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In order to explore the response mechanism of Passiflora edulis Sims to drought stress, the changes in morphological and physiological traits of Passiflora edulis Sims under different drought conditions were studied. A total of 7 germplasm resources of Passiflora edulis Sims were selected and tested under drought stress by the pot culture method under 4 treatment levels: 75%-80% (Control, CK) of maximum field water capacity, 55%-60% (Light Drought, LD) of maximum field water capacity, i.e., mild drought, 40%-45% (Moderate Drought, MD) of maximum field water capacity, i.e., moderate drought and 30%-35% (Severe Drought, SD) of maximum field water capacity, i.e., severe drought. On the 40th day of drought treatment, 13 indices, including seedling growth morphology, physiology, and biochemistry, were measured. The results showed that under drought stress, the height and ground diameter of P. edulis Sims gradually decreased with increasing drought stress, and there were significant differences in seedling height and ground diameter among the treatments. Drought stress significantly inhibited the growth of seven P. edulis Sims varieties. The contents of soluble sugar (SS), soluble protein (SP), proline (Pro), and other substances in P. edulis Sims basically increased with increasing drought stress. With the aggravation of drought stress, the malondialdehyde (MDA) content of P. edulis Sims tended to increase to different degrees, the superoxide dismutase (SOD) activity and peroxidase (POD) activity both tended to increase at first and then decrease, and the change in catalase (CAT) activity mostly showed a gradual increasing trend. The contents of endogenous hormones in P. edulis Sims significantly differed under different degrees of drought stress. With the aggravation of drought stress, the abscisic acid (ABA) content of P. edulis Sims tended to increase, whereas the contents of gibberellin (GA), indoleacetic acid (IAA), and zeatin nucleoside (ZR) exhibited a downward trend. A comprehensive evaluation of the drought resistance of seven P. edulis Sims varieties was conducted based on the principal component analysis method, and the results showed that the drought resistance decreased in the order XH-BL > XH-TWZ > TN1 > GH1 > ZJ-MT > LP-LZ > DH-JW. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of salinity and water stress on the physiological and functional characteristics of winter wheat (Triticum aestivum L.) under the foliar application of plant growth regulators (PGRs). The experiment was carried out as a split plot based on a randomized complete block design with three replications in two environments. In each environment, water stress at two irrigation levels (after 90 and 120 mm of pan evaporation) and with two EC of 1.5 and 10 dS/m in the main plots and spraying of PGRs including salicylic acid (SA), gibberellic acid (GA3), and cytokinins (CK) (purine) content with a concentration of 100 ppm and the control treatment (spraying solution with normal water) were placed in subplots. Results indicated that all treatments caused significant increases in functional and qualitative characteristics and yield of Triticum aestivum L. The saline environment and irrigation level after 120 mm of pan evaporation caused a reduction in grain yield in all traits except for seed proline, seed nitrogen content, and seed protein content. Also, the combined foliar application of GA3 + CK + SA increased yield in most traits. The highest RWC of flag leaves was observed in the foliar application of GA3 + SA (3.36 kg/ha) and then in the foliar application of GA3 + SA + CK (57.87 kg/ha). GA3 interacts with PGR spraying to balance another development under saline and non-saline conditions. [ABSTRACT FROM AUTHOR]

Water security and food security in the Indus basin are highly interlinked and subject to severe stresses. Irrigation water demands presently already exceed what the basin can sustainably provide, but per-capita food availability remains limited. Rapid population growth and climate change are projected to further intensify pressure on the interdependencies between water and food security. The agricultural system of the Indus basin must therefore change and adapt to be able to achieve the associated Sustainable Development Goals (SDGs). The development of robust policies to guide such changes requires a thorough understanding of the synergies and trade-offs that different strategies for agricultural development may have for water and food security. In this study, we defined three contrasting trajectories for agricultural system change based on a review of scientific literature on regional agricultural developments and a stakeholder consultation workshop. We assessed the consequences of these trajectories for water and food security with a spatially explicit modeling framework for two scenarios of climatic and socio-economic change over the period 1980–2080. Our results demonstrate that agricultural system changes can ensure per capita food production in the basin remains sufficient under population growth. However, such changes require additional irrigation water resources and may strongly aggravate water stress. Conversely, a shift to sustainable water management can reduce water stress but has the consequence that basin-level food self-sufficiency may not be feasible in future. This suggests that biophysical limits likely exist that prevent agricultural system changes to ensure both sufficient food production and improve water security in the Indus basin under strong population growth. Our study concludes that agricultural system changes are an important adaptation mechanism toward achieving water and food SDGs, but must be developed alongside other strategies that can mitigate its adverse trade-offs. [ABSTRACT FROM AUTHOR]

Nowadays, the identification and characterization of grapevine cultivars resilient to climate and water stress while preserving quality traits is crucial for the wine industry. Therefore, the objective of this work was to characterize according to their aromatic potential nine white and six red minority cultivars recently recovered from Castilla-La Mancha region (Spain), subjected to two different water-deficit regimes: rainfed, with subsistence irrigation, and irrigated. For this, the varietal aromatic potential index (IPAv) and the detailed aromatic composition were analyzed via HS-SBSE-GC/MS in extracts of two different pHs. For IPAv values, red varieties did not show a clear trend with respect to irrigation. However, in white minority varieties, higher values were obtained under irrigation conditions. Thus, a clear differentiation of the minority varieties in comparison to the references was observed, primarily attributed to the content of esters and acids, in both white and red varieties. A notable contrast was observed at different pHs, indicating a greater extractability of certain compounds like linalool, under more acidic conditions. This suggests that some recovered minority cultivars could be promising for cultivation in semi-arid regions with limited water, contributing to the sustainability of the wine sector in the future. [ABSTRACT FROM AUTHOR]

Dairy farming plays a crucial role in Saudi Arabia's agricultural industry. However, the intensive milk production process exerts pressure on local water and energy resources. This study aims to examine the impact of water stress and renewable energy consumption shocks on milk production in Saudi Arabia by using data from 2000 to 2021. The empirical analysis used the VAR model, Granger causality, forecast error variance decompositions (FEVDs), and impulse response functions (IRFs). The presence of a negative significant interdependence between total milk production and water stress levels in agriculture was observed. Significant bidirectional causality relationships among the variables were noted. The FEVD results show that water stress levels in agriculture are becoming a more dominant driver of variations in total milk production in Saudi Arabia, while the empirical evidence of the IRFs implies that milk production increases when both water stress levels and renewable energy are present. The adoption of water recycling and reuse systems on dairy farms can help farmers to improve water use efficiency. The encouragement of decision makers to formulate policies to support sustainable water resource management, reduce environmental impact, accelerate technological advancements, and initiate positive socioeconomic outcomes for the dairy industry is highly recommended. [ABSTRACT FROM AUTHOR]

Biochar (BC) and plant growth-promoting microbes (PGPR) could represent a suitable agronomical strategy to mitigate the impacts of drought in arid agro-environmental conditions. However, there is currently little understanding of the synergistic benefit of combining BC and PGPR to increase drought tolerance in oilseeds. In this study, the physiological response of two water-stressed canola (Brassica napus L.) plants subjected to the application of BC obtained from waste wood of Morus alba applied solely or in combination with PGPR strains (Pseudomonas sp.) was evaluated. The experiment consists of two genotypes and nine treatments [(C-Control, T1-15 days drought (15DD), T2-30 days drought (30DD), T3-15 days of drought + PG (15DD + PG), T4-30 days of drought + PG (30DD + PG), T5-15 days drought + biochar (15DD + BC), T6-30 days drought + biochar (30DD + BC), T7-15 days drought + biochar + PG (15DD + BC + PG), T8-30 days drought + biochar + PG (30DD + BC + PG)]. Drought stress decreased emergence energy (EE), leaf area index (LAI), leaf area ratio (LAR), root shoot ratio (RSR), moisture content of leaves (MCL), percent moisture content (%MC), moisture content of shoot (MCS) and moisture content of root (MCR), and relative water content (RWC) in both varieties of Brassica napus L., which in contrast, it is increased by the collective application of both biochar and PGPR. In both varieties, N, P, K, Mg, and Ca concentrations were highest in all the biochar and PGPRs separate and combined treatments, while lowest in 15 and 30 days drought treatments. Osmolyte contents like Glycine betaine (GB) and sugar remarkably increased in the stress condition and then reduced due to the synergistic application of biochar and PGPR. Drought stress has a repressive effect on the antioxidant enzymatic system like Peroxidase (POD), Superoxide dismutase (SOD), and glutathione reductase (GR) as well as total flavonoids, phenolics, and protein content. The antioxidant enzymes and phenolic compounds were dramatically increased by the combined action of biochar and PGPRs. A significant increase in EE, LAR, RSR, and RWC under 15 and 30 days drought conditions, evidently highlighting the synergistic effect of BC and PGPR. The results conclude a substantial and positive effect of the combined use of BC and PGPR strains on canola's response to induced drought stress, by regulating the physiological, biochemical, and agronomic traits of the plants. [ABSTRACT FROM AUTHOR]

