RDI-CC) plots with respect to non-stressed combination (FI-CC) plots, contrasting with cv. Marta, without a significant impact on productivity in all combinations. That is, the RDI (~3.000 m3 ha−1) strategy enabled acceptable productivity, offering promising possibilities for cultivation performance under water-scarcity scenarios. Important differences in Ψstem could be observed and ascribed to irrigation strategies, especially for Guara and Lauranne, but without significant effects due to the soil-management systems applied. No differences were observed in the tree nutritional status due to the presence or absence of CC; however, its presence increased the fixation of atmospheric carbon, which was not the case under BS conditions. Additionally, CC significantly fostered the microbial processes and enzymatic activities, particularly in upper soil layers (0–10 cm) and with plenty of water supply in FI-CC plots and to a lesser extent in RDI-CC plots, which could encourage prominent aspects for soil quality and health restoration. Thus, the cover crop is congruent with RDI to facilitate soil functionality and water savings in a changing climate, contributing to resilient farming systems in the Mediterranean environment. [ABSTRACT FROM AUTHOR]

AbstractStone fruits, including peaches, plums, cherries, apricots, and almonds, are economically significant crops that require careful nitrogen management to optimize growth, yield, and fruit quality. Nitrogen (N) is a crucial macronutrient for stone fruits, playing a vital role in leaf development, photosynthetic capacity, and in the formation of sugars and carbohydrates essential for fruit development. However, nitrogen application needs careful management, as both deficiency and excess of this nutrient element can adversely affect fruit size, quality, and yield. Excessive nitrogen can lead to decreased flesh firmness, reduced sweetness, and increased susceptibility to diseases. Additionally, nitrogen remobilization from senescing leaves to storage tissues is a key process that supports nutrient use efficiency and reduces reliance on external nitrogen inputs in deciduous fruit crops. The timing of nitrogen application is critical, with peak demand occurring during bud break, flowering, and fruit set. Among its method of application, fertigation has proven to be an effective method for delivering nitrogen, improving leaf nutrient status, vegetative growth, and fruit quality. The interaction between nitrogen fertilization and soil organic matter (SOM) is also significant, as nitrogen influences SOM dynamics and potentially enhance the soil fertility and structure. This comprehensive review consolidates current knowledge on nitrogen fertilization in stone fruits, emphasizing the importance of balanced nitrogen management to achieve optimal growth, yield, and fruit quality. Despite extensive research globally, there is need to tailor nitrogen management practices to local conditions and improve sustainable stone fruit production. [ABSTRACT FROM AUTHOR]

The nitidulid beetle Carpophilus truncatus is rapidly becoming a major pest of nut crops around the world. This insect first infested Australian almonds in 2013 and has since escalated to be the preeminent insect pest for the industry. Data pertaining to C. truncatus distribution are scant, but without awareness of its origin, distribution, and ecological factors that influence distribution, efforts to understand and manage the insect as a pest are stymied. Here, we employ an integrative approach to gain a multifaceted understanding of the distribution of C. truncatus in Australia. Methods employed were (1) reviewing historical records in insect collections to establish the presence of C. truncatus prior to commercial almond horticulture, (2) field trapping of insects to establish presence in regions of interest, (3) laboratory trials to determine the thermal limits of the organism, and (4) correlative species distribution modelling to describe its current distribution. We find that C. truncatus is more widespread across Australia than was previously known, with historical records preceding commercial almond production in Australia by a century. The methods developed in this study can be applied elsewhere in the world where C. truncatus is an emerging pest, or to novel pest species as they arise with increasing frequency in a globalised and warming world. [ABSTRACT FROM AUTHOR]

Introduction: The almond tree is a major global nut crop, and its production has surged dramatically in recent years. Super high-density (SHD) planting systems, designed to optimize resource efficiency and enhance precocity, have gained prominence in almond cultivation. A shift in cropping systems toward sustainable intensification (SI) pathways is imperative, and so maximizing branching density within the canopies of SHD trees is crucial to establish and maintain productive potential, especially for hedge-pruned trees. This study investigates the influence of different almond cultivars grafted onto a novel growth-controlling rootstock on tree architectural and growth parameters in a SHD orchard. This open field research provided valuable insights for the development and application of new tools and methods to increase productivity and sustainability in almond growing. Methods: Three cultivars (Lauranne® Avijour, Guara Tuono, and Filippo Cea) were evaluated in Gravina in Puglia (BA) over a two-year period. Canopy growth parameters, such as canopy volume and trunk cross-sectional area, and architectural traits, like branching density, branching angle, number and length of subterminal shoots, and number of brachyblasts, were measured through qualitative and quantitative measurements. Results and discussion: Results revealed significant differences in tree height, canopy thickness, width, volume, and vigor among the cultivars. Architectural traits, including branch parameters, brachyblast parameters, and subterminal shoots, varied among the cultivars. Lauranne displayed a more compact welldistributed canopy and exhibited the lowest vigor. Filippo Cea showed the highest vigor and the greatest canopy volume. Tuono had a higher number of buds and bud density. The best ideotype for SHD orchards is a smaller tree, with high branching density and smaller trunk diameters, i.e. the vigor. Cv. Lauranne seemed to be the best cultivar, mostly with the lowest tree vigor of all the cultivars involved. These findings provide valuable insights for almond growers and breeders seeking to optimize orchard design and management for enhanced SHD orchards productivity and sustainability. Future research will explore the relationship between canopy architecture and yield parameters, considering different scion/rootstock combinations in different environmental conditions. [ABSTRACT FROM AUTHOR]

Predicting the timing of phenological events is important in agriculture, especially high-revenue products. A project sponsored by USDA-ARS had the objective of adapting a previously developed model for estimating proportions of insects in different development stages as a function of temperature (degree) and time (days) for predicting bloom in almond orchards. Data for the model normally form a two-way table of counts, with rows corresponding to sample percentages of different development stages and columns to sampling times. In this study, we report a technique developed to estimate sample sizes of multinomial and product multinomial models using a method of moments and determine the empirical coverage of sample size. This study aims to determine an appropriate sample size for data collection. This involves establishing a sampling distribution for the Pearson statistic, defined as the product of the sample size and the deviance of empirical proportions from population proportions. The intended outcome is to predict the optimal timing for harvesting crops at desired development stages when coupled with the phenology model, for which variability of the maximum likelihood estimates of the phenology model depends on sample size. [ABSTRACT FROM AUTHOR]

Understanding and accurately predicting stomatal conductance in almond orchards is critical for effective water-management strategies, especially under challenging climatic conditions. In this study, machine-learning (ML) regression models trained on multispectral (MSP) and thermal infrared (TIR) data acquired from unmanned aerial vehicles (UAVs) are used to address this challenge. Through an analysis of spectral indices calculated from UAV-based data and feature-selection methods, this study investigates the predictive performance of three ML models (extra trees, ET; stochastic gradient descent, SGD; and extreme gradient boosting, XGBoost) in predicting stomatal conductance. The results show that the XGBoost model trained with both MSP and TIR data had the best performance (R2 = 0.87) and highlight the importance of integrating surface-temperature information in addition to other spectral indices to improve prediction accuracy, up to 11% more when compared to the use of only MSP data. Key features, such as the green–red vegetation index, chlorophyll red-edge index, and the ratio between canopy temperature and air temperature (Tc-Ta), prove to be relevant features for model performance and highlight their importance for the assessment of water stress dynamics. Furthermore, the implementation of Shapley additive explanations (SHAP) values facilitates the interpretation of model decisions and provides valuable insights into the contributions of the features. This study contributes to the advancement of precision agriculture by providing a novel approach for stomatal conductance prediction in almond orchards, supporting efforts towards sustainable water management in changing environmental conditions. [ABSTRACT FROM AUTHOR]

