Search

Intensive crop growth can modify regional climate by partitioning energy to latent heating through transpiration, cooling growing season temperatures. Recent work shows that cooling associated with agriculture can dampen anthropogenic warming over breadbasket regions. However, it is unknown whether climate models reproduce crop influences on regional climate, and thus the future risk of extreme climate events over global breadbasket regions. We show that models overestimate growing season temperatures and underestimate evapotranspiration (ET) over global croplands, and that these differences increase with cropped area. We trace this warm and dry difference through each model's representation of the surface energy budget, showing that model differences in transpiration, leaf area index, and the ratio of transpiration to total ET drive the overall effect. While the implications of these model deficiencies for future projections are uncertain, they point to the importance of improving representations of crop‐climate processes to better assess breadbasket vulnerability to climate change. Plain Language Summary: Agricultural land often contains very intense crop growth, and there is evidence that cropped regions are cooler and wetter than surrounding non‐cropped areas due to heightened transpiration. However, models used in climate impacts assessments do not simulate real‐world agricultural productivity. As such, models may miss the influence of intensive agriculture on cropland temperatures. We show that models generally overestimate temperatures over agricultural land, and that this overestimation of temperature is linked to an underestimation of transpiration. This low transpiration is associated with an underestimation of plant biomass over cropped regions. The implications of our results for future projections are unclear, but they highlight the importance of understanding vegetation processes over agricultural regions, and their effects on regional climate. Key Points: The Coupled Model Intercomparison Project (CMIP6) multi‐model mean is warmer by 1–3°C as compared to ERA5 reanalysis and CPC temperature observations over global croplandsThe differences in temperature and transpiration between CMIP6 models, ERA5‐Land, and GLDAS are larger over intensely cropped regionsModel underestimations of transpiration scale with the magnitude of the difference in temperature between CMIP6 and ERA5 [ABSTRACT FROM AUTHOR]

High temperature and water deficit are the most critical yield-limiting environmental factors for wheat in rainfed environments. It is important to understand the heat avoidance mechanisms and their associations with leaf morpho-physiological traits that allow crops to stay cool and retain high biomass under warm and dry conditions. We examined 20 morpho-physiologically diverse wheat genotypes under ambient and elevated temperatures (Tair) to investigate whether increased water use leads to high biomass retention due to increased leaf cooling. An experiment was conducted under well-watered conditions in two partially controlled glasshouses. We measured plant transpiration (Tr), leaf temperature (Tleaf), vapor pressure deficit (VPD), and associated leaf morpho-physiological characteristics. High water use and leaf cooling increased biomass retention under high temperatures, but increased use did not always increase biomass retention. Some genotypes maintained biomass, irrespective of water use, possibly through mechanisms other than leaf cooling, indicating their adaptation under water shortage. Genotypic differences in leaf cooling capacity did not always correlate with Tr (VPD) response. In summary, the contribution of high water use or the leaf cooling effect on biomass retention under high temperature is genotype-dependent and possibly due to variations in leaf morpho-physiological traits. These findings are useful for breeding programs to develop climate resilient wheat cultivars. [ABSTRACT FROM AUTHOR]

Climatic conditions in temperate montane forests vary over multiple temporal scales. This study examines the effects of inter-annual climatic variability on the long-term water balance of a small headwater catchment with gradually changing vegetation characteristics. The research is based on direct observations of basic hydrological variables (precipitation, stream discharge), and process-based modelling of difficult-to-measure variables (forest transpiration, wet canopy evaporation, snow sublimation). The catchment water balance is evaluated in terms of the catchment water storage. The uncertainty of the estimated storage changes is expressed as a convolution of partial uncertainties associated with the individual components of catchment water balance. The results suggest a significant decrease of catchment water storage over the study period. The decrease is assumed to be caused by increasing winter temperatures, resulting in a more frequent occurrence of liquid precipitation and less prominent spring snowmelt. Considering vegetation's conservative water-balance management proved essential for the studied environment. [ABSTRACT FROM AUTHOR]

Global climate change will modify plants in terms of growth and physiology. To better understand the consequences of this effect, the responses of the leaf water relations and nitrogen (N) use efficiency of barley and tomato plants to elevated CO2 (e[CO2], 800 ppm) combined with progressive drought stress at two levels of N supply (N1, 0.5 g N pot−1 and N2, 1.0 g N pot−1) were studied. The plants were grown in two separate phytotrons at ambient CO2 (a[CO2], 400 ppm) and e[CO2], respectively. The leaf physiological parameters as well as carbon (C) and N concentrations were determined; plant growth, water and N use efficiencies were evaluated. The results showed that e[CO2] increased photosynthesis and water use efficiency (WUE) while decreased specific leaf area (SLA) in both species, whereas N supply level differentially influenced WUE in barley and tomato plants. The abscisic acid (ABA)-induced stomatal closure during progressive soil drying varied between the two species where the stomatal conductance (gs) of barley plants was more sensitive to leaf ABA than tomato plants, though CO2 environment did not affect the response in both species. Compared to a[CO2], e[CO2] reduced plant transpiration rate (Tplant) in barley but not in tomato. e[CO2] increased the leaf C:N ratio ([C:N]leaf) in plants by enhancing leaf C concentration ([C]leaf) in barley and by dilution of leaf N concentration ([N]leaf) in tomato, respectively, but N2 substantially decreased [C:N]leaf, and thus, N treatment was the dominant factor controlling [C:N]leaf. Collectively, appropriate N supply may modulate the acclimation of plants to e[CO2] and soil water deficits. This study provides some novel insights into N management of different plant species for adapting to future drier and CO2-enriched environment. [ABSTRACT FROM AUTHOR]

Google Scholar Crossref Search ADS WorldCat 20 Cermák J, Kucera J, Nadezhdina N (2004) Sap flow measurements with two thermodynamic methods, flow integration within trees and scaling up from sample trees to entire forest stands. One of the giants in Czechoslovakia - now the Czech Republic - in plant water relations, Professor Jan Cermák, passed away on December 23, 2021, in Brno, Czech Republic. Cermák's focus on trees spanned from the use of an 87-m tall Liebherr 550 Crane with an 85-m jib to assess the crowns of tall trees in an old-growth I Pseudotsuga menzesii i / I Tsuga heterophylla i forest in the Washington State Cascades to under the surface roots of a 60-year-old I Quercus suber i tree in a deciduous forest near Lisbon, Portugal. This research initially (in 1993) presented a study on individual tree sap flow variation and transpiration using 24 trees ([18]) and then (in 1994 and 1995) one of the early comparisons of scaled sap flow estimates of stand transpiration with independent eddy covariance measurements ([33], [28]) and species-specific drought response ([27]). [Extracted from the article]

Background and aims: High and stable plant productivity is a major aim in agricultural research. Silicon fertilization improves yields of various crops under stress. Nonetheless, broad application of silicon is inhibited by the lack of a mechanism explaining this effect. Experimental System: To study the role of silicon in soil-grown plants under drought, we utilized a sorghum (Sorghum bicolor) mutant plant lacking the key silicon root channel – Low silicon 1 (SbLsi1). The sblsi1 mutant plants absorb 1/15 of the silicon absorbed by wild type plants, making them a suitable tool to examine silicon physiology in soil and under field conditions. Results: In mutant plants grown in pots, significant reductions in momentary and accumulated whole plant transpiration, photosynthesis rate, and stomatal conductance were found only under water stress. Root structure, root hydraulic conductance, and stomatal density were similar between wild type and sblsi1 plants. Similar leaf water contents between the genotypes suggested that the water uptake was balanced with transpiration. Conclusions: The similarity between the genotypes under benign conditions are in accordance with minor to no effects of silicon fertilization in non-stressed plants, and support the minor pleiotropic effects of the mutation. Early stomatal closure in the mutant plants under drought stress caused the reduced transpiration. Thise early response suggests that silicon may delay the onset of drought physiology by either reduced stress signaling or reaction. [ABSTRACT FROM AUTHOR]

Water inside plants forms a continuous chain from water in soils to the water evaporating from leaf surfaces. Failures in this chain result in reduced transpiration and photosynthesis and are caused by soil drying and/or cavitation‐induced xylem embolism. Xylem embolism and plant hydraulic failure share several analogies to 'catastrophe theory' in dynamical systems. These catastrophes are often represented in the physiological and ecological literature as tipping points when control variables exogenous (e.g., soil water potential) or endogenous (e.g., leaf water potential) to the plant are allowed to vary on time scales much longer than time scales associated with cavitation events. Here, plant hydraulics viewed from the perspective of catastrophes at multiple spatial scales is considered with attention to bubble expansion within a xylem conduit, organ‐scale vulnerability to embolism, and whole‐plant biomass as a proxy for transpiration and hydraulic function. The hydraulic safety‐efficiency tradeoff, hydraulic segmentation and maximum plant transpiration are examined using this framework. Underlying mechanisms for hydraulic failure at fine scales such as pit membranes and cell‐wall mechanics, intermediate scales such as xylem network properties and at larger scales such as soil–tree hydraulic pathways are discussed. Understudied areas in plant hydraulics are also flagged where progress is urgently needed. Summary statement: Hydraulic failure in plants and tipping points in ecosystem processes are examples of catastrophes in dynamical systems. Here, these phenomena are reviewed at bubble, xylem network and whole‐plant scales and the underlying mechanisms that result in these catastrophes are explored. [ABSTRACT FROM AUTHOR]