Drought stress is affecting crop production worldwide. One promising strategy to reduce the negative effect of drought stress is the foliar application of micronutrients, such as zinc or iron. However, the uptake efficiency over the leaf surface depends on nutrient solubility. In this study the effect of inorganic iron FeSO4 and lysine-chelated iron (Fe-Lys) on productivity and drought tolerance of Nigella sativa L. (Nigella or black cumin) was compared. Moreover, the role of lysine itself was investigated. Spraying leaves with Fe-Lys improved growth and yield under control and drought stress conditions, while FeSO4 had only minor effects. Surprisingly, plants on which only lysine was applied showed many of the improvements of Fe-Lys application, including increased activity of antioxidative enzymes and ion levels. Our results suggest that foliar Fe-Lys application is a promising approach to minimize drought stress effects in Nigella. Moreover, they point to an important function of lysine in drought stress tolerance. The molecular mechanism, further steps to improve the approach and the result's relevance for other plant species are discussed. [ABSTRACT FROM AUTHOR]

Smallholder maize farming systems in sub-Saharan Africa (SSA) are vulnerable to drought-induced yield losses, which significantly impact food security and livelihoods within these communities. Mapping and characterizing genomic regions associated with water stress tolerance in tropical maize is essential for future breeding initiatives targeting this region. In this study, three biparental F3 populations composed of 753 families were evaluated in Kenya and Zimbabwe and genotyped with high-density single nucleotide polymorphism (SNP) markers. Quantitative trait loci maping was performed on these genotypes to dissect the genetic architecture for grain yield (GY), plant height (PH), ear height (EH) and anthesis-silking interval (ASI) under well-watered (WW) and water-stressed (WS) conditions. Across the studied maize populations, mean GY exhibited a range of 4.55--8.55 t/ha under WW and 1.29--5.59 t/ha under WS, reflecting a 31--59% reduction range under WS conditions. Genotypic and genotype-by-environment (G E) variances were significant for all traits except ASI. Overall broad sense heritabilities for GY were low to high (0.25--0.60). For GY, these genetic parameters were decreased under WS conditions. Linkage mapping revealed a significant difference in the number of QTLs detected, with 93 identified under WW conditions and 41 under WS conditions. These QTLs were distributed across all maize chromosomes. For GY, eight and two major effect QTLs (>10% phenotypic variation explained) were detected under WW and WS conditions, respectively. Under WS conditions, Joint Linkage Association Mapping (JLAM) identified several QTLs with minor effects for GY and revealed genomic region overlaps in the studied populations. Across the studied water regimes, five-fold cross-validation showed moderate to high prediction accuracies (0.15--0.90) for GY and other agronomic traits. Our findings demonstrate the polygenic nature of WS tolerance and highlights the immense potential of using genomic selection in improving genetic gain in maize breeding. [ABSTRACT FROM AUTHOR]

Food insecurity has the potential to lead to hunger and famine, which can affect various industries, including the hospitality and tourism (H&T) industry. Despite this, there are very few research studies investigated the effects of these risks on the H&T industry. This lack of research means that the industry is unable to assess the potential impact of food insecurity on the businesses in the industry. Based on this perspective, the current study examines the potential impacts of food insecurity, water stress, and famine risks on the H&T industry. Moreover, this study addresses challenges related to economic sustainability and resilience that have gained importance in the wake of the recent pandemic and the conflict between Russia and Ukraine. In this article, risks associated with food insecurity are discussed and recommendations for future research are provided based on interdisciplinary research and published reports. [ABSTRACT FROM AUTHOR]

Context: The Australian pork industry is highly efficient, with a history of ongoing productivity and environmental improvement. The introduction of economy-wide environmental targets require delivering and tracking performance improvement. Aims: This study determined carbon footprint (greenhouse gas [GHG] and land use [LU] and direct land use change [dLUC] emissions, reported as kg CO2-e), fossil energy (MJ), freshwater consumption (L), water stress (L H2O-e), land occupation (m2) and eutrophication potential (nitrogen and phosphorus) for Australian pork for 2020 and 2022. Variability between housing, manure management systems, and regions were identified, and systems analysed to determine new options for low-impact pork. Methods: In the largest Australian study of its kind, data for ~70% of pigs produced were collected using a stratified design. Using attributional life cycle assessment, impacts were reported per kilogram of liveweight (LW), post-processed, retail, and boneless, fat-corrected pork. Results are presented as industry averages ± 2 × s.d. Key results: Key results were 3.0 ± 0.1 and 3.0 ± 0.1 kg CO2-e GHG, 0.4 ± 0.07 and 0.3 ± 0.03 kg CO2-e LU and dLUC, 12.9 ± 0.5 and 13.4 ± 0.5 MJ, 93.8 ± 9.6 and 52.5 ± 3.6 L, 68.4 ± 6.7 and 43.2 ± 3.3 L H2O-e, and 12.0 ± 0.9 and 12.7 ± 0.9 m2/kg LW in 2020 and 2022, respectively. Due to industry growth, total emissions were higher in 2022. Eutrophication potential for Australian pork (2.2 × 10−4 ± 3.0 × 10−5 kg phosphorus and 8.7 × 10−3 ± 3.5 × 10−4 kg nitrogen/kg LW), reported for the first time, was low compared with grazing systems and European piggeries. Conclusions: Industry has demonstrated long-term performance improvement, though the rate slowed between 2020 and 2022. Ongoing interventions are required to return to trend. Covered pond, deep litter, and outdoor systems produce lower carbon footprint pork and can provide other environmental benefits from renewable energy, and reduced fossil energy demand. Implications: There is potential to further reduce environmental impacts through practice change. If industry is to meet formal targets, investment and proactive policy settings are required to overcome barriers to adoption of existing technology and support the techno-economic case for novel strategies. This study assessed the environmental impacts of Australian pork, and is the most comprehensive (70–72% industry) of its kind in Australia. Eutrophication potential was generally lower than in international pork production. The rate of environmental improvement was slow compared with historic trends. Covered pond, litter-based and outdoor systems produce pork associated with lower greenhouse gas emissions. Australian pork has significant potential to further reduce environmental impacts. [ABSTRACT FROM AUTHOR]

In the context of global climate change and the increase in drought frequency, monitoring and accurately assessing the impact of hydrological process limitations on vegetation growth is of paramount importance. Our study undertakes a comprehensive evaluation of the efficacy of satellite remote sensing vegetation indices—Normalized Difference Vegetation Index (MODIS NDVI product), kernel NDVI (kNDVI), and Solar-Induced chlorophyll Fluorescence (GOSIF product) in this regard. Initially, we applied the LightGBM-Shapley additive explanation framework to assess the influencing factors on the three vegetation indices. We found that Vapor Pressure Deficit (VPD) is the primary factor affecting vegetation in southern China (18°–30°N). Subsequently, using Gross Primary Productivity (GPP) estimates from flux tower sites as a performance benchmark, we evaluated the ability of these vegetation indices to accurately reflect vegetation GPP changes during drought conditions. Our findings indicate that SIF serves as the most effective surrogate for GPP, capturing the variability of GPP during drought periods with minimal time lag. Additionally, our study reveals that the performance of kNDVI significantly varies depending on the estimation of different kernel parameters. The application of a time-heuristic estimation method could potentially enhance kNDVI's capacity to capture GPP dynamics more effectively during drought periods. Overall, this study demonstrates that satellite-based SIF data are more adept at monitoring vegetation responses to water stress and accurately tracking GPP anomalies caused by droughts. These findings not only provide critical insights into the selection and optimization of remote sensing vegetation product but also offer a valuable framework for future research aimed at improving our monitoring and understanding of vegetation growth status under climatic changes. [ABSTRACT FROM AUTHOR]

