Maryam Goodarzian Ghahfarokhi; Afrasyab Rahnama; Moosa Meskarbashee; Donald L. Smith
Abstract
Objective: Exogenous application of salicylic acid (SA) has the potential to improve photosynthetic performance and seed oil composition under heat stress. This study aimed to evaluate whether foliar SA treatment can mitigate terminal heat stress in safflower by enhancing photosynthetic traits and by ...
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Objective: Exogenous application of salicylic acid (SA) has the potential to improve photosynthetic performance and seed oil composition under heat stress. This study aimed to evaluate whether foliar SA treatment can mitigate terminal heat stress in safflower by enhancing photosynthetic traits and by altering seed oil fatty acid composition, and to compare responses between a heat-tolerant and a heat-sensitive cultivar.
Methods: A field experiment was conducted at Shahid Chamran University of Ahvaz using a split-plot RCBD with three replications. Main plots were two sowing dates: normal sowing (11 December) and late sowing (21 January). Subplots comprised a factorial combination of SA concentrations (0 and 400 μM) and two safflower cultivars: Parnian (heat-sensitive) and Faraman (heat-tolerant). Late sowing subjects the crop to severe terminal heat during flowering and grain filling. Photosynthetic parameters and fatty acid composition of seeds were measured, and grain yield was recorded.
Results: Late sowing (heat stress) significantly reduced photosynthetic rate, stomatal conductance, transpiration rate, substomatal CO2, carboxylation efficiency, and photosynthetic water-use efficiency. Foliar SA application mitigated these negative effects, with the most favorable responses under 400 μM SA and normal sowing. The Faraman cultivar sown at normal time and treated with 400 μM SA achieved the highest stomatal conductance (711 mmol m⁻² s⁻¹), carboxylation efficiency (1.079 mmol m⁻² s⁻¹), and grain yield (3120 kg ha⁻¹). Fatty acid responses to heat were cultivar-dependent: stearic acid decreased in Faraman but increased in Parnian under heat stress (−48% vs +64%, respectively). SA treatment under late sowing increased oleic and linoleic acids while reducing linolenic and palmitic acids, contributing to modified seed oil composition that is favorable under heat stress.
Conclusion: Terminal heat stress altered photosynthetic performance, yield, and seed oil fatty-acid profiles in safflower. Foliar SA application mitigated heat-induced declines in photosynthesis and influenced oil composition, with more pronounced benefits in the heat-tolerant Faraman cultivar. SA at 400 μM provides a viable means to enhance heat tolerance and potentially improve oil quality in safflower under heat stress.
elnaz farajzadeh
Abstract
Objective: The objective of the present study was to evaluate whether foliar application of plant-growth-promoting bacteria and vitamins can enhance growth, physiology, and yield of quinoa while reducing chemical inputs.Methods: A field experiment (2023–2024) was conducted in a split-plot arrangement ...
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Objective: The objective of the present study was to evaluate whether foliar application of plant-growth-promoting bacteria and vitamins can enhance growth, physiology, and yield of quinoa while reducing chemical inputs.Methods: A field experiment (2023–2024) was conducted in a split-plot arrangement within a randomized complete-block design with three replications. Factor A (bacteria strains) included: no bacteria, Pseudomonas fluorescens, Bacillus subtilis, and a combination of both strains. Factor B (vitamin concentrations) included 2, 4, and 6 g/L. Foliar sprays were applied twice during the growing season at two-week intervals, during the cooler evening hours (establishment and two weeks later). Measured traits included plant height, leaf area index (LAI), chlorophyll index, seed yield per plant, levels of cytokinin, auxin, gibberellin, seed protein, leaf soluble carbohydrate content, and total antioxidant capacity.Results: ANOVA revealed significant effects of foliar bacteria and vitamin treatments on several traits, including plant height, LAI, phytohormone contents (auxin, cytokinin, gibberellin), chlorophyll index, and grain yield. The tallest plants reached about 110 cm with Bacillus subtilis, representing a 12.2% increase over the control. Vitamin applications, particularly at 150 mg/L, increased plant height by approximately 6.8% and improved LAI. Foliar treatments also elevated leaf auxin and cytokinin concentrations, with the highest auxin observed under Bacillus subtilis plus 150 mg/L vitamins (≈81% increase). Combined bacterial and vitamin treatments generally outperformed single applications for chlorophyll synthesis and grain yield. Grain yield increased by about 23.15% with the Bacillus subtilis+ 150 mg/L vitamin treatment. Grain protein content was highest with Bacillus subtilis in year one.Conclusion: Foliar application of growth-promoting bacteria (B. subtilis and P. fluorescens) in combination with vitamins beneficially affected quinoa growth, physiology, and yield, with the combination often outperforming individual treatments. The Bacillus subtilis and 150 mg/L vitamin regime most consistently enhanced plant height, LAI, hormone balance, chlorophyll content, grain yield, and grain protein. These results suggest that integrating bacterial and vitamin foliar sprays can reduce reliance on chemical inputs while improving quinoa productivity under field conditions.