Indoor saffron farming systems under controlled conditions are required to meet the high demand for this valuable crop. The aim of the present study was to determine the flowering, growth, and yield responses of saffron grown using nutrient solutions with different electrical conductivity (EC) levels (0.7, 1.4, and 2.1 dS m−1). Sprouted saffron corms were cultured for 24 weeks under a volcanic rock-based aerated continuous immersion system. Vegetative growth and leaf gas exchange, but not flowering, were affected significantly by EC levels. The optimal EC in a balanced nutrient solution was 0.7 dS m−1, at which level the highest plant height, leaf area, biomass, photosynthetic rate, number of daughter corms, and percentage of corms ≥ 25 mm were recorded. An EC level of 2.1 dS m−1 decreased the photosynthetic rate, stomatal conductance, and transpiration rate of saffron but increased biochemical stress marker levels and elevated various antioxidant defense enzyme levels significantly in saffron leaves, possibly reflecting a defense response to the cellular damage provoked by the higher EC level. In terms of nutrient solution EC, 0.7 dS m−1 was optimal in saffron, whereas 2.1 dS m−1 caused oxidative stress that led to reduced growth and daughter corm production. [ABSTRACT FROM AUTHOR]

In the Northern China Plain (NCP), sunken solar greenhouses (SSG) are now increasingly being used for vegetable cultivation in winter due to low winter temperatures. Investigating plant transpiration and determining crop coefficients are helpful when developing irrigation scheduling and improving crop growth. In this study, a three-season experiment was conducted in a commercial tomato SSG to investigate changes in microclimate, sap flow (SF), photosynthesis traits and plant physiological parameters, and to calculate the crop coefficient and evaluate the irrigation efficiency using current irrigation management practices. Results show that the average transmissivity from top plastic covers was 0.69, and the inside temperature increased by approximately 10 °C in November and 15–18 °C in December, which guaranteed the growth of tomatoes in winter. The leaf photosynthesis rate (Pn) is linearly related to radiation, however, a concave quadratic function is a better fit for Pn and VPD, with the highest Pn at approximately 1.0 kPa VPD; leaf transpiration is positively and linearly related to both radiation and VPD. Therefore, increasing greenhouse transmissivity and maintaining an internal VPD of approximately 1 kPa could produce a high leaf Pn and low transpiration concurrently. Daily total SF was linearly correlated with solar radiation, VPD and temperature with determination coefficients of 0.87–0.96, 0.89–0.91 and 0.62–0.84, respectively. Correcting the slope of SF to radiation with VPD (SF = (0.12 + 0.14VPD)Rs), R2 increased by 0.08, and the root mean square error and relative error decreased by 0.047 mm day−1 and 6.53%, respectively. Therefore, this integrated equation is recommended to estimate daily tomato transpiration when plant height is approximately 1.5 m, and the leaf area index (LAI) is between 2 and 2.5. During the fruit expansion and ripening period, the average basal crop coefficients (Kcb) for greenhouse tomatoes in winter was between 0.99 and 1.11. The irrigation efficiency increased from 0.3 in the first season to 0.6–0.69 in the second and third seasons when the tensiometer method was used. Therefore, using the tensiometer method to guide tomato irrigation could markedly improve irrigation efficiency in greenhouses. [ABSTRACT FROM AUTHOR]

Partitioning evapotranspiration (ET) into its primary components, that is, evaporation (E) and plant transpiration (T), is needed in a range of hydrometeorological applications. Using vegetation index (VI) to obtain spatially resolved T:ET ratio over large areas has emerged as a promising approach in this regard. Here, we assess the effectiveness of this approach in differently managed wheat systems. Results show a weak relation between T:ET and VI in disturbed (i.e., grazed) systems. Furthermore, flux partition based on a canonical T:ET versus VI relation or the relation derived in a neighboring undisturbed wheat system introduce large errors in disturbed systems, thus underscoring the limits on the transferability of the VI‐based ET partitioning approach. The effectiveness of the VI‐based approach is found to be related to the strength of correlation between VI and vapor pressure deficit and/or radiation. This correlation metric can help identify settings where the approach is likely to be effective. Plain Language Summary: Evapotranspiration (ET) plays a significant role in water and climate cycles by affecting the energy and water balance over the land surface which in turn mediates the land‐atmosphere interactions. ET is composed of two primary components that is, direct evaporation (E) and plant transpiration (T). Partitioning total ET into its individual components (E and T) is of significant importance for better assessment of both regional and global water budgets. One of the primary approaches to partition ET over large areas is by using vegetation indices (VI), which indirectly capture plants' biophysical state. This approach has been used to partition ET in different landscapes, but its efficacy has not been tested in disturbed ecosystems, which cover a large fraction of Earth's vegetated area. Here, we assess the effectiveness of this VI‐based ET partitioning approach in disturbed (i.e., grazed) ecosystems. We find that the VI‐based ET partitioning introduces large errors in disturbed systems. Further investigation identifies conditions that can be used to filter‐out regions where the VI‐based partition is likely to be more (or less) effective. Key Points: Three Evapotranspiration (ET) partitioning methods were used to partition ET in differently managed wheat systemsGrazing altered the relation between T:ET and enhanced vegetation indexET partitioning errors were higher in disturbed (i.e., grazed) systems [ABSTRACT FROM AUTHOR]

Terrestrial photosynthesis requires the evaporation of water (transpiration) in exchange for CO2 needed to form sugars. The water for transpiration is drawn up through plant roots, stem, and branches via a water potential gradient. However, this flow of water—or sap ascent—requires energy to lift the water to the canopy and to overcome the resistance of the plant's water transporting xylem. Here, we use a combination of field measurements of plant physiology (hydraulic conductivity) and state‐of‐the‐science global estimates of transpiration to calculate how much energy is passively harvested by plants to power the sap ascent pump across the world's terrestrial vegetation. Globally, we find that 0.06 W/m2 is consumed in sap ascent over forest dominated ecosystems or 9.4 PWh/yr (equal to global hydropower energy production). Though small in comparison to other components of the Earth's surface energy budget, sap ascent work in forests represents 14.2% of the energy compared to the energy consumed to create sugars through photosynthesis, with values up to 18% in temperate rainforests. The power needed for sap ascent generally increases with photosynthesis, but is moderated by both climate and plant physiology, as the most work is consumed in regions with large transpiration fluxes (such as the moist tropics) and in areas where vegetation has low conductivity (such as temperate rainforests dominated by conifer trees). Here, we present a bottom‐up analysis of sap ascent work that demonstrates its significant role in plant function across the globe. Plain Language Summary: Trees transpire up to 100 gallons of water per day, which requires energy to overcome gravity and the resistance of specialized stem transportation tissues. We show that the energy used by trees to move water from the soil to the leaves for transpiration is of the same order of magnitude to the energy harvested by these plants from sunlight during photosynthesis. This work implies that the evolution of vascular plants has created a pump that passively harvests energy to lift water to plant canopies, which is a significant energetic benefit to plant function and helps fuel life on Earth. Key Points: Life on Earth is partially fueled by energy passively harvested from the environment to lift sap against frictional forces and gravityFor the first time, we quantify sap ascent power globally with remotely sensed and field measurements of plant fluxes, states, and traitsSap ascent power is 14.2% the size of photosynthetic energy and comparable to the production of all hydropower across the globe [ABSTRACT FROM AUTHOR]

pH of xylem sap (pHx) was determined in three trees (Malus domestica (apple tree), Picea abies and Pinus cembra) in response to seasonal changes. Conifer trees from lowland (600 m) were compared to trees growing at the alpine timberline (1950 m a.s.l.). Xylem sap was extracted with a Scholander pressure bomb and pHx was measured with a pH microsensor. In all species, pHx changed markedly with season. In spring, pHx was acidic; during winter, the pHx was more alkaline. In apple trees, the pHx did not show a significant correlation with temperature but was rather affected by developmental stage. During flushing in spring, xylem sap acidification took place concomitant to the developmental stage "tight cluster", when foliar development enables a significant transpiration and a consequent movement of water in the xylem. The xylem sap of the two studied conifers showed a significantly larger seasonal alkalinisation (+2.1) than found in apple trees (+1.2) and was significantly more pronounced at the timberline. Xylem sap acidification took place before bud break. pHx had a significant negative correlation with soil temperatures and corresponded to already reported pHx of angiosperms. Overall, pHx appears to be a sensitive stress marker and indicator of activity status in tree xylem. [ABSTRACT FROM AUTHOR]

Plant root hydraulic redistribution (HR) has been widely recognized as a phenomenon that helps alleviate vegetation drought stress. However, a systematic assessment of themagnitude ofHR and its drivers at the global scale are lacking. We collected 37 peer-reviewed papers (comprising 47 research sites) published in 1900-2018 and comprehensively analyzed the magnitude of HR and its underlying factors. We used a weighting method to analyze HR magnitude and its effect on plant transpiration. Machine learning algorithms (boosted regression trees) and structural equation modeling were used to determine the influence of each factor on HR magnitude. We found that the magnitude of HR was 0.249mm H2O d-1 (95% CI, 0.113-0.384) and its contribution to plant transpiration was 27.4% (3-79%). HR varied significantly among different terrestrial biomes and mainly occurred in forests with drier conditions, such as temperate forest ecosystems (HR = 0.502mm H2O d-1), where HR was significantly higher than in other ecosystems (p < 0.01). The magnitude of HR in angiosperms was significantly higher than that in gymnosperms (p < 0.05). The mean magnitude of HR first increased and then decreased with an increase in humidity index; conversely, themeanmagnitude of HR decreased with an increase in water table depth. HR was significantly positively correlated with root length and transpiration. Plant characteristics and environmental factors jointly accounted for 61.0% of the variation in HR, and plant transpiration was the major factor that directly influenced HR (43.1% relative importance; p < 0.001), and soil texture was an important indirect driver of HR. Our synthesis offers a comprehensive perspective of how plant characteristics and environmental factors influence HR magnitude. [ABSTRACT FROM AUTHOR]