Ensuring the sustainable management of water and sanitation for all is the primary goal of Sustainable Development Goal 6 (SDG 6). SDG indicator 6.4.2 (level of water stress) is critical for monitoring the progress toward SDG 6. The assessment of the SDG indicator 6.4.2 is currently based on statistical data at the national scale, i.e., one value for one country, which cannot reflect spatial variability in water stress in a country. The lack of data at sub-national scales limits the assessment of water stress in sub-national regions. This study developed a method of disaggregating national statistical renewable water resources (TRWR) and freshwater withdrawals (TFWW) to estimate the SDG 6.4.2 water stress indicator at a sub-national scale by combining satellite remote sensing data and model simulated data. Remote sensing (RS)-based precipitation (P); the difference between precipitation and evapotranspiration (P-ET); and the difference between precipitation, evapotranspiration, terrestrial water storage change (P-ET-dS), and model-simulated naturized runoff and withdrawal water use were used as spatial and temporal surrogates to disaggregate the national-scale statistics of TRWR and TFWW to the grid scale. Gridded TRWR and TFWW can be used to calculate the water stress of any interest regions. Disaggregated TRWR, TFWW, and water stress estimation were validated at three different spatial scales, from major river basins and provinces to prefectures in China, by comparing the corresponding statistical data. The results show that the disaggregation for TRWR is generally better than for TFWW, and the overall accuracy for water stress estimation can reach up to 91%. The temporal evolution of disaggregated variables also showed good consistency with statistical time series data. The RS-based P-ET and P-ET-dS have great potential for disaggregating TRWR at different spatiotemporal scales, with no obvious differences with the results using the model simulation as a surrogate for the disaggregation of SDG indicator 6.4.2. The disaggregation accuracy can be further improved when the sub-regional statistical data of TRWR and TFWW are applied to the disaggregation approach. [ABSTRACT FROM AUTHOR]

Water stress has been one of the most serious threat to the crop growth, development and yield quality in agricultural fields. Timely and accurate diagnosis of crop water stress can greatly contribute to the precision irrigation for the crop resilience and yield. In this study, the research object was taken from the summer maize in the typical dryland agricultural area of northwest China. A six-channel multispectral sensor was mounted on a drone to obtain the remote sensing image data of summer maize at the nodulatione and staminate pulling stage in 2022. At the same time, the stomatal conductance and phenotypic parameters of summer maize were also collected. The background was removed by supervised classification. The canopy vegetation index and image texture were obtained using the gray-scale covariance matrix. The sensitive vegetation index, image texture and phenotypic parameters and their combinations were screened out by the Bayesian information criterion and full subset filtering. The summer maize stomatal conductance estimation model was constructed to combine the three types of machine learnings: the extreme learning machine, the random forest, and the back-propagation neural network. The optimal model was mapped to estimate the stomatal conductance. The Pearson correlation coefficient of vegetation index and stomatal conductance were significantly positively correlated, whereas, the canopy reflectance of summer maize was weakly negatively correlated. Different types of image textures at different wavelengths were correlated with the stomatal conductance, and the highest correlation was found in the 550 nm band. The Pearson correlation coefficients between morphological structure phenotypes (plant height, stem thickness and leaf area) and stomatal conductance of summer maize were 0.72, 0.58 and 0.69, respectively, where the three types of phenotypic parameters data were correlated well with stomatal conductance. Vegetation indices with spectral reflectance data were used to assess the overall health and moisture status of the vegetation. Image texture was used to capture the spatial distribution, texture and structural features of crops. Crop phenotypic parameters were then used to reflect the physiological and morphological responses of the crop in a three-dimensional manner, providing visual information about the growth and moisture of the vegetation. The decision coefficients of the crop water stress diagnostic models that constructed from the three information sources increased from 0.728 and 0.750 to 0.841, respectively, compared with the single or two combinations, indicating the great potential to stomatal conductance prediction. The optimal combination of indicators was screened by Bayesian information criterion and full subset screening: DWSI, NDVI, MEA, ENT, plant height and leaf area. The back-propagation neural network model with the three complementary information sources was the optimal model for the water stress diagnosis of summer maize (coefficient of determination of 0.841, root mean square error of 0.043 mol/(m2 ·s), and mean absolute error of 0.034 mol/(m² ·s)). The underestimation of stomatal conductance was significantly improved, compared with the rest models. The inverse map with the optimal model was widely applied to easily and accurately diagnose the crop water stress for the purpose of irrigation strategies and resource allocation. The finding can provide a feasible and accurate diagnosis of water stress in summer maize. [ABSTRACT FROM AUTHOR]

Japanese plums have relatively high water requirements, which depend on supplementing rainfall volumes with accurately quantified irrigation water. There is a lack of knowledge on the seasonal water requirements of plum orchards. This gap in the literature poses an imminent threat to the long-term sustainability of the South African plum industry, which is particularly plagued by climate change and diminishing water resources. The systematic literature review conducted in this study aimed to provide a foundation for supporting water management in irrigated Japanese plum [Prunus salicina Lindl.] orchards. Seventeen peer-reviewed articles obtained from the literature were analyzed. Approximately 66% of the cultivars were cultivated under different regulated deficit irrigation regimes for water-saving purposes and to increase fruit quality. This review of our knowledge provided benchmark figures on the annual water requirements of Japanese plums. The full-year plum crop water requirements obtained from the literature ranged between 921 and 1211 mm a−1. Canopy growth, pruning and growing season length were the most common causes of differences in the water requirement estimates. Further research is required to measure the water requirement of plums from planting to full-bearing age and the response of plum trees to water stress, especially in the South African context. [ABSTRACT FROM AUTHOR]

Studying the dynamics of groundwater in mining areas is important from the perspective of impact on ecosystems. This study determines water stress for subarctic mining areas using modern methods—remote sensing, machine learning, GIS. The study is carried out using the example of the Kostomuksha mining cluster, located in the northwestern part of the Republic of Karelia, Russia. Water stress was studied based on changes in NDMI in different vegetation land cover classes. To bring different values of remote sensing data to a single scale, the method of normalization by pseudo-invariant features (PIF) was applied. Landscape, climatic, topographic, and anthropogenic factors that control changes in humidity were studied, for a total of 15 variables. The importance of predictors was assessed using the recursive feature elimination method. The most important predictors are vegetation LCC, valley depth, distance to road, elevation, and KdistQ. The topographical features of the area have a large influence on the natural dynamics of NDMI. The greatest negative changes occur on steep slopes, as well as hills and ridges. The accumulation of water in the valleys forms the positive dynamics of NDMI. The interaction of the influence of mining with natural patterns of changes in vegetation humidity has been studied. The greatest negative changes are manifested for all vegetation classes within the newly formed groundwater depression cones. In areas of previously formed depression cones, the adaptation of vegetation to water stress is noted. Deciduous vegetation in wetlands has been determined to be most sensitive to anthropogenic stress. [ABSTRACT FROM AUTHOR]

Alterations in leaf architecture can be used as an indicator of the substrate toxicity level as well as the potential of a given plant species in the phytoremediation of polluted areas, e.g., mining sludge. In this work, we demonstrated, for the first time, the nature and scale of alterations in leaf architecture at the tissue and cellular levels occurring in Norway maple growing on mining sludge originating from a copper mine in Lubin (Poland). The substrate differs from other mine wastes, e.g., calamine or serpentine soils, due to an extremely high level of arsenic (As). Alterations in leaf anatomy predominantly included the following: (1) a significant increase in upper epidermis thickness; (2) a significant decrease in palisade parenchyma width; (3) more compact leaf tissue organization; (4) the occurrence of two to three cell layers in palisade parenchyma in contrast to one in the control; (5) a significantly smaller size of cells building palisade parenchyma. At the cellular level, the alterations included mainly the occurrence of local cell wall thickenings—predominantly in the upper and lower epidermis—and the symptoms of accelerated leaf senescence. Nevertheless, many chloroplasts showed almost intact chloroplast ultrastructure. Modifications in leaf anatomy could be a symptom of alterations in morphogenesis but may also be related to plant adaptation to water deficit stress. The occurrence of local cell wall thickenings can be considered as a symptom of a defence strategy involved in the enlargement of apoplast volume for toxic elements (TE) sequestration and the alleviation of oxidative stress. Importantly, the ultrastructure of leaf cells was not markedly disturbed. The results suggested that Norway maple may have good phytoremediation potential. However, the general shape of the plant, the significantly smaller size of leaves, and accelerated senescence indicated the high toxicity of the mining sludge used in this experiment. Hence, the phytoremediation of such a substrate, specifically including use of Norway maple, should be preceded by some amendments—which are highly recommended. [ABSTRACT FROM AUTHOR]

