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Spatiotemporal patterns of plant water uptake, loss, and storage exert a first-order control on photosynthesis and evapotranspiration. Many studies of plant responses to water stress have focused on differences between species because of their different stomatal closure, xylem conductance, and root traits. However, several other ecohydrological factors are also relevant, including soil hydraulics, topographically driven redistribution of water, plant adaptation to local climatic variations, and changes in vegetation density. Here, we seek to understand the relative importance of the dominant species for regional-scale variations in woody plant responses to water stress. We map plant water sensitivity (PWS) based on the response of remotely sensed live fuel moisture content to variations in hydrometeorology using an auto-regressive model. Live fuel moisture content dynamics are informative of PWS because they directly reflect vegetation water content and therefore patterns of plant water uptake and evapotranspiration. The PWS is studied using 21,455 wooded locations containing U.S. Forest Service Forest Inventory and Analysis plots across the western United States, where species cover is known and where a single species is locally dominant. Using a species-specific mean PWS value explains 23% of observed PWS variability. By contrast, a random forest driven by mean vegetation density, mean climate, soil properties, and topographic descriptors explains 43% of observed PWS variability. Thus, the dominant species explains only 53% (23% compared to 43%) of explainable variations in PWS. Mean climate and mean NDVI also exert significant influence on PWS. Our results suggest that studies of differences between species should explicitly consider the environments (climate, soil, topography) in which observations for each species are made, and whether those environments are representative of the entire species range.

Dehydration and tomato spotted wilt virus (TSWV) infection substantially impact the feeding of western flower thrips, Frankliniella occidentalis. Until now, the dynamics between these biotic and abiotic stresses have not been examined for thrips. Here, we report water balance characteristics and changes in other biological parameters during infection with TSWV for the western flower thrips. There were no apparent differences in water balance parameters during TSWV infection of male or female thrips. Our results show that, although water balance characteristics of western flower thrips are minimally impacted by TSWV infection, the increase in feeding and activity when dehydration and TSWV are combined suggests that virus transmission could be increased under periods of drought. Importantly, survival and progeny generation were impaired during TSWV infection and dehydration bouts. The negative impact on survival and reproduction suggests that the interactions between TSWV infection and dehydration will likely reduce thrips populations. The opposite effects of dehydration on feeding/activity and survival/reproduction for virus infected thrips suggest the impact of vectorial capacity will likely be minor for TSWV transmission. As water stress significantly impacts insect-plant-virus dynamics, these studies highlight that all interactions and effects need to be measured to understand thrips-TSWV interactions in their role as viral vector to plants.

The countries within the Nile Basin have become increasingly water stressed with each passing year due to the intensification of climate change, and disagreements about water allocation rights between these countries only exacerbate the issue. For about a century, Ethiopia and Egypt have been quarrelling over rights to the Nile’s waters with no resolution in sight. In 2011, Ethiopia began construction of the Grand Ethiopian Renaissance Dam (GERD), which increased tensions. As of 2023, the dam’s construction was completed but negotiations have made no meaningful progress. The dam worsens political relations but impacts the environment, economy, and society in both positive and negative ways. Considering these impacts and the example of the demolition of the Klamath River dams, it was determined that dam demolition would be the most beneficial and equitable course of action, in the long run, for all the Nile River riparian countries. A policy memo was then constructed advocating for demolition of the GERD.

Nitrogen deposition and drought significantly influence plant growth and soil physicochemical properties. This study investigates the effects of nitrogen deposition and water stress on the growth and physiological responses of Quercus dentata , and how these factors interact to influence the overall productivity. Two-year-old potted seedlings were selected to simulate nitrogen deposition and water stress. Nitrogen was applied at rates of 0 kg·ha-1·year-1 (N0) and 150 kg·ha-1·year-1 (N150). The levels of water stress corresponded to 80% (W80), 50% (W50), and 20% (W20) of soil saturation moisture content. High nitrogen (N150) significantly increased stem elongation and stem diameter by enhancing photosynthetic parameters, including P n (W80) and G s (W50), and maintained higher water use efficiency. Under drought conditions, nitrogen enhanced leaf water content, stabilized electrical conductivity, regulated antioxidant enzyme activity, and increased the accumulation of proline. However, under severe drought, nitrogen did not significantly improve biomass, highlighting the critical role of water availability. Additionally, increased nitrogen levels enhanced soil enzyme activity, facilitated the uptake of crucial nutrients like K and Zn. Mantel tests indicated significant correlations between soil enzyme activity, water use efficiency, and leaf Fe content, suggesting that nitrogen deposition altered nutrient uptake strategies in Q. dentata to sustain normal photosynthetic capacity under water stress. This study demonstrates that nitrogen deposition substantially enhances the growth and physiological resilience of Q. dentata under W50 by optimizing photosynthetic efficiency, water use efficiency, and nutrient uptake. However, the efficacy of nitrogen is highly dependent on water availability, highlighting the necessity of integrated nutrient and water management for plant growth. [ABSTRACT FROM AUTHOR]

Precision field management and modeling crop growth requires precise, efficient, timely, nondestructive, and cost-effective measurements of structural component including leaf area index (LAI) and leaf orientation based on the foliage mean tilt angle (MTA), which is defined as the average leaf inclination angle of a canopy. Two experiments were carried out to investigate 1) the influence of different nitrogen (N) fertigation levels and 2) cycles of water deficit on leaf orientation (specifically, MTA) of young tomato (Solanum lycopersicum cv. Florida 47). N rates were 10, 50, 100, 200, and 300 mg·L-1 (mg N per liter of water) and irrigation treatments were well-watered and deficit irrigation. MTA was measured using the LAI-2200C Plant Canopy Analyzer. Across the experimental period, low N supply to leaves reduced the angle between leaf petiole and stem (high MTA) and produced plants with more erect leaves compared with N-sufficient plants. The MTA for the 10 mg·L-1-N treatment ranged from 54.3° to 73.6° and higher levels of N (50 to 300 mg·L-1-N) had MTA between 36.4° and 51.9°. Compared with lower N level (10 mg·L-1), LAI of tomato plants fertigated with a nutrient solution containing 300 mg·L-1-N increased by 3.6- to 4.9-fold across the study period. Similarly, canopy normalized difference vegetation index (NDVI) and leaf N% values at 300 mg·L-1-N were 2- to 3-fold higher than at 10 mg·L-1-N. However, MTA did not consistently differ across the 100 to 300 mg·L-1-N rates. In terms of water treatments, MTA of well-watered plants ranged from 32.3° to 40.5° whereas the same plants at water-deficit level had MTA between 45.7° and 51.8°. Although the relationship between MTA and canopy LAI, NDVI as well as leaf N was inconsistent or not significant under well-watered and water-deficit conditions, leaf gas exchange components (photosynthesis, stomatal conductance, and transpiration) showed a significant negative relationship (R², 0.39-0.81, P < 0.001) with MTA. Overall, leaf orientation, specifically MTA, was modulated by N levels (highest at 10 mg·L-1; lowest at 300 mg·L-1-N) and cycles of water deficit and therefore, MTA determination hold promise as a nondestructive method to assess N and water deficit in young tomato plants. [ABSTRACT FROM AUTHOR]

Brassica napus L. plants are sensitive to water stress conditions throughout their life cycle from seed germination to seed setting. This study aims at identifying quantitative trait loci (QTL) linked to B. napus tolerance to water stress mimicked by applications of 10% polyethylene glycol-6000 (PEG-6000). Two doubled haploid populations, each consisting of 150 genotypes, were used for this research. Plants at the two true leaf stage of development were grown in the absence (control) or presence (stress) of PEG-6000 under controlled environmental conditions for 48 h, and the drought stress index was calculated for each genotype. All genotypes, along with their parents, were genotyped using the Brassica Infinium 90K SNP BeadChip Array. Inclusive composite interval mapping was used to identify QTL. Six QTL and 12 putative QTL associated with water stress tolerance were identified across six chromosomes (A2, A3, A4, A9, C3, and C7). Collectively, 2154 candidate genes for water stress tolerance were identified for all the identified QTL. Among them, 213 genes were identified as being directly associated with water stress (imposed by PEG-6000) tolerance based on nine functional annotations. These results can be incorporated into future breeding initiatives to select plant material with the ability to cope effectively with water stress. [ABSTRACT FROM AUTHOR]