Summary: Heat waves occurring during droughts can have a devastating impact on yield, especially if they happen during the flowering and seed set stages of the crop cycle. Global warming and climate change are driving an alarming increase in the frequency and intensity of combined drought and heat stress episodes, critically threatening global food security.Because high temperature is detrimental to reproductive processes, essential for plant yield, we measured the inner temperature, transpiration, sepal stomatal aperture, hormone concentrations and transcriptomic response of closed soybean flowers developing on plants subjected to a combination of drought and heat stress.Here, we report that, during a combination of drought and heat stress, soybean plants prioritize transpiration through flowers over transpiration through leaves by opening their flower stomata, while keeping their leaf stomata closed. This acclimation strategy, termed 'differential transpiration', lowers flower inner temperature by about 2–3°C, protecting reproductive processes at the expense of vegetative tissues.Manipulating stomatal regulation, stomatal size and/or stomatal density of flowers could serve as a viable strategy to enhance the yield of different crops and mitigate some of the current and future impacts of global warming and climate change on agriculture. [ABSTRACT FROM AUTHOR]

Water stress has been the major limiting factor for the sustainable agriculture in the southern part of the North China Plain (NCP). It is a high demand to develop the water-saving agricultural practice for the winter wheat-summer maize double cropping system. Tillage practice has great effects on the soil water movement, water use efficiency, and crop growth, due to the changed soil physical properties and the disturbed soil materials. It is also essential to quantify the soil water dynamics and crop growth processes under different tillage practices for the reasonable tillage system. The objective of this study was to improve the Soil Water Heat Carbon Nitrogen Simulator (WHCNS) model, which was used to simulate the soil water movement and crop growth under different tillage practices. A system evaluation was also made to determine the tillage practices on the water balance, crop growth, and Water Use Efficiency (WUE). The WHCNS model was improved to add the tillage module using Erosion-Productivity Impact Calculator (EPIC) model. Among them, there were the effects of various tillage practices on the change of soil bulk density, soil hydraulic parameter, and soil water content. A two-year field experiment was conducted in the Shangqiu experimental station of Henan province (34°35.222′N,115°34.515′E) on a silty clay soil in the southern part of the NCP from 2015 to 2017. Three tillage treatments were designed, including the Deep Tillage (DT), No Tillage (NT), and Rotation Tillage (RT). Some parameters were measured to calibrate and evaluate the improved WHCNS model, including the soil water storage, Leaf Area Index (LAI), crop dry mass, and yield. The performance of model was then verified by the Relative Root Mean Square Errors (nRMSE), consistency index, Nash coefficient (NSE), and coefficient of determination (R²) between the simulated and measured values. The improved model was then used to analyze the effects of different tillage practices on the soil evaporation, crop transpiration, actual evapotranspiration (ET), crop yield, and WUE of the winter wheat and summer maize. The results showed that there was no significance in the crop yields among different tillage practices. The nRMSE between the simulated and measured values of soil water storage, LAI, and dry mass for all treatments were all less than 30%, the consistency index values were all greater than 0.90, the NSE were all greater than 0.58, R² were all greater than 0.93, and the R2 between the simulated and measured values of crop yields was reached 0.99. Compared with DT and NT in both winter wheat seasons, RT reduced the ET by 8.8%-10.8% and 13.8%-21.0%, and increased WUE by 6.7%-9.4% and 15.7%-24.9%, respectively. Compared with DT and RT in both summer maize seasons, NT reduced the ET by 12.5%-12.9% and 20.7%-22.2%, and increased the WUE by 13.4%-15.2% and 29.1%-31.3%, respectively. In summary, the improved WHCNS model performed the best to simulate the dynamic processes of soil water storage and crop growth under different tillage practices in the NCP. Correspondingly, the WUE of RT was the best performance for the winter wheat, whereas, the WUE of NT was the best for the summer maize. The finding can provide a powerful tool to optimize the field tillage management practices for the water-saving agriculture. [ABSTRACT FROM AUTHOR]

Forest transpiration is controlled by the atmospheric water demand, potentially constrained by soil moisture availability, and regulated by plant physiological properties. During summer periods, soil moisture availability at sites with thin soils can be limited, forcing the plants to access moisture stored in the weathered bedrock. Land surface models (LSMs) have considerably evolved in the description of the physical processes related to vegetation water use, but the effects of bedrock position and water uptake from fractured bedrock have not received much attention. In this study, the Community Land Model version 5.0 (CLM 5) is implemented at four forested sites with relatively shallow bedrock and located across an environmental gradient in Europe. Three different bedrock configurations (i.e., default, deeper, and fractured) are applied to evaluate if the omission of water uptake from weathered bedrock could explain some model deficiencies with respect to the simulation of seasonal transpiration patterns. Sap flow measurements are used to benchmark the response of these three bedrock configurations. It was found that the simulated transpiration response of the default model configuration is strongly limited by soil moisture availability at sites with extended dry seasons. Under these climate conditions, the implementation of an alternative (i.e., deeper and fractured) bedrock configuration resulted in a better agreement between modeled and measured transpiration. At the site with a continental climate, the default model configuration accurately reproduced the magnitude and temporal patterns of the measured transpiration. The implementation of the alternative bedrock configurations at this site provided more realistic water potentials in plant tissues but negatively affected the modeled transpiration during the summer period. Finally, all three bedrock configurations did not show differences in terms of water potentials, fluxes, and performances on the more northern and colder site exhibiting a transition between oceanic and continental climate. Model performances at this site are low, with a clear overestimation of transpiration compared to sap flow data. The results of this study call for increased efforts into better representing lithological controls on plant water uptake in LSMs. [ABSTRACT FROM AUTHOR]

Pivotal barrier properties of the hydrophobic plant cuticle covering aerial plant surfaces depend on its physicochemical composition. Among plant species and organs, compounds of this boundary layer between the plant interior and the environment vary considerably but cuticle-related studies comparing different organs from the same plant species are still scarce. Thus, this study focused on the cuticle profiles of Physalis peruviana, Physalis ixocarpa, Alkekengi officinarum, and Nicandra physalodes species. Inflated fruiting calyces enveloping fruitsmake Physalis, Alkekengi, and Nicandra highly recognizable genera among the Solanoideae subfamily. Although the inflation of fruiting calyces is well discussed in the literature still little is known about their post- floral functionalities. Cuticular composition, surface structure, and barrier function were examined and compared in fully expanded amphistomatous leaves, ripe astomatous fruits, and fully inflated hypostomatous fruiting calyces. Species- and organ-specific abundances of non-glandular and glandular trichomes revealed high structural diversity, covering not only abaxial and adaxial leaf surfaces but also fruiting calyx surfaces, whereas fruits were glabrous. Cuticular waxes, which limit non-stomatal transpiration, ranged from <1 μg cm−2 on P. peruviana fruiting calyces and N. physalodes fruits to 22 μg cm−2 on P. peruviana fruits. Very-long-chain aliphatic compounds, notably n- alkanes, iso-, and anteiso-branched alkanes, alkanols, alkanoic acids, and alkyl esters, dominated the cuticular wax coverages (≥86%). Diversity of cuticular wax patterns rose from leaves to fruiting calyces and peaked in fruits. The polymeric cutin matrix providing the structural framework for cuticular waxes was determined to range from 81 μg cm−2 for N. physalodes to 571 μg cm−2 for A. officinarum fruits. Cuticular transpiration barriers were highly efficient, with water permeabilities being ≤5 × 10−5 m s−1. Only the cuticular water permeability of N. physalodes fruits was 10 × 10−5 m s−1 leading to their early desiccation and fruits that easily split, whereas P. peruviana, P. ixocarpa, and A. officinarum bore fleshy fruits for extended periods after maturation. Regarding the functional significance, fruiting calyces establish a physicochemical shield that reduces water loss and enables fruit maturation within a protective microclimate, and promotes different seed dispersal strategies among plant species investigated. [ABSTRACT FROM AUTHOR]

Grown in different regions of Brazil, mango is of great importance at the national level. However, mango cultivation is directly related to physiological factors such as photosynthesis, stomatal conductance and chlorophyll. Physiological factors are related to the nutritional balance of the plant. Among the nutrients, potassium (K) can be highlighted, which, despite not being a structural element for the plant, stimulates, or is part of several physiological plant processes. Therefore, an experiment was carried out with the purpose of evaluating, in the vegetative period of 'Palmer' mango, the effect of different sources of K to accelerate the maturation stage of mango branches and verify their influence on physiological indexes and chlorophyll. Treatments consisted of three ripeners and a control, which were applied directly to the branches and leaves of "Palmer" mango trees. The variables analyzed were chlorophyll A, B and Total indexes; Internal concentration of CO2; Stomatal conductance; transpiration rate; Net photosynthesis; Instantaneous Carboxylation Efficiency and Water Use Efficiency. After collecting, and analyzing the data, it was concluded that the vegetative period of the "Palmer" mango tree, in relation to the different evaluation dates, was not influenced by potassium sources. The use of T4 treatment (SpeedFol® induction mango) can provide a greater increment of chlorophyll A, B and Total than KCl and K2SO4. [ABSTRACT FROM AUTHOR]