Background: Characterisation of the structure and water status of leaf tissues is essential to the understanding of leaf hydraulic functioning under optimal and stressed conditions. Magnetic Resonance Imaging is unique in its capacity to access this information in a spatially resolved, non-invasive and non-destructive way. The purpose of this study was to develop an original approach based on transverse relaxation mapping by Magnetic Resonance Imaging for the detection of changes in water status and distribution at cell and tissue levels in Brassica napus leaves during blade development and dehydration. Results: By combining transverse relaxation maps with a classification scheme, we were able to distinguish specific zones of areoles and veins. The tissue heterogeneity observed in young leaves still occurred in mature and senescent leaves, but with different distributions of T2 values in accordance with the basipetal progression of leaf blade development, revealing changes in tissue structure. When subjected to severe water stress, all blade zones showed similar behaviours. Conclusion: This study demonstrates the great potential of Magnetic Resonance Imaging in assessing information on the structure and water status of leaves. The feasibility of in planta leaf measurements was demonstrated, opening up many opportunities for the investigation of leaf structure and hydraulic functioning during development and/or in response to abiotic stresses. [ABSTRACT FROM AUTHOR]

Determining the factors that set species' range limits is of critical importance in an era of rapid climate and biotic change. Mangroves dominate global tropical coastlines, but their subtropical range limits are thought to be mainly constrained by cold air. However, several tropical mangrove range limits are conspicuously warm, arid, and dominated by cold water countercurrents. Despite speculation that the combination of cold water and aridity controls these range limits, investigations of this phenomenon are rare.Here, we conducted an experimental study examining the separate and interactive effects of cold water and aridity on survival, growth, and ecophysiological traits of three mangrove species from the arid, countercurrent range limit in Baja California, Mexico. It is one of the few range edges worldwide where red and white mangroves (Rhizophora mangle and Laguncularia racemosa, respectively), not the putatively stress‐tolerant black mangroves (Avicennia germinans), are the most poleward distributed mangroves, providing further opportunity to examine how mangrove ecophysiological traits affect species‐specific range limits.Black mangroves were surprisingly intolerant of cold water regardless of aridity, with no seedlings surviving in the lowest water temperature (13°C) after 8 months. In contrast, both white and red mangrove seedlings were able to survive at 13°C when humidity was 65% (but not 40%).In cold water and arid conditions, leaf stomatal conductance was consistently lowest for white mangroves, intermediate for red mangroves, and highest for black mangroves, suggesting that white mangroves were the most resistant to transpiration water loss in the arid conditions typical of Baja.Similarly, when exposed to drought after the eight‐month experiment, white mangroves grown in cold water survived longer than red and black mangroves.Synthesis: Ultimately, our results suggest that the species‐specific range limits of mangroves in Baja California reflects their species‐specific adaptations (or lack thereof) to cold water and aridity, with white and red mangroves surprisingly outperforming black mangroves. Further, the difference in our results compared to the same species in other ranges underscores the need to incorporate species and range‐specific traits when conducting distribution modelling to predict the effects of climate change on organism range limits. [ABSTRACT FROM AUTHOR]

Water shortages and population surges pose notable challenges to food security. North China is an important grain base of the country, with limited available water resources. Therefore, it is necessary to research the patterns of photosynthate accumulation, distribution, and transfer in summer maize under water stress. On the basis of existing methods, in this study, we considered the impact of water stress with two methods, namely the distribution coefficient method and the distribution index method. The results showed that the water correction coefficient indices of the stem–leaf ratio spike–stem ratio, and root–shoot ratio were 0.2705, 0.3530, and −0.2097, respectively, which revealed that water stress caused a decrease in the stem–leaf ratio and spike–stem ratio and an increase in the root–shoot ratio. Water stress caused a reduction in the stem distribution index and leaf distribution index and a slight increase in the spike distribution index. The filling stage was the critical period for water stress to affect the distribution coefficient of each organ, while the jointing stage was the critical period for water stress to affect the leaf distribution index. During the middle growth period, water stress exerted the greatest impact on the distribution parameters. Water stress imposed a greater influence on the distribution coefficient than on the distribution index. The two methods effectively simulated the accumulation and distribution process of photosynthates under water stress conditions, and the R2, average absolute percentage and root mean square error values were 0.9358–0.9997, 4.15–22.71%, and 2.6–24.37%, respectively. The change trend of the photosynthate transfer rate calculated by the distribution coefficient method under water stress conditions was more consistent with that of the actual values. The distribution coefficient method generally performed better than the distribution index method. This study avoids the problem of solely relying on experimental data to determine crop growth dynamics and provides a way to describe crop photosynthate accumulation continuously and quantitatively. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) has been studied for its potential to enhance stress tolerance in plant systems, but the role of hydrogen sulfide (H2S) in GSH‐induced water stress tolerance in sweet pepper (Capsicum annuum L.) is still under investigation. This study explores how H2S and GSH modulate water stress tolerance in pepper plants, addressing a research gap. The joint effect of sodium hydrosulfide (NaHS), a donor of H2S, and GSH on water stress tolerance was determined through pre‐treatment with the H2S scavenger 0.1 mM hypotaurine (HT). Pepper seedlings were sprayed with 1.0 mM GSH or GSH + 0.2 mM NaHS once a week, with soil moisture content set at 80% and 40% for full irrigation and water stress conditions for a duration of 2 weeks. The results showed that water stress significantly reduced total plant dry weight, chlorophyll a and b content, Fv/Fm, leaf water potential, and relative water content by 50%, 56%, 33%, 27%, 52%, and 34%, while increasing hydrogen peroxide (H2O2), proline, and H2S levels by 152%, 134%, and77%, respectively. Treatment with GSH and NaHS reduced water stress‐induced H2O2 production and improved plant growth, photosynthetic traits, proline, and the activity of L‐cysteine desulfhydrase (L‐DES), leading to the generation of H2S content. GSH reduced NADPH oxidase (NOX), superoxide dismutase (SOD), and H2O2 but increased glutathione peroxidase (GPX) activities. The interaction of NaHS and GSH led to further reductions in NOX, SOD, and H2O2 values but increased GPX activity. The combined GSH and NaHS treatment increased nitric oxide (NO) production but decreased the activity of S‐nitrosoglutathione reductase (GSNOR), potentially accelerating S‐nitrosylation. Hypotaurine negated the positive impacts of GSH on water stress tolerance by reducing H2S concentration in pepper plants, but this was corrected by the concurrent application of NaHS and GSH + HT. Therefore, water stress tolerance requires H2S. [ABSTRACT FROM AUTHOR]

China faces severe water resource shortages due to the uneven distribution of water resources and ever-increasing water demand driven by rapid industrialization and urbanization. The virtual water trade (VWT) is a potential solution to conserve water resources by transferring water from water-abundant/water-productive regions to water-scarce/less water-productive regions. Based on the inter-provincial input-output model, the provincial VWT of China was estimated at the sectoral level. The relationship of VWT with water resources in 30 provinces was analyzed in relation to the water stress index (WSI). It was found that (1) total inter-provincial VW trade showed a downward trend during the study period, with 363.91 km3 in 2002, 283.72 km3 in 2007, and 285.23 km3 in 2012. Overall, the primary industry dominated the VWT for most provinces. (2) China's virtual water flowed from the relatively underdeveloped central and western regions to the east with a relatively developed economy from the inter-provincial level. This trend became increasingly prominent. (3) In many instances, VW was transferred from water-poor to water-rich areas. These results imply that China needs to improve its water use efficiency and optimize its regional industrial structure. Additionally, establishing an ecological compensation mechanism is considered a valuable measure for China to alleviate regional water resource pressure. [ABSTRACT FROM AUTHOR]

Copyright of Mustafa Kemal University Journal of Agricultural Sciences / Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi is the property of Mustafa Kemal University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, we analyzed the effect of water stress and acid pH on the growth of the endemic fodder legume Chamaecytisus albidus, inoculated with four strains of Bradyrhizobium, from three different symbiovars previously isolated from the plant grown in different eco-geographical areas of Morocco. We also assessed the competitiveness of the three symbiovars for plant nodulation under water stress and acidity. We analyzed the strain's nodulation ability, rates of nodules occupancy, shoot, and root dry weights of plants grown at -100, -80, and − 60 MPa water potential, and 6.0 and 7.0 pH values. The strains CM64 and CJ2 belong to the symbiovar genistearum and strains CA20 and CB10 to the symbiovars retamae and lupini, respectively. The strains CB10 and CJ2 were the most infective regardless of the pH and water potential at which the plants were grown. The strain CB10 was also the most abundant in nodules from plants grown at any conditions examined. Reductions in the water potential altered the nodulation ability, the strains CB10 and CJ2 still being the more infective. These strains were also the most infective at pH 6.0 and 7.0. The highest values of shoot and root dry weights were recorded in plants inoculated with strain CA20 under all the irrigation regimes used. The reduction from 100% to 80 and 60% field capacity decreased the shoot dry weight of the plants by 31.23 and 67.06%, respectively. Moreover, there was a 37.95 and 61.74% decrease in plant root dry weight when grown at 80 and 60% of field capacity, respectively. Despite variations in the efficiency of each strain, overall, the pH did not affect either the SDW or the RDW of the plants. The inoculation of C. albidus with a mix of the four strains did not result in further improvement of nodulation or symbiotic efficiency. These results show that water deficiency drastically affects the growth of C. albidus and that the retamae symbiovar was the most effective under the conditions examined. This is the first report on the competitiveness of symbiovars for the nodulation of a legume under stress. [ABSTRACT FROM AUTHOR]