Male and female dioecious plants often show sexual dimorphism, differing in morphological, physiological and life‐history traits. Most previous studies have focused on differences between males and females during or after reproduction, paying little attention to the pre‐reproductive stages of the individuals.Here we assessed the response of male and female individuals of the dioecious plant Silene latifolia to abiotic stress at different life stages, including pre‐reproductive (i.e. seedlings and young plants) and reproductive individuals. We measured growth, resource allocation and discrimination against 13C under nutrient deficiency, water stress, as well as their interaction.We observed sexual dimorphism in root growth, with female seedlings having longer main roots than male plants. Pre‐reproductive male and female plants also responded differently, in terms of root allocation, to nutrient and water availability. At reproduction, females grew more roots than males when water was not limiting. These differences could help explain the female‐skewed sex ratios found in natural populations of S. latifolia. We found no evidence of sexual dimorphism in aboveground dry mass, although females had longer leaves than males at the seedling stage.We conclude that sexual dimorphism in S. latifolia may occur not as a consequence of reproduction, but well before it. [ABSTRACT FROM AUTHOR]

The investigation of the response mechanisms of Cyperus esculentus to water and salt stresses is crucial for the enhancement of the productivity of saline soils. Previous studies have indicated that plant hormones, antioxidant systems, and osmoregulation may contribute to the stabilization of yield. However, the contributions and interactions of these mechanisms remain poorly understood under combined water and salt stress in natural environments. A dual-factor (salt and water) orthogonal test was used to investigate the growth and biochemical responses of C. esculentus, under combined salt and water stress in a field experiment conducted on a typical saline area in northern China. The findings reveal that C. esculentus adjusted its biomass allocation strategies and activated hormone responses, antioxidant system, and osmoregulation mechanisms to maintain stable yield. Due to the negative synergism when salt and water stress coexist, the homogeneous limitations of both are weakened. Thus, the key to maintaining yields under combined water and salt stress may depend on indirectly enhancing tolerance to oxidative damage through abscisic acid, rather than focusing on accumulating low molecular weight osmoregulants and antioxidant enzymes to directly alleviate homogeneous limitations. Also, under combined salt and water stress, insufficient irrigation may have a greater impact on morphological characteristics than high salinity. The above results contribute to a deeper understanding of the process of adapting C. esculentus to combined salt and water stress. [ABSTRACT FROM AUTHOR]

Anthropogenic activities such as cattle grazing and forest clearing have led to the establishment of early successional grass layers in some native forests, which may inhibit or entirely prevent native tree regeneration. We hypothesize that increased grass coverage reduces or eliminates the establishment of native tree seedlings by limiting water availability to seeds and seedlings. This study aims to evaluate the impact of grass cover on tree seedling survival under varying levels of soil water stress. We conducted a field experiment using 36 experimental exclosures in two northwest Patagonian valleys, representing a regional gradient in altitude, rainfall, and tree canopy openness. Additionally, a greenhouse experiment was performed with 36 pots, manipulating four levels of grass cover and three levels of water stress. Results from both experiments showed similarities: in the field, the likelihood of finding a live tree seedling was approximately 2.78 times higher in areas without grass compared with grass‐covered sites. In the greenhouse, the presence of grass reduced the final number of established seedlings by an average of 43% across all irrigation levels, indicating significant water competition. These findings suggest that management practices promoting grass invasion could severely hinder tree regeneration in forests not adapted to large herbivore intensive grazing. Such situation may be exacerbated in regions suffering water limitation in the growing season or where the climate change would intensify water stress. [ABSTRACT FROM AUTHOR]

The remobilization of stored assimilates from stems to seeds plays a pivotal role in augmenting barley yield, particularly under water stress conditions. This study examines the molecular mechanisms underlying stem reserve utilization by conducting a comparative analysis of the proteome and metabolome across three barley contrasting genotypes: Yousef, Morocco, and PBYT17. Evaluations were performed at 21 and 28 days after anthesis (DAA) under both water stress and control conditions. The results indicate that the Yousef genotype exhibits superior remobilization of stem reserves, thereby demonstrating its potential to thrive even in adverse environmental conditions. Utilizing advanced quantitative proteomics and targeted metabolomics, this investigation identified a significant number of metabolites and proteins exhibiting differential accumulation across the genotypes. Specifically, 17 metabolites and 1580 proteins were catalogued, highlighting the intricate biochemical responses to water stress. Noteworthy enzymes such as sucrose synthase, inositol monophosphatase 3, and galactokinase were found to be closely associated with remobilization efficiency. In the drought-tolerant genotype, these enzymes maintained stable levels, in stark contrast to the decline observed in the susceptible genotype. This stability is crucial for promoting seed development through ascorbic acid synthesis and for mitigating oxidative stress, which is exacerbated by drought conditions. The elevated levels of certain metabolites, including glucose 6-phosphate, and UDP-glucose, in the drought-tolerant genotype suggest a robust mechanism for maintaining signalling molecules for carbon availability, which is then instrumental in regulating plant growth and seed size development. The findings from this study strongly imply that the drought-tolerant genotype, through enhanced antioxidant capacity, can effectively produce energy-rich storage compounds, thereby optimizing carbon allocation under water stress. Such insights are invaluable for future breeding strategies aimed at improving barley resilience in the face of climate variability. [ABSTRACT FROM AUTHOR]

Environmental change requires more crop production per water use to meet the rising global food demands. However, improving crop intrinsic water use efficiency (iWUE) usually comes at the expense of carbon assimilation. Sorghum is a key crop in many vulnerable agricultural systems with higher tolerance to water stress (WS) than most widely planted crops. To investigate physiological controls on iWUE and its inheritance in sorghum, we screened 89 genotypes selected based on inherited haplotypes from an elite line or five exotics lines, containing a mix of geographical origins and dry versus milder climates, which included different aquaporin (AQP) alleles. We found significant variation among key highly heritable gas exchange and hydraulic traits, with some being significantly affected by variation in haplotypes among parental lines. Plants with a higher proportion of the non-stomatal component of iWUE still maintained iWUE under WS by maintaining photosynthetic capacity, independently of reduction in leaf hydraulic conductance. Haplotypes associated with two AQPs (SbPIP1.1 and SbTIP3.2) influenced iWUE and related traits. These findings expand the range of traits that bridge the trade-off between iWUE and productivity in C4 crops, and provide possible genetic regions that can be targeted for breeding. [ABSTRACT FROM AUTHOR]

Given the challenges posed by climate change and population growth, Iraq faces increasing demands for food production and water resources. To enhance agricultural productivity and optimize water management for crop efficiency, this study evaluated various wheat varieties, specifically Mawaddah, Bohuth 10, Aba99, and Babel113, under different irrigation level. These level were based on depletion levels of available water at 40%, 55%, and 70%. Key metrics measured included actual evapotranspiration, water use efficiency (WUE), grain yield, spike number, grains per spike, and the weight of 100 grains over the growing seasons of 2022–2023 and 2023–2024. The findings revealed that water consumption varied with depletion levels for all wheat varieties, amounting to 435.53, 397.13, and 365.13 mm season-1, and 465.7, 422.10, and 385.40 mm season-1 for the respective depletion levels of 40%, 55%, and 70%, across the two seasons. WUE ranged from 1.01 for Babel 113 at the 70% depletion level to 1.85 for Bohuth and Mawaddah at the 40% depletion level. Among the plant traits, Mawaddah had the best performance at the 40% depletion level, while Babel113 had the lowest performance at the 75% depletion level. The drought sensitivity index varied among the varieties due to their genetic differences. Our research supports the feasibility of utilizing water at depletion levels up to 75% when cultivating drought-tolerant wheat varieties in semi-arid and arid conditions. [ABSTRACT FROM AUTHOR]

Pigeon pea (Cajanus cajan (L.) Millsp.), a potential legume as an economic source of protein, is commonly cultivated in tropical and subtropical regions of the world. It possesses medicinal properties and acts as a cash crop, benefiting low-income farmers economically. The identification of pigeon peas exhibiting drought tolerance has become crucial in addressing water scarcity issues in the agriculture sector. In addition, exploring the genetic diversity among genotypes is important for conservation, management of genetic resources, and breeding programs. The aim of this study was to evaluate the morpho-physiological and biochemical responses of selected pigeon pea genotypes under pot-induced water stress conditions through different field capacities as well as the genetic diversity using start codon targeted (SCoT) markers. A significant variation was observed for the physiological traits studied. The accumulation of fresh weight (FW) and dry weight (DW) was significantly reduced in moderate and severe drought stress conditions. The lowest % DW decrease was found in LM (35.39%), KAT (39.43%), and SM (46.98%) than other genotypes at severe drought stress. Analyses of physiological responses including the photosynthetic efficiency (Phi2), the chlorophyll content (SPAD), and the relative water content (RWC) revealed positive and negative correlations with various parameters, reflecting the impact of drought stress on the chlorophyll content. The results revealed that biochemical traits including the total phenolic content, soluble sugars, proline, total protein, total amino acids, and free amino acids were variably and significantly increased under water stress. Antioxidant enzyme activity levels, specifically ascorbate peroxidase (APX) and catalase, varied among the genotypes and in response to severe water stress, offering further insights into adaptive responses. The eight genotypes analysed by use of 20 SCoT markers revealed 206 alleles and an average of 10.3 alleles per locus. Genetic similarity ranged from 0.336 to 0.676, clustering the pigeon pea genotypes into two major groups by the unweighted pair group method of arithmetic averages (UPGMA) cluster analysis. Principal coordinate analysis (PCoA) explained 43.11% of genetic variation and based on analysis of molecular variance, a high genetic variation (80%) within populations was observed, emphasizing the potential for genetic improvement. Among the eight genotypes studied, LM and KAT were drought tolerant and genetically diverse and therefore could be used as parents for developing drought tolerance in pigeon pea. [ABSTRACT FROM AUTHOR]