Khashayar Rigi; Mehdi Dahmardeh; Seyyed Mohsen Mousavi Nick
Abstract
Objective: Intercropping can reduce production risk and improve resource use efficiency. Foliar spraying of methanol is reported to mitigate drought stress and possibly increase yield. This study investigates the effects of methanol foliar spraying on a triple intercrop of roselle (Hibiscus sabdariffa), ...
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Objective: Intercropping can reduce production risk and improve resource use efficiency. Foliar spraying of methanol is reported to mitigate drought stress and possibly increase yield. This study investigates the effects of methanol foliar spraying on a triple intercrop of roselle (Hibiscus sabdariffa), aloe vera, and peanuts to identify the optimal intercropping pattern and methanol percentage under the climatic conditions of the Sistan region, southeast Iran.
Methods: A factorial experiment based on a randomized complete block design with three replications was conducted at the Zabol University experimental field. The main factor was methanol foliar spray at three levels (10%, 20%, 30% v/v), and the secondary factor was mixed cropping pattern at nine levels (intercropping configurations). Individual crops were grown at their typical densities: roselle 50 cm between plants in a row, peanuts 15 cm, and aloe vera 50 cm. In the mixed treatments, the final densities were achieved by altering intra-row plant spacing while keeping row spacing fixed at 50 cm. Each plot consisted of six rows of 3 m length (81 plots total). All treatments included one row of peanuts, one row of roselle, and one row of aloe vera. Glycine was added to the methanol solutions at 2 g L⁻¹ to mitigate methanol toxicity. Foliar spray was applied 60 days after planting, with two applications at 14-day intervals until run-off.
Results: The interaction between intercropping pattern and methanol level significantly affected all quantitative peanut traits and nutrient uptake. The highest peanut seed yield and the highest absorption of potassium and zinc occurred with 30% methanol in pure peanut cultivation (i.e., monoculture) and with 10% methanol in a mixed intercrop of 100% roselle + 25% peanut + 75% aloe vera, respectively.
Conclusions: To achieve the highest peanut yield and nutrient uptake, monoculture peanut production with foliar spraying of 30% methanol is recommended.
Naser Samsami; Jalal Jalilian; Esmaeil Gholinezhad; Raheleh Tahmasebi
Abstract
Objective: Salinity stress poses a substantial environmental challenge that negatively impacts agricultural productivity, particularly in arid and semi-arid regions where soil salinity is prevalent. This study evaluates the effects of varying salinity levels on the morphological and phenological ...
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Objective: Salinity stress poses a substantial environmental challenge that negatively impacts agricultural productivity, particularly in arid and semi-arid regions where soil salinity is prevalent. This study evaluates the effects of varying salinity levels on the morphological and phenological traits of Galega officinalis across three planting environments: greenhouse, open-air pots, and field.
Methods: A randomized complete block design (RCBD) with three replications was conducted in three cultivation environments (greenhouse, open-air pots, and field) during the 2024 crop year at the Agricultural Faculty of Urmia University. Plants were subjected to three salinity levels (0.1, 5, and 10 dS m⁻¹) over a defined growth period. Traits assessed included seed yield; morphological traits (plant height, inflorescence length, number of leaves, number of main branches, number of secondary branches, leaf dry weight, stem dry weight, and aerial dry weight); and phenological traits (days to germination, days to flowering, days to physiological maturity, days to inflorescence formation, and days to 4 leaves).