The infertility of sandy soil hampers the growth of many crops. Typically, chemical fertilizers are used to handle this issue, but they are expensive and have deleterious implications on the ecosystem. A two-year field investigation was carried out on cowpea cultivated in sandy soil to assess the effects of different watering levels (70, 80, 90, and 100% of the actual irrigation requirements), chemical fertilizers, organic fertilizers, and biofertilizer (Bradyrhizobium sp.), and their combinations on the morpho-physiological traits and yield of cowpea (Vigna unguiculata L. Walp, cv. Giza 18). Overall, the findings showed that cowpea osmoregulatory molecules (sugars, proteins, and proline) demonstrated greater accumulation, with the content depending on the watering level. The applied fertilizers demonstrated improved cowpea performance at the regular watering level, with chopped potato tops outperforming other fertilizer formulations. Furthermore, the combination of water stress treatments and fertilizer formulations was impactful in relieving the detrimental consequences of water stress as it enhanced plant growth performance, production efficiency, metabolic homeostasis, nutritional value, and mineral ions composition. Subsequently, our results demonstrated agro-wastes, particularly chopped potato tops, could be an effective substitute for chemical fertilizers in sandy soils to sustainably increase soil fertility as well as cowpea yield performance. [ABSTRACT FROM AUTHOR]

Leucojum aestivum L. is an Amaryllidaceae bulbous plant with two alkaloids that have remarkable medicinal potential: galanthamine and lycorine. Although the presence of galanthamine in L. aestivum has commercial value for the pharmaceutical industry and the effect of water stress (WS) applications on secondary metabolite enhancement is well established in a variety of plants, no studies have been carried out to reveal the effectiveness of WS on this beneficial medicinal plant. Objective of the study was to investigate the effects of eight different WS treatments [Control, waterlogging (WL) condition, and drought stress conditions (water deficiency generated by water deficit irrigation-WDI 25%, 50%, and 75%- and polyethylene glycol-PEG 6000 15%, 30%, and 45%-)] on growth parameters, alkaloid levels (galanthamine and lycorine), non-enzymatic antioxidant activities (total phenol-flavonoid content and free radical scavenging activity), and enzymatic antioxidant activities [superoxide dismutase (SOD) and catalase (CAT)] of L. aestivum in a pot experiment. Based on the findings, maximum increases in growth parameters were obtained with PEG-induced WS treatments. Moderate water deficiency (50% WDI) produced the highest levels of galanthamine and lycorine, total phenol-flavonoid content, and antioxidant capacity, along with moderately elevated CAT activity in the bulbs. All WS treatments resulted in increased CAT activity in the bulbs. It was observed that bulbs had higher SOD and CAT activities under WL conditions had lower fresh weights and were close to control in terms of alkaloid levels, total phenol-flavonoid content, and free radical scavenging activity. When all of the outcomes were taken into account, it can be concluded that moderate water-deficit stress (50% WDI) was regarded as the most effective treatment for increasing the pharmaceutical value of L. aestivum. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Agronomy is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study employed the bibliometric software CiteSpace 6.1.R6 to analyze the correlation between thermal infrared, spectral remote sensing technology, and the estimation of economic forest water stress. It aimed to review the development and current status of this field, as well as to identify future research trends. A search was conducted on the China National Knowledge Infrastructure (CNKI) database using the keyword “water stress” for relevant studies from 2003 to 2023. The visual analysis function of CNKI was used to generate the distribution of annual publication volume, and CiteSpace 6.1.R6 was utilized to create network maps illustrating collaboration among authors and institutions. The study also analyzed the hotspots and frontiers of economic forest water stress. As a result, a total of 6664 academic journal articles related to water stress were retrieved. Considerable collaboration networks were observed among scholars and institutions, with a focus on using crown temperature monitoring to diagnose crop water stress. Based on the research findings, it was evident that the primary research trend involved the use of thermal infrared and spectral remote sensing technology for estimating water stress, making it a future research hotspot. [ABSTRACT FROM AUTHOR]

Purpose: Mexico faces severe water availability problems, resulting in higher stress on its distribution in many states. To resolve the increasing water demand, it is essential to evaluate public water management to ensure the success of any decision-making policies to decrease the water pressure in the country. Methodology/Approach: For water management systems, benchmarking their performance relative to others can be an appropriate way to identify possible improvements. Using data from the National Census for drinking water and sanitation in 109 municipalities in the northwest region of Mexico, this analysis aims to evaluate the water management efficiency based on a two-stage Bootstrap Data Envelopment Analysis model with intermediate variables. Findings: The study found average efficiency in water system management but very low efficiency in system improvements. Additionally, no relationship was identified between the two stages or population size and density. Research Limitation/implication: The study highlights the need for transparent water policies to address the country's shortage. It is important to adjust municipal public water system management operations and design future strategic planning. Originality/Value of paper: The presented analysis investigates a relationship between water management and water system improvements. [ABSTRACT FROM AUTHOR]

The rapid decline in water availability for irrigation on the Texas High Plains (THP) is a significant problem affecting crop production and the viability of a large regional economy worth approximately USD 7 billion annually. This region is the largest continuous cotton-producing area in the United States, and the timely delivery and efficient use of irrigation water are critical to the sustainability and profitability of cotton production in this region. Current irrigation scheduling must be improved to reduce water consumption without compromising crop production. Presently, irrigation scheduling based on reference evapotranspiration (ETo) is limited due to the lack of reliable and readily available in-field weather data and updated crop coefficients. Additionally, in-field variability in crop water demand is often overlooked, leading to lower irrigation efficiency. To address these challenges, we explored the potential use of an unmanned aerial vehicle (UAV)-based crop monitoring system to support irrigation management decisions. This study was conducted in Lubbock, Texas, in 2022, where high temporal and spatial resolution images were acquired using a UAV from a cotton field experiment with four irrigation levels. Soil moisture and canopy temperature sensors were deployed to monitor crop response to irrigation and rainfall. The results indicated a significant effect of water stress on crop growth (revealed by UAV-based canopy cover (CC) measurements), yield, and fiber quality. Strong correlations between multi-temporal CC and lint yield (R2 = 0.68 to 0.88) emphasized a clear trend: rainfed treatments with lower yields exhibited reduced CC, while irrigated plots with higher CC displayed increased yields. Furthermore, irrigated plots produced more mature and uniform fibers. This study also explored various evapotranspiration calculation approaches indicating that site-specific CC measurements obtained from a UAV could significantly reduce irrigation application. A regression model linking evapotranspiration to canopy cover demonstrated promising potential for estimating water demand in crops with an R2 as high as 0.68. The findings highlight the efficacy of UAV-based canopy features in assessing drought effects and managing irrigation water in water-limited production regions like the THP. [ABSTRACT FROM AUTHOR]

The purpose of this work is to study the influence of reduced irrigation rates on the productivity of corn (FAO group 600) grown for grain in the Plovdiv region and to establish the parameters of the “Total yieldirrigation rate” relationship. The experiment was carried out in the period 2004-2018 in Agricultural University – Plovdiv, with the late hybrid “Knezha-613”. The variants of the experiment are: 1) without irrigation; 5) optimal irrigation (pre-irrigation soil moisture 75% of FC for the layer 0-80 cm); 2, 3, and 4) irrigation with respectively 25, 50 and 75 % of the rate for variant 5. The relationship is determined based on three types of formulas – regression equation, quadratic formula, and power formula. The highest accuracy is achieved by power relationship at power exponent n=1.3 and r=0.725. The quadratic formula is recommended when relative yield data are only under non-irrigated conditions. These two variants of relationship give a sufficiently accurate forecast for the yield when irrigation rates are reduced by up to 25%. The regression is also usable, but it is inferior to the power and quadratic variants. [ABSTRACT FROM AUTHOR]

