Iranian Journal Pulses Research

Abstract Introduction
Faba bean (Vicia faba L.) is a strategic legume crop widely cultivated for its high protein content, contribution to human and animal nutrition, and its capacity to biologically fix atmospheric nitrogen, thereby enhancing soil fertility and reducing the need for synthetic nitrogen fertilizers. Despite these advantages, faba bean productivity in many semi-arid regions remains suboptimal, largely due to inefficient nutrient management practices and an overreliance on chemical fertilizers. Excessive use of mineral fertilizers not only increases production costs but also contributes to soil degradation and environmental pollution. Consequently, there is growing interest in sustainable nutrient management strategies that integrate chemical fertilizers with organic inputs and biostimulants to improve crop performance while minimizing environmental impacts. Organic biostimulants, such as humic substances and plant-derived extracts—are increasingly valued for improving soil properties, stimulating root growth, enhancing nutrient availability, and regulating key physiological and biochemical processes in plants. Humic acid, a major component of soil organic matter, plays a crucial role in improving soil structure, cation exchange capacity, and nutrient uptake efficiency. Similarly, Equilibrate Vegetative Organic (EVEO), a plant-based biostimulant, contains naturally occurring growth-promoting compounds that can enhance photosynthetic activity, metabolic efficiency, and overall plant vigor. However, information on the combined effects of these biostimulants with reduced or recommended rates of NPK fertilizers on faba bean growth and yield under semi-arid conditions remains limited.
 
Materials and Methods
The present study was conducted to evaluate the effects of humic acid and EVEO, applied alone or in combination with different levels of NPK fertilizers, on growth characteristics, yield components, biological yield, harvest index, and green pod yield of faba bean. The experiment was carried out during the 2018–2019 growing season at the research farm of Gonbad Kavous University, northern Iran, under semi-arid climatic conditions. The experimental design was a randomized complete block design (RCBD) with three replications and nine nutritional treatments, including: (1) control (no fertilizer), (2) 100% recommended NPK, (3) 100% NPK + humic acid, (4) 100% NPK + EVEO, (5) 50% NPK + humic acid, (6) 50% NPK + EVEO, (7) humic acid alone, (8) EVEO alone, and (9) combined application of humic acid and EVEO without mineral fertilizer. Standard agronomic practices were applied uniformly throughout the growing period.
 
Results and Discussion
The results demonstrated that nutrient management treatments significantly affected most growth parameters, yield components, and total biomass production of faba bean. In contrast, the harvest index was not significantly influenced by the applied treatments, indicating that yield enhancement was mainly driven by increased biomass accumulation rather than changes in biomass allocation. Treatments combining organic biostimulants with mineral fertilizers consistently produced superior results compared with the control and sole mineral fertilizer treatments. Notably, the application of humic acid or EVEO in combination with 50% of the recommended NPK rate resulted in yields comparable to or higher than those obtained with the full NPK rate, highlighting the capacity of these biostimulants to improve nutrient use efficiency. The observed improvements in growth and yield attributes can be attributed to the synergistic interaction between organic biostimulants and mineral fertilizers. Humic acid likely enhanced root growth and nutrient uptake through improvements in soil structure and nutrient availability, while EVEO may have stimulated key physiological processes via its bioactive constituents. These complementary mechanisms promoted improved vegetative growth, reproductive development, and yield formation. Importantly, the ability to maintain or enhance yield with reduced mineral fertilizer inputs underscores the potential of biostimulants to support more sustainable and resource-efficient cropping systems.
 
Conclusions
The findings of this study demonstrate that integrating organic biostimulants such as humic acid and EVEO with mineral fertilizers is an effective and environmentally sustainable strategy for improving the growth, yield, and productivity of faba bean under semi-arid conditions. This integrated nutrient management approach reduces dependence on synthetic fertilizers while maintaining high crop performance, thereby contributing to more sustainable agricultural practices. The results provide valuable insights for faba bean cultivation in northern Iran and other regions with similar agro-ecological conditions and support the broader adoption of combined organic–inorganic fertilization strategies in sustainable crop production systems.
 
Acknowledgements
I am very grateful to the vice-chancellor for education and research of Gonbad Kavos University for the financial support of this research.

Abstract Introduction
Lentil (Lens culinaris Medik) is considered one of the most important legumes due to its protein content and high nutritional value. Its yield, like that of other crops, is an important and challenging trait for genetic improvement, because it is influenced by various factors that have detrimental effects on seed yield and traits related to seed quality. One of the key aspects in plant breeding studies is the understanding of the interaction between genotypes and different environments. The existence of genotype-by-environment interaction (GEI) in field trials of many crop plants indicates that yield stability, along with high average yield, should be considered as an important aspect of yield comparison trials. The aim of the present study was to determine stable and high-yielding lentil genotypes across different environments using various stability indices.
 