In the present work, a subset extracted from a core collection of common beans (Phaseolus vulgaris L.) landrace accessions from the Lazio region in central Italy was used to identify the most suitable drought-tolerant or -susceptible genotypes. By applying several morpho-physiological and agronomic selection criteria recommended by the available literature, we conducted a pre-screening experiment under controlled conditions on a primary group of 24 landraces. These landraces were chosen to represent the diversity in the Lazio region in terms of geographical provenance, elevation, landform, growth habit, customary water management in the field, and native gene pool. Pre-screening under controlled conditions allowed us to identify two subsets of landraces: one exhibiting the most drought-tolerance and one showing the most susceptibility to drought. These two subsets were then tested in field trials using two water treatments, i.e., normal irrigation versus no irrigation. Such field experiments were simultaneously conducted at two sites within the Lazio region, deliberately chosen to maximize their differences in terms of pedo-climatic conditions. This notwithstanding, the core findings from the two separate field experiments were remarkably consistent and coherent among each other, highlighting a notable degree of variability within the group of the tested landraces. In general, the morpho-physiological traits considered were found to be less responsive to water shortage than yield parameters. A statistically significant Landrace × Treatment interaction was found for almost all the yield parameters considered, suggesting that certain genotypes are more susceptible than others to water shortage. By taking into account the concept of "yield stability", i.e., the ability to maintain comparatively high yields even under conditions of water scarcity, certain common bean landraces were found to be the most promising, in terms of drought tolerance. Two genotype pairs, in particular, could be of interest for studying the morpho-physiological and molecular mechanisms underlying drought tolerance in common bean, as well as for identifying quantitative trait loci associated with water scarcity, which could be beneficially employed in breeding programs. The results reported here also suggest that pre-screening under laboratory conditions, followed by targeted field trials, can constitute a reliable, efficient, and resourceful combined approach, in which morpho-physiological traits measured on juvenile plants might play a role in predicting drought tolerance at the agronomic level. [ABSTRACT FROM AUTHOR]

The main role of the nucleolus is ribosomal biogenesis, but it also responds to stress with changes in number, area, and/or morphology. Nucleoli with transcriptionally active ribosomal RNA genes are selectively stained by silver nitrate. Hypothesising that fire recurrence and/or polyethylene glycol (PEG)-induced water stress would cause nucleolar changes in Pinus pinaster roots, nucleolar parameters were analysed upon the germination of seeds harvested in post-fire naturally regenerated stands with different fire regimes. An unburned stand was used as a control. The nucleoli number varied from 1 to 15 among stands and PEG treatments, but a mode of five or six nucleoli was found. The number of nucleoli per interphase (N) increased (p < 0.001) with fire recurrence (stand effect). Increasing PEG concentration (treatment effect) decreased the nucleoli number, notably in the stand with the highest fire recurrence. The nucleolar area decreased (p < 0.001) with increased nucleoli number, fire recurrence, and/or PEG concentration. Fire recurrence and water scarcity are forecasted for future climate scenarios. As demonstrated earlier, these factors could influence protein synthesis or the cell cycle's regularity, which are crucial processes for root growth and pine seedling establishment. Furthermore, this work revealed that nucleolar parameters could be suitable biomarkers for pine stress studies. [ABSTRACT FROM AUTHOR]

Surging water demand necessitates strategic water management to maintain efficiency and accessibility. In Thailand's Eastern Economic Corridor Project, water demand escalated from 2005 to 2018 by 54%, prompting water management plans using pipe diversion. However, this plan merely shifts scarcity issues due to limitations and climate uncertainties. The Water Stress Index assessed the impact using distributed hydrological modelling, revealing the 3Rs scenario, and a dry season rice cultivation lowered by 26%. Specific basins still face extreme stress. Integrating scenarios can refine and alleviate stress, suggesting a combined scenario approach, improving Water Stress Index and efficiently identifying vital water reduction strategies. [ABSTRACT FROM AUTHOR]

The worldwide demand for the development of drought-tolerant coffee plants is increasing due to the impacts global climate changes have caused in large and small coffee plantations throughout the world. Thus, the genetic improvement of the coffee plant has become indispensable for the continuity and rentability of this agricultural culture. For this, the coffee genetic improvement programs require morphological and physiological information concerning the plants in their germplasm banks to serve as subsidies for the development of cultivars. The current study aims to emphasize the importance of characterizing the genetic material of the coffee plants in the germplasm banks. By way of a literature review, it considered the impact of drought on some aspects of coffee plant physiology and morphology, and the need for genetic improvement programs to understand their germplasm to use it as a starting point in the development of cultivars that mitigate the production losses caused by drought. [ABSTRACT FROM AUTHOR]

The integration of remote sensing technology and machine learning algorithms represents a new research direction for the rapid and large-scale detection of water stress in modern agricultural crops. However, in solving practical agricultural problems, single machine learning algorithms cannot fully explore the potential information within the data, lacking stability and accuracy. Stacking ensemble learning (SEL) can combine the advantages of multiple single machine learning algorithms to construct more stable predictive models. In this study, threshold values of stomatal conductance (gs) under different soil water stress indices (SWSIs) were proposed to assist managers in irrigation scheduling. In the present study, six irrigation treatments were established for winter wheat to simulate various soil moisture supply conditions. During the critical growth stages, gs was measured and the SWSI was calculated. A spectral camera mounted on an unmanned aerial vehicle (UAV) captured reflectance images in five bands, from which vegetation indices and texture information were extracted. The results indicated that gs at different growth stages of winter wheat was sensitive to soil moisture supply conditions. The correlation between the gs value and SWSI value was high (R2 > 0.79). Therefore, the gs value threshold can reflect the current soil water stress level. Compared with individual machine learning models, the SEL model exhibited higher prediction accuracy, with R2 increasing by 6.67–17.14%. Using a reserved test set, the SEL model demonstrated excellent performance in various evaluation metrics across different growth stages (R2: 0.69–0.87, RMSE: 0.04–0.08 mol m−2 s−1; NRMSE: 12.3–23.6%, MAE: 0.03–0.06 mol m−2 s−1) and exhibited excellent stability and accuracy. This research can play a significant role in achieving large-scale monitoring of crop growth status through UAV, enabling the real-time capture of winter wheat water deficit changes, and providing technical support for precision irrigation. [ABSTRACT FROM AUTHOR]

Biofertilizers constitute a safe way to alleviate the impacts of water shortage and the overload of chemical fertilizers. This work focuses on the effects of Arbuscular Mycorrhizal Fungi (AMF) and Plant Growth-Promoting Rhizobacteria (PGPR) on potato's agro-physiological response, beneath the reduction of water, nitrogen (N), phosphorous (P) and potassium (K) fertilizers. Five microbioal treatments (C: Control, AMF: Mycorhizae, B1: Bacillus halotolerans , B2: Bacillus amyloliquefaciens and B1B2: B. halotolerans + B. amyloliquefaciens) were tested in arrangement with two nitrogen-phosphorous-potassium (NPK) rates (F1: Entire rate, F ½: Half rate) and three irrigation levels (100 % of crop water requirement: 100 % ETc; 75 % ETc; 50 % ETc) in a two year factorial split plot design. We studied vegetative growth, photosynthetic activity, chlorophyll fluorescence, water status, osmoticums, N, P, K and enzymatic antioxidants accumulation. Data obtained in 2019–2022 showed that AMF and B1B2 biofertilizers were beneficial to improve Root/Shoot, Dry Underground Part/Aerial Part, leaf area (LA), water saturation deficit (WSD), chlorophyll index (SPAD) and tuber yield under 75 % ETc. The photosynthetic promoter effect of biofertilizers under 75 % ETc, compared to 50 % ETc was observed in the following trend B1B2>AMF>B1. The efficacy of B1B2 and AMF were coupled to high catalase (CAT) activity. Potatoes treated with B1B2 were found to be efficient for 75 % ETc in terms of proline accumulation. The AMF was more effective in terms of soluble sugars (SS) accumulation and control of osmotic potential (Ψs). Taking together, the B1B2 and AMF could be regarded as efficient biofertilizers under 75 % ETc, alleviating the impacts of water stress and the problem of excessive fertilization in potatoes. 100 % ETc: 100 % crop water requirement; 75 % ETc: 75 % crop water requirement; 50 % ETc: 50 % crop water requirement; F1: 100 % NPK; F1/2: 50 % NPK; AMF: arbuscular mycorhizal fungi; B1: B. halotolerans ; B2: B. amyloliquefaciens ; B1B2: B. halotolerans + B. amyloliquefaciens (B1B2). [Display omitted] • Pooled PGPR bacteria and mycorhizae are efficient biofertilizers for 75 % ETc potatoes. • Efficacy of pooled PGPR and mycorhizae is linked to enhanced catalase activity. • Pooled PGPR enhanced proline accumulation. • Mycorhizae increased sugars accumulation and controlled the osmotic potential. [ABSTRACT FROM AUTHOR]

