Relative Water Content Research Articles

Impact of salt stress on physiological traits in tomato (Lycopersicon esculentum Mill.)

Salt stress is a major abiotic factor that limits plant growth and development globally, primarily due to the use of low-quality irrigation water and soil salinization caused by seawater intrusion. This study examines physiological parameters, antioxidant enzymes and the K/Na ratio in response to salt stress in various tomato genotypes at a salinity level of 8 dS m-1 during the vegetative stage. Specifically, it investigates superoxide dismutase activity, relative water content, electrolyte leakage, proline content, chlorophyll fluorescence and potassium and sodium ion content in roots, shoots and leaves. The results revealed significant variation in salt tolerance among the different genotypes. Genotypes LE-14 and LE-1 demonstrated superior performance under salt stress, displaying higher relative water content, reduced electrolyte leakage, increased superoxide dismutase activity, elevated proline content and favorable K/Na ratios. Principal component analysis showed significant eigenvalues, accounting for 72.5% of the total variability. These findings provide valuable insights into the mechanisms of salt tolerance in tomato crops and highlight the potential of LE-14 and LE-1 for cultivation in saline environments. The study emphasizes the importance of conducting field trials to validate these results for sustainable production in saltaffected areas.

Green remediation of lead (pb) from Pb-toxic soil by combined use of silicon nanomaterials and leguminous Lens culinaris L. plants

Lead (Pb) toxicity is a major issue due to anthropogenic activities that is faced by farmers nowadays which inhibits plant growth and decreases crop yields. From contaminated soils, Pb absorbed by the plants and then ultimately enters into the food chain. Silicon (Si) can reduce Pb availability to plants and can be helpful in Pb immobilization in the soils. Moreover, Si in its nano-form, is expected to augment the beneficial attributes of applied Si. However, very little is known regarding the prospects of nano-Si application and leguminous lentil for alleviating the effects of Pb stress. To assess the effectiveness of bulk Si and nano-Si for reducing Pb toxicity and improving the yield of lentils, a pot study was conducted. Lentil variety Punjab Masoor 2020 was examined under normal and Pb toxic conditions as affected by applied Si and nano-Si. There were eight treatments comprised of different combinations of Si at 100 and 200 mg Si kg− 1 soil, and nano-Si at 125 mg kg− 1 soil, which were tested against Pb at 500 mg kg− 1 soil. A completely randomized design with factorial arrangements was applied along with three replications each. The result showed that Pb toxicity reduced the plant growth, yield, total chlorophyll contents, membrane stability index, relative water content, shoot fresh weight and dry weights of lentil. Whereas Si and nano-Si lessened the negative effect of Pb toxicity by significantly reducing its concentration in plant roots and shoot, and improved agro-physiological traits of lentil in normal and Pb-toxic soil conditions. In soil spiked with 500 mg kg− 1 Pb, the application of 100 and 200 mg bulk Si per kg of soil and 125 mg kg− 1 nano-Si reduced the Pb concentration in shoot by 31, 62 and 84% respectively over controls. In squat, the application of nano-Si most significantly (p ≤ 0.05) reduced the root and shoot Pb concentration in lentil.

Metal ferrite nanocomposite treatment reduced oxidative stress to improve the growth dynamics of Cucumis sativus in hydroponics

Abstract Green synthesized nanoparticles have various applications but their use for improving plant productivity and agricultural sustainability recommends their usage as nano-fertilisers. In this context, the present study reports the positive influence of hydroponically exposed green synthesized Tri-metal ferrite TiO2-Al2O3-ZnFe2O4 nanocomposites (TMFN) on Cucumis sativus (cucumber). Cucumber is rich in polyphenols and an important part of the human diet because of its water-rich and low-calorie nature. A considerable increase in the length of shoot-roots, relative water content, and chlorophyll level of cucumber was observed on TMFN exposure. An increase of 25–82 and 94–220% in carbohydrate and protein levels on TMFN treatment was observed. Likewise, the phenols, flavonoids, and free radical scavenging potential of the plants were increased by 22-88, 64-211, and 4-18%, respectively, on TMFN exposure. As a result, there was an observable decrease of 62-86 and 14-68% in the oxidative stress indicators, MDA and H2O2, respectively. A simultaneous and significant increase in the inorganic nitrate, nitrite content, nitrate reductase, and glutamate synthetase activity was evident. However, ammonia content and glutamate dehydrogenase activity decreased significantly by 27-82 and 31-85%, respectively. Overall, the TMFN induced significant morphological and biochemical changes in cucumber indicated their probable role as potential plant growth promoters. However further research is required for understanding the molecular and genetic aspects of the effects of green synthesised TMFN on other plants as well as crops grown hydroponically.