Dried fruits are renowned for their nutritional value, particularly their seeds. However, their skins, shells, and hulls also hold significant nutritional and commercial potential, yet remain largely unexplored for their bioactive compounds. This study examines the teguments and shells of three types of dried fruits – hazelnut, peanut, and two almond varieties. Ethanol extracts from these by-products reveal a variety of phytochemicals with antioxidant, antimicrobial, anti-inflammatory, and antiviral properties, confirmed through in vitro and in vivo assays. Teguments contain higher polyphenol levels compared to shells, with 24 compounds identified via HPLC analysis. The Achak almond tegument extract demonstrates strong antiradical activity, significant antimicrobial effects, and notable antiviral properties at a low concentration. Moreover, extracts from Achak almond tegument and hazelnut shells exhibit notable anti-inflammatory properties. This underscores the potential of utilizing dried fruit by-products to create innovative, value-added products, supporting environmental sustainability and boosting the competitiveness of the dried fruit industry. [ABSTRACT FROM AUTHOR]

Hyperspectral sensors provide near-continuous spectral data that can facilitate advancements in agricultural crop classification and characterization, which are important for addressing global food and water security issues. We investigated two new-generation hyperspectral sensors, Germany's Deutsches Zentrum für Luft- und Raumfahrt Earth Sensing Imaging Spectrometer (DESIS) and Italy's PRecursore IperSpettrale della Missione Applicativa (PRISMA), within California's Central Valley in August 2021 focusing on five irrigated agricultural crops (alfalfa, almonds, corn, grapes, and pistachios). With reference data from the U.S. Department of Agriculture Cropland Data Layer, we developed a spectral library of the crops and classified them using three machine learning algorithms (support vector machines [SVM], random forest [RF], and spectral angle mapper [SAM]) and two philosophies: 1. Full spectral analysis (FSA) and 2. Optimal hyperspectral narrowband (OHNB) analysis. For FSA, we used 59 DESIS four-bin product bands and 207 of 238 PRISMA bands. For OHNB analysis, 9 DESIS and 16 PRISMA nonredundant OHNBs for studying crops were selected. FSA achieved only 1% to 3% higher accuracies relative to OHNB analysis in most cases. SVM provided the best results, closely followed by RF. Using both DESIS and PRISMA image OHNBs in SVM for classification led to higher accuracy than using either image alone, with an overall accuracy of 99%, producer's accuracies of 94% to 100%, and user's accuracies of 95% to 100%. [ABSTRACT FROM AUTHOR]

This document is a summary of an editorial article titled "Effects of Agronomical Practices on Crop Quality and Sensory Profile" published in the journal Agronomy. The article discusses the importance of agronomical practices in improving crop quality and sensory properties. It highlights the challenges faced in achieving sustainable development goals related to poverty, hunger, clean water, climate action, and sustainable agriculture. The article presents research on various crops, including tomatoes, citrus fruits, apples, olives, and almonds, and explores topics such as growing conditions, cultivars, irrigation strategies, and postharvest treatments. The findings emphasize the need for breeding programs and consumer preferences in developing crop varieties that meet both climatic conditions and consumer demands. The article also discusses the impact of irrigation strategies on olive oil quality and the importance of trellis systems in grapevine cultivation. Additionally, it explores the potential of Boesenbergia rotunda as a medicinal plant for preventing SARS-CoV-2 infection and the utilization of prickly pear peel flour in cake production. [Extracted from the article]

In a 42-day study, 195 growing pigs (Landrace × Yorkshire × Duroc) weighing 23.83 ± 1.95 kg were randomly divided into three treatments, each with 13 replicates and 5 pigs (3 barrows and 2 gilts) per pen. The treatments were control (CON)—basal diet, and basal diet with 3% and 6% almond hull as treatment (TRT) 1 and 2, respectively. The results show a significant increase (p < 0.05) in average daily gain (ADG) and average daily feed intake (ADFI) for both treatment 1 and treatment 2 by week 6 when compared to the control group. This improvement in ADG and ADFI exhibits a consistent trend (p < 0.10) throughout the overall trial period in comparison to the control group. Additionally, there is a tendency for enhanced gain-to-feed ratio (G:F) at the end of week 6 (p < 0.10) in comparison to the control group and remained constant (p > 0.05). No significant impact (p > 0.05) on nutrient digestibility and fecal microbiota was observed. However, NH3 gas showed a tendency to decrease (p < 0.10). Results suggested that almond hulls could improve growth and reduce ammonia gas without adverse effects on digestion, microbiota, and fecal score. [ABSTRACT FROM AUTHOR]

Simple Summary: Almond hull (AH) is a by-product of almond production that can be used in ruminant feeding, but their composition is variable and needs further characterization. We observed that there were significant differences in chemical composition and nutritional value of samples of AH from two varieties, with AH from Guara variety having more energy and protein than those from Soleta variety in samples collected in two different almond campaigns in the South of Spain. Moreover, harvesting year affected the chemical composition and nutritive value of AH, making necessary their chemical analysis before being used as feed in the practice. In addition, we conducted in vitro trials to investigate the effects of including increasing amounts of AH in diets for dairy ruminants on diet degradability and methane production. Methane is a greenhouse gas with high warming potential that is produced during feed fermentation in the rumen. The results indicate that dried AH can replace up to 16% of conventional feed ingredients in diets for dairy ruminants, but methane production was not reduced. In conclusion, the tested AH can be used as alternative feed for ruminants, although this by-product does not contain antimethanogenic compounds. Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations. [ABSTRACT FROM AUTHOR]

Almonds are becoming a central element in the gastronomic and food industry worldwide. Over the last few years, almond production has increased globally. Portugal has become the third most important producer in Europe, where this increasing trend is particularly evident. However, the susceptibility of almond trees to changing climatic conditions presents substantial risks, encompassing yield reduction and quality deterioration. Hence, yield forecasts become crucial for mitigating potential losses and aiding decisionmakers within the agri-food sector. Recent technological advancements and new data analysis techniques have led to the development of more suitable methods to model crop yields. Herein, an innovative approach to predict almond yields in the Trás-os-Montes region of Portugal was developed, by using machine learning regression models (i.e., the random forest regressor, XGBRegressor, gradient boosting regressor, bagging regressor, and AdaBoost regressor), coupled with remote sensing data obtained from different satellite platforms. Satellite data from both proprietary and free platforms at different spatial resolutions were used as features in the study (i.e., the GSMP: 11.13 km, Terra: 1 km, Landsat 8: 30 m, Sentinel-2: 10 m, and PlanetScope: 3 m). The best possible combination of features was analyzed and hyperparameter tuning was applied to enhance the prediction accuracy. Our results suggest that high-resolution data (PlanetScope) combined with irrigation information, vegetation indices, and climate data significantly improves almond yield prediction. The XGBRegressor model performed best when using PlanetScope data, reaching a coefficient of determination (R2) of 0.80. However, alternative options using freely available data with lower spatial resolution, such as GSMaP and Terra MODIS LST, also showed satisfactory performance (R2 = 0.68). This study highlights the potential of integrating machine learning models and remote sensing data for accurate crop yield prediction, providing valuable insights for informed decision support in the almond sector, contributing to the resilience and sustainability of this crop in the face of evolving climate dynamics. [ABSTRACT FROM AUTHOR]