The soil water and nitrogen (N) levels are the important factors affecting turfgrass growth. However, the impact of the water–N interaction on tall fescue (Festuca arundinacea Schreb) in terms of the N metabolism and plant morphology remains uncertain. Therefore, the objective of this study was to investigate the impacts of different N and water levels on the physiological and morphological responses of tall fescue. The experiment was designed with N (N0, N2, and N4 representing N application rates of 0, 2, and 4 g m–2, respectively) and irrigation [W1, W2, W3, W4, and W5 representing field water capacities (FWCs) of 90~100%, 75~85%, 60~70%, 45~55%, and 30~40%, respectively] treatments, and the relevant indexes of the soil water content and soil NH4+–N and NO3−–N levels as well as the physiology and morphology of the tall fescue were determined. The results demonstrated significant changes in the contents of soil water (SWC) and N and the physiological and morphological indexes, except for the enzymes related to N metabolism, including nitrite reductase (NiR), glutamate dehydrogenase (GDH), and glutamate synthetase (GOGAT). The water stress significantly enhanced the water and N use efficiencies (WUE and NUE), except the NUE in the W5 treatment. The N stress significantly influenced the SWC, soil NO3−–N content, and physiological and morphological indexes, excluding malondialdehyde, NiR, GOGAT, and above- (AGB) and below-ground biomass, resulting in the increased WUE and NUE. The application of a low N rate effectively alleviated the detrimental impacts of water stress on the SWC and glutamine synthetase activity. In conclusion, W2 and N2 are deemed more appropriate treatments for the low-maintenance measures of tall fescue turf. Among all the treatments, N2W2 is recommended as the optimal water–N interaction treatment due to its ability to conserve resources while still ensuring high turf quality. [ABSTRACT FROM AUTHOR]

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Rising temperatures and water scarcity due to climate change are significant challenges for Mediterranean viticulture, particularly in the Douro Valley, a prominent winemaking region. Silicon (Si) has gained attention as a potential solution for mitigating these environmental stresses, especially in areas with limited water resources. This study explores the foliar application of Si as a promising strategy to reduce water requirements in vineyards, specifically for the Touriga Franca variety, thereby supporting more sustainable water use. Four treatments were tested: non-irrigated control (C−), an irrigated control under a deficit irrigation regime (25% ETc; C+), and two Si concentrations (7% Si-Si1 and 20% Si-Si2) applied to non-irrigated plants. Results demonstrate that Si-treated plants improved physiological resilience, as evidenced by enhanced photosynthetic efficiency, greater water-use efficiency, and higher biochemical quality in both leaves and berries. Additionally, Si application increased leaf flavonoids and simultaneously improved must composition due to its overall influence on vine physiology, indicating its potential as a sustainable alternative to irrigation for reducing summer stress. This research suggests that foliar Si application could be a valuable, eco-friendly strategy to support sustainable viticulture under increasingly arid conditions, reducing the irrigation needs. [ABSTRACT FROM AUTHOR]

Aims An ectomycorrhizal fungus (ECMF) may enhance plant drought resistance. However, there is limited information regarding the effects of ECMFs on drought resistance in Pinus massoniana Lamb., a native species representing an afforestation pioneer tree in subtropical regions of China. Methods In this study, a pot experiment was conducted to determine the effects of ECMF Suillus luteus inoculation on the root morphology and endogenous hormones of P. massoniana, including roots, leaves, and stems, under various water treatment conditions. Four water levels (regular, light, moderate, and severe drought) and three inoculations (inoculated Suillus luteus, numbered S12 and S13, and non-ECMF-inoculated) were compared using a factorial design. Results Under drought stress, P. massoniana seedlings inoculated with S12 and S13 had significantly increased root morphology development (p < 0.05). Light drought positively influenced root development, resulting in a more than twofold increase in root length and root surface area compared to non-inoculated seedlings. Concentrations of gibberellic acid (GA), zeatin riboside (ZR), and indole-3-acetic acid (IAA) in roots, stems, and leaves of inoculated S12 and S13 plants were elevated, whereas abscisic acid (ABA) concentrations were significantly lower, compared to non-inoculated seedlings. The ABA concentrations in the roots of S12 and S13 inoculated seedlings under light drought stress were 1.5 times lower than those in non-inoculated controls. Moreover, root development was positively correlated with plant total GA, IAA, and ZR but negatively correlated with ABA. ConclusionsS. luteus can promote the root growth and development of P. massoniana seedlings, notably by regulating the balance in the concentration of endogenous hormones, thus improving the drought resistance of P. massoniana seedlings. [ABSTRACT FROM AUTHOR]

Abiotic stress is one of the key factors harming global agriculture today, seriously affecting the growth and yield of vegetables. Pepper is the most widely grown vegetable in the world, with both high nutritional and economic values. Currently, the increase in global extreme weather events has heightened the frequency of abiotic stresses, such as drought, high and low temperatures, waterlogging, and high salt levels, which impairs pepper growth and development, leading to its reduced yield and quality. In this review, we summarize the research progress on the responses of pepper to abiotic stress in recent years in terms of physiology, biochemistry, molecular level, and mitigation measures. We then explore the existing problems and propose future research directions. This work provides a reference for the cultivation and development of new pepper varieties resistant to abiotic stress. [ABSTRACT FROM AUTHOR]

To further evaluate the effect of water stress on soil respiration (RS), reveal the influencing factors of daily and seasonal RS, and systematically evaluate and compare the sensibility of different machine learning algorithms (multiple nonlinear regression [MNR], support vector machine regression [SVR], backpropagation artificial neural network [BPNN]) to estimate RS from a maize field under water stress condition, the field experiments were conducted within a maize field in Inner Mongolia, China, during the entire 2019 growing season. Various levels of deficit irrigation were conducted in the vegetative, reproductive, and mature stages. Our research indicated that soil CO2 fluxes from 100% evapotranspiration treatment (Tr1) were significantly greater than various deficit irrigation treatments (Tr2, Tr3, Tr4) during each growth stage of summer maize. The cumulative soil CO2 fluxes of Tr2, Tr3, and Tr4 decreased 24.8%, 30.3%, and 43.7% compared with Tr1, respectively. We determined that the drivers affecting the daily RS were soil temperature at 5 cm depth (TS,5) and soil surface temperature (TSF), followed by water‐filled porosity (WFPS) at 5 cm depth, but no significant correlations were observed at 25 cm depths. TS,5 and TSF also performed similar correlation with seasonal RS with R greater than 0.753 among all water treatments, followed by chlorophyll content with R greater than 0.726. During the whole growing season, the BPNN model exhibited the best predicting result, and could explain the 60%–80% and 87.8% of the variations of RS at the daily and seasonal scales, with root mean square error of 48.7–100.9 mg m−2 h−1 and 91.5 mg m−2 h−1, respectively. The SVR and MNR models could estimate the 47.9%–57% and 39.9%–52.1% of the daily RS and 81.4% and 78.6% of the seasonal RS, respectively. Overall, our study indicated the machine learning algorithms could be successfully applied to estimate RS at daily and seasonal scales from a maize field under water stress condition. [ABSTRACT FROM AUTHOR]