Knowledge of crop water requirements and the effects of management practices on the amounts of water used for crop transpiration and that lost through soil evaporation is essential for efficient agricultural water management. Therefore, this study investigated the temporal evolution of weekly evaporation and transpiration rates under varying soil water conditions in a conventionally managed soybean field by partitioning evapotranspiration based on a water and δ18O-stable isotope mass balance. The estimated rates were considered in combination with vertical soil water distribution, atmospheric demand (based on crop evapotranspiration), actual evapotranspiration, and the plant development stage. This allowed for the weekly rates to be compared to the current conditions resulting from dry periods, rain or irrigation events, and the extent of the canopy. The range of weekly transpiration/evapotranspiration, from blossom to maturation, was between 0.60 (±0.11) and 0.82 (±0.10). Within this range, transpiration/evapotranspiration shifted depending on the vertical soil water distribution and meteorological conditions. During dry soil surface periods, evaporation dropped to almost zero, whereas a wet surface layer substantially increased evaporation/evapotranspiration, even under a closed canopy. Under given conditions, the application of a few intense irrigations before the drying of the soil surface is recommended. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the effects of lower water levels on leaf intercellular spaces and to assess their relations with the gas exchange, anatomy, and growth of Sorghum bicolor. Experiments were conducted in a greenhouse, in which plants were subjected to three water conditions (ten replicates, n = 30): well-irrigated, decreased irrigation, and limited irrigation. Lower water levels had no significant effect on the growth of S. bicolor but increased the biomass of the roots. Moreover, the number of leaves, leaf area, and leaf size as well as the chlorophyll content were not affected by lower water levels, and no significant changes were detected for whole plant photosynthesis, transpiration, or stomatal conductance. The water content of the plants and the water potential remained unchanged. However, compared with other treatments, the decreased irrigation decreased water loss and increased the water retention. Lower water levels increased the intercellular CO2 percentage, mesophyll area, and proportion of stomatal cavities and promoted minor changes in leaf tissue and stomatal traits. The increased stomatal cavities provided higher CO2 uptake and prevented excessive water loss. Thus, modifications to the intercellular spaces promoted conditions to avoid excessive water loss while concurrently improving CO2 uptake, which are important traits for drought-tolerant plants. [ABSTRACT FROM AUTHOR]

The knowledge of crop water requirements is critical for agricultural water conservation, especially for accurate irrigation decision making in the greenhouse. Investigating the water demand pattern of the tomato in the solar greenhouse environment and constructing an appropriate irrigation decision-making model are urgently needed to improve irrigation water use efficiency. We designed four irrigation-level treatments: 100% ET0 (T1), 85% ET0 (T2), 70% ET0 (T3), and 55% ET0 (T4), and conducted a two-vegetation-season tomato planting trial under drip irrigation conditions in a solar greenhouse. The Pearson's correlation coefficient method analyzed the intrinsic linkage and influence between soil–crop–environment and tomatoes' water demand patterns. Indicators suitable for irrigation decision making in greenhouse tomatoes were selected, and regression functions were constructed for environmental and crop physiological parameters by combining path analysis and multiple regression methods. Finally, a fusion irrigation decision-making model was constructed by introducing a distance function in the Dempster–Shafer (D–S) theory primary probability assignment (BPA) synthesis algorithm and combining it with a triangular affiliation function. The results showed that: (1) the soil coefficient of variation was shallow > middle > deep, and tomatoes absorbed water mainly in the 0–60 cm soil layer; (2) the crop stem flow rate, net photosynthetic rate, and transpiration rate were positively correlated with irrigation water and had the highest correlation with net radiation, relative humidity, and relative humidity, with correlation coefficients of 0.9441, 0.9441, and 0.7679, respectively; (3) the constructed decision model had a significantly lower value of uncertainty than other methods, while the highest decision value could reach over 0.99, which achieved the best decision accuracy compared to other algorithms. [ABSTRACT FROM AUTHOR]

This study aimed to identify the genetic control of morphological, water status, and root traits in four inbred lines and their pre-selected hybrid combinations of popcorn, and to identify the best parents and hybrids. The plants were grown under greenhouse conditions, and with two water conditions—water-stressed (WS) and well-watered (WW). We evaluated shoot biomass (SB), whole plant leaf area (WPLA), chlorophyll content, carbon isotope discrimination, net CO2 assimilation rate, the stomatal conductance, transpiration, cumulative plant transpiration, and root weight density in three sections. The reductions in SB and WPLA are attributed to stomatal causes, given the maintenance of water condition values in water-stressed plants. In fact, the stomata were closed for long periods during plant growth under the water-stressed condition, as indicated by the more negative carbon isotope discrimination values. The root weight density, regardless of soil depth and water conditions, was higher in hybrids. There was a preponderance of non-additive effects in the control of morphological and root traits, especially in the WS condition, and heterosis was shown to be the fundamental strategy for obtaining superior hybrids. For water status traits, it is essential to choose the female parent in the crossing block, given the maternal effect expressed by net CO2 assimilation rate, stomatal conductance, and transpiration. [ABSTRACT FROM AUTHOR]

As the source of replenishment, rainfall has an extensive impact because its variability shapes biologically efficient pulses of soil moisture recharge across layers from rainfall events. In this paper, a mathematical model is proposed to explore the importance of transpiration from agricultural crops and aerosols on the pattern of rainfall. For the system without seeding, the simulation results show destabilizing roles of parameters related to formation of cloud drops due to transpiration of agricultural crops, formation of raindrops due to cloud drops and growth of agricultural crops due to rain. The model without seeding is extended to its stochastic counterpart to encapsulate the uncertainty observed in some important parameters. We observe the variability in the system's variables and found their distributions at certain fixed times, which explore the importance of stochasticity in the system. Our findings show that transpiration through agricultural crops plays an important role in cloud formation, and thus, affects the effectiveness of different rainfall events. Moreover, the combined actions of transpiration and seeding are much more beneficial in producing rain. Finally, we see the behavior of system by considering seasonal variations of some rate parameters. [ABSTRACT FROM AUTHOR]

The plant hormone abscisic acid (ABA) triggers cellular tolerance responses to osmotic stress caused by high-salinity and water-deficient conditions. ABA controls the turgor pressure of guard cells in the plant epidermis through ionic fluxes via ion transporters anchored at the plasma membrane, leading to stomatal closure to limit transpiration and prevent the loss of water. However, stomatal apertures should be reversibly opened by a light signal to uptake carbon dioxide for photosynthesis, even under osmotic stress conditions. Plants utilize various strategies to regulate ABA-mediated stomatal closure in response to stressful conditions. Basically, plants regulate the accumulation of ABA, the signaling molecule induced in response to osmotic stress, during multiple metabolic processes (biosynthesis, catabolism, and conjugation) that occur in different subcellular organelles. In addition, the ABA signaling pathway in guard cells is modulated by ABA-dependent physical interactions among its core components, namely ABA molecules, receptors (e.g., pyrabactin resistance [PYR]/PYR1-like/regulatory components of ABA receptors), protein phosphatases (e.g., protein phosphatase type 2C), and kinases (e.g., sucrose non-fermenting-related protein kinase 2). Moreover, ABA induces the expression of numerous genes encoding proteins exerting either positive or negative effects on its accumulation, transportation, and signaling network. In parallel, the ABA signaling network can be desensitized by degradation of its core components via the ubiquitin-26S proteasome system or endocytic/vacuolar pathway in an ABA-dependent manner. This chapter details the mechanisms by which ABA constitutes a regulatory loop to finely tune its own homeostasis and signaling network, thereby modulating the stomatal operation. [ABSTRACT FROM AUTHOR]

Plant growth occurs during both day and night and is associated with water loss via stomata. This chapter looks at the processes which are associated with water uptake and transpirational water loss during day and night, and how these processes relate to leaf growth and may be affected differently by the salt stress. Potential advantages and disadvantages of a night-time water loss and growth are discussed, particularly in the context of salinity and the uptake of excess Na+ and Cl- by the root system. The potential importance of aquaporins to enable a more selective uptake of water, compared with Na+ and Cl-, by the root under salinity is addressed. Both stomata and root aquaporins control plant water flow. Climate change and associated increases in temperature during the day and night period have the potential to impact differently on day- and night-time processes and on the adaptation of plants to salt stress. [ABSTRACT FROM AUTHOR]

The individual application of pure and active compounds such as methionine may help to address water scarcity issues without compromising the yield of wheat. As organic plant growth stimulants, amino acids are popularly used to promote the productivity of crops. However, the influence of the exogenous application of methionine in wheat remains elusive. The present investigation was planned in order to understand the impact of methionine in wheat under drought stress. Two wheat genotypes were allowed to grow with 100% field capacity (FC) up to the three-leaf stage. Twenty-five-day-old seedlings of two wheat genotypes, Galaxy-13 and Johar-16, were subjected to 40% FC, denoted as water deficit-stress (D), along with 100% FC, called control (C), with and without L-methionine (Met; 4 mM) foliar treatment. Water deficit significantly reduced shoot length, shoot fresh and dry weights, seed yield, photosynthetic, gas exchange attributes except for transpiration rate (E), and shoot mineral ions (potassium, calcium, and phosphorus) in both genotypes. A significant increase was recorded in superoxide dismutase (SOD), catalase (CAT), hydrogen peroxide (H2O2), malondialdehyde (MDA), and sodium ions (Na+) due to water deficiency. However, foliar application of Met substantially improved the studied growth, photosynthetic, and gas exchange attributes with water deficit conditions in both genotypes. The activities of SOD, POD, and CAT were further enhanced under stress with Met application. Met improved potassium (K), calcium (Ca2+), and phosphorus (P) content. In a nutshell, the foliar application of Met effectively amended water deficit stress tolerance by reducing MDA and H2O2 content under water deficit conditions in wheat plants. Thus, we are able to deduce a positive association between Met-induced improved growth attributes and drought tolerance. [ABSTRACT FROM AUTHOR]