Impact of Biochar and Hydroretentive Polymers on the Biochemical and Physiological Traits of Satureja rechingeri Jamzad Under Water Deficit Stress

Satureja rechingeri is a valuable medicinal plant, but its growth can be significantly impacted by water deficit stress. To investigate the effects of biochar (BC) and hydroretentive polymers (HPs) on various eco-physiological traits of savory under a water deficit, an experiment was conducted over two consecutive cropping seasons (2017–2019). A randomized complete block design with a split-plot factorial arrangement and three replications was used. The treatments consisted of three levels of irrigation (95 ± 5, 75 ± 5, and 55 ± 5% FC), which were applied to the main plots, and combinations of two levels of biochar and two levels of HPs, which were applied to subplots. The results show that a water deficit reduced the relative water content (RWC), chlorophyll content, and dry matter yield of the shoots. Furthermore, the activity of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and malondialdehyde (MDA) increased in two-year-old plants. The MDA content significantly decreased by 15.6% in the second year compared to in the first year under a water deficit. The application of HPs caused a decrease of 26.4%, 32.5%, and 27.5% in POD, CAT, and APX enzyme activities, respectively, compared to their control levels. In the biochar treatment, there was a significant reduction in the activity of POD, APX, and CAT in the leaves.

Rapeseed (Brassica napus L.) response to salinity and seed priming with NaCl

AbstractLaboratory and pot trials were conducted to study germination performance of rapeseed (Brassica napus L., genotype Excalibur) under NaCl salinity after seed priming with 20 mM NaCl for 24 h. In the laboratory trial, salinity levels of 80, 160, and 240 mM NaCl reduced the germination percentage by 14, 56, and 80 percentage points, respectively compared to the non‐saline control. NaCl priming lowered the detrimental effect of salt stress on germination by promoting germination from 81% to 85% under salinity of 80 mM, from 39% to 68% under salinity of 160 mM, and from 15% to 56% under salinity of 240 mM NaCl (maximum alleviation). Furthermore, NaCl priming increased the germination tolerance index and the vigour index of seedlings as compared with the control seeds. Relative water content of the leaves was decreased with increasing salinity, showing limited water availability and a loss of turgor in the leaves. NaCl priming reduced the decrease in relative water content under salinity. Concerning the pot trial, the salinity level of 240 mM NaCl reduced the dry weight of rapeseed seedlings by 80.9% in the non‐primed seeds and by 55.8% in the primed seeds. NaCl priming improved the mean productivity index by 1.26 times under salinity of 240 mM NaCl and the harmonic mean index by 1.98 times under salinity of 240 mM NaCl compared with non‐primed seeds. Salinity limited seed performance of rapeseed, whereas NaCl priming improved seed performance and early growth in saline environment. The priming method needs to be examined in a selection of relevant genotypes under a range of saline conditions.

Improving Washington Navel orange yield under drought: effects of artificial mulch and shade netting

ABSTRACT This study evaluates the impact of synthetic ground cover and shade netting on Washington Navel orange trees (Citrus sinensis L.) in a semi-arid region to mitigate high temperatures and solar radiation. Over four years (2020–2023), treatments included mulch, shade netting, their combination, and a control. Parameters assessed included nutrient concentrations, physiological traits, growth, fruit quality, and thermal regulation. The combination of mulch and shade netting enhanced leaf nutrient levels, with phosphorus and potassium increasing by 100% and 53.3%, respectively. Leaf area expanded by 82.9%, relative water content rose by 27.7%, and photosynthetic efficiency improved by 136.8%. Fruit set and yield increased by 99.19% and 46.08%, respectively, while fruit sunburn was reduced by 76.78%. Canopy and soil temperatures decreased by up to 17.50% and 19.49%, respectively. Principal Component Analysis (PCA) highlighted improved water use efficiency and tree health with these treatments. These findings demonstrate that combining mulch and shade netting effectively enhances citrus orchard resilience, productivity, and economic viability under drought and heat stress. This sustainable approach is recommended to optimise citrus orchard performance in challenging environmental conditions.

