Effects Of Water Stress Research Articles

Changes in the Major Antioxidant Compounds of Red Cabbage Under Water Stress Applied at Different Vegetative Growth Periods

Effective and efficient use of water resources has become an important issue in recent studies, where the impacts of climate change has become more apparent and alternative solutions are discussed. There, however, are limited studies that look at the impacts of water stress at different vegetative periods. For this reason, in this study, different levels of water treatment (0%, 30%, 70%) were applied to red cabbage at two stages of development (early and late vegetative) in a two-year field study. The effect of water stress on the major antioxidant compounds, as well as on yield and some morphological parameters were investigated. According to the findings, the least yield loss (22%) occurred in the early vegetative period of the second-year trial where 70% irrigation water was applied, while the highest yield loss (56%) was obtained during the early vegetative period of the first-year trial where no irrigation was applied. Biochemical analyses revealed that the highest accumulation of flavonoids, 0.83 mg g-1, and anthocyanins, 1.51 mg g-1, occurred in the early vegetative period with the trial that received no irrigation treatment. The phenolic compound content was determined as 1.62 mg g-1, and the antioxidant capacity was found to be 1.93 mg g-1 during the late vegetative period in the trials without irrigation treatment. These findings suggest that in regions with limited water resources, water conservation can be practiced during different vegetative periods in order to get higher biochemical benefits with a lower yield loss when cultivating red cabbage.

Impact of Water Stress on Metabolic Intermediates and Regulators in Broccoli Sprouts, and Cellular Defense Potential of Their Extracts.

Drought and flood (water stress) alter plant metabolism, impacting the phytochemical content and biological effects. Using spectrophotometric, HPLC, and electrophoretic methods, we analyze the effects of water stress on broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) sprouts. Drought and flood differently influenced chlorophylls, carotenoids, and porphyrins, with drought having a stronger inhibitory effect on chlorophyll a, total chlorophyll, and porphyrins. Carotenoids and glucosinolates increased under drought but decreased with flooding, suggesting that these compounds play a crucial role in drought tolerance. Nitrate increased with drought from 13.11 ± 1.05 mg/g dw to 22.41 ± 1.20 mg/g dw but decreased under flooding to 5.17 ± 1.03 mg/g dw, and oxalic acid was reduced by drought only (from 48.94 ± 1.30 mg/g dw to 46.43 ± 0.64 mg/g dw). Flood reduced proteins by 29%, phenolics by 15%, flavonoids by 10%, flavonols by 11%, tannins by 36%, and proanthocyanidins by 19%, while drought decreased flavonoids by 23%. Total phenolics and proanthocyanidins were increased by drought by 29% and 7%, respectively, while flooding decreased hydroxycinnamic acids by 13%. Both stress types influenced individual polyphenols differently: drought diminished ferulic acid by 17% and increased sinapic acid by 30%, while flooding reversed these effects and enhanced kaempferol by 22%. These compounds, along with proline (which increased by 139% under drought), emerged as biomarkers of water stress. Flood impacted antioxidant capacity more significantly, while drought-stressed broccoli extracts better protected plasmid DNA against oxidative damage. These findings underline the metabolic plasticity of broccoli sprouts and their potential in targeted crop management for water stress resilience.

Effect of water stress on vegetative growth and leaf concentration of flavonoids in mint (mentha x piperita) under protected cultivation conditions