When utilizing the Crop Water Stress Index (CWSI), the most critical factor is accurately measuring canopy temperature, which is typically done using infrared sensors and imaging cameras. In this study, however, we aimed to develop a machine learning model capable of predicting leaf temperature based on environmental data, without relying on sensors, for calculating CWSI. The data underwent preprocessing to remove outliers and missing values. The number of training data points for each factor was 307,924. After data preprocessing, a Pearson correlation analysis (bivariate correlation coefficient) was conducted to select the training data for model operation. The relationship between leaf temperature and air temperature showed a strong positive correlation of 0.928 (p < 0.01). Solar radiation and relative humidity were also found to have high correlations. However, wind speed and soil moisture tension showed very low correlations with leaf temperature and were excluded from the model operation. The Decision Tree, Random Forest, and Gradient Boosting models were selected, and each model was evaluated using RMSE (Root Mean Squared Error), MAE (Mean Absolute Error), MSE (Mean Squared Error), and R2 (coefficient of determination). The evaluation results showed that the Gradient Boosting model had a high R2 (0.97) and low RMSE (0.88) and MAE (0.54), making it the most suitable model for predicting leaf temperature. Through the leaf temperature prediction model developed in this study, labor and costs associated with sensors can be reduced, and by applying it to real agricultural settings, it can improve crop quality and enhance the sustainability of agriculture. [ABSTRACT FROM AUTHOR]

Water security is a critical global issue that has gained increasing attention from researchers, policymakers, and practitioners over the past few decades. This paper presents a comprehensive overview of the evolution of potable water security indices from the 1980s to the 2020s, focusing on the key research themes, trends, and influential factors in the field. We conducted a comprehensive search of the relevant literature and examined the development of water security indices to provide insights into the current state of research and identify future research directions. This paper will explore the historical context, key indicators, sector-specific challenges, climate change implications, governance and policy considerations, technological advancements, community engagement efforts, and future directions for research in this critical field. Researchers and policymakers will find this review valuable as it offers insights into the existing knowledge and the areas that require further exploration to address global water security challenges. [ABSTRACT FROM AUTHOR]

Background: Ophiocordyceps sinensis (O. sinensis) is the dominant bacterium in the asexual stage of Chinese cordyceps, and its growth usually suffers from water stress. Thus, simulating its ecological growth environment is crucial for artificial cultivation. This study aimed to reveal the mechanism underlying the water stress tolerance of Ophiocordyceps sinensis (O. sinensis) by combining metabolomic and transcriptome analyses to identify crucial pathways related to differentially expressed genes (DEGs) and metabolites (DEMs) involved in the response to water stress. Results: Gene coexpression analysis revealed that many genes related to 'betalain biosynthesis', 'tyrosine metabolism', 'linoleic acid metabolism', 'fructose and mannose metabolism', and 'starch and sucrose metabolism' were highly upregulated after 20d-water stress. Metabolomic analysis revealed that many metabolites regulated by these genes in these metabolic pathways were markedly decreased. On the one hand, we surmised that carbohydrate metabolism and the β-oxidation pathway worked cooperatively to generate enough acyl-CoA and then entered the TCA cycle to provide energy when exposed to water stress. On the other hand, the betalain biosynthesis and tyrosine metabolism pathway might play crucial roles in response to water stress in O. sinensis by enhancing cell osmotic potential and producing osmoregulatory substances (betaine) and antioxidant pigments (eumelanin). Conclusions: Overall, our findings provide important information for further exploration of the mechanism underlying the water stress tolerance of O. sinensis for the industrialization of artificial cultivation of Chinese cordyceps. [ABSTRACT FROM AUTHOR]

The CmXTH11 gene, a member of the XTH (xyloglucan endotransglycosylase/hydrolase) family, plays a crucial role in plant responses to environmental stress. In this study, we heterologously expressed the melon gene CmXTH11 in Arabidopsis to generate overexpressing transgenic lines, thereby elucidating the regulatory role of CmXTH11 in water stress tolerance. Using these lines of CmXTH11 (OE1 and OE2) and wild-type (WT) Arabidopsis as experimental materials, we applied water stress treatments (including osmotic stress and soil drought) and rewatering treatments to investigate the response mechanisms of melon CmXTH11 in Arabidopsis under drought stress from a physiological and biochemical perspective. Overexpression of CmXTH11 significantly improved root growth under water stress conditions. The OE lines exhibited longer roots and a higher number of lateral roots compared to WT plants. The enhanced root system contributed to better water uptake and retention. Under osmotic and drought stress, the OE lines showed improved survival rates and less wilting compared to WT plants. Biochemical analyses revealed that CmXTH11 overexpression led to lower levels of malondialdehyde (MDA) and reduced electrolyte leakage, indicating decreased oxidative damage. The activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), were significantly higher in OE lines, suggesting enhanced oxidative stress tolerance. The CmXTH11 gene positively regulates water stress tolerance in Arabidopsis by enhancing root growth, improving water uptake, and reducing oxidative damage. Overexpression of CmXTH11 increases the activities of antioxidant enzymes, thereby mitigating oxidative stress and maintaining cellular integrity under water deficit conditions. These findings suggest that CmXTH11 is a potential candidate for genetic improvement of drought resistance in crops. [ABSTRACT FROM AUTHOR]

Water stress in the Amazon is exacerbated by rising temperatures and reduced moisture levels. However, understanding forest responses to increased aridity is hindered by limited in situ water potential observations in the Amazon. Remote sensing of water content has emerged as a promising metric. Vegetation Water Content (VWC) diurnal dynamics is hypothesized to reflect water stress responses. Conventional sensors' low sampling rates impede capturing and studying sub‐daily VWC dynamics. Leveraging Global Navigation Satellite System Reflectometry (GNSS‐R) with unprecedented sampling rates, this study reveals significant disparities in morning and evening VWCs in the Amazon, for example, by ≈ ${\approx} $1.1 and 1.0 kg/m2 ${\mathrm{m}}^{2}$ during the wet and dry seasons of 2019. A strong correlation (R=0.8) $(R=0.8)$ between Δ ${\Delta }$VWC (the difference between evening and morning VWCs) and vapor pressure deficit is observed in Amazonian peatland. This highlights the potential of VWC from innovative remote sensing techniques in elucidating water stress dynamics in critical ecosystems. Plain Language Summary: In the Amazon rainforest, rising temperatures and decreasing moisture levels are causing plants to experience more water stress. However, scientists have struggled to understand how the forests are responding to these drier conditions as direct measurements of plant moisture content do not provide sufficient coverage. Recently, researchers have started using satellites to measure water in plants, which could help us understand how they are coping with the lack of water. However, conventional sensors hardly offer measurements often enough to capture the daily changes in plant water levels. This study uses a novel satellite observation technique, Global Navigation Satellite System Reflectometry, that offers measurements with unprecedented frequency. It is found that there are significant differences in plants' water content in the morning compared to the evening in the Amazon, for example, by ≈ ${\approx} $1.1 and 1.0 kg/m2 ${\mathrm{m}}^{2}$ during the wet and dry seasons of 2019. This study reveals that the difference level responds significantly to environmental aridity. As a result, novel satellite methods could help us better understand how water stress is affecting the Amazon rainforest. Key Points: Global Navigation Satellite System Refractometry offers unprecedented sampling, unveiling Amazon's diurnal vegetation water contentVegetation water content generally peaks in mornings, fluctuating significantly throughout the dayAmazonian peatland's VWC diurnal cycle correlates strongly (R=0.8) $(R=0.8)$ with vapor pressure deficit, proposed as a water stress indicator [ABSTRACT FROM AUTHOR]

The natural forests of south‐central Chile are known as world biodiversity hotspot. Due to increasing societal demands and certification commitments, a vast extension of these forests that was replaced by commercial exotic tree plantations is now to be restored. Given the magnitude of the area involved, large‐scale approaches based on natural regeneration require consideration. However, experimental evidence for this approach to restoration is lacking in different regions. We conducted a large‐scale replicated experiment to evaluate the response of natural regeneration of native tree species to different harvesting treatments (clearcut, strip‐cutting, and unharvested control) in 20‐year‐old Pinus radiata plantations. For 2 years, we monitored variations in (1) regeneration basal area (dRBA), (2) maximum sapling height (dMH), (3) frequency of free‐growing regeneration (dFGR), and (4) diversity of regenerating tree species. The harvesting treatment had significant effects on dRBA, dMH, and dFGR. The clearcuts showed the highest values of dRBA and dFGR of native species, but also, the highest dRBA of P. radiata regeneration. The strip‐cuttings showed the highest dMH of native species and the highest values of richness, Shannon, and Simpson diversity. Our results suggest that both clearcuts and strip‐cuttings facilitate natural regeneration. Although clearcuts may allow higher rates of natural regeneration establishment than strip‐cuttings, they require periodic control of P. radiata regeneration to prevent suppression of established native regeneration. Strip‐cuttings may require fewer management interventions and allow for higher initial species diversity, although with a potentially longer establishment period and higher risk of damage from residual P. radiata trees experiencing wind throw. [ABSTRACT FROM AUTHOR]