Results: Analysis of variance indicated that salinity stress significantly affected several traits, including days to flowering, branch numbers, dry weights of plant organs, and grain yield. In the greenhouse, salinity at 10 and 5 dS m⁻¹ reduced days to flowering by 19% and 2%, main branches by 40% and 30%, secondary branches by 78% and 15%, and leaf dry weight by 49% and 10%, respectively, relative to the control (0.1 dS m⁻¹). In open-air pots, harvest maturity, inflorescence formation, plant height, inflorescence length, and aerial organ fresh and dry weights declined at higher salinities by 6% and 2%, 41% and 4%, 26% and 18%, 23% and 15%, 41% and 6%, and 32% and 9%, respectively, with grain yield decreasing by 29% and 4%. Field cultivation exhibited the greatest sensitivity, with grain yields dropping by 78% at 10 dS m⁻¹ and 67% at 5 dS m⁻¹. The highest plant height (71.66 cm) occurred in field conditions, while the lowest (31.64 cm) occurred in open-air pots. The maximum numbers of secondary and main branches were observed in greenhouse conditions (41.33 and 3.33, respectively), with the minimums in open-air pots (3.66 and 1.00). The longest inflorescence length was produced under no-salt conditions in the field (12 cm), while the shortest (5.28 cm) occurred at 10 dS m⁻¹ in open-air pots.
Conclusions: The findings indicated that field cultivation under control conditions (0.1 dS/m) yielded significantly higher grain compared to greenhouse and open-air pot methods. It is recommended that farmers favor field conditions for growing Galega officinalis and maintain salinity levels below 5 dS/m to mitigate adverse effects on both morphological and phenological traits. Field cultivation under control conditions (0.1 dS/m) yielded significantly higher grain compared to greenhouse and open-air pot methods.
Amin Najafi Alivar; Mehdi Hadadinejad; Abdolrahman Mohammadkhani; Dariush Madadi
Abstract
Objective: This study examines the impact of various grape rootstocks on the growth characteristics, physiological properties, and nutrient content of the seedless white scion, a cultivar of significant commercial importance in Iran’s agricultural sector.
Methods: A completely randomized ...
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Objective: This study examines the impact of various grape rootstocks on the growth characteristics, physiological properties, and nutrient content of the seedless white scion, a cultivar of significant commercial importance in Iran’s agricultural sector.
Methods: A completely randomized greenhouse experiment at the Horticulture Department, Shahrekord University, compared six treatments: a control (Sultana cuttings), own-rooted Sultana/Sultana, and grafted combinations of the seedless white scion onto rootstocks (Yaghuti, Asgari, Khushnam, and red Sultana). Traits assessed included morphometric, biological, and physiological parameters, as well as concentrations of Ca, K, and P.
Results: The lowest root number occurred in the own-rooted treatment. In contrast, self-grafted (seedless white scion on seedless white rootstock) showed the highest accumulation of photosynthetic pigments, the longest root length, and the greatest Ca absorption. Seedless white rootstock exhibited notably higher carotenoid content. Chlorophyll analysis revealed that Khoshnam and seedless white combinations had higher chlorophyll a, while Asgari and Yaghuti combinations had higher chlorophyll b and total chlorophyll. Leaf area was greatest with the Asgari rootstock, and internode diameter was largest with Khoshnam. Scion height increased significantly with rootstock: 57% higher with Khoshnam and 34% higher with Asgari than the control. Root volume was significantly greater with Yaghuti and Asgari rootstocks compared with control. Mineral content showed higher Ca in the seedless white scion alone; for seedless white on Khoshnam, K and P levels were notably affected, with lower K and higher P concentrations observed.
Conclusions: Grafting markedly influences grape growth and physiology. Own-rooted combinations exhibited enhanced Ca uptake, longer roots, and richer photosynthetic pigment content. Rootstocks such as Khoshnam and Asgari effectively increased scion height and root volume. These findings support strategic rootstock–scion selection as a viable approach to improve grape vigor and nutritional profiles.
Parvin Sabzaliyan; Sepideh Kalateh jari; Marzieh Ghanbari Jahromi
Abstract
Objective: This study evaluated the mitigating effects of different selenium formulations on salt-stressed French lettuce (Lactuca sativa), focusing on growth parameters and mineral uptake dynamics. We aimed to identify the optimal selenium form and concentration for alleviating salinity-induced growth ...
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Objective: This study evaluated the mitigating effects of different selenium formulations on salt-stressed French lettuce (Lactuca sativa), focusing on growth parameters and mineral uptake dynamics. We aimed to identify the optimal selenium form and concentration for alleviating salinity-induced growth inhibition, ionic imbalance, and oxidative stress, and to determine dose–response relationships across salinity levels for practical guidance in saline agriculture.
Methods: In a controlled environment, a factorial completely randomized design was used with three salinity levels (0, 3, and 6 dS m−1 NaCl) and five selenium treatments: control (0), sodium selenate (5 and 10 mg L−1), and nano-selenium (2 and 4 mg L−1), with three replicates. Lettuce was grown hydroponically and subjected to salinity during the vegetative stage. Measured variables included morphological parameters (plant height, leaf area, fresh and dry biomass), ionic contents (Na+, K+, Cl−), and selenium accumulation. Mineral quantification employed atomic absorption spectroscopy and ion chromatography. Data were analyzed by two-way ANOVA with Duncan’s multiple range tests (p ≤ 0.05) to assess main effects and interactions.