Medicinal plants, such as mint, contain active ingredients, which, although they are responsible for the therapeutic properties attributed to them, are also responsible for poisoning and adverse reactions that can occur if they are used in inadequate doses, high doses, or for prolonged periods. Many of these plant species have survived for millions of years thanks to their ability to produce substances that protect them from predators or extreme conditions. Even though some of these compounds (condensed tannins, phenols, alkaloids, oligosaccharides, and saponins) can produce a violent and immediate reaction, in most cases, they have a subtle effect that manifests itself with prolonged ingestion. By applying computational chemistry, the structures of bioactive molecules were revealed, representing them three-dimensionally after virtual screening. Therefore, in the project's development, the effect of water stress on the production of flavonoids in the protected mint crop was studied, using the previously measured field capacity and ultimately controlling the irrigation. This was divided into four irrigation application treatments (each 3, 6, 9, and 12 days), evaluating different agronomic variables and through a foliar analysis of the content of flavonoids present in the four treatments under study. The findings of this study, with their significant implications for medicinal plant cultivation, underscore how water stress can affect the production of flavonoids in mint. This knowledge can be directly applied to optimize cultivation practices and enhance the quality of medicinal plants, thereby benefiting the agricultural and pharmaceutical industries.

Effect of water stress on the nutrient uptake of cocoa genotypes in Southwest of Nigeria

SCA 6, SCA 9, NA 32, ICS 96, N 38, PA 7 and PA 150 were either self or cross pollinated to form six cocoa genotypes namely: SCA 9 * SCA 12, NA 32 * NA 32, ICS 95 * ICS 95, N 38 * N 38, PA 7 * PA 150 and SCA 12 * SCA 9. The selection of the parent cocoa clones were based on their reported varied genotypic and traits to water stress conditions. The seeds of the six cocoa genotypes were pre-germinated for two weeks before their seedlings were transplanted into 4 kg topsoil inside each of the plastic pots in a greenhouse where they were examined for their responses to three different watering regimes at 25, 50 and 100 field capacity (fc) for 30 weeks. Data were collected on the physico-chemical properties of the experimental soil as the leaf contents for N, P, K, Ca, Mg and Fe nutrients. The leaf N, P, Ca and Fe contents showed higher concentrations at lower fc while K and Mg contents increased at higher water regimes. The results showed genotypic differences in the nutrient uptake performances of the cocoa seedlings.

Biochar‐Amended Soils: A Water‐Saving Strategy for Quinoa Cultivation in the Andes

ABSTRACTIntroductionPrevious studies showed that biochar amended soils significantly enhanced the growth and yield of quinoa under water limitations. So it becomes an emerging agronomic strategy to consider for sustainable quinoa production. Biochar can specifically be considered for the area particularly receiving low annual rainfall and more vulnerable to current climate change conditions.Materials and MethodsA field experiment was conducted using the quinoa variety INIA 415 Pasankalla, employing a factorial design to assess the effects of different application rates of biochar made of municipal pruning waste and agricultural waste (0, 1, 2, and 3 t·ha⁻¹), and three irrigation intervals (irrigation every 5 days, irrigation every 10 days, and irrigation every 15 days). The volumetric soil moisture content, the soil hydraulic properties, and quinoa's biometric characteristics and yield components were evaluated.ResultsThe results indicated that the longest irrigation intervals (10 and 15 days) resulted in soil moisture levels between 19% and 40% below the wilting point (soil matric potential: −1.5 MPa), creating water stress conditions. However, biochar application increased the field capacity from 0.31 to 0.38 g H₂O g⁻¹ soil, raised soil air content from 22% to 29% at irrigation, and promoted the quinoa's soil water absorption below the wilting point. Furthermore, the application of 3 t·ha⁻¹ of biochar significantly enhanced quinoa yield, increasing it from 3.18 to 4.22 t·ha⁻¹, along with improvements in leaf area, total biomass, root length, and panicle length by 70.74%, 76.54%, 14.34%, and 16.55%, respectively.ConclusionsIt was concluded that a 3 t·ha⁻¹ biochar application mitigated the negative effects of water stress caused by prolonged irrigation intervals. This biochar treatment improved the soil's physical properties and enabled the quinoa variety INIA 415 Pasankalla to achieve yields close to its theoretical productive potential.