Exploring the drought resistance characteristics of Pinus tabulaeformis, a major afforestation tree species for soil and water conservation, under different water stress to provide a scientific basis for the management of F. tabulaeformis artificial forests in the region. Methods］ Using one -- year F. tabulaeformis seedings as the research subject, four levels of water stress treatments were set up, which were control group (CK)，mild stress (RE25 %), moderate stress (RE50 %) and severe stress (RE75 %), respectively, the growth characteristics, hydraulic function and osmotic regulatory substance content of P.tabulaeformis seedlings were analyzed after different water stress treatments, and their correlation was analyzed. Results］ (1) Compared with the CK treatment, after twenty months of RE5()% and RE75% treatment, the aboveground biomass of F. tabulaeformis significantly decreased by 19.1% and 37.()%, respectively, while the underground biomass significantly increased by 13. 7% and 23.9%，respectively. (2) Tn the CK, RE25%, RE5()% and RE75% treatments, the water potential threshold for embolism resistance of F. tabulaeformis new branches was 一1.43: 一2.()4戈 一().91 and--().58 MPa, respectively. (3) Compared with CK, in the RE5()% and RE75% treatments, the soluble sugar content in the coarse roots significantly increased by 123.3% and 121.9%，respectively, the starch content significantly increased by 15.()% and 58.()%，respectively, and the total non structural carbohyd rate (NSC) content significantly increased by 1()4. ()% and 83.2%, respectively. Tn the RE75 % treatment, the proline content in the new branches significantly decreased by 43.0%, while the K+ content decreased by 23.7% compared with the CK group. (4) The contribution rates of various osmotic regulating substances in various organs to hydraulic function under different water stress were as follows: NSC, starch, soluble sugars, K+, proline and soluble sugars in tracheid sap. _Conclusion] Mild water stress could enhance the embolism resistance of new branches. F. tabulaeformis seedlings maintained their metabolism by increasing root carbon storage. Meanwhile, the numerous organs of F. tabulaeformis improved cell concentration, reduced osmotic potential, and preserved hydraulic function to adapt to water stress environment by coordinating the accumulation of osmotic regulating substances. This study advanced the understanding of F. tabulaeformis' drought resistance mechanism and provided a scientific basic for the management of F. tabulaeformis artificial forests on the Loess Plateau. [ABSTRACT FROM AUTHOR]

Introduction Wheat (Triticum aestivum L.) is one of the oldest and most widely used crops in the world and is the most important source of human food that grows in a wide range of climatic conditions in the world. In arid and semi-arid regions, water is the main limitation. Iran is a dry and semi-arid country with limited precipitations. Therefore, the mean annual rainfall in Iran is even less than one third of the global average. There are many solutions for sustainability in agriculture, one of which is the use of biological fertilizers. Among these biofertilizers are mycorrhizal fungi. The symbiotic relationship between the arbuscular mycorrhizal fungus and the roots of the host plant significantly increases the growth and absorption of plant nutrients. In this research, the aim is to investigate the effect of arbuscular mycorrhizal fungus on improving the yield, yield components, and chlorophyll index of wheat by applying water deficit stress through increasing the interval of irrigation cycles. Materials and Methods This factorial experiment was conducted based on a randomized complete block design in four replications in the research farm of the Azad Islamic University of Miandoab, northwestern Iran in 2021. The experimental factors included the application of arbuscular mycorrhiza fungus species in three levels, control (without inoculation), inoculation with Glomus mosseae and inoculation with Glomus intraradices and three levels of irrigation regimes (i.e. irrigation after every 6, 13 and 20 days). Seeds of Elvand wheat cultivar were inoculated with mycorrhizal fungus, then the inoculated seeds were immediately planted into a depth of 3. Before planting, 15 tons/ha of manure and 25 kig of nitrogen fertilizer in the form of urea were uniformly applied to the soil. During the growing season, 50 kg of nitrogen fertilizer in the form of urea was used during the two stages of stem growth and spike formation. To measure wheat grain yield components, 10 plants were harvested and to determine grain yield and plant above- ground dry mass, 0.25 m-2 was taken from each plot. In this way, after removing two rows from each side and half a meter from the beginning and end of all rows as a margin, sampling of experimental units was done. The evaluated traits included the spikes/plant, grains/spike, the thousand-grain weight, plant aboveground dry mass, grain yield, harvest index, and greenness index Results and Discussion Results indicated that the effect of irrigation intervals and mycorrhiza fungus were significant for grains/spike, thousand-grain weight, grain yield, above-ground dry mass, harvest index, chlorophyll index, photosynthetic pigments and proline concentrations. G. mosseae species increased the grains/spike, thousand-grain weight, above-ground dry mass, harvest index, and chlorophyll concentration compared to G. intraradices species by 5.21, 9.73, 8.86, 6.96 and 4.08% and increased the above-mentioned attributes compared to the control by 29.94, 30.28, 39.68, 27.90 and 21.43%, respectively. The highest spikes/plant, grain yield, chlorophyll index and concentration of chlorophyll a belonged to irrigation interval of 6 days and inoculation with G. mosseae species with 6.34, 612.45 g m-2, 62.89 SPAD unit, and 0.306 mg g-1 FW, respectively. Prolongation of irrigation interval by creating water deficit stress caused the sterility of the spikes and significantly reduced the grains/spikes. The irrigation regime had a significant effect on the grain yield and by reducing the irrigation intervals, the grain yield was increased. The drought-induced decrease in grain yield stemmed from the decrease in green index, chlorophyll concentration, spikes/plant and grains/spike, leading to decrease in the harvest index. With increase in the irrigation interval, the concentration of chlorophyll a and b decreased, but the mycorrhizal inoculation led to significant increase in the concentration of chlorophyll a and b under water deficit stress. The plants inoculated with mycorrhizal fungus suffered less from water deficit stress than the non-colonized plants, and as a result, the concentration of proline increased less compared to the plants deprived from mycorrhizal fungus. According to these results, irrigation of wheat plants every 13 days and application of G. mosseae can produce the desirable grain yield, while decreasing water consumption for wheat production. Conclusions Mycorrhizal fungus increased the plant's resistance to drought stress by improving the absorption of water and nutrients under water stress deficit. G. mosseae was more effective in increasing the resistance of wheat against water deficit stress and as a result, it increased the grain yield, yield components, chlorophyll index and chlorophyll concentration of wheat to a greater extent compared to G. intraradices. In order to make the best use of water resources and soil nutrients, irrigation of wheat should be done every 13 days and must be accompanied by inoculation with G. mosseae to achieve an acceptable grain yield. [ABSTRACT FROM AUTHOR]

Research into alternative vineyard practices is essential to maintain long-term viticulture sustainability. Organic mulching on the vine row improves vine cultivation properties, such as increasing soil water retention and nutrient availability. This study overviewed the effects of three organic mulches (spent mushroom compost (SMC), straw (STR), and grapevine pruning debris (GPD)) and two conventional soil practices (herbicide application (HERB) and tillage (TILL)) on grapevine physiology, agronomy, and grape quality parameters over three years. SMC mulch enhanced soil moisture and nutrient concentration. However, its mineral composition increased soil electrical conductivity (0.78 dS m⁻1) and induced grapevine water stress due to osmotic effects without significantly affecting yield plant development. Only minor differences in leaf physiological parameters were observed during the growing season. However, straw (STR) mulch reduced water stress and increased photosynthetic capacity, resulting in higher pruning weights. Organic mulches, particularly SMC and STR, increased grape pH, potassium, malic acid, and tartaric acid levels, while reducing yeast assimilable nitrogen. The effect of organic mulching on grapevine development depends mainly on soil and mulch properties, soil water availability, and environmental conditions. This research highlights the importance of previous soil and organic mulch analysis to detect vineyard requirements and select the most appropriate soil management treatment. [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]

This study systematically reviews the integration of artificial intelligence (AI) and remote sensing technologies to address the issue of crop water stress caused by rising global temperatures and climate change; in particular, it evaluates the effectiveness of various non-destructive remote sensing platforms (RGB, thermal imaging, and hyperspectral imaging) and AI techniques (machine learning, deep learning, ensemble methods, GAN, and XAI) in monitoring and predicting crop water stress. The analysis focuses on variability in precipitation due to climate change and explores how these technologies can be strategically combined under data-limited conditions to enhance agricultural productivity. Furthermore, this study is expected to contribute to improving sustainable agricultural practices and mitigating the negative impacts of climate change on crop yield and quality. [ABSTRACT FROM AUTHOR]