Many terrestrial biosphere models depend on an understanding of the relationship between stomatal conductance and photosynthesis. However, unlike the measurement of photosynthetic parameters, such as the maximum carboxylation capacity, where standard methods (e.g. CO2 response or AC i curves) are widely accepted, a consensus method for empirically measuring parameters representing stomatal response has not yet emerged. Most models of stomatal response to environment represent stomatal conductance as being bounded by a lower intercept parameter (g 0), and linearly scaled based on a multivariate term described by the stomatal slope parameter (g 1). Here we employ the widely used Unified Stomatal Optimization model, to test whether g 1 and g 0 parameters are impacted by the choice of measurement method, either on an intact branch or a cut branch segment stored in water. We measured paired stomatal response curves on intact and excised branches of a hybrid poplar clone (Populus deltoides Bartr. ×  Populus nigra L. OP367), measured twice over a diurnal period. We found that predawn branch excision did not significantly affect measured g 0 and g 1 when measured within 4 h of excision. Measurement in the afternoon resulted in significantly higher values of g 1 and lower values of g 0, with values changing by 55% and 56%, respectively. Excision combined with afternoon measurement resulted in a marked effect on parameter estimates, with g 1 increasing 89% from morning to afternoon and a 25% lower g 1 for cut branches than those measured in situ. We also show that in hybrid poplar the differences in parameter estimates obtained from plants measured under different conditions can directly impact models of canopy function, reducing modeled transpiration by 18% over a simulated 12.5-h period. Although these results are only for a single isohydric woody species, our findings suggest that stomatal optimality parameters may not remain constant throughout the day. [ABSTRACT FROM AUTHOR]

Using Pinus bungeana, Platycladus orientalis, Koelreuteria paniculata and Ginkgo biloba as research objects, three open-top chambers with different ozone-concentration gradients were set up (NF, NF40 and NF80) based on trunk sap-flow technology to study the difference in ozone absorption by trees under different ozone concentrations. The results showed that the monthly and diurnal variations of sap-flow density of different tree species decreased with the increase in ozone concentration, and the increase in ozone concentration reduced the water consumption, ozone uptake rate (FO3), net photosynthetic rate (Pn) and water-use efficiency (WUE) of different tree species. The sap-flow density, water consumption, FO3 and WUE of Koelreuteria paniculata and Ginkgo biloba were higher than those of Pinus bungeana and Platycladus orientalis under different ozone concentrations. The sap-flow density, water consumption, FO3 and WUE of Koelreuteria paniculata and Ginkgo biloba decreased significantly at the ozone concentrations of NF40 and NF80; compared with the ozone concentration of NF, the sap flow density of Koelreuteria paniculata and Ginkgo biloba decreased by 1.04 and 1.03 times as much as that of Pinus bungeana and Platycladus orientalis, respectively; the water consumption of Koelreuteria paniculata and Ginkgo biloba decreased by 1.82 and 1.56 times that of Pinus bungeana and Platycladus orientalis, respectively; the decline rate of FO3 in Koelreuteria paniculata and Ginkgo biloba was 1.30 and 1.04 times that of Pinus bungeana and Platycladus orientalis, respectively; and the decline rate of WUE of Koelreuteria paniculata and Ginkgo biloba was 1.52 and 1.64 times that of Pinus bungeana and Platycladus orientalis, respectively. Pinus bungeana and Platycladus orientalis have stronger tolerance to ozone, while Koelreuteria paniculata and Ginkgo biloba were weak. A variety of conifers can be planted in areas with serious ozone pollution. [ABSTRACT FROM AUTHOR]

Dust is the collection of fine particles of solid matter, and it is a major issue of atmospheric pollution. Dust particles are becoming the major pollutants of the urban environment due to hyperbolic manufacturing and automobile pollution. These atmospheric pollutants are not only hazardous for human beings, but they also affect tree growth, particularly in urban environments. This study was designed to examine the changes in morphological and physiological traits of three tree species seedlings (Eucalyptus camaldulensis, Conocarpus erectus, and Bombax ceiba) in response to different dust types. In a pot experiment under controlled conditions, three-month-old seedlings of selected trees species were subjected to four treatments of dust: T1 = controlled; T2 = wood dust; T3 = soil dust; and T4 = carbon dust. During the whole experiment, 10 g/plant/dose was applied in 8 doses with a one-week interval. The results depicted that the growth was the maximum in T1 (control) and the minimum in T4 (carbon dust). In our findings, B. ceiba performed better under the same levels of dust pollution as compared with the other two tree species. The B. ceiba tree species proved to be the most tolerant to dust pollution by efficiently demolishing oxidative bursts by triggering SOD, POD, and CAT under different dust types compared to controlled conditions. Stomatal conductance, photosynthetic rate, and transpiration rate were negatively influenced in all three tree species in response to different dust applications. Based on the findings, among these three tree species, B. ceiba is recommended for dust polluted areas followed by E. camaldulensis and Conocarpus erectus due to their better performance and efficient dust-foraging potential. [ABSTRACT FROM AUTHOR]

• Water stress has reduced gas exchange capacity of Smyrna and San Pedro fig cultivars. • Fig cultivars responded almost similarly to water stress in each growing conditions. • Fig showed an adaptive behaviour to prolonged water stress. • Fig adopted an avoidance strategy by stomatal closure and leaf abscission. • Fig could be considered as a stress-tolerant species through its growth recovery. Climate change scenarios predict that drought and high temperatures will become the main stress factors affecting fruit tree's production. This study was undertaken in order to evaluate ecophysiological behaviour of young fig plants of cultivars Zidi and Bither Abiadh under two water regimes ('T50' and 'T100', supply of respectively 50% and 100% of water requirement) in different growing conditions (open-air, tunnel covered with insect proof and polyethylene greenhouse). During the first cycle of measurements, it has been concluded that the decrease of stomatal conductance was the primary response to water stress, which controlled transpiration and photosynthesis rates and regulated leaf temperature. Fig cultivars reduced leaf stomatal conductance after 7 days of changing environments and reducing irrigation to 50% of required water supply. Measurements carried out after 15 days showed a decrease of photosynthetic parameters even for fig plants irrigated with 100% of their water requirement, due to the effect of high temperatures associated with low air humidity in the different growing conditions. During the second cycle, measurements carried out on persistent leaves showed that fig cultivars were adapted to prolonged water stress. Overall, Zidi and Bither Abiadh responded almost similarly to water stress and exhibited the same ecophysiological behaviour in each growing condition during the first and the second cycle of measurements. Despite leaf abscission, fig plants revealed drought stress memorizing by showing a rapid growth recovery once the stress was relieved. [ABSTRACT FROM AUTHOR]

Guava fruit have a very short shelf life due to high rate of respiration. Storage of guava fruits at room temperature causes weight loss, microbial disease, physiological disorders and physical injuries and is moreover, highly susceptibility to chilling injury making low temperature storage less possible. Therefore, the present investigation was carried out at the Department of Fruit Science, College of Horticulture, Mandsaur, Madhya Pradesh, India during the year 2019-2020 with an objective to extend shelf-life of guava fruits cv. Rewa-72. The treatments comprised of post-harvest treatments with Chitosan, Carboxymethyl cellulose, Aloe vera gel. The physico-chemical, functional and sensory quality of guava fruits were significantly influenced by application Chitosan @ 1.5% and Carboxymethyl cellulose @ 1.5%) coating up to 12 days of storage. It was found that the CMC or Chitosan bilayer coating was equally effective as the commercial polyethylene wax in enhancing glossy appearance of guava fruits because it is a good moisture barrier, thus preventing the water loss by transpiration. Chitosan @ 1.5% and CMC @1.5% treated fruits had more overall acceptability because this coating helped in improving the colour, aroma, taste, texture, appearance and quality of fruits. Hence, this technology could be more useful for increase shelf life of fruits, low cost and reduce the postharvest loss of fruits it also helps to replace the use of harmful chemicals by growers and traders. [ABSTRACT FROM AUTHOR]