Almond cultivation is of great socio-economic importance worldwide. With the demand for almonds steadily increasing due to their nutritional value and versatility, optimizing the management of almond orchards becomes crucial to promote sustainable agriculture and ensure food security. The present systematic literature review, conducted according to the PRISMA protocol, is devoted to the applications of remote sensing technologies in almond orchards, a relatively new field of research. The study includes 82 articles published between 2010 and 2023 and provides insights into the predominant remote sensing applications, geographical distribution, and platforms and sensors used. The analysis shows that water management has a pivotal focus regarding the remote sensing application of almond crops, with 34 studies dedicated to this subject. This is followed by image classification, which was covered in 14 studies. Other applications studied include tree segmentation and parameter extraction, health monitoring and disease detection, and other types of applications. Geographically, the United States of America (USA), Australia and Spain, the top 3 world almond producers, are also the countries with the most contributions, spanning all the applications covered in the review. Other studies come from Portugal, Iran, Ecuador, Israel, Turkey, Romania, Greece, and Egypt. The USA and Spain lead water management studies, accounting for 23% and 13% of the total, respectively. As far as remote sensing platforms are concerned, satellites are the most widespread, accounting for 46% of the studies analyzed. Unmanned aerial vehicles follow as the second most used platform with 32% of studies, while manned aerial vehicle platforms are the least common with 22%. This up-to-date snapshot of remote sensing applications in almond orchards provides valuable insights for researchers and practitioners, identifying knowledge gaps that may guide future studies and contribute to the sustainability and optimization of almond crop management. [ABSTRACT FROM AUTHOR]

Simple Summary: Apis mellifera is a managed pollinator that experiences cycles of extreme losses at the population level. Several culprits have been associated with these mass losses. Most notably, the parasitic mite Varroa destructor is a consistent suspect in periodic mass losses of honey bee colonies. Our team performed diagnostic screening of pathogens and parasites in operations that experienced extreme losses during the winter of 2023. The direct cost to replace lost colonies and the immediate economic harm imparted from severe losses are described. United States commercial beekeepers prepare honey bee colonies for almond pollination in California each year in late January to early February. This represents the largest managed pollination event in the world and involves more than half of all U.S. honey bee colonies. In winter 2023, numerous colonies in Florida, which were graded as suitable for almonds (larger than ten frames of bees), dwindled suddenly or altogether died within several weeks, just prior to movement for almonds. The timing of these losses and the resulting morbidity caused severe economic harm to affected operations. This study reports interviews with affected stakeholders, their economic harm, and analyses of pathogens and parasites found in their colonies. [ABSTRACT FROM AUTHOR]

Simple Summary: Managed honey bees are virtually exclusive pollinators of almonds in commercial agricultural contexts such as that of California's Central Valley where 80% of the world's almonds are produced. Streamlining almond pollination by utilizing honey bee colonies in the most efficient way aims to support both the growers and beekeepers as demand for pollination services and per unit costs are increasing. This study examines whether hive entrance orientation and hive strength influence the pollinating activity of honey bees in almond orchards. We have found that hives facing east have a marked advantage in starting their activity in the morning compared to hives facing west. Similarly, strong colonies show a significantly earlier start of activity than weak colonies. The practical implication of these findings lies in configuring the placement of colonies of varying strengths in a way that favours their foraging activity. The foraging activity of honey bees used to pollinate almonds was examined in relation to their hive entrance orientation and colony strength. Twenty-four colonies of honey bees, twelve in each group, were situated with their entrances facing east and west cardinal points. Bee out counts were recorded continuously and hive weight data at ∼10 min intervals from 17 February to 15 March 2023. Colony strength was assessed using the frames of adult bees (FOB) metric. East-facing hives started flight 44.2 min earlier than west-facing hives. The hive direction did not affect the timing of the cessation of foraging activity. The hive strength played a significant role: hives assessed as weak (≤3.0 FOB) commenced foraging activity 45 min later than strong hives (>3.0 FOB) and ceased foraging activity 38.3 min earlier. Hive weight data did not detect effects of either the hive direction or colony strength on the commencement and cessation of foraging activity, as determined using piecewise regression on 24 h datasets. However, the hive weight loss due to foraging activity at the start of foraging activity was significantly affected by both direction (East > West) and colony strength (Strong > Weak). Our study showed that, during almond pollination, both hive entrance exposure and hive strength have quantifiable effects on colony foraging behaviour and that these effects combine to regulate the overall foraging activity of the pollinating colonies. [ABSTRACT FROM AUTHOR]

Field experiments were conducted in three successive seasons (2019–2021) to evaluate the effects of four commercial organo-mineral fertilizers with biostimulating action (Hendophyt®, Ergostim®, and Radicon®) on the vegetative and productive performance of young almond trees (Prunus dulcis, cv. Tuono) grown in a semiarid climate in Southern Italy. Foliar treatments were applied three times during each season (at the swollen bud, beginning of flowering, and fruit set-beginning of fruit growth stages). Both 2020 and 2021 were adversely affected by late frosts, resulting in damage to the flowers and small fruits without any positive effect of the biostimulant applications. In contrast, the results obtained during the normal climate year (2019) indicated that the growth of trunk diameter and shoot length of trees tended to increase in biostimulant treatments compared to those of the control. The number of buds and flowers per unit length of the branch revealed no significant differences among years and all compared treatments. However, in 2019, the fruit set percentage, number, and weight of kernels per tree were significantly higher in the biostimulant treatments compared to those of the control. To this regard, the use of biofertilizers is suitable for maintaining soil fertility and improving crop productivity This information holds significance for almond tree growers. [ABSTRACT FROM AUTHOR]

Wild bees (Hymenoptera: Apoidea) play an important role as pollinators of many crops and managed populations of Osmia spp. (Megachilidae), through the installation of trap-nests, proved to be efficient in several fruit orchards. In order to optimize the trap-nest protocols, it is necessary to understand which environmental factors play a major role in the reproductive success of these bees. Here, we studied how climate, land use and vegetation affect nest occupation rate (OR, i.e. total number of colonized tunnels/total number of tunnels in the trap-nest), brood productivity (BP, i.e. total number of brood cells built in a completed nest tunnel) and parasitism rate (PR, i.e. total number of parasitized brood cells/BP) in Osmia bees nearby almond orchards in South-East Spain, a largely understudied Mediterranean area. We found that the summer solar radiation positively influenced all three parameters, while spring solar radiation positively affected OR and BP, and negatively PR. Higher abundance of pastures and forests compared with crops increased OR, though not BP, and reduced PR. Vegetation evenness and diversity of dominant plant species also positively affected OR and BP, while they were unimportant for PR. OR was not affected by climate, but BP increased with maximum temperature in the warmest month and decreased with temperature annual range. PR also increased with high temperature, as well as with precipitation. Arid conditions limited OR and BP and boosted parasitism. Overall, it seems that Osmia bees nearby almond field in this area would benefit from trap-nest installation in well solar-radiated, hot and humid sites with a diverse vegetation. Since we have also found a negative association between PR and BP in nests with at least one parasitized cell, environmental conditions which improve productivity will also likely reduce parasitism in these bees. Implications for insect conservation Optimization of trap-nesting protocols for maintaining abundant Osmia populations is crucial to an effective use of these bees as managed pollinators. In our study we suggest that trap-nests locations should be chosen also taking into account a number of local climatic and habitat factors, given their importance in affecting key traits of reproductive success in these solitary bees. [ABSTRACT FROM AUTHOR]

ABC (ATP-binding cassette) transporter proteins are one of the most extensive protein families known to date and are ubiquitously found in animals, plants, and microorganisms. ABCs have a variety of functions, such as plant tissue development regulation, hormone transport, and biotic and abiotic stress resistance. However, the gene characterization and function of the ABC gene family in almond (Prunus dulcis) have not been thoroughly studied. In this study, we identified 117 PdABC genes using the whole genome of 'Wanfeng' almond obtained by sequencing and explored their protein characterization. The PdABC family members were classified into eight subfamilies. The members of the same subfamily had conserved motifs but poorly conserved numbers of exons and introns and were unevenly distributed among the eight subfamilies and on the eight chromosomes. Expression patterns showed that PdABC family members were significantly differentially expressed during almond development, dormant freezing stress, and salt stress. We found that PdABC59 and PdABC77 had extremely high expression levels in pollen. PdABC63 and PdABC64 had high expression levels during almond petal development and multiple stages of flower development. PdABC98 was highly expressed in annual dormant branches after six temperature-freezing stress treatments. PdABC29, PdABC69, and PdABC98 were highly expressed under different concentrations of salt stress. This study preliminarily investigated the expression characteristics of ABC genes in different tissues of almond during flower development, freezing stress and salt stress, and the results will provide a reference for further in-depth research and breeding of almond in the future. [ABSTRACT FROM AUTHOR]