Results: Salinity and selenium treatments interacted significantly (p < 0.01) for all measured traits. Under severe salinity (6 dS m−1), growth was markedly inhibited (e.g., plant height −48.6%, shoot fresh weight −44.8%, leaf area −54.2%), with a 2.24-fold increase in Na+ and a 42.7% decrease in K+ in shoots. Nano-selenium at 4 mg L−1 substantially mitigated stress, increasing shoot fresh weight by 28.6% and root dry weight by 30.4%, and improving the K+/Na+ ratio by 31.2% via selective ion regulation. At equivalent selenium doses, nano-selenium enhanced leaf area by 16.8% more than selenate. Under moderate salinity (3 dS m−1), nano-selenium promoted architecture (stem diameter +22.3%, canopy spread +18.5%), reduced root Cl− content by 32.5%, and increased shoot selenium accumulation by 25.7% versus untreated stressed plants.
Conclusion: Lettuce displays pronounced sensitivity to salinity, with substantial biomass loss and ionic toxicity under high salt. Selenium supplementation mitigates these effects, with nano-formulations providing superior protection than conventional sodium selenate. The 4 mg L−1 nano-selenium treatment yielded the greatest overall benefits, improving growth and nutrient homeostasis across salinity levels. These findings support the potential of selenium nanofertilizers as an agronomic strategy to enhance salt tolerance in lettuce, with possible applicability to other salt-sensitive horticultural crops.
Aliasghar Fozouni; Babak Andalibi; Mehrdad Chaichi; Sajjad Nasiri
Abstract
Objective: Drought and limited water resources threaten global potato production. This study evaluated the effects of foliar potassium silicate on agronomic performance and physiological traits of three potato cultivars under water-deficit
Methods: The experiment followed a split–split-plot design ...
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Objective: Drought and limited water resources threaten global potato production. This study evaluated the effects of foliar potassium silicate on agronomic performance and physiological traits of three potato cultivars under water-deficit
Methods: The experiment followed a split–split-plot design in a randomized complete-block arrangement with three replications. Irrigation interval (main plot) comprised 7, 10, and 13 days. Foliar treatments (sub-plot) included: (i) control (no spray), (ii) a single spray at 50 days after planting, and (iii) two sprays at 40 and 80 days after planting at 2 L K2SiO3 per 1000 L water. Cultivars (sub-sub plot) were Corsica, Sante, and Vog. Measured traits were tuber yield, total chlorophyll, soluble protein, total carbohydrate, proline, and malondialdehyde (MDA) content.
Results: The triple interaction among irrigation interval, foliar treatment, and cultivar significantly affected all traits. The highest tuber yield (44.61 t ha⁻¹) occurred with 7-day irrigation, two foliar sprays, and the Corsica cultivar; the lowest yield (39.60 t ha⁻¹) occurred with 13-day irrigation without foliar spray in Sante. Total chlorophyll was highest under non-stress conditions with two sprays in Corsica (2.26 mg g⁻¹ FW). Proline accumulation peaked in Sante under severe drought (13-day irrigation, no spray) (53.69 μmol g⁻¹ FW). Soluble protein (14.94 mg g⁻¹ DW) and total carbohydrate (21.12 mg g⁻¹ DW) were greatest under 10-day irrigation with two sprays in Corsica. MDA content was lowest with two sprays under 7-day irrigation (3.02 nmol g⁻¹ FW) and highest in Sante under severe drought without spray (25.14 nmol g⁻¹).
Conclusions: In Corsica, two foliar applications of potassium silicate under 7-day irrigation improved physiological performance and water-use efficiency while reducing oxidative stress indicators. Mild drought stress also enhanced accumulation of protective compounds (soluble carbohydrates and proteins) in Corsica. In contrast, Sante under severe drought without foliar application showed the greatest oxidative damage and yield reduction. Overall, combining two potassium silicate foliar applications with selecting drought-tolerant cultivars such as Corsica offers a promising, sustainable approach to maintaining yield, enhancing quality, and optimizing water use in drought-prone regions.
sara sabertanha; fatemeh amini; ali Izadi Darbandi; Seyed Ahmad Sadat Noori
Abstract
Objective: To evaluate the forage quality of Festuca pratensis genotypes under water deficit stress and identify drought-tolerant lines that maintain high nutritional value.Methods: Twenty Festuca pratensis genotypes were obtained from NordGen (Sweden) and the ART Institute (Switzerland). Field experiments ...