Citrus is one of the most valuable crops in Syria, with the largest production areas in the Tartus and Latakia provinces. Water-saving policies have been adopted to modernize the irrigation systems and increase water productivity. Following dedicated research, this study aimed to evaluate the water balance in clementine trees irrigated with diverse methods and schedules using the SIMDualKc software model. Two experiments are reported: one with 10–14 years old trees irrigated with different methods (2007−2011) and the other with the same trees but now 18−20 years old, irrigated with different schedules (2015−2019). The SIMDualKc model successfully simulated the soil water contents measured in the various field plots, with root mean square error values lower than 0.004 m3 m−3 and modeling efficiencies up to 0.83. The model-calibrated standard basal crop coefficients (Kcb) were approximately constant throughout all growing stages, assuming values of 0.54−0.55 for the mature trees having smaller height (h) and fraction of ground cover (fc), and 0.64 for older trees with larger canopies, i.e., larger h and fc. With drip irrigation, single Kc had a higher value (1.14) at the end, non-growing, and initial stages, and a lower value (0.75–0.76) during mid-season (Kc mid), because precipitation was lesser then, contributing less to soil evaporation. On the other hand, Kc values were nearly constant with micro-sprinkler and surface irrigation techniques because the ground was fully wetted. The Kcb values derived from the fraction of ground cover and height (A&P approach) were similar to those obtained from the model, thus showing that the A&P approach represents a practical alternative to estimate Kcb in the practice of irrigation management. The soil water balance further revealed a large weight of the terms corresponding to the non-beneficial water consumption and non-consumptive water use when the fraction wetted was large and the application efficiencies were low. These terms were reduced, namely, evaporation losses when drip irrigation was used. This study, thus, provides a valuable tool for improving the irrigation management, water saving, and water productivity of Syrian citrus production systems. [ABSTRACT FROM AUTHOR]

Evaporation losses of rainfall intercepted by canopies depend on many factors, including the temporal scale of observations. At the event scale, interception is a few millimetres, whereas at a larger temporal scale, the number of times that a canopy is filled by rainfall and then depleted can make the interception an important fraction of the rainfall depth. Recently, a simplified interception/evaporation model has been proposed, which considers a modified Merrian model to compute interception during wet spells and a simple power-law equation to model evaporation from wet canopy during dry spells. Modelling evaporation process at the sub hourly temporal scale required the two parameters of the power-law, describing the hourly evaporation depth and the evaporation rate. In this paper, for branches of lemon trees, we focused on the evaporation process from wet branches starting from the interception capacity, S, and simple models in addition to the power-law were applied and tested. In particular, for different temperature, T, and vapour pressure deficit, VPD, conditions, numerous experimental testes were carried out, and the two parameters describing the evaporation process from wet branches were determined and linked to T, VPD and S. The results obtained in this work help us to understand the studied process, highlight its complexity, and could be implemented in the recently introduced interception/evaporation model to quantify this important component of the hydrologic cycle. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board 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.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office 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.)

Reducing water losses in agriculture needs a solid understanding of when evaporation (E) losses occur and how much water is used through crop transpiration (T). Partitioning ecosystem T is however challenging, and even more so when it comes to short‐statured crops, where many standard methods lead to inaccurate measurements. In this study, we combined biometeorological measurements with a Soil‐Plant‐Atmosphere Crop (SPA‐Crop) model to estimate T and E at a Swiss cropland over two crop seasons with winter cereals. We compared our results with two data‐driven approaches: The Transpiration Estimation Algorithm (TEA) and the underlying Water Use Efficiency (uWUE). Despite large differences in the productivity of both years, the T to evapotranspiration (ET) ratio had relatively similar seasonal and diurnal dynamics, and averaged to 0.72 and 0.73. Our measurements combined with a SPA‐Crop model provided T estimates similar to the TEA method, while the uWUE method produced systematically lower T even when the soil and leaves were dry. T was strongly related to the leaf area index, but additionally varied due to climatic conditions. The most important climatic drivers controlling T were found to be the photosynthetic photon flux density (R2 = 0.84 and 0.87), and vapor pressure deficit (R2 = 0.86 and 0.70). Our results suggest that site‐specific studies can help establish T/ET ratios, as well as identify dominant climatic drivers, which could then be used to partition T from reliable ET measurements. Moreover, our results suggest that the TEA method is a suitable tool for ET partitioning in short‐statured croplands. Plain Language Summary: To reduce water losses linked to agriculture, we need to understand how much water the crops transpire and how much water is evaporated from irrigation surplus. Measuring how much water plants transpire is however difficult, especially for short‐statured crops like wheat or barley, because they are too small for the usual measurement techniques. In our study, we use detailed climate and vegetation measurements at a cropland in Switzerland combined with a model, and compare with two other data‐driven partitioning approaches (Transpiration Estimation Algorithm (TEA), underlying Water Use Efficiency (uWUE)). Our results show that the measurements combined with a model compared well with one of the approach (TEA), while the other (uWUE) was less well suited for our cropland. Our results demonstrate that there are ratios of the transpiration to evapotranspiration (i.e., including evaporation) that tend to be stable for specific ecosystems, and that could therefore be used once they are known for an ecosystem. Our results also show that the amount of light and the atmospheric demand for water vapor are important drivers for transpiration on a daily basis, while the plant cover determines the overall rate. Key Points: High agreement between transpiration (T) from measurements combined with a process‐based model (Soil‐Plant‐Atmosphere Crop) and a data‐driven method (Transpiration Estimation Algorithm)Diurnal and seasonal T to evapotranspiration ratios were relatively similar despite differences in crop and productivity between yearsDetailed crop specific models are a powerful method for partitioning T in short‐statured croplands to address lack of measurement methods [ABSTRACT FROM AUTHOR]

Among several alien weeds Eichhornia Crassipes (water hyacinth) is ranked as one of the world's worst invasive weeds due to its ability to rapidly cover the entire water surface. This weed was introduced in Ethiopia in 1964 but its aggressiveness has been realized recently after it has invaded a number of lakes and rivers in the country. This study focuses on the estimation of water losses by transpiration from root-clipped, leafclipped plants (treatments) and makes comparison with those of the normal plants (control). Besides evaporative losses, crop factors and plant coefficients were also determined and compared. Plant transpiration losses were obtained from the difference in the volume of water from the pan containing the treatment and control plants and the volume of water lost from the pan evaporation. For this calibration first was done to correlate the depth of water level (in the pan) from the top of the pan to the water level in order to know the volume of water lost by evapotranspiration. Data analysis was made using Microsoft Office Excel and comparisons were made using one-way ANOVA followed by pair comparisons. Evapotranspiration estimation for Zeway area was done using the modified and optimized Temesgen-Melesse's method, and the study was conducted for 17 days. The result showed that the evapotranspiration by normal plants (control group), plants with clipped roots (CR), and plants with clipped leaves (CL) were 2.25L/d (7.96 mm/d), 0.85L/d (3.01 mm/d), and 1.51 L/d (5.34 mm/d), respectively, compared to mean daily pan evaporation of 0.88 L/d (3.11 mm/d). The transpiration rates from the normal and leaf-clipped plants were 1.37L/d (4.85 mm/d) and 0.72 L/d (2.55mm/d), respectively. The root-clipped plants did not show any transpiration at all. Additionally, the value of crop factors (Cp) calculated showed 1.09, 0.40 and 0.73 for C, RC and LC, respectively. The crop coefficient (Kc) result showed 1.42, 0.54, and 0.95 for C, RC and LC, respectively. ANOVA results of T, Cp showed significant differences between treatments and the control and also within treatments. The conclusion drawn is that root-clipping has better effect than clipping of leaves when it comes to reducing the rate of transpiration from the plant. It is better to find other physical methods of illmanaging the plant rather than trying to remove the entire plant from water bodies since it is too cumbersome. [ABSTRACT FROM AUTHOR]

Water hyacinth (Echhornia crassipes) is one of the invasive and is considered as one of the most notorious aquatic weeds because of its fast spread and crowded growth. Manual removal of the plant is considered to be the most environmentally friendly way of controlling the plant but it is laborious when the plant covers large area. Field experiment study was conducted on water hyacinth plants collected from Ziway Lake to estimate the effect of colored plastic covers on the transpiration rates of the plant. In addition, crop factors (Kc) and coefficients of evaporation (Cp) of the covered plants were also compared with the uncovered plants. Transpiration losses were determined from the difference in the volume of water from the pan containing the treatment and control plants and the volume of water lost from the pan evaporation. The water losses from the pans were calculated from the differences in the depths of water in the pans before and after the successive measurement days. For this, calibration was done to correlate the depth of water level (in the pan) to the volume of water lost by evapotranspiration. Besides, water loss measurements, pictures were also taken for visual observation of the plants at every level during the experiment. Data analysis was made using Microsoft Office Excel. Comparisons were made using one-way ANOVA followed by pair comparisons Evapotranspiration estimation for Zeway area was done using the modified and optimized Temesgen-Melesse's method. The result showed that the mean ET of the uncovered plant, those covered by Black plastic (Bpc) and transparent plastic covered (Tpc) plants were 2.25L/d (7.96mm/d), 0.26L/d (0.92 mm/d) and 0.35L/d (1.24mm/d), respectively, compared to the mean daily pan evaporation of 0.88 L/d (3.11 mm/d). The transpiration rate from the control plants was 1.37L/d (4.85 mm/d), but those covered by Tp and Bp did not show any transpiration. Additionally, the Cp calculated showed 1.09, 0.40 and 0.30 for the control, Tpc and Bpc plants, respectively. The Kc result showed 1.42, 0.22, and 0.16 for the control, Tpc and Bpc plants, respectively. ANOVA results of T, Cp showed significant differences between treatments and the control but no differences within treatments. Out of the two, the transparent plastic cover showed superior performance in adversely affecting the performance of the plant and in terms of its endurance in resisting the external environment. This study showed promising result in killing the plant so that it would be easy to remove the plant from the water body. However, we recommend the study to be conducted in the real environment of the plant (on lakes, or dams infested with water hyacinth). [ABSTRACT FROM AUTHOR]