Comprehensive genome-wide analysis of ARF transcription factors in orchardgrass (Dactylis glomerata): the positive regulatory role of DgARF7 in drought resistance

Auxin response factor (ARF), a transcription factor, is crucial in controlling growth, development, and response to environmental stress. Orchardgrass (Dactylis glomerata) is an economically significant, widely cultivated forage grass. However, information on the genome-wide information and functional characterization of ARFs in orchardgrass is limited. This study identified 27 ARF genes based on the orchardgrass genome database. These DgARFs were unevenly distributed across the seven orchardgrass chromosomes and clustered into four classes. Phylogenetic analysis with multispecies of ARF proteins indicated that the ARFs exhibit a relatively conserved evolutionary path. Focusing on hormone signaling responses, DgARF7 demonstrated a potential positive regulatory role in response to 3-indole acetic acid, methyl jasmonate, gibberellin, salicylic acid, and abscisic acid signals. Additionally, exposure to drought stress induced noticeable oscillatory changes in DgARF7 gene. Notably, DgARF7 enhanced drought tolerance through heterologous expression in yeast and overexpression in Arabidopsis. Overexpressed Arabidopsis lines of DgARF7 exhibited a markedly higher relative water content and superoxide dismutase activity, while the malondialdehyde content was significantly decreased compared to wild type under drought stress. DgARF7 also accelerated flowering time by inducing the flowering-related gene expression levels in Arabidopsis. This research provides important insights into the role of DgARF7 in orchardgrass and provides further understanding in molecular breeding.

Evaluation of wheat drought resistance using hyperspectral and chlorophyll fluorescence imaging.

Photosynthesis drives crop growth and production, and strongly affects grain yields; therefore, it is an ideal trait for wheat drought resistance breeding. However, studies of the negative effects of drought stress on wheat photosynthesis rates have lacked accurate evaluation methods, as well as high-throughput techniques. We investigated photosynthetic capacity under drought stress in wheat varieties with varying degrees of drought stress resistance using hyperspectral and chlorophyll fluorescence (ChlF) imaging data. We analyzed various morpho-physiological traits involved in wheat drought tolerance, including tiller number, leaf relative water content, and malondialdehyde content, to determine the relationships between drought resistance and hyperspectral and ChlF data. The results showed that the spectral first derivative ratio (FDR) between drought stress and control conditions in the 680-760nm region was closely related to photosynthetic capacity and drought tolerance and that hyperspectral imaging can be used to monitor ChlF parameters, with bands sensitive to ChlF identified in two spectral regions (539-764nm and 832-989nm). The spectral first derivative at 989nm had the strongest linear relationship with the minimal fluorescence (R2=0.49). An uninformative variable elimination algorithm indicated that FDRs in the green (504-609nm), red (724-751nm), and near-infrared (944-946nm) light regions had great potential as indices of drought resistance. A support vector machine model based on the FDRs of these characteristic bands identified wheat drought resistance with 97.33% accuracy. These findings provide insight into the application of high-throughput technologies in studying drought resistance and photosynthesis in wheat.

GhRAP2.4 enhances drought tolerance by positively regulating the strigolactone receptor GhD14 expression in cotton (Gossypium hirsutum L.).