The aim of the study is to establish the parameters of the relationship „Yield-ET by swaths” in a grass mixture of English ryegrass (Lolium perenne L.) and Red fescue (Festuca rubra L.). Data from an experiment with the application of a regulated water deficit, conducted at the Forestry University - Sofia, were used. The output data included the relative values of yield and evapotranspiration (ET) for each of the sub-crops separately. Two types of formulas were used: for the relationship „Yield-seasonal ET” and for the relationship „Yield-ET by phenophases”. From the first group, the two-power equation is recommended, according to which the first three swaths have greater requirements for ET, which can form some yield when providing at least 40-50% of the maximum ET. The fourth and fifth swaths show smaller requirements, but the differences compared to the first three swaths are in the range of 10-30%. Of the second group of equations, Steward’s linear formula, modified for use in swath crops, is recommended. It presents the relationship most realistically with R=0.983 and minimal difference between different swaths in terms of their sensitivity. [ABSTRACT FROM AUTHOR]

Grapevines are frequently subjected to heatwaves and limited water availability during ripening. These conditions can have consequences for the physiological health of the vines. Moreover, the situation is often exacerbated by intense solar radiation, resulting in reduced yield due to sunburn and a decline in quality. In light of these challenges, our study aimed to develop a fruit-zone cooling system designed to mitigate grape sunburn damage and improve the microclimate conditions within the vineyard. The system comprises a network of proximal sensors that collect microclimate data from the vineyard and an actuator that activates nebulizers when the temperature exceeds the threshold of 35°C. The research was conducted over two years (2022 and 2023) in Bologna (Italy) using potted Sangiovese and Montepulciano vines. These two vintages were characterized by high temperatures, with varying amounts of rainfall during the test period, significantly impacting the evaporative demand, which was notably higher in 2023. Starting from the veraison stage we compared three treatments: Irrigated control vines (WW); Control vines subjected to 50% water restriction during the month of August (WS); WS vines treated with nebulized water in the bunch area during the stress period (WS+FOG). The application of nebulized water effectively reduced the temperature of both the air around the clusters and the clusters themselves. As we expected, Montepulciano showed better single leaf assimilation rate and stomatal conductance under non-limiting water conditions than Sangiovese while their behavior was unaffected under water-scarce conditions. Importantly, for the first time, we demonstrated that nebulized water positively affected gas exchange in both grape varieties. In addition to this, the vines treated with the misting system exhibited higher productivity compared to WS vines without affecting technological maturity. In the 2023 vintage, the activation of the system prevented the ripening blockage that occurred in Montepulciano under water stress. Regarding the concentration of total anthocyanins, a significant increase in color was observed in WS+FOG treatment, suggesting a predominant role of microclimate on anthocyanin biosynthesis and reduction of oxidative phenomena. In conclusion, the fruitzone cooling system proved to be an invaluable tool for mitigating the adverse effects of multiple summer stresses. [ABSTRACT FROM AUTHOR]

The development of non-invasive methods and accessible tools for application to plant phenotyping is considered a breakthrough. Thiswork presents the preliminary results using an electronic nose (E-Nose) and machine learning (ML) as affordable tools. An E-Nose is an electronic system used for smell global analysis, which emulates the human nose structure. The soybean (Glycine Max) was used to conduct this experiment under water stress. Commercial E-Nose was used, and a chamber was designed and built to conduct the measurement of the gas sample from the soybean. This experiment was conducted for 22 days, observing the stages of plant growth during this period. This chamber is embedded with relative humidity [RH (%)], temperature (°C), and CO2 concentration (ppm) sensors, as well as the natural light intensity, which was monitored. These systems allowed intermittent monitoring of each parameter to create a database. The soil used was the red-yellow dystrophic type and was covered to avoid evapotranspiration effects. The measurement with the electronic nose was done daily, during the morning and afternoon, and in two phenological situations of the plant (with the healthful soy irrigated with deionized water and underwater stress) until the growth V5 stage to obtain the plant gases emissions. Data mining techniques were used, through the software "Weka™" and the decision tree strategy. From the evaluation of the sensors database, a dynamic variation of plant respiration pattern was observed, with the two distinct behaviors observed in the morning (~9:30 am) and afternoon (3:30 pm). With the initial results obtained with the E-Nose signals and ML, it was possible to distinguish the two situations, i.e., the irrigated plant standard and underwater stress, the influence of the two periods of daylight, and influence of temporal variability of the weather. As a result of this investigation, a classifier was developed that, through a non-invasive analysis of gas samples, can accurately determine the absence of water in soybean plants with a rate of 94.4% accuracy. Future investigations should be carried out under controlled conditions that enable early detection of the stress level. [ABSTRACT FROM AUTHOR]

Solanum tuberosum is one of the most widely cropped plant species worldwide; unfortunately, drought is one of the major constraints on potato productivity because it affects the physiology, biochemical processes, and yield. The use of arbuscular mycorrhizal fungi (AMF) has exhibited beneficial effects on plants during drought. The objective of this study was to analyse the effect of AMF inoculation on two genotypes of potato plants exposed to water stress, and the photosynthetic traits, enzymatic antioxidant activity, and exudation of low-molecular-weight organic acids (LMWOAs) of potato plants inoculated with two strains of AMF, Claroideoglomus claroideum (CC) and Claroideoglomus lamellosum (HMC26), were evaluated. Stomatal conductance exhibited a similar trend in the CC and HMC26 treatments for both potato genotypes; moreover, the photosynthetic rate significantly increased by 577.9% between the 100% soil humidity (S0) and 40% soil humidity (S2) stress levels for the VR808 genotype under the CC treatment. The activities of the enzymes catalase (CAT) and ascorbate peroxidase (APX) showed similar trends. In this study, there were different responses among genotypes and treatments. Inoculation with CC under S2 stress levels is a promising potential approach for improving potato growth under drought conditions. [ABSTRACT FROM AUTHOR]

This work aimed to verify if it is possible to select soybean genotypes tolerant to diseases and water stress. The experimental design was randomized blocks (RBD), with thirty soybean genotypes, in four replications, totaling 120 experimental units. Evaluations were performed based on crop yield components and disease incidence in thirty soybean cultivars in field conditions. Analysis of variance was performed at 5% probability using the F test. Variables that showed significance were compared using Scott-Knott's grouping of means at 5% probability. Pearson's linear correlation coefficients were calculated between pairs of variables, with significance imposed by the t test at 5% probability. The Euclidean distances were calculated and the UPGMA grouping was performed to construct the genetic dissimilarity dendrogram, after which the biplot principal components were used to identify the association trend between variables and cultivars. It was possible to select soybean genotypes for grain production and disease tolerance in an environment with water stress. Cultivars M 5947 IPRO, TEC 6702 IPRO, M 6410 IPRO showed the highest grain yield. The cultivar TEC 6702 IPRO showed the best agronomic performance for morphological and productive characteristics, associated with the lowest incidence of diseases. [ABSTRACT FROM AUTHOR]

In the current study, a collection of forty-seven tomato accessions divided into five groups and the sensitive control MoneyMaker were evaluated based on their performance under the condition of reduced irrigation. The tomato accessions were exposed to water stress (50% reduced irrigation). The reproductive traits (flower and fruit number, fruit set) and fruit weights were used in assessing the drought tolerance. A decrease in the flower number, fruit number, the fruit set and fruit weight from 2nd to 5th inflorescence was observed in scarcity. Among the studied tomato groups, the indeterminate, the large fruited ones were the most strongly affected by the stress: reductions of 41.5% in the number of fruits and 40.0% of the average fruit weight were observed. The studied “Cherry” tomato and the accessions from Solanum pimpinellifolium L. have had a better drought tolerance compared to other groups. The cluster analysis showed that the individual accessions belonging to sensitive groups also possessed a better tolerance to water deficit. [ABSTRACT FROM AUTHOR]