Water scarcity threatens agriculture in California. During the last two decades, historically severe droughts have led to severe water shortages. Under projected changes in climate, droughts of greater severity and duration will exacerbate this situation. California produces 80% of the world's almonds, which require consistent water supplies for irrigation. Almonds are the most commonly grown crop in California, covering nearly 1.4 million acres over about 8,000 farms. In response to these challenges, almond growers are considering a myriad of management strategies to save water and mitigate climate change. The Tree-Crop Remote Sensing of Evapotranspiration Experiment (T-REX) aims to identify water and orchard management opportunities to maximize water use efficiency and carbon sequestration in almonds and other woody perennial tree crops. The project combines satellite, uncrewed aerial vehicles, and proximal sensing technologies to retrieve key variables used to model surface fluxes and biophysical properties. We aim to advance our understanding of water management and cultural practices on water-carbon relationships in tree-perennial agroecosystems. Through new methods, such as evapotranspiration-based irrigation scheduling, even a modest 10% decrease in almond orchard irrigation across the state equates to about a third of the water in Lake Oroville, California's second-largest reservoir, at average levels. From a carbon perspective, almond orchards could sequester 8% of the state's current greenhouse gas emissions by transitioning toward climate-smart practices. As such, the almond industry is uniquely positioned to curb water use and contribute to climate change mitigation while maintaining economic viability of almond production. An overview of initial results related to evapotranspiration observational and modeling uncertainty and carbon sequestration potential are presented in this article. [ABSTRACT FROM AUTHOR]

Almond growers are seeking ways to reduce costs but maintain yield. Intensive planting systems with greater planting densities using trees on growth-controlling rootstocks, combined with mechanical pruning and shake-and-catch harvesting are becoming popular. In this study we examined the responses of six almond cultivars with distinctive architecture grafted onto five rootstocks with varying degrees of vigor control. Trees were planted in 2018 in a nursery row and left to grow without pruning until Winter 2021. Pruning involved a rudimentary hedging treatment akin to mechanical pruning. Branching and tree structure were recorded in 2020, before pruning, and again at the end of 2021, after one season's growth following pruning. A rating system was developed to record qualitative data on central leader dominance and the number, length, basal diameter, and, in some cases, branching angle of axillary shoots and including scaffold branches. Relatively few changes were recorded in the basic growth habit of these trees in response to pruning. Before pruning, the most common rootstock effect was on axillary shoot production. After pruning, the most common rootstock effects were on scaffold branching and the length of subterminal axillary shoots. Further studies are required to determine how these differences produced by the interaction between pruning and rootstock may affect the productivity of fruit-bearing trees. Although in this study with young trees we were not able to record crop yield, the results highlight that it is mainly the scion-rootstock combination, with or without pruning, that determines the potential productivity of fruiting canopies. Scion-rootstock combinations that produce narrow upright canopies naturally with strong central leader dominance and highly branched canopies are preferred for superintensive growing systems with or without use of mechanical hedging. [ABSTRACT FROM AUTHOR]

The rootstock genotype plays a crucial role in determining various aspects of scion development, including the scion three-dimensional structure, or tree architecture. Consequently, rootstock choice is a pivotal factor in the establishment of new almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) intensive planting systems, demanding cultivars that can adapt to distinct requirements of vigor and shape. Nevertheless, considering the capacity of the rootstock genotype to influence scion development, it is likely that the scion genotype reciprocally affects rootstock performance. In the context of this study, we conducted a transcriptomic analysis of the scion/rootstock interaction in young almond trees, with a specific focus on elucidating the scion impact on the rootstock molecular response. Two commercial almond cultivars were grafted onto two hybrid rootstocks, thereby generating four distinct combinations. Through RNA-Seq analysis, we discerned that indeed, the scion genotype exerts an influence on the rootstock expression profile. This influence manifests through the modulation of genes associated with hormonal regulation, cell division, root development, and light signaling. This intricate interplay between scion and rootstock communication plays a pivotal role in the development of both scion and rootstock, underscoring the critical importance of a correct choice when establishing new almond orchards. [ABSTRACT FROM AUTHOR]

In the current study, the Koyck model was used to determine the effect of almond prices on almond production in Türkiye. In the study, the period of 1970-2021 was examined and almond production was used as the dependent variable and almond price was used as the independent variable. According to the results of the analysis, the correlation between almond prices and the amount of almond production was found to be 0.952. The study determined that almond production is influenced by almond prices, and that any change in almond prices can lead to a noticeable change in almond production within a time frame of 2.67 years. On the other hand, it was determined that for the examined period, a one TL increase in almond prices in the current year led to a production increase of 0.002771 tons, while a one TL increase in almond prices in the previous period resulted in a production increase of 0.002015057 tons. [ABSTRACT FROM AUTHOR]

The production of almonds and pistachios in California's Central Valley employs insecticides for the management of their primary pest, navel orangeworm. The pyrethroid Bifenthrin is commonly used, and now a strain of Amyelois transitella Walker (Lepidoptera: Pyralidae) (R347) obtained from Kern County almond orchards with a history of Bifenthrin use has acquired >110-fold resistance toward pyrethroids. One method to improve control is to use additives and spray adjuvants, which are applied simultaneously with an insecticide to increase coverage and/or duration of control. We tested 2 levels of the naturally occurring clay Kaolin as an additive, alone and in combination with either Bifenthrin or the diamide Chlorantraniliprole, to determine if it could reduce feeding damage and decrease survival of pyrethroid-resistant A. transitella on almonds in the laboratory and improve the efficacy of Chlorantraniliprole in the field. Larval performance was measured for the strains R347 and ALM (34.7-fold resistance compared to susceptible lab strain) reared on treated almonds. Strain R347 had 1.9-fold greater survival and caused 1.3-fold more feeding damage than strain ALM across all treatments, although both strains were susceptible to the combination of Kaolin + insecticide. Kaolin synergized Bifenthrin for R347, decreasing survival by 10.0%. Kaolin did not reduce feeding damage for either strain. When combined with insecticide, feeding damage was similar to insecticide alone, but the addition of Kaolin to the insecticide generally decreased survival more than the insecticide alone. In the field, the addition of Kaolin to Chlorantraniprole during application helped retain activity against this challenging pest. [ABSTRACT FROM AUTHOR]

The leaffooted bug, Leptoglossus clypealis Heidemann, is a seed-feeding economic pest of crops including almonds and pistachios. The historical distribution of L. clypealis has been considered to be West of the Mississippi in the United States. L. clypealis was recently found in sorghum in the Coastal Bend of Texas, representing a new host record and new collection locality. This study investigated the genetic diversity of L. clypealis museum voucher samples from the Western United States (i.e. Texas, California, and Idaho) collected from 1994 to 2019, including the L. clypealis samples from the Coastal Bend. Eleven new sequences were obtained. Sample sequences were compared with public sequences of L. clypealis from the Western United States. The mitochondrial DNA cytochrome oxidase 1 (mtDNA COI) barcode gene region revealed differences among and within the collection regions. Texas, Idaho, and California all had samples with unique genotypes, and the combined dataset had a haplotype diversity of 1.0. The Texas specimens recently collected in the Coastal Bend did not match genotypes from California or Idaho, and it is unlikely they were recently introduced. Overall, L. clypealis from Texas, Idaho, and California have a high level of genetic diversity, and the 3 regions appear to be within the native range of the species. [ABSTRACT FROM AUTHOR]