Drought poses significant challenges to crop productivity, necessitating a deeper understanding of plant adaptive mechanisms. Strigolactones (SLs), a class of phytohormones, have been recognized as crucial regulators in plant responses to drought, yet the specific role of SL receptor in drought tolerance in cotton (Gossypium hirsutum L.) remains underexplored. In this study, we identified and characterized DWARF14 (GhD14), a SL receptor in cotton. Silencing GhD14 in cotton compromised drought tolerance by reducing leaf relative water content and chlorophyll content, slowing stomatal closure, increasing reactive oxygen species levels, and decreasing antioxidant enzyme activities. Conversely, overexpression of GhD14 in Arabidopsis d14 mutants rescued their drought-sensitive phenotype. Further, we identified a 197-bp fragment (-697 to -894 bp) in the GhD14 promoter that plays a crucial role in the drought stress response. RELATED TO APETALA 2.4 (GhRAP2.4), a dehydration responsive element binding protein (DREB) transcription factor, binds directly to the GhD14 promoter, enhancing its transcription under drought conditions. Silencing GhRAP2.4 in cotton resulted in reduced drought tolerance. This study not only elucidates the molecular interplay between GhRAP2.4 and GhD14 in cotton's drought response but also provides a potential target for genetic modification to improve drought resilience in crops.

Boron contributes to enhance antimony tolerance in rice (Oryza sativa L.) by activating antioxidant system, modifying the cell wall component and promoting cell wall deposition of Sb.

Boron (B) is essential for plant growth and helps mitigate metal toxicity in various crop plants. However, the potential role and underlying mechanisms of B in alleviating antimony (Sb) toxicity in rice remain unexplored. In this study, we investigated the effects of H₃BO₃ supplementation (30, 50, and 75μM) on morphological growth, physiological and biochemical traits, Sb content, and the subcellular distribution of Sb in rice plants under 100μM Sb stress during the seedling stage in a hydroponic system. The results revealed that Sb toxicity severely impaired rice growth, reducing shoot biomass by 38.3%, shoot and root length by 38.9% and 23.2%, and leaf relative water content by 15.5%. Supplementation with 30μMB mitigated these adverse effects by enhancing photosynthesis and chlorophyll synthesis, restoring root activity, and improving oxidative balance through increased antioxidant enzyme activities in rice tissues. Furthermore, B supplementation significantly reduced Sb concentration in roots by 56.28%, while promoting Sb distribution in the cell wall (CW) fraction. Scanning electron microscopy equipped with energy-dispersive X-ray (SEM-EDS) microanalysis confirmed that B enhanced Sb adsorption on root CWs. Fourier transform infrared spectroscopy (FTIR) analysis indicated increased carboxyl groups in the CWs following B application under Sb treatment. Moreover, B supplementation increased the levels of pectin and hemicellulose and elevated pectin methylesterase (PME) activity by 22.0%, 69.0%, and 29.0% in roots, respectively, thus promoting Sb chelation onto the CWs. Taken together, our results provide a scientific basis and theoretical guidance for applying B to alleviate Sb toxicity in crops.

Simultaneous Alleviation of Antimony Toxicity in Rice and In-Vitro Bio-accessibility by Using Biochar and Seaweed Based Fertilizer Blend

Antimony (Sb) toxicity is a significant threat to crop production and humans. Its concentration is increasing in soil and water due to human activities which needs dire attention to address this challenge. Biochar is a promising amendment to remediate polluted soils, however, its role in mitigating the toxic impacts of Sb on plants is still unclear. Seaweed-based fertilizer (SBF) has shown appreciable results in improving plant performance, however, its role against metal toxicity has not been studied yet. Therefore, this study tested the impacts of BC and SBF in mitigating the harmful effects of Sb on rice. The study was carried out with the following treatments; control, Sb stress (600 mg kg-1), Sb stress + biochar (2%), Sb stress + seaweed-based fertilizer (SBF: 2%), and Sb stress + BC (1%) and SBF (1%). The results showed that Sb toxicity adversely affected rice growth and productivity by impeding photosynthetic pigments, leaf relative water contents, increasing production of oxidative stress biomarkers (electrolyte leakage: EL, hydrogen peroxide: H2O2, malondialdehyde: MDA), and accumulation of Sb in plant parts. Contrarily, BC and SBF blends mitigated Sb-induced growth and yield damages in rice by improving photosynthetic efficiency, osmolyte synthesis, nutrient uptake, soil enzymatic activity, and antioxidant activities. Moreover, BC and SBF blend also reduced the bio-accessible Sb concentration (95.63%), bio-accessibility of Sb (25.40%), and Sb transport coefficient (35.70%) by decreasing the soil Sb antimony concentration (52.74%) and converting the Sb into more stable forms. Given these findings, the co-application of BC and SBF showed a profound improvement in rice yield by regulating photosynthetic performance, antioxidant activities, oxidative stress markers, antioxidant activities, and soil properties.