Assessing the effects of water stress and bio-organic fertilizers on English and French Lavandula species in different locations

A study was conducted utilizing a factorial split-plot design within complete randomized blocks to evaluate the effects of water stress (at 95±5, 75±5, 50±5, and 25±5% of the field capacity (FC)) and various fertilizer sources (Azotobacter-Psedomonas Bacterial (APB), arbuscular mycorrhizal fungi (AMFs), and biochar (BI), applied individually and in combination, along with a control treatment on the two species of lavender (French and English) in two distinct climates (Fars and Hamedan) in Iran. The results revealed that severe water deficit stress reduced the growth, yield, and essential oil content in both lavender species. APB+AMFs+BI and APB+BI led to the highest flower yield for French lavender in Fars and Hamedan while subjected to well-watered conditions. The essential oil yield significantly decreased in both experimental regions under 25% FC. Employing APB+BI under 75 and 50% FC treatments led to the highest essential oil content (4.23 and 1.56%, respectively) in English lavender. Linalool showed the highest average (22.46 to 30.06%) in both species. French and English lavender in Fars showed significant differences in fatty acid compositions, but no such differences were reported in Hamedan. APB+BI emerged as the most effective fertilizer combination in terms of total fatty acids and rank index. Simultaneous use of bio-organic fertilizers yielded appropriate results under water-deficient conditions. Finally, the study underscored the strong correlation between climatic parameters such as rainfall and temperature, as well as the efficacy of different fertilizer sources, emphasizing that climatic condition and plant species can significantly impact the effectiveness of fertilizer use.

Geopolitical Risk and Foreign Direct Investment Inflows: The Moderating Role of Water and Energy Risks

ABSTRACTUsing a panel of 43 economies between 1985 and 2022, this article establishes a link between foreign direct investment (FDI) inflows and geopolitical risk. We distinguish the idiosyncratic component of geopolitical risk from the global geopolitical risk index provided by Caldara and Iacoviello (2022. American Economic Review, 112, 1194–1225.). We then incorporate both global and idiosyncratic risks into a static FDI regression model, controlling for other economic and institutional determinants. Our findings suggest that both global and idiosyncratic geopolitical risks pose significant obstacles to FDI inflows. Additionally, we investigate whether water and energy risks, when interacting with geopolitical risk, influence the behaviour of international investors. To test this hypothesis, we estimate the interaction effect of water stress and energy intensity as proxies for water and energy risks, respectively. Our findings imply that foreign investors perceive high energy intensity and water stress as moderating factors that could motivate host country policymakers to avoid involvement in geopolitical confrontations, thereby supporting peacebuilding to prevent or resolute conflicts.

Adopting a strategic approach to dormant seeding and initial soil water management for rainfed lentil agroecosystems

The initial soil water (ISW) content and dormant seeding management (DSM) also resulted in better use of precipitation and escape from the heat and drought stresses in late spring and early summer. However, the effect of initial soil water content under DSM as an adaptation option on crop yield has not been fully evaluated, especially in developing countries. We aimed to assess sowing date and ISW on yield of lentil cultivars in 37 selected locations representing six arid and semi-arid agro-climates in Iran. We utilized the SSM-Legume model to quantify the sensitivity of lentil production to ISW and sowing date. Our results showed that the ISW creates the early appearance of stress on late-sown lentil, while DSM1 (dormant seeding around 20 December) of lentil conserved higher soil water throughout the crop growth period. On the other hand, DSM1 and short cycle cultivar explored a higher amount of soil water and thus increasing the productivity. Hence, to minimize the effect of soil water stress in lentil rainfed agroecosystems, the best management combination of a short-cycle cultivar, DSM1, and an ISW ranges from 32 up to 52 mm produced the highest grain yield over all studied agro-climate types (779–605 kg ha−1) due to lower plant water stress. Improving total production can be especially effective in arid and semi-arid areas. These results can offer advice to farmers and decision-makers in enhancing rainfed lentil production in arid and semi-arid agroecosystems by managing soil water and DSM.