Exposure to agrochemical sprays containing pesticides and tank-mix adjuvants has been implicated in post-bloom mortality, particularly of brood, in honey bee colonies brought into California almond orchards for pollination. Although adjuvants are generally considered to be biologically inert, some adjuvants have exhibited toxicity and sublethal effects, including decreasing survival rates of next-generation queens. Honey bees have a highly developed olfactory system to detect and discriminate among social signals. To investigate the impact of pesticide-adjuvant combinations on honey bee signal perception, we performed electroantennography assays to assess alterations in their olfactory responsiveness to the brood ester pheromone (BEP), the volatile larval pheromone β-ocimene, and the alarm pheromone 2-heptanone. These assays aimed to uncover potential mechanisms underlying changes in social behaviors and reduced brood survival after pesticide exposure. We found that combining the adjuvant Dyne-Amic with the fungicide Tilt (propiconazole) and the insecticide Altacor (chlorantraniliprole) synergistically enhanced olfactory responses to three concentrations of BEP and as well exerted dampening and compensatory effects on responses to 2-heptanone and β-ocimene, respectively. In contrast, exposure to adjuvant alone or the combination of fungicide and insecticide had no effect on olfactory responses to BEP at most concentrations but altered responses to β-ocimene and 2-heptanone. Exposure to Dyne-Amic, Altacor, and Tilt increased BEP signal amplitude, indicating potential changes in olfactory receptor sensitivity or sensilla permeability to odorants. Given that, in a previous study, next-generation queens raised by nurses exposed to the same treated pollen experienced reduced survival, these new findings highlight the potential disruption of social signaling in honey bees and its implications for colony reproductive success. [ABSTRACT FROM AUTHOR]

Animal feed ingredients, especially those abundant in high quality protein, are the most expensive component of livestock production. Sustainable alternative feedstocks may be sourced from abundant, low value agricultural byproducts. California almond production generates nearly 3 Mtons of biomass per year with about 50% in the form of hulls. Almond hulls are a low-value byproduct currently used primarily for animal feed for dairy cattle. However, the protein and essential amino acid content are low, at ~30% d.b.. The purpose of this study was to improve the protein content and quality using yeast. To achieve this, the almond hulls were liquefied to liberate soluble and structural sugars. A multi-phase screening approach was used to identify yeasts that can consume a large proportion of the sugars in almond hulls while accumulating high concentrations of amino acids essential for livestock feed. Compositional analysis showed that almond hulls are rich in polygalacturonic acid (pectin) and soluble sucrose. A pectinase-assisted process was optimized to liquefy and release soluble sugars from almond hulls. The resulting almond hull slurry containing solubilized sugars was subsequently used to grow high-protein yeasts that could consume nutrients in almond hulls while accumulating high concentrations of high-quality protein rich in essential amino acids needed for livestock feed, yielding a process that would produce 72 mg protein/g almond hull. Further work is needed to achieve conversion of galacturonic acid to yeast cell biomass. [ABSTRACT FROM AUTHOR]

Background: Water stress during the growing season of the almond tree is the factor that most limits its yield. Different strategies have been studied in recent years to reduce its negative effects, such as deficit irrigation and the application of reflective spray compounds. A 3‐year experiment (2019–2021) was set in a factorial design in which the effect of regulated deficit irrigation and foliar kaolin spray was evaluated on morphological characteristics (weight, length, width, and thickness of the nut and kernel, shell thickness, kernel yield, double kernels, and damaged kernels), color properties, nutritional value (carbohydrates, fat, proteins and ash) and chemical parameters (free sugars and fatty acids profiles). Results: In general, the significant differences between the treatments did not have a similar trend in the 3 years of the study. Regulated deficit irrigation and kaolin had no detrimental impact on almond morphological and color characteristics. The almond free sugars concentration was relatively stable under deficit irrigation and kaolin application. On the other hand, kaolin application positively affected the synthesis of linoleic acid. Conclusion: Reducing the amount of irrigation water applied to almonds contributes to the sustainability of production without negatively affecting quality and even improving some quality parameters. In general, the foliar application of kaolin did not show significant differences in the evaluated morphological parameters. However, in terms of chemical composition, kaolin led to an increase in the concentration of linoleic acid and sucrose. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The infraorder Cicadomorpha is a diverse group comprising several species considered important pests of economic crops and species that may act as vectors of plant pathogens. In Europe, the gram‐negative bacterium Xylella fastidiosa is one of the most important and severe insect‐borne plant pathogens associated with the infraorder Cicadomorpha.Therefore, the knowledge of the abundance and diversity of native Cicadomorpha insect vectors related to the different agroecosystems is essential to design and implementing specific measures to control insect‐borne plant pathogens.In this work, in two consecutive years (2018 and 2019), five almond orchards, five vineyards, five olive orchards, and five scrublands distributed in the North of Portugal were sampled in three different periods (early summer, summer and autumn) to investigate species composition, richness, and diversity of the Cicadomorpha community. Also, in 2019, five lemon orchards were sampled.A total of 6056 individuals were collected (2322 in 2018 and 3734 in 2019), belonging to 71 species of three families. Observing several considered pests or vectors of vicious pathogens within these species was possible. The confirmed vectors of X. fastidiosa (Philaenus spumarius (Linnaeus, 1758) and Neophilaenus campestris (Fallen, 1805)) were captured in all agroecosystems and, in general, with more abundance in autumn. The highest abundance, richness, and diversity of Cicadomorpha were observed in vineyards. However, these parameters (abundance, richness and diversity) significantly differed between the agroecosystem and sampling period.Further research on how the composition of the vegetation cover shapes the Cicadomorpha community is essential to implement strategies to reduce the spread of insect‐borne pathogens if they are introduced into agroecosystems. [ABSTRACT FROM AUTHOR]

Knowledge of the response of growth parameters of almond (Badam) trees to different water supply conditions is important for Badam production. To identify growth parameters that are sensitive to water deficit in almond trees, field experiments were conducted during a median water year to monitor the major growth characteristics of almond trees under different irrigation conditions in Shache County, Xinjiang, China. A field (in-situ) monitoring system was also constructed using various sensors for the continuous and non-destructive monitoring of the growth parameters, such as soil water in the root zone, canopy temperature depression, trunk diameter, and fruit diameter of almond trees. The results confirmed the reliability of the monitoring system. Both canopy temperature depression and the diameter shrinkage of the trunk and fruit were significantly negatively correlated (r values ranging from −0.996 to −0.823) with the irrigation water quantity. This correlation was observed from the young fruit stage to the maturation stage of almond trees, under irrigation conditions representing 50–100% of crop evapotranspiration (ETc). These parameters were sensitive (|r| ≥ 0.778) to the water deficit status of almond trees from 14:00 to 18:00 in sunny weather. These results can provide both technical and theoretical support for real-time non-destructive assessment of the water deficit status of almond trees. [ABSTRACT FROM AUTHOR]

This study was carried out between 2016 and 2017 to determine the population development of Anthonomus amygdali Hustache, which is a pest in almond orchards in Gaziantep (Şahinbey), Kahramanmaraş (Pazarcık) and Adıyaman (Besni) provinces. The study used the beating method in almond orchards, where the population was followed. It was determined that A. amygdali started its flights between April and May in the region where the study was conducted and continued until the end of June. While the pest reached its highest level, with 52 units/100 knocks in Besni district on 20 May 2016, the next year, its population reached its maximum level with 44 units/100 knocks, in Besni district on 01 June 2017. Thus, the highest pest population was Besni district of Adıyaman province. The pest has also been found to be an early pest in almond orchards, feeding on the buds and flowers of almonds. [ABSTRACT FROM AUTHOR]