Evaluation of the rainfed and irrigated conditions on biomass and essential oil yield of German chamomile (Matricaria chamomilla) in response to melatonin foliar application

German chamomile (Matricaria chamomilla L.) is a valuable medicinal plant known for its rich content of bioactive compounds, including chamazulene, α-bisabolol, and α-bisabololoxide A. Drought stress poses a significant challenge to agricultural productivity and negatively affects the growth and yield of chamomile. This study aimed to investigate the effects of foliar-applied melatonin on the antioxidant capacity and secondary metabolite production of M. chamomilla under both rainfed and irrigated conditions. The research was conducted using a randomized complete block design with three replications during the 2022–2023 period. To impose drought stress, we compared rainfed and irrigated treatments, while melatonin was applied at three concentrations (0, 100, and 200 mM). The composition of essential oils was analyzed using gas chromatography-mass spectrometry (GC/MS). Results indicated that the application of melatonin significantly improved essential oil content and plant performance under drought conditions. In rainfed situations, applying 100 mM of melatonin increased the essential oil rate by 45%, reaching 1.45% compared to the control group. Under irrigated conditions, the highest essential oil yield of 0.33 g per plant was also achieved with 100 mM melatonin. The maximum proline content of 4.05 mg/g of fresh weight was found in rainfed cultivation with 200 mM melatonin. Plants receiving irrigation with 200 mM melatonin demonstrated the highest values for relative water content (83.2 mg/g fresh weight), total chlorophyll (3.99 mg/g fresh weight), and dry matter (16.61 g). GC and GC-MS analyses revealed that secondary metabolites ranged from 39.85 to 56.97%, with α-bisabolol, chamazulene, and α-bisabololoxide B being the major components. Path analysis showed strong direct effects of essential oil rate (0.921), proline (1.397), and relative water content (1.115) on dry mass, with R² values reaching 95.4% in the final model. The analysis indicated that all measured traits influenced dry mass, with relative water content directly affecting dry mass and essential oil rate positively influencing both proline and dry mass. Based on these findings, combining rainfed cultivation with melatonin application is a promising and environmentally friendly strategy to enhance drought tolerance, growth, and biochemical content in German chamomile.

Morpho-physiological and water use performance of soybean cultivars under drought stress at early growth stages

Drought is an important environmental stress for soybean (Glycine max (L) Merr.), which frequently occurs under second-crop conditions in the Mediterranean region of Türkiye and negatively affects early plant growth. In this study, we investigated the effects of drought stress (soil water content maintained at a constant 50% field capacity) on the early growth stage (V3 stage) of different soybean cultivars (Ataem-7, BATEM Erensoy, Göksoy, and Lider). Twenty-seven-day-old soybean plants were exposed to drought stress for 20 days. Morphological (plant height, root length, seedling fresh and dry weight, root fresh and dry weight, and leaf area), physiological (leaf temperature, chlorophyll rate (CR), leaf relative water content (RWC), and electrolyte leakage (EL)), and water use (total water consumption (TWC), and water use efficiency (WUE)) traits were assessed. The results revealed a significant decrease in plant height, root length, leaf area, root and shoot fresh and dry weights, and RWC, and an increase in CR under drought stress. Although Lider and BATEM Erensoy exhibited better growth than the other cultivars under control conditions, their root and shoot growth decreased significantly under water stress. Notably, Ataem-7 presented a lower TWC and WUE difference between the drought treatment and the control, and this cultivar efficiently used water for dry matter production in the shoot and root parts. As a result, there were significant genotypic differences in drought susceptibility among the soybean cultivars, and Ataem-7 showed greater tolerance to drought than the other soybean cultivars did during the early growth stage.