INFLUENCE OF THE TIMING OF THE APPLICATION OF SALICYLIC ACID ON THE QUANTITATIVE YIELD AND SOME BIOCHEMICAL CHARACTERISTICS OF BARLEY (Hordeum vulgare L.) UNDER DEFICIT IRRIGATION

Using salicylic acid (SA) to feed drought-stressed plants plays a vital role in reducing the adverse effects of water stress and improving plant performance. This study explores the role of salicylic acid and different barley cultivars in mitigating the effects of drought stress on barley.The study examined three irrigation levels—one-time irrigation (severe stress), two-time irrigation (moderate stress), and four-time irrigation (control)—along with foliar and non-foliar applications of salicylic acid (SA) at three key stages of the Zadoks Growth Scale (ZGS): ZGS 29 (end of tillering), ZGS 34 (50% stem elongation), and ZGS 39 (completion of flag leaf emergence). These treatments were applied to three barley cultivars—Khatam, Reyhan, and Nosrat— which are considered semi-tolerant to drought stress. The findings showed that the interaction of reduced irrigation and SA increased chlora (8.8%) and b (7.12%) in the ZGS34 treatment under control conditions compared to the treatment without SA. The proline content increased with increasing drought stress, with the highest proline content obtained at the end of the tillering stage in the control condition. Compared to the control, which had no foliar spraying, the specific leaf area increased by 3.8, 1.8, and 0.4%, respectively. Relative water content in Khatam (35.6%), Reyhan (33.3%) and Nosrat (30.5%) decreased with increasing stress in the control treatment compared to the minimum stress. The most sensitive cultivar to lack of irrigation was Khatam. The rate of yield increase by SA compared to the control was (10.33%) among the barley cultivars cultivated, the cultivar Reyhan had a comparative advantage in more measures, mainly when applied at ZGS29. In conclusion, SA improved the drought tolerance of the barley and increased the yield by improving the biochemical characteristics.

The effects of water stress and plant density on vegetative and reproductive characteristics of safflower in the semi-arid region

The limited availability of water for irrigation in semi-arid areas necessitates the use of deficit irrigation techniques. Deficit irrigation is an irrigation practice whereby water supply is reduced below maximum levels and a mild water-deficit stress affect the crop yield. Current field experiment was aimed to investigate different densities of safflower (Carthamus tinctorius L.) (33, 40, 50, 66 plants m2 abbreviated as P33, P40, P50, and P66, respectively) under different soil moisture content (irrigation up to 100%, 70%, and 50% field capacity showed as FC100, FC70, and FC50, respectively) on the growth characteristics of safflower in a semi-arid region in the northwest of Iran. Number of days to maturity decreased significantly under deficit irrigation (FC70 and FC50). The longest growth period was recorded for plants grown under P66-FC100 conditions which was 7% higher than P50-FC100. The decrease in plant density caused an increase in chlorophyll content and this trend was more evident under Fc100. Increasing the density under FC100 conditions increased the plant height. However, this trend was not observed under deficit irrigation conditions. Decreasing the plant density per unit area induced the lateral growth, and increased the number of capitula per plant, the weight of capitulum, the number of achenes per capitulum and the 1000-achenes weight. This trend was more prominent under FC100 conditions. Mild deficit-irrigation (irrigation up to FC70) resulted approximately 20% reduction in achene yield. Thus, water management is very important to certify a conservational water supply in semi-arid regions. Irrigation up to FC70 under the studied area is a reasonable and good management method to save irrigation water.

Impact of Salicylic Acid and Potassium Silicate in Ameliorating the Drought Stress Effect on Sorghum (Sorghum bicolor L. Moench)