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Objective: To evaluate the forage quality of Festuca pratensis genotypes under water deficit stress and identify drought-tolerant lines that maintain high nutritional value.Methods: Twenty Festuca pratensis genotypes were obtained from NordGen (Sweden) and the ART Institute (Switzerland). Field experiments were conducted over three consecutive years (2022–2024) at the Research Farm, Faculty of Agricultural Technology, University of Tehran. A split-plot design in time within a randomized complete block design (RCBD) with three replications was used. Two irrigation regimes were imposed after full establishment: normal (100% field capacity) and water deficit (50% field capacity). Sampling occurred at the mid-flowering stage following two years of stress (May 2023 and May 2024). Forage quality, measured traits included acid detergent fiber (ADF), neutral detergent fiber (NDF), cellulose, lignin, nitrogen content, ash, dry matter intake (DMI), in vitro dry matter digestibility (IVDMD), metabolizable energy (ME), and relative feed value (RFV).Results: The ANOVA showed that drought stress significantly affected all measured traits at P < 0.01. Significant main effects were observed for genotype and harvest, with significant stress× genotype and genotype× harvest interactions, and a significant stress× genotype× harvest interaction for all traits except cellulose. The stress× harvest interaction was significant for all traits except ash. Based on mean comparisons, genotypes 2, 13, 14, 15, 16, and 17 exhibited superior performance under drought, characterized by higher crude protein and lower ADF and NDF values, indicating enhanced forage quality under water-limited conditions.Conclusions: Evaluating forage quality under water deficit is an effective strategy for identifying high-value, drought-tolerant Festuca pratensis genotypes. The selected genotypes demonstrate strong potential for deployment in arid and semi-arid regions. Integrating forage quality indicators with drought-tolerance traits can improve the precision of genotype selection in breeding programs. We recommend long-term, multi-location trials to assess adaptability and stability across diverse environments. The findings may inform water resource management strategies for forage production under comparable climatic conditions.
Soraya Ghassemi; Gholam Akbari; elias soltani; Maryam Mansori
Abstract
Objective: Drought and soil salinity are major constraints limiting crop performance and global productivity. Niger seed (Guizotia abyssinica), an oilseed-forage species in the Asteraceae, exhibits rapid life cycle and notable drought and salinity tolerance, making it a candidate for marginal environments. ...
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Objective: Drought and soil salinity are major constraints limiting crop performance and global productivity. Niger seed (Guizotia abyssinica), an oilseed-forage species in the Asteraceae, exhibits rapid life cycle and notable drought and salinity tolerance, making it a candidate for marginal environments. This study evaluated the ecophysiological responses of Niger seed germination under controlled drought and salinity stress to inform potential cultivation in stress-prone regions.Methods: Two controlled-laboratory experiments were conducted in a completely randomized design with four replications. Drought stress was simulated with polyethylene glycol 6000 (PEG-6000) at six osmotic potentials: 0 (control), −0.2, −0.4, −0.6, −0.8, and −1.0 MPa. Salinity stress was imposed using NaCl at five concentrations: 0 (control), 50, 100, 150, and 200 mM. Germination dynamics were quantified using maximum germination percentage (Gmax), time to 10% germination (R10), and time to 50% germination (R50) as key metrics of seed vigor and germination pace under stress.Results: Under drought, Gmax peaked at 95% at −0.2 MPa and declined to 6% at −1.0 MPa. R10 was highest in the control (mean ≈6.5 seeds·day⁻¹) and dropped to 0.04 seeds·day⁻¹ at −1.0 MPa. R50 reached a maximum of 1.3 seeds·day⁻¹ in control, with no germination at –1.0 MPa. Under salinity, Gmax decreased from 98% (control) to 58% at 200 mM NaCl. R10 ranged from 1.8 seeds·day⁻¹ (control) to 0.44 at 200 mM NaCl, and R50 declined from 1.62 seeds·day⁻¹ (control) to 0.09 seeds·day⁻¹ at 200 mM NaCl.Conclusions: Niger seed germination is sensitive to both drought and salinity, particularly under severe stress, but shows resilience under low to moderate stress levels where germination percentage and speed are less affected. These findings suggest Niger seed has potential as an alternative crop in semi-arid regions with limited water and moderately saline soils. Further research could optimize management strategies for stress-prone environments