Nurturing with nature: the efficacy of arbuscular mycorrhizal fungi microbe for cocoa sector environmental management

Despite the proven effectiveness of fertility-promoting microbes such as Arbuscular Mycorrhizal fungi (AMF) to minimize the adverse effects of environmental deterioration and climate change, there is limited understanding on its efficacy to improve cocoa resilience. Cocoa mortality (70%) caused by climate change induced drought within two years of transplanting to the field is a major constrain to farmers’ productivity. This study assessed the effect of AMF and Potassium (K) nutrition on the biochemical characteristics of cocoa and its field survival from 2019 to 2022. A split-plot factorial design was used. The treatments were cocoa varieties (CRG8914 × PA150 [V1], AMAZ15-15 × EQX78 [V2], PA150 × CRG 0314 [V3]), potassium (0 g, 2 g, 4 g plant−1), AMF (AMF, Non-AMF) and watering regimes (water-stressed and supplementary irrigation). Soil samples (0–20 cm) from cocoa rhizosphere were examined for native AMF spores and structures using the Wet Sieving and Decantation methodology and Sucrose Centrifugation. The AMF inoculum was prepared using the trap-culture technique. Under drought conditions, V1, V2 and V3 without K had leaf chlorophyll of 19.4 μmol/m2, 20.5 μmol/m2, 19.9 μmol/m2 respectively, but with 2 g KxAMF, chlorophyll increased to 21.6 μmol/m2, 26.4 μmol/m2, 26.8 μmol/m2 respectively. Phosphorus uptake and relative water content had similar pattern. Rhizophagus irregularis was morphologically identified as the AMF in soils under the cocoa trees. Multivariate Adaptive Regression Splines predicted leaf chlorophyll and phosphorus uptake as the key factor influencing cocoa survival and resilience. Considering the threat of drought caused by climate change on cocoa production in West Africa, the results have implications for farmers livelihood, cocoa survival and the sustainability of cocoa soils.

Salicylic acid confers cadmium tolerance in wheat by regulating photosynthesis, yield and ionic homeostasis

Wheat (Triticum aestivum L.) productivity and quality can be threatened by soil cadmium (Cd) contamination, posing a concern to food security. Salicylic acid (SA) is an endogenously produced signaling molecule that activates the defense system imparting abiotic stress tolerance in plants. Hence, an experiment was conducted to explore the roles of foliar application of SA in ameliorating Cd toxicity in two wheat varieties. The treatments comprised of, a) Cd stress: i) Cd0 = control (No Cd), Cd1 = 500 µM Cd stress at 30 days after sowing (DAS); SA applications: (i) SA0 = control (No SA) (ii) SA1 = 0.5 mM SA at 32 DAS, and c) Wheat varieties: (i) Anaj-17 and (ii) Akbar-19. The experiment was carried out with three replicates in a completely randomized design (CRD). The findings of the study have revealed that Cd stress prominently reduced the plant growth and yield, gaseous exchange attributes, and relative water content of both wheat varieties, and more reduction was observed in Anaj-17 as compared to Akbar-19. Plant height, economic yield, photosynthetic rate, and relative water content were decreased by (9.80 and 8.20%), (12.2 and 6.58%), (20 and 11.32%), and (12.5 and 10%) in Anaj-17 and Akbar-19 respectively. Further, SPAD value and chlorophyll fluorescence decreased under Cd toxicity in both wheat cultivars as compared to non-stress conditions. Contrarily, electrolyte leakage and Cd contents were increased in the plants as compared to the control. However, the foliar applications of SA in Cd-stressed plants significantly improved the plant growth and yield attributes, relative water content, gas exchange attributes, and chlorophyll content in both wheat varieties as compared to control-no SA applied. In addition, chlorophyll fluorescence and nutrient uptake were also improved under SA applications as compared to control. However, SA played an ameliorative role in reducing Cd-toxicity by reducing the electrolyte leakage and Cd uptake by the plants. Among the varieties, Akbar-19 outperformed the Anaj-17 to impart Cd toxicity under SA applications based on plant morphophysiological attributes. Hence, the outcomes of the experiment recommended that the foliar treatment of SA amended the Cd tolerance of wheat varieties by improving plant physiological and biochemical attributes.