Aims: The present study highlights the impact of salicylic acid and potassium silicate in reducing the deleterious effect of drought stress on sorghum. Study Design: Split plot design. Place and Duration of Study: Agricultural College Farm, Bapatla, Andhra Pradesh during rabi, 2023-24. Methodology: The experiment consist of two main treatments i.e., water stress treatments viz., M1 (stress treatment i.e., moisture stress was imposed from vegetative to flowering (25-70 DAS) and M2 (No stress treatment) and eight sub treatments viz., No spray (S1), K-Silicate @50ppm at 35+45 DAS (S2), K-Silicate @100ppm at 35+45 DAS (S3), SA @150ppm at 35+45 DAS (S4), SA @200ppm at 35+45 DAS (S5), K-Silicate @50ppm + SA @200ppm at 35+45 DAS (S6), K-Silicate @100ppm + SA @200ppm at 35+45 DAS (S7) and K-Silicate @150ppm + SA @200ppm at 35+45 DAS (S8) replicated thrice. The plant samples were collected on 30, 50 and 70 DAS. Results: The sorghum plants under water stress showed drastic reductions in chlorophyll content (54.9%), relative water content (34.1%) and increase in membrane injury index (1.9 folds), proline content (1.8 folds) and catalase activity (3.6 folds). The combined spray of potassium silicate @100ppm + SA @200ppm exhibited superior performance by enhancing the chlorophyll content by 59.1%, relative water content by 32.5, proline content by 26.1%, catalase activity by 30.4% and reducing membrane injury index by 28.9%. Conclusion: It can be concluded that the foliar application of @100ppm + SA @200ppm at 35 + 45 DAS helped the sorghum plants from the negative effects of water stress from vegetative to flowering stages.

Leaf Aquaporin Expression in Grafted Plants and the Influence of Genotypes and Scion/Rootstock Combinations on Stomatal Behavior in Grapevines Under Water Deficit.

This study investigates the impact of water stress on grapevines, specifically examining the role of rootstocks and aquaporins. Two experiments on potted plants were conducted in central Chile during the summer, under conditions of high water demand, involving various rootstock genotypes and combinations of Cabernet Sauvignon (CS) grafted onto rootstocks. Significant differences were observed among plants in terms of stem water potential, stomatal conductance, and growth rate. Notably, the CS/CS combination consistently displayed the slowest growth rate, regardless of the irrigation treatment. The study also analyzed the expression levels of plasma membrane intrinsic protein (PIP) and tonoplast intrinsic protein (TIP) aquaporins in the leaves of grafted plants. Specifically, VvPIP2;2 aquaporins showed reduced expression after 14 days without irrigation, whereas VvTIP1;1 and VvTIP2;1 expression levels correlated positively with gs responses in grafted plants, suggesting their role in modulating water content in leaves under water stress. TIP aquaporins likely play a significant role in the differential responses of CS plants towards near-isohydric or anisohydric behavior. The CS/CS combination exhibited near-isohydric behavior, correlating with lower TIP aquaporin expression, while the combination of CS onto 1103P and 101-14 showed higher expression, indicating anisohydric behavior. The findings suggest that grafted plants are more resilient to water stress, supporting the idea that rootstocks can mitigate the effects of water stress on the scion.

Ovule and seed development of crop plants in response to climate change

The ovule is a plant structure that upon fertilization, transforms into a seed. Successful fertilization is required for optimum crop productivity and is strongly affected by environmental conditions including temperature and precipitation. Climate change refers to sustained changes in global or regional climate patterns over an extended period, typically decades to millions of years. These shifts can result from natural processes like volcanic eruptions and solar radiation fluctuations, but in recent times, human activities—especially the burning of fossil fuels, deforestation, and industrial emissions—have accelerated the pace and scale of climate change. Human-induced climate change impacts the agricultural sector mainly through global warming and altering weather patterns, both of which create conditions that challenge agricultural production and food security. With food demand projected to sharply increase by 2050, urgent action is needed to prevent the worst impacts of climate change on food security and allow time for agricultural production systems to adapt and become more resilient. Gaining insights into the female reproductive part of the flower and seed development under extreme environmental conditions is important to oversee plant evolution, agricultural productivity, and food security in the face of climate change. This review summarizes the current knowledge on plant reproductive development and the effects of temperature and water stress, soil salinity, elevated carbon dioxide, and ozone pollution on the female reproductive structure and development across grain legumes, cereal, oilseed, and horticultural crops. It identifies gaps in existing studies for potential future research and suggests suitable mitigation strategies for sustaining crop productivity in a changing climate.