Autumn phenology, determined mainly by temperature and photoperiod, is essential for ecosystem carbon sequestration. Usually, the variations in the maximum rate of Rubisco (Vcmax) and the maximum rate of ribulose-bisphosphate regeneration (Jmax) are taken as the mechanism regulating the seasonal pattern of photosynthetic rates and autumn phenology. In this study, we used Quercus mongolicus seedlings as an example to examine the photosynthetically physiological mechanism of leaf coloration onset (LCO) responding to different warming and photoperiod treatments based on experimental data acquired from large artificial climate simulation chambers. The results indicated that: (1) LCO and the net CO2 assimilation rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), Vcmax, and Jmax of Quercus mongolicus seedlings were significantly affected by the changes of photoperiod. (2) LCO was significantly correlated only with the Pn approach, supporting the view that leaf senescence is the result of a trade-off between nutrient resorption and reserves. (3) The major variation in stomatal conductance (Gs) is the mechanism by which photoperiod regulates the seasonal pattern of photosynthetic rates, implying that both limitations of stomatal and photosynthetical capacity (Vcmax and Jmax, non-stomatal limitation) are able to modulate LCO. Our study riches the knowledge of phenology and provides a reference for phenological modelling and ecosystem carbon estimation. [ABSTRACT FROM AUTHOR]

Taking advantage of novel IoT technologies, a new multifunctional device, the "TreeTalker", was developed to monitor real-time ecophysical and biological parameters of individual trees, as well as climatic variables related to their surrounding environment, principally, air temperature and air relative humidity. Here, IoT applied to plant ecophysiology and hydrology aims to unravel the vulnerability of trees to climatic stress via a single tree assessment at costs that enable massive deployment. We present the performance of the TreeTalker to elucidate the functional relation between the stem water content in trees and respective internal/external (stem hydraulic activity/abiotic) drivers. Continuous stem water content records are provided by an in-house-designed capacitance sensor, hosted in the reference probe of the TreeTalker sap flow measuring system, based on the transient thermal dissipation (TTD) method. In order to demonstrate the capability of the TreeTalker, a three-phase experimental process was performed including (1) sensor sensitivity analysis, (2) sensor calibration, and (3) long-term field data monitoring. A negative linear correlation was demonstrated under temperature sensitivity analysis, and for calibration, multiple linear regression was applied on harvested field samples, explaining the relationship between the sample volumetric water content and the sensor output signal. Furthermore, in a field scenario, TreeTalkers were mounted on adult Fagus sylvatica L. and Quercus petraea L. trees, from June 2020 to October 2021, in a beech-dominated forest near Marburg, Germany, where they continuously monitored sap flux density and stem volumetric water content (stem VWC). The results show that the range of stem VWC registered is highly influenced by the seasonal variability of climatic conditions. Depending on tree characteristics, edaphic and microclimatic conditions, variations in stem VWC and reactions to atmospheric events occurred. Low sapwood water storage occurs in response to drought, which illustrates the high dependency of trees on stem VWC under water stress. Consistent daily variations in stem VWC were also clearly detectable. Stem VWC constitutes a significant portion of daily transpiration (using TreeTalkers, up to 4% for the beech forest in our experimental site). The diurnal–nocturnal pattern of stem VWC and sap flow revealed an inverse relationship. Such a finding, still under investigation, may be explained by the importance of water recharge during the night, likely due to sapwood volume changes and lateral water distribution rather than by a vertical flow rate. Overall, TreeTalker demonstrated the potential of autonomous devices for monitoring sap density and relative stem VWC in the field of plant ecophysiology and hydrology. [ABSTRACT FROM AUTHOR]

Vegetation water content is a critical aspect of ecosystem water balance and plant physiology, including how plants cope with drought. Deciduous trees store significant water for use in transpiration throughout the growing season in the boreal forest of Alaska. Water content of shrub stems, and their role in the water balance, remains unquantified for many woody species in boreal and arctic tundra ecosystems. We adapted time-domain reflectometry (TDR) to continuously measure shrub water content. We created calibration equations relating apparent dielectric constant to volumetric water content of shrub stems of felt-leaf willow (Salix alaxensis), diamond-leaf willow (S. pulchra) and dwarf birch (Betula nana). Our results show seasonal patterns of volumetric stem water content ranging from 40 to 70%. Stem water content prior to leaf-out was minimal (scaled by biomass, <2mm) compared to total snowmelt water, implying little water uptake of snowmelt water. Stem water content was small compared to other components of the hydrologic water budget (precipitation, runoff, evaporation, evapotranspiration, infiltration), indicating the importance of shrub transpiration and dependence of shrubs on available soil moisture for uptake. The technique and findings here are needed to quantify the role of deciduous shrub vegetation in the hydrologic cycle of ecosystems, particularly those where shrubs predominate. [ABSTRACT FROM AUTHOR]

Plants often need to withstand multiple types of environmental stresses (e.g., salt and low temperature stress) because of their sessile nature. Although the physiological responses of plants to single stressor have been well-characterized, few studies have evaluated the extent to which pretreatment with non-lethal stressors can maintain the photosynthetic performance of plants in adverse environments (i.e., acclimation-induced cross-tolerance). Here, we studied the effects of sodium chloride (NaCl) pretreatment on the photosynthetic performance of tomato plants exposed to low temperature stress by measuring photosynthetic and chlorophyll fluorescence parameters, stomatal aperture, chloroplast quality, and the expression of stress signaling pathway-related genes. NaCl pretreatment significantly reduced the carbon dioxide assimilation rate, transpiration rate, and stomatal aperture of tomato leaves, but these physiological acclimations could mitigate the adverse effects of subsequent low temperatures compared with non-pretreated tomato plants. The content of photosynthetic pigments decreased and the ultra-microstructure of chloroplasts was damaged under low temperature stress, and the magnitude of these adverse effects was alleviated by NaCl pretreatment. The quantum yield of photosystem I (PSI) and photosystem II (PSII), the quantum yield of regulatory energy dissipation, and non-photochemical energy dissipation owing to donor-side limitation decreased following NaCl treatment; however, the opposite patterns were observed when NaCl-pretreated plants were exposed to low temperature stress. Similar results were obtained for the electron transfer rate of PSI, the electron transfer rate of PSII, and the estimated cyclic electron flow value (CEF). The production of reactive oxygen species induced by low temperature stress was also significantly alleviated by NaCl pretreatment. The expression of ion channel and tubulin-related genes affecting stomatal aperture, chlorophyll synthesis genes, antioxidant enzyme-related genes, and abscisic acid (ABA) and low temperature signaling-related genes was up-regulated in NaCl-pretreated plants under low temperature stress. Our findings indicated that CEF-mediated photoprotection, stomatal movement, the maintenance of chloroplast quality, and ABA and low temperature signaling pathways all play key roles in maintaining the photosynthetic capacity of NaCl-treated tomato plants under low temperature stress. [ABSTRACT FROM AUTHOR]

Plant transpiration dominates terrestrial latent heat fluxes (LE) and plays a central role in regulating the water cycle and land surface energy budget. However, currently Earth system models (ESM) disagree strongly on the amount of transpiration, and thus LE, leading to large uncertainties in simulating future climate. Thus it is crucial to correctly represent the mechanisms controlling the transpiration in models. At the leaf-scale, transpiration is controlled by stomatal regulation, and at the canopy-scale, through turbulence, which is a function of canopy structure and wind. The coupling of vegetation to the atmosphere can be characterized by a coefficient O. A value of O x 0 implies a strong coupling of vegetation and the atmosphere, leaving a dominant role to stomatal conductance in regulating water (H2O) and carbon dioxide (CO2) fluxes, while O - 1 implies a complete decoupling of leaves from the atmosphere, that is, the transfer of H2O and CO2 is limited by aerodynamic transport. In this study, we investigated how well the land surface model ORCHIDEE (v7266), simulates the coupling of vegetation to the atmosphere by using empirical daily estimates of O derived from flux measurements from 106 FLUXNET sites. Our results show that ORCHIDEE generally captures the O in forest vegetation types (0.27±0.10) compared with observation (0.26±0.09), but underestimates O in grasslands and croplands (0.26±0.16 for model, 0.33±0.17 for observation). The good model performance in forests is due to compensation of biases in surface conductance (Gs) and aerodynamic conductance (Ga). Calibration of key parameters controlling the dependence of the stomatal conductance to the water vapor deficit (VPD) improves the simulated Gs, and O estimates in grasslands and croplands (0.30±0.21). To assess the underlying controls of O, we applied random forest (RF) models to both simulated and observation-based O. We found that large observed O are associated with periods of low wind speed, high temperature, low VPD and related to sites with large leaf area index (LAI) and/or short vegetation. The RF models applied to ORCHIDEE output generally agree with this pattern. However, we found the ORCHIDEE underestimated the sensitivity of O to VPD when VPD is high, overestimated the impact of LAI on O, and did not correctly simulate the temperature dependence of O when temperature is high. Our results highlight the importance of observational constraints on simulating the vegetation-atmosphere coupling strength, which can help improve predictive accuracy of water fluxes in Earth system models. [ABSTRACT FROM AUTHOR]