Commercial beekeepers transporting honey bees across the United States to provide almond pollination services have reported honey bee deaths, possibly due to pesticide applications made during crop bloom. Pesticides are often applied as "tank mixes", or mixtures of fungicides and insecticides combined into a single application. Spray adjuvants are often added to tank mixes to improve the application characteristics of a pesticide and include spreaders, stickers, or surfactants. The goal of this research was to determine toxicity of adjuvants to adult worker honey bees, both when applied alone and in adjuvant-pesticide tank mixtures. Field-relevant combinations of formulated products were applied to 3-day-old adult worker honey bees using a Potter Spray Tower, and mortality was assessed 48 h following exposure. Adjuvants tested included Activator-90, Attach, Choice Weather Master, Cohere, Dyne-Amic, Induce, Kinetic, LI 700, Liberate, Nu-Film P, PHT Latron B-1956, and Surf-90; fungicides tested include Luna Sensation (Fluopyram and Trifloxystrobin), Pristine (Pyraclostrobin and Boscalid), Tilt (Propiconazole), and Vangard (Cyprodinil), and insecticides tested include Altacor (Chlorantraniliprole), Intrepid 2F (Methoxyfenozide), and a positive control Mustang Maxx (Zeta-cypermethrin). Results demonstrated that exposure to some adjuvants causes acute honey bee mortality at near-field application rates, both when applied alone and in combination with pesticides. Some adjuvant-pesticide combinations demonstrated increased toxicity compared with the adjuvant alone, while others demonstrated decreased toxicity. A better understanding of adjuvant and adjuvant-pesticide tank mixture toxicity to honey bees will play a key role in informing "Best Management Practices" for pesticide applicators using spray adjuvants during bloom when honey bee exposure is likely. [ABSTRACT FROM AUTHOR]

A comparative genomic analysis was conducted for 171 Salmonella isolates recovered from raw inshell almonds and raw almond kernels between 2001 and 2013 and for 30 Salmonella Enteritidis phage type (PT) 30 isolates recovered between 2001 and 2006 from a 2001 salmonellosis outbreak-associated almond orchard. Whole genome sequencing was used to measure the genetic distance among isolates by single nucleotide polymorphism (SNP) analyses and to predict the presence of plasmid DNA and of antimicrobial resistance (AMR) and virulence genes. Isolates were classified by serovars with Parsnp, a fast core-genome multi aligner, before being analyzed with the CFSAN SNP Pipeline (U.S. Food and Drug Administration Center for Food Safety and Applied Nutrition). Genetically similar (≤18 SNPs) Salmonella isolates were identified among several serovars isolated years apart. Almond isolates of Salmonella Montevideo (2001 to 2013) and Salmonella Newport (2003 to 2010) differed by ≤9 SNPs. Salmonella Enteritidis PT 30 isolated between 2001 and 2013 from survey, orchard, outbreak, and clinical samples differed by ≤18 SNPs. One to seven plasmids were found in 106 (62%) of the Salmonella isolates. Of the 27 plasmid families that were identified, IncFII and IncFIB plasmids were the most predominant. AMR genes were identified in 16 (9%) of the survey isolates and were plasmid encoded in 11 of 16 cases; 12 isolates (7%) had putative resistance to at least one antibiotic in three or more drug classes. A total of 303 virulence genes were detected among the assembled genomes; a plasmid that harbored a combination of pef, rck, and spv virulence genes was identified in 23% of the isolates. These data provide evidence of long-term survival (years) of Salmonella in agricultural environments. [ABSTRACT FROM AUTHOR]

The objective of the present study was to carry out a technical study of the gasification of almond shells and husks at different temperatures and, subsequently, an economic analysis for the in situ installation of a decentralized unit to produce electricity, through a syngas generator, that would overcome the use of fossil fuels used in this agroindustry. The gasification tests were carried out at three different temperatures (700, 750 and 800 °C) and the results for the tests carried out were as follows: a 50:50 mixture of almond husks and shells was found to have a lower heating value of value of 6.4 MJ/Nm3, a flow rate of 187.3 Nm3/h, a syngas yield of 1.9 Nm3/kg, cold gas efficiency of 68.9% and carbon conversion efficiency of 70.2%. Based on all the assumptions, a 100 kg/h (100 kWh) installation was proposed, located near the raw material processing industries studied, for an economic analysis. The technical–economic analysis indicated that the project was economically viable, under current market conditions, with a calculated net present value of k€204.3, an internal rate of return of 20.84% and a payback period of 5.7 years. It was concluded that thermal gasification is a perfectly suitable technology for the recovery of raw materials of lignocellulosic origin, presenting very interesting data in terms of economic viability for the fixed bed gasification system. [ABSTRACT FROM AUTHOR]

Recent economic, environmental, and regulative concerns force farmers to precise their fertilization practices. Yet, a critical knowledge gap concerning the temporal variability in perennials' nutritional requirements renders most fertilization applications inefficient. While mass balance studies could illustrate the dynamics of crops' mineral uptake, their association to field conditions remains a challenge. Hence, we constructed an empirical framework to convert data from lysimeter studies to applicable farming information. We fitted quadratic equations to the correlations between irrigation and drainage mineral concentrations of three perennial crops—almond, avocado, and pomegranate. Then, we derived the optimal irrigation mineral composition by the interpolation point of the nitrogen, phosphorus, and potassium curves. We also matched polynomials to the relations between leaf mineral concentrations and fertilization compositions and established mineral diagnostic references for each sampling period. Repeated measures of the crops' response curves illustrated a temporal variability in their nutrient uptake, highlighting that the evergreen avocado extracts nutrients throughout winter, early blooming almond extracts nutrients in spring, and late fruiting pomegranates obtain minerals throughout summer. Moreover, the deciduous almond and pomegranate require extensive summer fertilization for the following spring's bloom. Recurrent leaf diagnosis exhibited that almond leave's optimal nitrogen concentrations drop by midsummer. Optimal phosphorus concentrations in avocado and pomegranates doubled during summer, as did the optimal potassium concentration in pomegranates' leaves. Accordingly, we established an empirical approach to process data from lysimeter studies and constructed specific fertigation assays for almond, avocado, and pomegranate trees. [ABSTRACT FROM AUTHOR]

The almond (Prunus dulcis) constriction canker caused by Diaporthe amygdali is considered one of the most important diseases of this crop in the European continent, especially in the Mediterranean countries. Field surveys conducted in Sicily, Italy, revealed the occurrence of almond trees severely infected by the disease. Symptoms of twig canker, shoot blight and gummosis were widely distributed in almond orchards grown with both local and international cultivars. The highest disease incidence and severity (DI and DS) were observed in the orchards grown with 'Ferragnes', 'Supernova' and 'Tuono' cultivars, whereas those grown with local sicilian cultivars such as 'Pizzuta' and 'Romana' showed the lowest DI and DS. Laboratory isolations yielded a total of 58 Diaporthe-like isolates. Morphological observations and molecular analysis based on sequencing and phylogenetic analyses of ITS, tef1-α and tub2 gene regions of representative isolates identified the causal agent as D. amygdali. The effect of temperature (5, 10, 15, 20, 25, 30 and 35 °C) was evaluated on mycelial growth rate on PDA and on lesion development in inoculated detached shoots, with the isolates tested showing an optimum growth temperature around 25 and 20 °C, respectively. Pathogenicity tests were conducted by means on detached almond shoots and on potted almonds plants. Results showed that all the isolates were pathogenic in all tissues evaluated showing significant differences in aggressiveness among the isolates. According to our results, this is the most updated study of constriction canker in Italy, including a molecular characterization of D. amygdali, since its first identification in 1936. [ABSTRACT FROM AUTHOR]