Interactive Effects of Dichlorvos, Dimethoate, And Cypermethrin On Growth and Oxidative Homeostasis in Maize (Zea Mays)

This study investigates the effects of dichlorvos, dimethoate, and cypermethrin, individually and in combinations, on maize (Zea mays) growth and physiology. Maize seeds were grown in pesticide-treated soil, and growth parameters, oxidative stress markers, and enzymatic activities were evaluated. Growth was significantly inhibited by pesticide exposure, with Group H (triple pesticide combination) showing the most severe reduction in plant height (48% lower) and stem girth (40% lower) compared to the control (p < 0.05). Biochemical assays revealed significant declines in catalase (CAT) and superoxide dismutase (SOD) activities across all tissues, indicating compromised oxidative stress defenses. For instance, CAT activity in roots decreased by 65% in Group H compared to the control (p < 0.05). Concurrently, malondialdehyde (MDA) concentrations, a marker of lipid peroxidation, increased significantly, with Group H showing a 75% rise in leaves relative to the control (p < 0.05). Relative water content (RWC) also decreased substantially, with Group H recording the lowest hydration levels (37% reduction, p < 0.05). These findings suggest synergistic or cumulative toxicity from combined pesticide exposure, with the most pronounced effects observed in triple pesticide treatments. Statistical analyses (ANOVA, Tukey's test) confirmed significant differences across groups (p < 0.05), reinforcing the reliability of the results. This study highlights the adverse impacts of pesticide combinations on maize growth and physiological stability, emphasizing the need for sustainable pest management strategies, such as integrated pest management (IPM), to mitigate the ecological and agricultural risks of pesticide use.

Foliar application of nano biochar solution elevates tomato productivity by counteracting the effect of salt stress insights into morphological physiological and biochemical indices

Nano-biochar considers a versatile and valuable sorbent to enhance plant productivity by improving soil environment and emerged as a novel solution for environmental remediation and sustainable agriculture in modern era. In this study, roles of foliar applied nanobiochar colloidal solution (NBS) on salt stressed tomato plants were investigated. For this purpose, NBS was applied (0%, 1% 3% and 5%) on two groups of plants (control 0 mM and salt stress 60 mM). Tween-20 was used as a surfactant to prolong NBS effective stay on plant leaf surface. The results showed that 3% NBS application effectively improved the plant height, plant biomass, fruit count and fruit weight under non-stressed and stressed plants. In addition, 3% NBS application further increased the plant pigments such as chlorophyll by 72% and 53%, carotenoids by 64% and 40%, leaf relative water content by 4.1 fold and 1.07 fold under both conditions, respectively. NBS application stabilized the plasma membrane via reducing electrolyte leakage by 30% as well as reduced the lipid peroxidation rates by 46% and 29% under non-stressed and stressed plants, respectively. 3% NBS application also significantly enhanced the plants primary and secondary metabolites, as well as activities of antioxidant enzymes compared to control plants. Overall, NBS foliar application significantly improved all growth and yield indices, pigments, primary and secondary metabolites, leaf water content, antioxidant enzyme activities as well as reduced electrolyte leakage and lipid peroxidation rates in tomato to combat stress conditions. In future, studies on nano biochar interactions with soil microbiota, surface modifications, long-term environmental impacts, reduced methane gas emissions, and biocompatibility could provide insights into optimizing its use in sustainable agriculture.

A plant-derived biostimulant Aminolom Enzimatico® application stimulates chlorophyll content, electrolyte leakage, stomata density and root yield of radishes under salinity stress.