Cover cropping consists in sowing non-cash crops to improve regulating and supporting services without seeking provisioning services. Cover cropping has the potential for spatio-temporal diversification of cropping systems to help address food security while also improving environmental sustainability. However, cover crops are still poorly adopted by farmers worldwide. One of the key reasons behind this poor adoption is the difficulties in ensuring cover crop establishment that is further exacerbated by the current knowledge gaps. On the other hand, no study has yet summarized key published and unpublished information on cover crop emergence and field establishment that may help fill these knowledge gaps. In light of this, for the first time, we comprehensively review the literature to summarize and quantify information related to cover crop emergence and propose strategies for improving their field establishment. The major findings are as follows. (1) Detailed statistics on the share of arable land sown to cover crops are lacking, but the available information suggests that this share is increasing over the years ranging from 4% in the USA to 9% in the EU. (2) Four key factors—regulations and public policy incentives, economic factors, knowledge factors, and environmental factors—influence the adoption or non-adoption of cover crops by farmers. (3) Poor emergence and field establishment, due to unfavorable environmental conditions, is one of the most important obstacles to cover crop adoption across temperate regions worldwide. (4) Five forms of cover crop sowing are practiced by farmers that can be grouped into two major sowing strategies—sowing before and after harvesting cash crops—each of them presenting several strengths and limits. (5) A wide range of sowing equipment is available for farmers but their choice depends on several factors including work output and costs. Finally, we emphasize the role of a decision support system and modeling, for an optimal cover crop sowing and field establishment, which are key for enhanced quantity of biomass production and ecosystem service provisioning. [ABSTRACT FROM AUTHOR]

Globally, numerous ecosystems have been co‐invaded by multiple exotic plant species that can have competitive or facilitative interactions with each other and with native plants. Invaded ecosystems often exhibit spatial heterogeneity in soil moisture and nutrient levels, with some habitats having more nutrient‐rich and moist soils than others. The stress‐gradient hypothesis predicts that plants are likely to engage in facilitative interactions when growing in stressful environments, such as nutrient‐deficient or water‐deficient soils. In contrast, when resources are abundant, competitive interactions between plants should prevail. The invasional meltdown hypothesis proposes that facilitative interactions between invasive species can enhance their establishment and amplify their ecological impact. Considering both hypotheses can offer insights into the complex interactions among invasive and native plants across environmental gradients. However, experimental tests of the effects of soil moisture and nutrient co‐limitation on interactions between invasive and native plants at both interspecific and intraspecific levels in light of these hypotheses are lacking. We performed a greenhouse pot experiment in which we cultivated individual focal plants from five congeneric pairs of invasive and native species. Each focal plant was subjected to one of three levels of plant–plant interactions: (1) intraspecific, in which the focal plant was grown with another individual of the same species; (2) interspecific, involving a native and an invasive plant; and (3) interspecific, involving two native or invasive individuals. These plant–plant interaction treatments were fully crossed with two levels of water availability (drought vs. well‐watered) and two levels of nutrient supply (low vs. high). Consistent with the stress‐gradient and invasional meltdown hypotheses, our findings show that under low‐nutrient conditions, the biomass production of invasive focal plants was facilitated by invasive interspecific neighbors. However, under high‐nutrient conditions, the biomass production of invasive focal plants was suppressed by invasive interspecific neighbors. When competing with native interspecific neighbors, high‐nutrient conditions similarly enhanced the biomass production of both invasive and native focal plants. Invasive and native focal plants were neither competitively suppressed nor facilitated by conspecific neighbors. Taken together, these results suggest that co‐occurring invasive exotic plant species may facilitate each other in low‐nutrient habitats but compete in high‐nutrient habitats. [ABSTRACT FROM AUTHOR]

Maize is widely growth in arid and semi-arid region where, drought is common and a limiting factor for crop production. Potassium plays a key role in enhancing plant growth under drought condition. The objective of this study is to determine the effect of K fertilization with and without NP on maize growth grown in sandy loam soil under adequate and deficit irrigation conditions. The following treatments were investigated in pot experiment: (1) control with no fertilizer application (C); (2) 128 kg N + 328 kg P2O5 ha-1 (NPK0); (3) 128 kg N + 328 kg P2O5 ha-1 + 152.5 kg K2O ha1 (NPK1); (4) 128 kg N + 328 kg P2O5 ha-1 + 305 kg K2O ha-1 (NPK2); and 128 kg N + 328 kg P2O5 ha-1 + 457.5 kg K2O ha-1 (NPK3). Treatments were investigated under adequate and deficit soil moisture content. Each pot filled with 3.5 kg air-dry soil and seeded with maize and pots were watered according to the treatments. The results indicated that plant growth and nutrient uptake were significantly reduced under water stress condition. The application of NP increased plant growth and nutrient uptake and further were increased with K application. K application also enhanced plant tolerance to deficit soil moisture condition. In addition, K enhanced nutrient uptake and leaf chlorophyll content. Based on the results, it can be concluded that application of NP for maize was not adequate to achieve the highest plant growth, unless it is combined with K application. In addition, K application enhances plant tolerance to water stress. [ABSTRACT FROM AUTHOR]

The "One Village One Dam (1V1D)" is a rainwater harvesting technology initiated by the Government of Ghana in 2017 to make water available all year round for animal watering, irrigation and domestic use in dryland areas in northern Ghana. However, scepticism about the potential of the 1V1D to stave off water stress and its associated impact on local livelihood activities is still prevalent in the country. This case study of Savelugu Municipality investigated the impact of the 1V1D on local livelihood activities and the work-life balance of women. Using qualitative data collection methods, 12 focus group discussions and seven key informant interviews were conducted in six communities in the municipality. The results showed that after >5 years of implementation, not much has been achieved for the intended purposes of the project, namely water for animal watering, irrigation and household consumption. Non-performance of the dams was attributed to engineering flaws like poor design and small size which often resulted in early dry out of the dams in the dry season. However, emerging activities like water commercialisation have provided a source of sustenance to water vendors. The services of the vendors save women time to fulfil the demands of work, family and personal life. Overall, the persistence of water stress in the study communities and activities of Fulani herdsmen, who allowed their cattle to pollute the dams' water, necessitates the government to address the design flaws through retrofitting the existing dams and mainstreaming future 1V1D projects to effectively tackle water stress in Ghana's dryland areas. [ABSTRACT FROM AUTHOR]

• No clear pattern was observed in the grouping of samples exposed to water stress. • Younger leaves of one month and four months old had a strong clustering of high activity samples as compared to older leaves of six months old. • Plant materials harvested during the flowering growth stage had a strong grouping of samples producing high antityrosinase activity as compared to the budding and vegetative growth stages. Greyia radlkoferi Szyszyl (Melianthaceae) is a native plant to southern Africa identified as a viable commercial crop. The leaf extract is rich in flavonoid compounds with the ethanolic leaf extract found to treat skin hyper-pigmentation of humans without adverse effects (anti-tyrosinase activity value IC 50 17.86 μg/ml). Anti-tyrosinase activity is found to be variable between plants, even when planted at the same site, which raises concerns regarding commercial production, necessitating the need for cultivation interventions that will not compromise the activity of the extract. Interventions to limit the variation were thus explored by imposing targeted water stress (different durations) before harvesting and determining the effect on the different phenological growth stages and activity of different leaf ages. The inhibitory tyrosinase activity was evaluated using mushroom tyrosinase and kojic acid as a control and data was presented as IC 50 values. The metabolomics investigation was conducted through the use of nuclear magnetic resonance (1H NMR) analysis coupled with the multivariate statistical data set. Pattern recognition methods such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA) were employed to obtain the metabolic discrimination between the treatments. No clear pattern was observed in the grouping of samples exposed to targeted water stress on both plant age and leaf position, except for younger leaves of one month and four months old which had a strong clustering of high activity samples as compared to older leaves of six months old. However, plant materials harvested during the flowering growth stage had a strong grouping of samples producing high anti-tyrosinase activity as compared to the budding and vegetative growth stages. The study determined the changes in the concentration of various compounds, although quantification of compounds should be determined in the future. [ABSTRACT FROM AUTHOR]