The plant-pathogenic bacterium Xylella fastidiosa is a major threat to agriculture and the environment worldwide. Recent devastating outbreaks in Europe highlight the potential of this pathogen to cause emergent diseases. X. fastidiosa subsp. multiplex ESVL and IVIA5901 strains that belong to sequence type 6 were isolated from almond orchards within the outbreak area in Alicante province (Spain). Both strains share more than 99% of the chromosomal sequences (average nucleotide identity), but the ESVL strain harbors two plasmids (pXF64-Hb_ESVL and pUCLA-ESVL). Here, virulence phenotypes and genome content were compared between both strains, using three strains from the United States as a reference for the phenotypic analyses. Experiments in microfluidic chambers, used as a simulation of xylem vessels, showed that twitching motility was absent in the IVIA5901 strain, whereas the ESVL strain had reduced twitching motility. In general, both Spanish strains had less biofilm formation, less cell aggregation, and lower virulence in tobacco compared with U.S. reference strains. Genome analysis of the two plasmids from ESVL revealed 51 unique coding sequences that were absent in the chromosome of IVIA5901. Comparison of the chromosomes of both strains showed some unique coding sequences and single-nucleotide polymorphisms in each strain, with potential deleterious mutations. Genomic differences found in genes previously associated with adhesion and motility might explain the differences in the phenotypic traits studied. Although additional studies are necessary to infer the potential role of X. fastidiosa plasmids, our results indicate that the presence of plasmids should be considered in the study of the mechanisms of pathogenicity and adaptation in X. fastidiosa to new environments. [ABSTRACT FROM AUTHOR]

This study examined the level of knowledge, attitude, and practice toward organic fertilizer adoption in Uruzgan, Afghanistan. A total of 116 structured questionnaires were distributed to almond smallholder farmers in the Tarin Kowt district. The results revealed a medium level of knowledge and attitude, and a high level of practice toward organic fertilizer adoption among the almond smallholder farmers. The finding showed that 97.4% of the farmers used cow manure and 20.7% used poultry manure. About 62.9% of the farmers used 0.67-1.08 tons of organic fertilizer per acre and all (100%) farmers used it in the fall season. The result further showed that friends, family members and radio are the main sources of information. The major problems limiting almond production were pests and disease, limited access to certified almonds varieties, limited access to organic fertilizers, lack of market availability for almonds and limited access to extension services. This research provides indicators of organic and inorganic fertilizer use, as well as insights for policymakers to better consider the sustainable application of organic fertilizer and its adoption among farmers in order to achieve sustainable development. [ABSTRACT FROM AUTHOR]

The purpose of the research was to identify the physiological–biochemical and anatomical–morphological peculiarities found during in vitro cultivation of Corylus avellana L. and Prunus dulcis (Mill.) D.A.Webb, which occur as a result of the action of trophic and phytohormonal determinants. The research was conducted on three hazelnut varieties (Trapezund, Jefferson, Tonda Gentile Romana) and four almond varieties (E5 Borozan, M41 Alex, Georgia, Louise). A theoretical and experimental rationale for their use in the microclonal propagation of these cultures has been developed. The effectiveness of the preparatory stage before introduction into aseptic conditions for growing mother plants in closed soil conditions with scattered artificial lighting and microbiological protection has been proven. This reduced self-intoxication by oxidation products with phenol-like substances and microflora contamination of primary explants. Among the nutrient media compared, the best was Nas and Read (NRM) for hazelnuts and Nas Almond Medium (NAM) for almonds. Passaging on the same media leads to a decrease in regeneration indicators. In regenerants of almonds, the rosette of the shoots was noted, and in hazelnuts, the death of apical buds was also found. To prevent this, alternating NRM and driver and kuniyuki walnut (DKW) media for hazelnuts and NAM and Quirin and Lepoivre (QL) for almonds was effective. Long-term cultivation on media with a high content of synthetic analogues of phytohormones leads to the accumulation of phytotoxic effects with each subsequent passage. The phytotoxic effect of cytokinins was manifested in hyperhydration of shoots and of auxins in callus fertilisation. On comparing the ontogenesis of regenerants from explants isolated from mother plants aged 30–180 days, it was found that the optimal age for hazelnut and almond was 90 days. To reset the trophic and hormonal determinants, the introduction of explant donors into a state of dormancy has been successfully used. At the final fourth stage of microclonal propagation, in order to adapt plants simultaneously with an increase in the number of regenerants, it is effective to use the photoautotrophic method of microclonal propagation with intensive lighting and air enriched with carbon dioxide. For the transition of plants from conventional heterotrophic propagation to autotrophic cultivation, an intermediate stage of pre-adaptation of regenerants in wet chamber conditions is effective. [ABSTRACT FROM AUTHOR]

Maximizing water use efficiency, yield, and plant survival under drought is a relevant research issue for almond-tree-growing areas worldwide. The intraspecific diversity of this species may constitute a valuable resource to address the resilience and productivity challenges that climate change poses to crop sustainability. A comparative evaluation of physiological and productive performance of four almond varieties: 'Arrubia', 'Cossu', 'Texas', and 'Tuono', field-grown in Sardinia, Italy, was performed. A great variability in the plasticity to cope with soil water scarcity and a diverse capacity to adapt to drought and heat stresses during fruit development were highlighted. The two Sardinian varieties, Arrubia and Cossu, showed differences in water stress tolerance, photosynthetic and photochemical activity, and crop yield. 'Arrubia' and 'Texas' showed greater physiological acclimation to water stress while maintaining higher yields, as compared to the self-fertile 'Tuono'. The important role of crop load and specific anatomical traits affecting leaf hydraulic conductance and leaf gas exchanges efficiency (i.e., dominant shoot type, leaf size and roughness) was evidenced. The study highlights the importance of characterizing the relationships among almond cultivar traits that affect plant performance under drought in order to better assist planting choices and orchard irrigation management for given environmental contexts. [ABSTRACT FROM AUTHOR]

There is a controversy regarding when it is appropriate to apply the irrigation restriction in almond trees (Prunus dulcis Mill.) to save water without penalizing yield. We hypothesized that knowing when plants demand fewer photoassimilates would be a good indicator of less sensitivity of the crop to water deficit. One parameter that defines the photosynthetic capacity is the triose phosphate utilization (TPU). Due to its connection to the export of sugars from the leaves to other sink organs, it is a good candidate for being such an indicator. The objective was to analyze the seasonal evolution of the photosynthetic capacity of three almond cultivars (cvs Guara, Marta and Lauranne) subjected to water stress during vegetative, kernel-filling and postharvest stages. Two sustained deficit irrigation (SDI) treatments (SDI75 and SDI65 with water reductions of 25 and 35%, respectively) and a control treatment (FI) consisting of fully irrigated trees were applied. The response of curves AN-Ci was analyzed to assess the maximum carboxylation rate (Vcmax), maximum rate of electron transport (Jmax), TPU and mesophyll conductance to CO2. In addition, leaf water potential and yield were measured. Our experimental findings showed any significant differences in the variables analyzed among cultivars and irrigation treatments. However, consistent differences arose when the results were compared among the phenological stages. During the kernel-filling and the postharvest stages, a progressive limitation by TPU was measured, suggesting that the demand for photoassimilates by the plant was reduced. This result was supported by the correlation found between TPU and fruit growth rate. As a consequence, a downregulation in Jmax and Vcmax was also measured. This study confirms that the kernel-filling stage might be a good time to apply a reduction in the irrigation and suggests a method to detect the best moments to apply a regulated deficit irrigation in almond trees. [ABSTRACT FROM AUTHOR]