Effect of elevated temperature and water stress on seed germination of the Himalayan medicinal herb Aconitum spicatum

Effect of elevated temperature and water stress on seed germination of the Himalayan medicinal herb <i>Aconitum spicatum</i>

Response of Helenium amarum to Environmental Stressors in the Presence of Mycorrhizal Fungi and Its Role as a Pollinator Resource

Globally, climate change is causing shifts in precipitation patterns. Shifting precipitation patterns can be a stressor for many species. One species that is experiencing such stress is Helenium amarum Raf (H. Rock). H. amarum, thrives in dry upland pastures and low-lying grassy and sandy habitat in the mid-Atlantic (USA), where it persists despite storm-driven standing water. Helenium amarum is a species that is toxic to livestock and has been found outside its native range. Temperature and light impacts on germination are already known, but the role of water availability and potential ameliorating effects of mycorrhizae during water stress have not been studied. We planted seeds collected from nature in the Aquatics Facility at Old Dominion University under varied water regimes (drought, flood, intermediate) and evaluated supplemental mycorrhizal fungi impacts on plant traits. Plants in soil with supplemental mycorrhizae grew to nearly twice the height of ‘no supplement’ controls (x¯mycorrhizae = 23.16, S.D. = 7.33 cm; x¯control = 13.70, S.D. = 6.33 cm; p &lt; 0.001). Leaf length was also greater with supplemental mycorrhizae ( x¯mycorrhizae = 3.52, S.D. = 1.27 cm; x¯control = 2.66, S.D. = 0.75 cm; p = 0.0239). Leaf number was greater in high water treatments, with supplemental mycorrhizae (high-water: x¯mycorrhizae = 27.47, S.D. = 10.66; x¯control = 13.50, S.D. = 6.80; p &lt; 0.001; pulse-water x¯mycorrhizae = 30.50, S.D. = 8.64; x¯control = 22.38, S.D. = 7.42; p = 0.0254). This work demonstrates that H. amarum tolerates both dry and moist soil during germination, which may be relevant for successful invasiveness. Supplemental mycorrhizal fungi buffer the effects of water stress, which is significant as climate change impacts precipitation. Additionally, we have documented that pollinators frequently visit flowers of the plant, which is indicative that the species provides ecosystem services in the form of pollinator resources.

Daily and seasonal variations of soil respiration from maize field under different water treatments in North China

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

Effects of water stress on chlorophyll fluorescence and growth of Rorippa amphibia: a well-adjusted invasive plant in China

Effects of water stress on chlorophyll fluorescence and growth of Rorippa amphibia: a well-adjusted invasive plant in China

Characterizing the hysteretic effects of water and salinity stresses on root-water-uptake

Characterizing the effects of previous water and salinity stresses is critical for the evaluation of plant water status, which, in turn, is essential for understanding soil-plant water relations and optimizing irrigation schemes. Recent research has found that hysteresis of plant response following water stress alone can be described by an exponential function of the stress degree on the previous day. To explore and quantify the effects of hysteresis concerning salinity stress and combined water-salinity stress, a hydroponic experiment and a soil column experiment on winter wheat, and a field experiment on cotton were conducted. Like water stress, previous salinity stress and combined water-salinity stress also resulted in hysteretic effects on root-water-uptake. Leaf stomatal conductance and plant transpiration rate of stressed crops could only recover gradually from a previous stressed status after re-watering. When stress was mild, compensatory recovery was found, while incomplete recovery occurred when stress was severe. Although the recovery process was closely related to stress history and type, a recovery coefficient was quantified universally with an exponential function of the stress extent on the previous day (with a coefficient of determination R2 ≥ 0.60). Consideration of hysteresis for water and salinity stresses with a mathematical model led to significant improvement in the simulation of both relative transpiration rate (R2 = 0.94, root mean squared error RMSE = 0.04, maximal absolute error MAE = 0.12) and soil water content (R2 = 0.90, RMSE = 0.01 cm3 cm–3, MAE = 0.03 cm3 cm–3), especially during the recovery periods severely affected by historical stress. Consideration of hysteresis is expected to benefit regulation of soil water and salinity and thus enhance water use efficiency. However, the mechanisms underlying hysteresis, especially the compensatory recovery mechanisms, still need to be further investigated.