Numerous plant hydrodynamic models have started to be implemented in vegetation dynamics models, reflecting the central role of plant hydraulic traits in driving water, energy and carbon cycle, as well as plant adaptation to climate change. Different numerical approximations of the governing equations of the hydrodynamic models have been documented, but the numerical accuracy of these models and its subsequent effects on the simulated vegetation function and dynamics have rarely been evaluated. Using different numerical solution methods (including implicit and explicit approaches) and vertical discrete grid resolutions, we evaluated the numerical performance of a plant hydrodynamic module in the Functionally Assembled Terrestrial Ecosystem Simulator (FATES-HYDRO) based on single point and global simulations. Our simulation results showed that when near-surface vertical grid spacing is coarsened (grid size > 10 cm), the model significantly overestimates above ground biomass (AGB) in most of the temperate forest locations, and underestimates AGB in the boreal forest locations, as compared to a simulation with finer vertical grid spacing. Grid coarsening has a small effect on AGB in the tropical zones of Asia and South America. In particular, coarse surface grid resolution should not be used when there are large and prolonged water content difference among soil layers at depths due to long dry season duration and/or well-drained soil, or when soil evaporation is a dominant fraction of evapotranspiration. Similarly, coarse surface grid resolution should not be used when there is lithologic discontinuity along the soil depth. This information is useful for uncertainty quantification, sensitivity analysis, or training surrogate models to design the simulations when computational cost limits the use of ensemble simulations. [ABSTRACT FROM AUTHOR]

Interactions between above and below ground parts of plants can be considered under the (overlapping) categories of energy, material and information. Solar energy powers photosynthesis and transpiration by above ground structures, and drives most water uptake through roots and supplies energy as organic matter to below ground parts, including diazotrophic symbionts and mycorrhizas. Material transfer occurs as water and dissolved soil-derived elements transport up the xylem, and a small fraction of water moving up the xylem with dissolved organic carbon and other solutes down the phloem. The cytosolic nature of sieve tubes accounts for at least some of the cycling of K, Mg and P down the phloem. NO3- assimilation of above ground parts requires organic N transport down phloem with, in some cases, organic anions related to shoot acid-base regulation. Long-distance information transfer is related development, biotic and abiotic damage, and above and below ground resource excess and limitation. Information transfer can involve hydraulic, electrical and chemical signaling, with their varying speeds of transmission and information content. Interaction of above and below ground plant parts is an important component of the ecosystem service of storing atmospheric CO2 as organic C in soil, a process that has decreased since the origin of agriculture. [ABSTRACT FROM AUTHOR]

Smart irrigation is one application of digital agriculture that can be used to achieve improved crop yields while saving water and energy. Many variations of smart irrigation can be applied, but there is no consensus among the scientific community as to which method is the best practice. The objective of this research was to evaluate two smart irrigation methods: a soil moisture–based method using sensors and an evapotranspiration- (ET-) based technique. The selected crop was sweet corn. Growth variables (biomass, yield, harvest index, and water productivity) were compared for each of the two methods. Three irrigation regimes were applied for each method: 60%, 90%, and 120% of crop evapotranspiration (ETc) for the ET-based method, and 25%, 30%, and 35% of the total soil moisture for the soil moisture–based method. Corn sap flow was measured in response to the three treatments in the soil moisture–based experiment to measure transpiration. The results showed that the ET-based method is easier to implement with less infrastructure, and it can result in similar yields compared to the soil moisture–based method. Although the fresh yield was 16% higher using the soil moisture–based method, grain yield can be sustained with the ET-based method using 8% less water. Selection of an appropriate irrigation scheduling method should be based on marketable yield: keeping the soil water content near field capacity will result in a higher fresh yield but will not translate into more dry matter. If grain yield is the target, the ET-based method is less expensive and more farmer friendly, but care should be taken to properly estimate irrigation losses to avoid underirrigation. An evaporative stress index (determined using sap flow measurements) of 70% will cause a 22% reduction in fresh sweet corn yield but only a 7% reduction in grain yield. Transpiration peaked when the soil moisture was above 85% of the available water (i.e., at 38% in the calcareous clay soil of the experiment). [ABSTRACT FROM AUTHOR]

The use of biostimulants in modern agriculture has rapidly expanded in recent years, owing to their beneficial effects on crop yield and product quality, which have come under the scope of intensive research. Accordingly, in the present study we appraised the efficacy of two plant-derived biostimulants, the legume-derived protein hydrolysates Trainer® (PH), and the tropical plant extract Auxym® (TPE) on two lettuce cultivars (green and red salanova®) in terms of morpho-physiological and biochemical traits (primary and secondary metabolites). The two cultivars differed in their acquisition capacity for nitrate and other beneficial ions, their photosynthetic and transpiration rates, and their ability to synthetize and accumulate organic acids and protective metabolites. The biostimulant effect was significant for almost all the parameters examined but it was subjected to significant cultivar × biostimulant interactions, denoting a cultivar-dependent response to biostimulant type. Notwithstanding this interaction, biostimulant application could potentially improve the yield and quality of lettuce by stimulating plant physiological processes, as indicated by the SPAD index (leaf chlorophyll index), ACO2 (assimilation rate), E (transpiration), and WUEi (intrinsic water use efficiency), and by increasing concurrently the plant mineral content (total N, K, Ca, Mg) and the biosynthesis of organic acids (malate, citrate), phenols (caffeic acid, coumaroyl quinic acid isomer 1, dicaffeoylquinic acid isomer 1), and flavonoids (quercetin-3-O-glucuronide, quercetin-3-O-glucoside). Biostimulant action may facilitate the bio-enhancement of certain lettuce cultivars that are otherwise limited by their genetic potential, for the accumulation of specific compounds beneficial to human health. [ABSTRACT FROM AUTHOR]

Microwave technology has wide applications, including extraction of active compounds in biomass and compost for agricultural use. A study was carried out to determine the effects of microwave power level from 0 (control) to 1000 W on the properties and active microbial groups in vermicast, and how it may impact the photosynthesis, plant growth, and yield of kale (Brassica oleracea var. sabellica) 'Red Russian'. Heat accumulation in the vermicast increased rapidly to a peak of 86 °C at 400 W before declining to 68 °C at 1000 W. Vermicast water loss increased exponentially up to 800 W before declining. The C:N ratio of the vermicast was reduced at ≥600 W while the pH remained the same. In a 2D-principal component analysis biplot, vermicast treated at 600, 800 and 1000 W were associated with Gram-positive (G+), GGram-negative (G−), G + G− bacteria, protozoa, and fungi groups while the 0, 200, and 400 W treated vermicast were associated with eukaryotes. However, the trend for total microbial mass was 200 W = 400 W > 0 W > 600 W = 800 W = 1000 W. Kale leaf anthocyanin, chlorophylls, and carotenoids were significantly (p = 0.001) increased by the 400 W or 600 W treatment compared to the other treatments. Stomatal conductance, transpiration, and photosynthesis rates were increased by the 400 W followed by the 600 W. As a result, yield of kale grown in the 400 W microwaved vermicast was the highest. Future studies will explain the functions of specific microbial populations and elemental composition in microwaved vermicast. [ABSTRACT FROM AUTHOR]

Grape is one of the most important horticultural crops and economically produced in world and Iran which is cultivated in a wide range of climatic conditions. Duo to the difficulties of cultivating grape is its relatively sensitive to salinity stress. Salinity can cause significant anatomical changes in the internal tissues of plant organs. The effect of using low-quality water on the anatomical structure of grapevine organs has not yet been studied. This study aimed to evaluate the structural behavior of roots, stems, leaves, petioles, and main veins of grape leaves in Yaghooti cultivar under progressive salt stress. Materials and Methods This study was carried out based on a completely randomized design with three replications during two consecutive years 2020-2021. Salinity treatment at four levels, including zero (control), 25, 50, and 100 mM NaCl on one year old rooted cuttings under greenhouse conditions. Plant various organs consisting of roots, stems, leaves, petioles, and main veins were microscopically investigated through the conventional methods of sampling, fixing, sectioning and staining. Results and Discussion In the stem, the epiderm thickness increased until 50 mM level, and decreased in 100 mM level. In 100 mM, sclerenchyma thickness, pith diameter, and vascular bundles number increased, while collenchymas thickness, cambium, phloem, metaxylem, protoxylem, and stem cortex decreased. In the root, cortex thickness reduced, but the vascular bundles' thickness, their number, as well as pith and vascular cylinder diameters increased, and more periderm thickness as well as the centralization of xylem vessels toward pith tissue were observed. In the petiole, in 100 mM level, an increase in sclerenchyma thickness and vascular bundles number was observed along with a decrease in phloem thickness, cambium, metaxylem, protoxylem, and cortex. In the leaf and main vein, palisad parenchymal cells became smaller and denser with an increase in their number; furthermore, a decrease in spongy parenchymal cells thickness along with the increase of their intercellular space and the increase of epiderm thickness were observed. In addition, vascular bundles number, sclerenchyma thickness, and pith diameter increased, while the decrease of vascular bundles' thickness and collenchymas thickness was found in the main vein. Moreover, a large number of salt crystals were observed in all the plant organs, especially in the roots. Conclusion Overall, the results of this study revealed that salinity stress caused changes in the anatomical structure of roots and various aerial organs in Yaghooti grapevine saplings. It appears that at a stress of 100 mM salinity, the increase of epiderm and sclerenchyma thickness in the aerial organs contributed to preventing transpiration and preserving water content. Besides, periderm thickness at the root as a physical barrier to further absorption, transport of soluble substances, and protection of vascular cylinders helped the plant to tolerate salinity conditions. In addition, a large number of vascular bundles were involved in the secondary uptake of salt in the surrounding parenchymal cells. Therefore, most of the anatomical changes in the studied organs can be considered as a kind of adaptation to increase the chances of the plant survival against salinity. [ABSTRACT FROM AUTHOR]