Due to water scarcity challenges, efficient management of irrigation water is becoming crucial. Water use efficiency (WUE) involves increasing crop productivity without increasing water consumption. This study was carried out to study the effect of hydrogel, deficit irrigation and soil type on WUE, soil hydro-physical properties and lettuce productivity. For this purpose, four irrigation treatments (100%, 85%, 70% and 60% of full irrigation requirements), four hydrogel concentrations (0, 0.1, 0.2 and 0.3% w/w) and three soil textural classes (clay, loamy sand, and sandy-clay soil) were conducted in pot experiment at open field during two consecutive seasons. The results revealed that crop growth parameters and soil hydro-physical properties were significantly affected by hydrogel application rates. Hydrogel addition significantly enhanced head fresh and dry weights, chlorophyll content, number of leaves and WUE. Application of hydrogel at 0.3% and 85% of irrigation requirements achieved the highest WUE without significant yield reductions. Changes in the studied hydro-physical properties of soil were more dependent on soil texture and hydrogel application rate than on the amount of irrigation water. The significant decrease in soil saturated hydraulic conductivity and bulk density confirms that super absorbent hydrogels could be recommended to improve soil water retention and enhance water use efficiency under deficit irrigation conditions. [ABSTRACT FROM AUTHOR]

The evolutionary dynamics of tree species are influenced by their specific climatic environments, and their ability to persist is determined by adaptive strategies such as broad climate tolerance, phenotypic plasticity or genetic differentiation. Biogeographical predictions indicate that populations located at the edges of their ranges are more likely to experience heightened vulnerability to climatic fluctuations due to approaching tolerance limits. However, if local phenotypic acclimation or genetic adaptation has taken place, trees near the edge of their range could demonstrate comparable sensitivity to freeze and drought as the rest of the sampled population. Nevertheless, there remains uncertainty regarding the extent of developmental and evolutionary adjustments in climate sensitivity across the entire ranges of many tree species.Here, we document the biogeography of tree growth sensitivity to freeze and soil water and vapour pressure deficits during 1950–2018 using an extensive multi‐species tree‐ring dataset of 35,784 trees at 4535 sites covering boreal, temperate conifer and temperate deciduous forests of Canada. We quantify the relationships between tree radial growth increment and seasonal climate variables and explore factors driving the observed patterns of annual growth and climate sensitivity such as species, regional climate and local site conditions, and tree age and size.Freeze and drought had widespread impacts on tree growth that were contingent on the presence of focal species in interaction with tree size. An indirect growth thermal limitation towards cold/wet edges, occurring through the site moisture conditions, was observed in seven widespread species (e.g. Picea glauca, Picea mariana and Larix laricina). Moreover, six species had negative drought impacts more strongly expressed towards their warm/dry edges (e.g. Abies balsamea, Betula papyrifera and Pseudotsuga menziesii). However, widespread Picea, Pinus and Populus species showed no indication of increased sensitivity to soil water conditions at these edges.Synthesis. Our findings support the idea of evolutionary or acclimatization adjustments in the development of populations in response to long‐term climate conditions experienced in their respective locations. This underscores the importance of incorporating phenotypic and genomic data into future analyses of climate change impacts, which would enhance our ability to predict potential ecological shifts. [ABSTRACT FROM AUTHOR]

To address the lack of effective monitoring, evaluation, and prediction methods for water stress in citrus seedlings, we conducted 10 sets of water stress gradient experiments. Based on the experimental dataset, we constructed, trained, and improved an MLP classification model for citrus seedling water stress. In addition, we developed a monitoring, evaluation, and prediction system based on this model. The experiments demonstrated that 7 days of slight water stress can induce changes in overall root wilting and growth stagnation, and the chlorophyll content in the leaves can decrease by up to 11.78%. Furthermore, the optimal VWC for seedlings was [45%, 50%], the boundary of drought was [20%, 25%], and the boundary of waterlogging was [50%, 55%]. We validated the effectiveness of the system in assessing the growth status of seedlings over the past 7 days and predicting it after 7 days through testing sets and experiments on slight water stress. We found that the system achieved non-destructive remote monitoring, evaluation, and prediction of slight water stress in citrus seedlings, thus enhancing seedling quality. These research findings provide valuable insights into water stress management in citrus seedlings and other crops. [ABSTRACT FROM AUTHOR]

Aims: Combining multiple features of UAV-based multispectral images with the stacking ensemble model, to improve the feasibility and accuracy of evaluating water stress in winter wheat. Methods: UAV-based multispectral images of winter wheat with different moisture treatments were acquired, from which the features such as spectrum, texture, and color moments were extracted. The soil moisture content (SMC) as well as fuel moisture content (FMC), plant moisture content (PMC), and above-ground biomass (AGB) were collected for charging the degree of water stress. The basic models were used to build ensemble models such as stacking and weighted stacking (WE-stacking), and we estimated SMC, FMC, PMC and AGB combined with multiple features. The performance of these models was evaluated. Results: The more severe the water stress, the lower values of SMC, FMC, PMC and AGB were obtained with estimation models. The performance of estimation models based on multi-feature fusion outperformed single feature in the evaluation of winter-wheat water stress. In the estimation of SMC, both stacking and WE-stacking models performed better than the basic models. Compared to the stacking model, the WE-stacking model had higher accuracy, with R2 increased between 1.98% and 3.62% at different soil depths. The WE-stacking model with multi-feature fusion still had sufficient stability and high accuracy in FMC, PMC and AGB estimation, with R2 of 0.866, 0.881 and 0.884, respectively. Conclusions: The multi-feature fusion of UAV multispectral images combined with WE-stacking model has great application potential and provides technical support in evaluating crop water stress. [ABSTRACT FROM AUTHOR]

Response of 20 genotypes of sorghum to both full irrigation (100% ET) and deficit irrigation (60% ET) which were evaluated to identify water stress effects on yield and its attributes. The field experiments were conducted in Assiut Research Station, Assiut Governorate, Egypt, during 2021 and 2022 growing seasons. Two experiments were practiced separately under normal irrigation and water stress conditions. The combined analysis of variance for 20 genotypes across two years under two locations (normal (100% ET) and stress (60% ET) revealed highly significant differences among genotypes for all studied traits. Moreover, the genotypes × irrigation interaction variance was also highly significant or significant for all the studied traits except for panicle length. The highest means value for 1000-kernel weight across two years under two treatments (27.33 g) was given by EXO-27 genotype and for grain yield (24.20 ard. /fed.) by EXO-27. Ten and twelve of genotypes in 2021 and 2022 respectively, gave drought susceptibility indexes less than one, indicating less susceptibility. Under stress a positive and highly significant correlation was found between number of green leaves plant-1 and each of panicle width and panicle length (0.612, 0.427, respectively). On the other hand, there are negative and significant correlations (-0.375) between 50% flowering and grain yield under normal irrigation. [ABSTRACT FROM AUTHOR]

Egypt suffers from limited water resources, which threatens food security and reduces the chances of horizontal expansion by reclaiming new desert lands. Therefore, it was necessary to achieve this target for the productivity and quality of crops under harsh conditions. Field experiments proceeded at the Nubaria research station under sandy soil conditions to evaluate the effects of different silicon sources (silica gel, algae rich in silicon, and potassium silicate) on sugar beet yield and quality under different irrigation regimes (100%, 75%, and 50%) of water requirement (WR) during the growing seasons of 2020 and 2021. Results showed that potassium silicate was most effective for increasing chlorophyll content and growth parameters compared with other sources under water stress conditions. Also, improved nutrient contents in the root and shoot of sugar beet gave the highest values on N (0.58%, 2.54%), P (0.132%, 0.318%), K (0.42%, 1.05%), Fe (67.18, 83.28 ppm), and Zn (11.29, 12.73 ppm) content, respectively, when applied with K2SiO3 compared with deficit irrigation conditions. Stimulating rich-Si remains the most effective for enhancing the growth, quality, and yield of sugar beet grown under deficit irrigation regimes, which makes plants more resistant to weather conditions and water stress. [ABSTRACT FROM AUTHOR]

Fifteen accessions of Macroptilium lathyroides (L.) Urb. were collected in three semi-arid Brazilian municipalities and evaluated to characterize their morphology and yield in a greenhouse for three 60-day growth cycles. In the first two cycles, chlorophyll a and b, carotenoids, and soil plant analysis development index (SPAD) were estimated, and root dry mass was determined in the third cycle. Data were analyzed by analysis of variance and Kruskall-Wallis test when appropriate. Principal component analysis and clustering were performed for all accessions. Leaf length, leaf number, leaf mass and total aerial mass production differed between accessions and growth cycles. Root dry mass differed between accessions and SPAD index and stem dry mass between growth cycles. The first two principal components (representing 67% of the variation) generated three clusters based on leaf and leaflet length, plant height, and total aerial mass. The variation in plant height, leaf number, and leaf and total aerial mass in all accessions of M. lathyroides indicates that there is merit in collecting further germplasm of this species to support future breeding programs. Access 62F (Bom Jardim) stands out considering most of the morphological and productive. [ABSTRACT FROM AUTHOR]