Maize (Zea Mays L.) Response to Deficit Irrigation Levels at Different Growth Stages on its Yield and Water Use Efficiency at Koka, Central Rift Valley of Ethiopia

Water scarcity is among the major limitations for crop production. Improving water use efficiency of irrigated crops through water management options is crucial in water scarce areas. Field experiment was carried out at Wondo Genet Agricultural Research Center Koka Research site, to investigate the effect of water stress at different growth stage on yield and water use efficiency of maize. one optimum irrigation and eight growth stage based deficit levels(100% ETC at all growth stages, 75% ETC at all growth stages, 50% ETC at all growth stages, 75% ETC at development growth stage, 50% ETC at development growth stage, 75% ETC at mid growth stage, 50% ETC at mid growth stage, 75% ETC at late growth stage and 50% ETC at late growth stage) were imposed on maize (Zea mays L.) variety Melkassa II as a treatment and laid out in randomized complete block design (RCBD) with three replications. Results indicated that the different levels of growth stage based deficit levels had significant (p&lt;0.01) effect on crop yield, harvest index and water use efficiency. Grain yield reduced with increased stress, whereas water use efficiency was increased with stress level increased. The highest grain yield of 6.4 t/ha and WUE of 1.01 kg/m3 were obtained at 100% ETC and 50% ETC at all growth stages, respectively. Also, 75% ETC at development stage and late stage treatments showed no significant variation with 100% ETC in grain yield. Water use efficiency observed at 75% ETC all growth stages treatment was statistically similar with that of 50% ETC at all growth stages treatment. Grain yield obtained from 50% ETC at mid growth stage was similar with 50% ETC at all growth stages, and water use efficiency was the least and this shows that maize was sensitive to moisture stress at mid growth stage than development and late growth stages. Therefore, maize could be irrigated at 75% ETC at all growth stages and by stressing development or late growth stages up to 50% ETC to increase water use efficiency with a small grain yield reduction for stressed scenario and for non stressed scenario with 100% ETC at all growth stages.

The role of salicylic acid in modulating phenotyping in spring wheat varieties for mitigating drought stress

Climate change-related droughts that recur frequently are one of the biggest obstacles to wheat (Triticum aestivum L.) productivity. Worldwide, attempts are being done to establish drought-resistant cultivars. However, progress is slow since drought tolerance is a complex trait controlled by numerous genes, and its expression is influenced by the environment. Phenotypic, biochemical physiological, and genotyping approaches are highlighted as critical research components for leveraging genetic variation in eight wheat genotypes. Treatments included eight spring wheat genotypes (IPK_040, IPK_046, IPK_050, IPK_071, IPK_105, WAS_007, WAS_024 and WAS_031), normal irrigation (NI), drought stress (D) (30% field capacity (FC)), normal irrigation with 0.5 mM SA (NSA), and drought treated with SA (DSA). The results revealed that there was a reduction in relative water content, an increase membrane leakage, and leaf chlorophyll content under drought stress. SA induced the defense responses against drought by increasing the osmolytes and the antioxidative enzymes activities. Compared to the NI group, the DSA treatment improved the water regulation, antioxidant capacity, and drought stress resistance. SA significantly reduced the deleterious effects of water stress on phenotyping more in WAS_ 024 and IPK_ 105 genotypes. The most responsive genotypes to salicylic acid were IPK_ 046 among the IPK genotypes, whereas WAS_031 genotype was amongst WAS genotypes based on the morpho-physiological traits. The findings of this study give a solid foundation for assessing drought resistance in T. aestivum and developing cultivation-specific water management methods.Graphical