Increasingly frequent severe drought events are pushing Mediterranean forests to unprecedented responses. Lack of management leads to dense forests that are highly susceptible to drought stress, potentially resulting in extensive dieback and increased vulnerability to other disturbances. Forest treatments like thinning and slash burning reduce competition for resources and have the potential to enhance tree growth and vigor and minimize tree vulnerability to drought. Here, we used tree rings to study the growth and physiological response of black pine (Pinus nigra) to drought in northeastern Spain under different treatments, including two thinning intensities (light and heavy, with 10% and 40% basal area reduction, respectively) followed by two understory treatments (clearing alone and in combination with slash burning), resulting in a research design of four treatments plus an untreated control with three replicates. Specifically, we studied basal area increment (BAI), resilience indices, and intrinsic water use efficiency (iWUE) using carbon and oxygen isotope composition (δ13C and δ18O in tree‐ring cellulose) before and after treatments. Our results showed that BAI and resistance to drought increased in the heavy‐thin (burned and unburned) and light‐thin burned units. Resilience increased in the burned units regardless of the thinning intensity, while recovery was not affected by treatment. Slash burning additionally increased BAI in the light‐thin and resistance and resilience in the heavy‐thin units compared with clearing alone. The stable isotope analysis revealed a minor effect of treatments on δ13C and δ18O. No change in iWUE among treatments was presumably linked to a proportional increase in both net CO2 assimilation and stomatal conductance, which particularly increased in the heavy‐thin (burned and unburned) and light‐thin burned units, indicating that these trees were the least affected by drought. This study shows that management approaches aimed at reducing wildfire hazard can also increase the vigor of dominant trees under drought stress. By reducing competition both from the overstory and the understory, thinning followed by clearing alone or in combination with slash burning promotes tree growth and vigor and increases its resistance and resilience to drought. [ABSTRACT FROM AUTHOR]

Key message: We have identified poplar clones suitable for dryland forestry, which stand out for their resistance to cavitation, level of anisohydrism, adjustment of cellular water relations and high water use efficiency. In drylands, such as the arid western region of Argentina, poplar afforestation depends on intermittent furrow irrigation, subjecting the plantations to variable water availability both in time and space. Our objective was to study stem biomass production and drought resistance responses of eight poplar clones, to explore whether there are more suitable varieties for forestry in drylands than those currently cultivated, i.e. the hybrid Populus × canadensis clones 'Conti' 12 and 'Guardi'. We conducted a pot experiment with three levels of water availability (control, moderate stress and severe stress), studying four clones of P. × canadensis, 'Conti 12', 'Guardi', 'I-214' and 'I45/51', as well as four clones of the Populus deltoides species, 'Stoneville 67', 'Catfish 2', 'Dvina' and 'Australiano 129/60'. We found that the clones that were more productive under water stress, 'I-214' and 'I45/51', were also the most resistant to cavitation. However, these clones were not very productive under high water availability. The 'Guardi' and 'Australiano 129/60' clones performed best in this situation, showing moderately high productivity under water stress. These clones exhibited the highest degree of anisohydrism, high water use efficiency and 'Australiano 129/60' stood out for its low water potential at the point of wilting due to osmotic adjustment. The currently most cultivated variety in Cuyo region, 'Conti 12', was less productive, did not make cellular adjustments and had low water use efficiency. These results suggest that other available clones may be more suitable for poplar forestry in drylands and should be evaluated in field trials. [ABSTRACT FROM AUTHOR]

Chloranthus spicatus is one of the main scented tea varieties cultivated mainly in the Huangshan region, and dried flowers of these plants are mainly used for imparting a characteristic aroma to the tea. However, climatic variations in Huangshan limit its cultivation, with water deficit (WD) being the main limiting factor. The present study evaluated the effects of different WD intensities on the growth and physiological parameters of C. spicatus seedlings to determine the optimal soil moisture content for their large-scale cultivation. The experimental design comprised a control group (95–100%) and three treatment groups, namely mild WD (75–80%), moderate WD (55–60%), and severe WD (35–40%). Each treatment lasted 45 days and was given to 10 potted C. spicatus seedlings, with 3 replicates. Measurements were conducted for the shoot length and diameter; biomass; photosynthesis parameter; activities of antioxidant enzymes, namely superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and soluble protein (SP) and malonylaldehyde (MDA) contents of the seedlings. The results indicated that mild and moderate WD positively affected C. spicatus seedlings in terms of shoot length, diameter, biomass, root/shoot ratio, photosynthesis rate, intercellular CO2 concentration, water use efficiency, and carboxylation efficiency. Moreover, the growth and photosynthesis were increased in the mild and moderate WD seedlings but decreased in the severe WD seedlings. Mild and moderate WD also led to a significant decrease in the antioxidant enzyme activities and the MDA content of seedlings (p < 0.05), all of which exhibited higher levels in severe WD seedlings. These results indicated that severe water stress restricted the growth of seedlings, while mild and moderate stress proved beneficial. SP content of the seedlings increased under mild and moderate WD but decreased under severe WD. We infer that the strong hydrophilicity of SPs in the seedlings results in the accumulation of water in plant cells, thus conferring resistance to drought stress. In conclusion, reducing the soil moisture content by 55–80% in the Huangshan region may be a promising strategy for boosting its cultivation. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of Glycine Betaine (GB), Salicylic Acid (SA), and Ascorbic Acid (AsA) on the yield and quality of cotton plants during the 2021 and 2022 growing seasons at Harran University's experimental fields in Şanlıurfa, Turkey. The research employed a split-plot design with three replications. Main plots were assigned for chemical applications (GB, SA, and AsA), while subplots were designated for different irrigation levels (IW1: Kp;1.00, IW2: Kp;0.75, and IW3: Kp;0.50). The study revealed that crop evapotranspiration varied between 400 to 728 mm in 2021 and 489 to 841 mm in 2022. The application of GB, SA, and AsA increased irrigation water productivity, especially under drought stress (DS) conditions, indicating the potential to enhance water productivity in cotton plants. DS resulted in significant reductions in various parameters such as plant height, shoot fresh weight, shoot dry weight, SPAD values, boll number, boll weight, cotton yield, ginning outturn, and 100-seed weight. However, the application of GB, SA, and AsA led to statistically significant (P ≤ 0.05) increases in these parameters under DS. Contrary to this, the application of GB, SA, and AsA did not have a statistically significant effect on ginning outturn and 100-seed weight under DS. GB, SA, and AsA applications demonstrated effectiveness in enhancing drought tolerance in cotton. These applications can help reduce yield losses in cotton production under drought conditions. Importantly, by conserving water and preventing yield losses, they offer valuable support to the textile industry. [ABSTRACT FROM AUTHOR]

Water deficiency in semiarid regions is a limiting factor that affects crop quality and yield. In Punjab, Pakistan, a 27% decline in maize yield was detected over the past two decades just because of water scarcity. Currently, no studies have reported the effects of organically activated biochar (AB) on crop productivity under natural field conditions. For this purpose, a field experiment in a split-split-plot design was conducted with three amendment levels (0, 2, and 4 tonnes ac−1), and three maize hybrids (DK-9108, DK-6321, and Sarhaab) under 100%, 70%, and 50% irrigation water (IW) of crop evapotranspiration (ETc). The AB significantly improved the soil's physical and chemical properties, and maximum improvement was recorded in 4 tonnes ac−1 AB amendment in organic matter (16.6%), total organic carbon (17%), phosphorus (11.43%), and available potassium (29.27%). The 4 tonnes ac−1AB amendment in soil had a significant impact on total chlorophyll content (0.3–1-fold in DK-6321), carotenoid content (3.9–4.4-fold in Sarhaab), and relative water content (30% and 21% in Sarhaab) under 50% irrigation water (IW) of ETc at V14th and R3 stages, respectively. Moreover, a significant decline in stress markers (proline content and sugar content) was detected at both growth stages in all maize hybrids in AB amended soil. The analysis of plant metabolites indicated increased intensities of phenolics, alkyl esters, and carbohydrates by 2.5–7%, 17–80%, and 40–43% in DK-6321 under 50% IW in 2–4 tonnes ac−1 AB amended soil, respectively. The highest improvement in growth and yield attributes among maize hybrids was detected in the order DK-6321¿DK-9108¿Sarhaab in 2–4 tonnes ac−1AB amended soil under 70% and 50% IW of ETc, respectively. Hence, this research might help to develop an effective soil amendment to restore degraded soils and improve maize growth under arid climatic conditions. [ABSTRACT FROM AUTHOR]

CITRUS is one of the most important fruit crops grown in the worldwide, especially in Mediterranean countries. Deficit irrigation (DI) is a proposed strategy many years ago to overcome the scarcity of water, especially in arid and semiarid regions. The vegetative growth, enzymatic activities, proline and phenolic content, fruit yield and quality in response to deficit irrigation levels (T1 (irrigation every 15 days as a control), T2 (irrigation every 20 days), T3 (irrigation every 25 days), and T4 (irrigation every 30 days), were evaluated. The results showed that the P, K, proline, phenols, vitamin C, SSC contents, and catalase and peroxidase activities were increased by T2 and T3. While the N content, fruit yield, weight, peel thickness, juice volume, and transpiration rate were increased by T1 and T2 compared to T3 and T4. The fruit yield, weight, and physical properties were not negatively affected by light and medium deficit irrigation (T2 and T3), which positively affected enzymatic activities, proline and phenol contents, and chemical fruit properties (SSC and Vitamin C). [ABSTRACT FROM AUTHOR]