Monitoring the performance of a predator long‐term reared on a non‐prey diet when switches to a prey is extremely important to have a successful biological control program. In the current study, the efficacy of Neoseiulus cucumeris Oudemans long‐term reared on almond pollen during 30 generations in encountering with its natural prey, Tetranychus urticae Koch was evaluated under laboratory conditions. Every 10 generations (G1, G10, G20 and G30), the development, reproduction, population growth potential and predation capacity of the predator were determined after exposure to the natural prey, for one (S1), three (S3) or five (S5) successive generations. The results indicated that the pre‐adult duration of N. cucumeris before diet switching did not differ from those after diet switching in G1, G20 and G30. Similarly, the values of the intrinsic rate of increase (r) and finite rate of increase (λ) were not significantly affected by the diet switching in all generations tested. Furthermore, there was no significant difference in pre‐adult duration between the individuals reared on natural prey for one generation or more in all generations tested, except for G1. Continuous feeding on the prey for five generations (G1‐S5 and G30‐S5) significantly reduced the fecundity compared with those reared for three generations (G1‐S3 and G30‐S3). We found that continuous feeding on natural prey for three or five generations after different periods of feeding on almond pollen did not significantly change the most important life history traits and predation capacity. In other words, the overall performance of the mass‐reared predator remained effective after exposure to natural prey for five generations. It can be concluded that almond pollen is a good food source for the rearing of N. cucumeris because the population growth potential and reproduction of the predator remained constant during the long‐term rearing and after switching to the natural prey. [ABSTRACT FROM AUTHOR]

Canker symptoms were observed on almond trees in the Fez-Meknes region, Morocco. Isolations were conducted from the infected branch and trunk showing internal and external brown lesions. Four representative fungal isolates were screened, and their identities were confirmed by cultural traits and sequence analysis of DNA using two genes, the ITS region (internal transcribed spacer) and calmodulin (cmdA). The identified fungi were Curvularia hawaiiensis, Fusarium ambrosium, Lasiodiplodia theobromae, and Chondrestereum purpureum. The pathogenicity test on almond twigs revealed that these species were pathogenic to their host with different degrees of virulence, with Lasiodiplodia theobromae as the most virulent causing the longest necrotic lesion (285.17 mm) and the death of twigs. Physiological traits analysis of the above-mentioned fungi showed that the optimum mycelium growth response at different temperatures varies from 10 to 35 °C, while the pH ranges between 3.0 and 8.0. This study confirms the presence of canker pathogens on almond trees, which will contribute valuable information to improve the understanding of the contemporary status of almond trees, thus helping the improvement of the management of almond orchards. To our knowledge, all these fungi represent new records in Morocco and some of them are confirmed on the almond trees for the first time in the world. [ABSTRACT FROM AUTHOR]

Flowering crops are heavily managed during bloom to both promote pollination and prevent disease. Disease management practices can alter the floral microbiome, including pathogens and nontarget microbes. However, whether agrochemical presence or altered microbiome composition affect pollinator foraging and pollination services is unclear.We assessed effects of orchard management tactics and landscape context on the flower microbiome in almond, Prunus dulcis. Fourteen orchards (five conventional, four organic and five conventional with habitat augmentation) were sampled at early and peak bloom to characterize bacterial and fungal communities associated with floral tissues. The surveys were complemented by an artificial flower experiment to assess effects of fungicides and microbes on honey bee foraging. Finally, a field trial was conducted to test effects of fungicides and microbes on pollination.As bloom progressed, bacterial and fungal abundance and diversity increased across all floral tissue types and management strategies. The magnitude by which microbial abundance and diversity were affected varied, with proximity to apiaries and orchard management having notable effects on bacteria and fungi respectively.Experiments revealed that fungicides reduced nectar removal by honey bees; however, neither fungicide nor microbe treatments affected pollination, as measured through pollen tube initiation and growth.Synthesis and applications. Our results reveal that microbiota associated with flowers of a pollinator‐dependent crop are temporally dynamic and sensitive to management practices. However, pollination services in almond may be resilient to both agrochemical disturbance and microbial augmentation of flowers, the latter of which may become more prominent as microbial solutions to disease management are embraced in agroecosystems. [ABSTRACT FROM AUTHOR]

In drought years, almond growers have to restrict fresh water application, either stressing the trees with inadequate water or adding saline water and reducing water stress but causing salt stress. Tree response to combined water and salt stress are critical consideration on management decisions but there is no appropriate information currently. That's why, it was investigated the water and salt stress and combined water-salt stress on two almond varieties in a two year (2015 and 2016) outdoor experiment with young trees. Trees were 1 year old at the beginning of the experiment. The experiment was conducted USDA (United States Department of Agriculture) Salinity Laboratory, Riverside, California, USA. Drought treatments consisted of 100%, 80% and 60% of tree evapotranspiration (ET) and salt treatments of Electrical Conductivity (EC= 0.55, 1.20, 2.40 and 3.0 dS m-1), for a total of 120 trees in twelve treatments with two varieties and five replicates. We examined water use, trunk diameter and physiological parameters (leaf net photosynthetic rate, stomatal conductance and leaf water potential). Photosynthetic rate values (Pn) ranged between 3.53 and 11.08 µmol CO2 m-2 s-1 for Nonpareil and 4.58 and 9.48 µmol CO2 m-2 s-1 for Aldridge. Stomatal conductance values ranged between 0.076 and 0.283 mol H2O m-2 s-1 for Nonpareil and 0.097 and 0.302 for Aldridge. All parameters showed significant decline starting at 80% water application and EC 1.2 dS m-1. In terms of growth rather than survival, almond was sensitive to water as well as salt stress. We evaluated combined stress using three stress response models: additive stress, dominant stress model and a multiplicative stress model where the predicted growth loss is obtained by multiplying the relative growth response for the individual stresses. Equation (2) for reduction in trunk growth were developed for treatments with either salinity only or water only stress. Both varieties grafted to Nemaguard rootstock were very sensitive to salinity with growth loss starting at EC 1.2 dS m-1. The results indicate that the Nonpareil is more sensitive to drought and salt stress than Aldridge. Aldridge almond variety can be recommended for areas where water supplies are scarce and salinized. [ABSTRACT FROM AUTHOR]

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Monitoring pesticide exposures in honey bees provides fundamental risk information that informs efforts to improve regulatory policy, pesticide use, and beekeeping management so pollinators are protected in realistic field conditions. We investigated pesticide exposures to bee colonies while colonies moved along commercial migratory routes in 2022 and 2023 to pollinate multiple pollinator-dependent, high-value U.S. specialty crops (e.g., almonds in California and apples and cherries in Washington). We found evident pesticide exposure patterns, including increasing exposures (both levels and number of pesticides) to fungicides during almond pollination, higher exposures to insecticides and persistent exposures to fungicides during springtime fruit pollination, and declining exposures in summer. Exposure risk assessment by risk quotient (RQ) model based on residues in bee bread indicates no concern of acute toxicity to adult honey bees during pollination, however, during colony inspections we found severe brood mortality in fields associated with high exposure to buprofezin, an insect growth regulator (IGR) thought to be safe for adult bees, which is permitted for use any time across the season. Our results suggest a need to improve compliance with insecticide label requirements during tree fruit pollination and a need for further research into the negative impacts of IGR on colony health especially on immature bees to inform potential policy changes. [Display omitted] • Pesticide exposures in honey bees exhibit a seasonal pattern in the northwestern U.S. • The risk of pesticide exposures is most severe during spring fruit pollination. • Insect growth regulators, a class of unregulated insecticides, threaten bee health. • California policy and conservation efforts reduce insecticide exposures in pollinators. [ABSTRACT FROM AUTHOR]