Biostimulants stimulate plant growth and tolerance to salinity stress, which creates unfavorable conditions for plant growth from emergence to harvest; however, little is known about their roles in triggering salt tolerance. Therefore, the study aimed to determine how applying a foliar plant-derived biostimulant (Aminolom Enzimatico® 24%) affects the growth (leaf area, biomass weight, root diameter, root fresh weight, and water-soluble dry matter), physiology (chlorophyll content, electrolyte leakage, cell membrane stability, and relative water content), and stomata of the lower and upper parts of leaves in radish plants (Raphanus sativus L.) under salinity stress. Radish plantlets at 7 d old were irrigated with saline water (i.e., 50, 100, 150, and 200 mM NaCl), and the biostimulant was sprayed twice at 7 d intervals. Under salinity stress, increased water-soluble dry matter content was detected, along with reduced plant biomass weight, root fresh weight, and root diameter. Meanwhile, the foliar biostimulant increased the mean root fresh weight, biomass fresh weight, and leaf area by 12%, 13.6%, and 24% compared to the control, respectively. Increasing NaCl dramatically reduced leaf area and relative water content, whereas chlorophyll content and stomata densities on both sides of the leaves improved. By regulating physiological parameters and thereby promoting root and leaf growth, the biostimulant application improved the radish plants' tolerance to salinity stress up to 100 mM NaCl. Spraying the biostimulant can also boost plant growth, root yield, and radish quality under moderate salinity stress.

Enhancing salt stress tolerance in Carthamus tinctorius L. through selenium soil treatment: anatomical, biochemical, and physiological insights

Selenium (Se) plays a crucial role in ameliorating the negative impact of abiotic stress. The present study was performed to elucidate the efficacy of soil treatment of Se in reducing salt-induced stress in Carthamus tinctorius L. In this study, three different levels of Na2SeO4 (0, 0.01, and 0.02 g kg− 1) and four levels of NaCl (0, 0.5, 1.5, and 2.5 g kg− 1) were applied. The findings revealed that while NaCl decreased seed germination parameters, growth characteristics, K+ content, relative water content (RWC), and photosynthetic pigments, it increased Na+ content, soluble carbohydrates, H2O2 content, and malondialdehyde (MDA) level. The application of Se showed a positive effect on seed germination and growth characteristics under salinity conditions, which is linked to alterations in anatomical, biochemical, and physiological factors. Anatomical studies showed that treatment with Se led to increased stem diameter, cortical parenchyma thickness, and pith diameter under salinity stress. However, variations in the thickness of the xylem and phloem did not reach statistical significance. The application of Se (0.02 g kg− 1) raised Na+ content (7.65%), K+ content (29.24%), RWC (15%), Chl a (17%), Chl b (21.73%), Chl a + b (16.9%), Car (4.22%), and soluble carbohydrates (11%) in plants subjected to NaCl (2.5 g kg− 1) stress. Furthermore, it decreased H2O2 (25.65%) and MDA (11.9%) in the shoots. The findings of the current study advocate the application of the Se-soil treating technique as an approach for salt stress mitigation in crops grown in saline conditions.

Soil-driven physiological and biometric traits in Ceiba pentandra (L. Gaertn) via cleft grafting and seed propagation in Southern India

Ceiba pentandra, a multipurpose tree species, is widely utilized in agroforestry and afforestation projects. Evaluating its growth in diverse soil types via sexual and asexual propagation is essential for its promotion in various ecological regions. Thus, the current study was carried out to assess the growth of kapok in Tamil Nadu black soil and red laterite soil. Seeds for sexual propagation and scion wood for asexual propagation (cleft grafting) of Ceiba pentandra were obtained from four superior trees in Coimbatore and Theni districts. Six-month-old nursery-raised seedlings were used as rootstock. Seeds were sown and cleft grafting was conducted in February 2023. Both seedlings and grafts were transplanted to two study locations in September 2023. Significant variations in biometric parameters among different sources, soil types and propagation techniques were observed. CP-29 ramet recorded maximum height, volume index, greater photosynthetic rate and relative water content. Significant correlations between growth attributes and physiological traits were documented in the current study. Positive correlation between photosynthetic rate, number of leaves and stomatal conductance were noted. Principal component analysis (PCA) revealed that principal component 1 (PC1) accounted for 59.7% of the total variability and PC2 accounted for 35.1%. Ramets established through cleft grafting in black soil have shown favourable growth. Thus, the CP29 and MTP01 exhibited superior performances based on growth traits.