Mungbean is a rich source of edible protein and contributes significantly adding the atmospheric N2 to the soil. During the cultivation of mungbean, drought is one of the major constraints which negatively impact on the production of mungbean. Therefore, it is important to find eco-friendly management options to overcome drought stress. The current study was undertaken to find out the yield response of mungbean to irrigation at different pheno-phases in terms of crop growth rate (CGR), leaf area index (LAI), root growth, harvest index and water use efficiency (WUE). Treatments were two mungbean genotypes, namely BMX-08010‑2 (drought stress tolerant) and BARI Mung‑1 (drought stress sensitive) and five different irrigation schedules viz., i) No irrigation (drought stress): I0; ii) Irrigation at 1st trifoliate leaf stage (20 DAS): I1; iii) Irrigation at flowering stage (35 DAS): I2; iv) Irrigation at 1st trifoliate leaf stage (20 DAS) + flowering stage (35 DAS): I3 and v) Irrigation at 1st trifoliate leaf stage (20 DAS) + flowering stage (35 DAS) + pod-filing stage (45 DAS): I4. The study was arranged in a split-plot design distributing irrigation levels to the main plots and genotypes to the sub-plots with three replications under a rain-out shelter Calculated (based on the existing soil moisture content) irrigation water was applied manually in each treatment plot up to the field capacity level. Drought stress (no irrigation) reduced the growth and yield and shortened the life cycle. The BMX-08010‑2 genotype maintains higher performance under drought stress indicated as a drought tolerance genotype. The treatments which got two or three stages of irrigation (I3 or I4) had considerably more yield than those which got only one-stage irrigation (I1 and I2). The flowering stage (I3) was the most sensitive growth stage reducing about 18% of yield compared to the I4 treatment. It is exhibited that, if irrigation sources are available, at least two irrigation at trifoliate leaf stage (I2 at 20 DAS) and flowering stages (I3 at 35 DAS) should be ensured for obtaining higher yield. The harvest index can be increased by increasing the number of irrigation stages irrespective of irrigation at any specific stage. A strong association was also found among the growth and yield traits with the seed yield of mungbean due to different irrigation scheduling. Therefore, the parameters can be used as an effective marker to identify and develop superior genotypes suited to drought-prone environments. [ABSTRACT FROM AUTHOR]

Both silicic and salicylic acids have been reported to be effective in mitigating the harmful effects of environmental stresses. The effects of silicic acid (Si), salicylic acid (SA), and their combination on dry matter yield (DM), nitrogen yield (NY) and N2-fixation (Ndfa) in lentil grown under varying levels of water stress (high I1, mild I2 and well-watered I3) were assessed in a pot experiment in which Si (150 mg L−1) and/or SA (10−5mol L−1) were applied as foliar spraying. The 15N isotope dilution method was employed for estimating Ndfa using barley as a reference crop. A significant decline in the DM, NY and Ndfa of lentil plants was observed due to water stress. However, the exogenous application of Si and/or SA significantly enhanced the overall growth performance particularly under high water stress (I1). Among spraying treatments, the solely applied Si in I1 showed better DM and NY yields as compared to the other treatments, particularly in root growth enhancement. Positive and significant impacts on N2 fixed in response to Si and/or SA were generally observed in plants grown under high water stress.. Decrease in soil N uptake by lentil plants in Si+SA treatment was associated with a higher amount of N2-fixation. These findings may illustrate the importance of dual application of Si+SA in saving irrigation water and alleviating water stress influences to ensure higher N2-fixation and lower consumption of soil nitrogen. Overall, response to Si and/or SA was expressed more clearly when lentil plants were exposed to water stress. The co-application of these two compounds may be considered as important environmentally friendly and sound agricultural practice inputs for improving the symbiotic performance of N2-fixing plants by mitigating the adverse effects of water stress influences. [ABSTRACT FROM AUTHOR]

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Climate change has impacted the environmental conditions in which forest plantations grow worldwide. Droughts and extreme temperatures have compromised the survival and productivity of plantations, and the effects on carbon and water balance have increased risks to sustained productivity and sustainability. Interestingly, opportunities for improvement rely on a better understanding of the ecophysiological response of species or genotypes, their tolerance or resistance to thermal and water stress, and genetic–environmental interactions. Our manuscript summarizes tree and stand-level major reported ecophysiological responses that could challenge the establishment and development of forest plantations under future climate change scenarios. The manuscript discusses potential climate change effects on plantation forest productivity, carbon balance, water use, and water use efficiency, and suggests some potential silvicultural strategies to avoid or reduce risks under uncertain climate scenarios. An integrated approach to understanding the linkages between water resource availability and plant-stand carbon balance is proposed to provide sustainable management that may alleviate the social and environmental concerns associated with challenges relating to climate change for managed forests and the forest industry. [ABSTRACT FROM AUTHOR]

The change in the structural characteristics of mitochondrial membranes isolated from epicotyls of Nemchinovsky 100 pea seedlings under the effect of sodium hydrosulfide at various concentrations has been studied. It was shown that seed treatment with sodium hydrosulfide solution at doses of 2 × 10–4 M and 5 × 10–6 M caused a shift of thermally induced structural transitions in mitochondrial membranes to lower temperatures and to an increase in the microviscosity of both lipid and protein regions of mitochondrial membranes with a decrease in their crystallinity. The presence of exogenous NaHS, as well as endogenous hydrogen sulfide, could increase the activity of antioxidant defense enzymes and caused the accumulation of osmolytes. As a result, the microviscosity of the lipid bilayer could increase. To test this hypothesis, the effect of the antioxidant resveratrol on the microviscosity of the mitochondrial lipid bilayer of epicotyles of pea seedlings was studied with both untreated and pretreated with NaHS seeds. The bioenergetic characteristics of mitochondria were also studied. Data have been obtained that confirm the effect of hydrogen sulfide on the structural characteristics of mitochondrial membranes by activating enzymes of antioxidant protection and accumulation of osmolytes. [ABSTRACT FROM AUTHOR]

The effect of the plant growth regulator ambiol on the functional state of mitochondria of etiolated pea seedlings was studied. The drug prevented the activation of lipid peroxidation in mitochondrial membranes in the concentration range of 10–5–10–6 and 10–9 M. The introduction of ambiol into the incubation medium of these organelles resulted in an increase in the oxidation rates of NAD-dependent substrates. The most effective concentrations were 10–5 and 10–6 M. Changes in the bioenergetic characteristics of mitochondria were accompanied by changes in the fatty acid composition of mitochondrial membranes. The most significant changes occurred in the content of 18:2ω6 and 18:3ω3 fatty acids. It was hypothesized that an increase in the content of these fatty acids in the membranes of mitochondria indicated an increase in the content of cardiolipin, which ensured the effective functioning of the mitochondrial respiratory chain and, consequently, the maintenance of energy metabolism at a high level. The treatment of pea seeds with ambiol not only prevented a decrease in the growth rate of pea seedlings under conditions of water stress, but also stimulated their growth. [ABSTRACT FROM AUTHOR]

Water stress is a major environmental issue and has a significant impact on the sustainability of urban areas worldwide. This study examines the changes in land surface temperature (LST) and their relationship with variations in vegetation cover during wet and dry periods in Zayandeh Rood. To accomplish this, Landsat TM, ETM, and OLI satellite images from three dry years (2001, 2009, and 2018) and three wet years (2005, 2006, and 2020) were used. The research findings indicate that, in 2006, when water was flowing in the river bed, vegetation cover decreased from 36% (201 km2) to 23% (km2) in 2018, when the river bed had no water. Over the last two decades, the Earth's surface temperature has increased. The highest average temperature was observed in 2018, at 40/4 degrees Celsius, and the maximum temperature in the dry years of 2001, 2009, and 2018 was higher than in the wet years of 2005, 2006, and 2020. The highest density of heat islands was observed in regions 2, 4, 5, 6, 7, 14, and east of region 15, which is concentrated on barren lands and then on urban areas. In the dry year of 2009, the total area of temperature classes 42-49 increased by approximately 12% compared to the dry year of 2001 and also increased by about 25% in 2018. In contrast, it was zero in the wet years of 2005 and 2006, and in 2020, it decreased by around 34% compared to 2018. Furthermore, urban development, which has grown by 7/3% over the past two decades, has contributed to the reduction of vegetation and intensified the urban heat island effect. Examining the average temperature changes at different distances from the Zayande Rood indicated that the temperature increased by about 1 degree Celsius with the distance from the river. [ABSTRACT FROM AUTHOR]