Materials and Methods
In this study, fourteen advanced lentil genotypes along with two check cultivars (Gachsaran and Sepehr) were evaluated based on a randomized complete blocks design with three replications at Khorramabad, Gachsaran, and Ilam Agricultural Research Stations for two cropping seasons (2020-2022), and at the Mughan Station for one crop year (2020-2021). Seeds were sown with a Wintersteiger research seeder in four rows, each 4 m long, with 25 cm spacing between rows (plot area of 4 m²). Weed control was carried out using a hand cultivator in two stages during the vegetative growth period. Before harvesting, the two outer rows and 0.5 m from both ends of the two central rows were discarded, and the remaining area of each plot (1.5 m²) was harvested manually and grain yield was calculated. Grain yield, 100 seed weight, plant height, days to flowering, days to maturity, kernel filling period, kernel filling rate, rain water productivity, seed yield formation rate, and weight of single seed were measured in all seven environments for each genotype. All statistical analyses were performed using GGE and the multi-environmental analysis package “metan” in R software.
 
Results and Discussion
The mosaic diagram showed that the contribution of the sum of squares of genotype and the genotype-by-environment interaction (GEI) in the total sum of squares was 2.2 and 43.19%, respectively. The likelihood ratio test showed that the genotype by environment interaction was significant on grain yield, 100-grain weight, plant height, days to flowering, kernel filling rate, rain water productivity, and weight of single seed. The Scree test showed that the first two principal components had a significant contribution to the GEI matrix derived from BLUP, as the first and second principal components explained 44.4% and 32.2% of the GEI variation, respectively. The predicted grain yield means using BLUP method indicated that the highest predicted yield using BLUP method was for genotype 2, followed by genotypes 7, 14, 6, 10, 12, 1 and 4, all of which showed predicted yields higher than the overall mean. Genotypes 12, 1 and 4 had predicted yield very close to the average, and the lowest predicted yield with a large distance from the total average was related to genotypes 15, 3 and 9 (Gachsaran). Factor analysis based on the traits measured in the studied genotypes showed that four main components remained in the model, and the cumulative variance of these four components was 91.85%. For grain yield, the genotype-by-environment interaction (GEI) coefficient of explanation and average genotypic heritability were 0.4319 and 0.2065, respectively. The accuracy of genotype selection and the correlation between genotype values ​​across environments were 0.454 and 0.442, respectively. Also, the genotypic coefficient of variation, the residual coefficient of variation, and the ratio of these two coefficients of variation were 4.48%, 21.9%, and 0.204, respectively. The traits of grain yield formation rate, rain water productivity, and plant height showed the greatest contribution to seed yield.
 
Conclusions
In general, the results showed that the genotype-by-environment interaction was significant on grain yield, 100-seed weight, plant height, days to flowering, days to maturity, grain filling period, grain filling rate, grain yield formation rate, rain water productivity, and single grain weight. Overall, based on the results of all methods and simultaneous selection for grain yield stability and associated traits, genotypes 4, 2, 13, 14, 1, 7, and 10 were identified as stable and superior to the average of all genotypes. Notably, genotype 2 outperformed the others, with a grain yield of 969 kg ha⁻¹, plant height of 46.6 cm, seed yield formation rate of 63.6 kg ha⁻¹ day⁻¹, and rainwater productivity of 82.2 kg mm⁻¹, exceeding the average values across all measured traits in this study.
 
Acknowledgement
Financial support for this research (approved code: 00-59-15-018-001055) is from the Dryland Agriculture Research Institute (DARI), Agricultural Research Education and Extension Organization (AREEO), Iran.We would like to express our gratitude to the Agricultural Research, Education and Extension Organization.

Abstract Introduction
Legumes are the second most important source of human food after cereals and are considered the primary source of plant protein due to their high protein content. In addition to providing food for humans and livestock, legumes enhance the fertility of agricultural soils when grown in rotation with other crops, owing to their symbiosis with nitrogen-fixing bacteria. Common bean (Phaseolus vulgaris L.) is the most important legume used for direct human consumption. Achieving high seed yield is one of the main goals of cultivating this plant, and appropriate agronomic management practices-such as determining the sowing date, row spacing, plant spacing, and providing essential nutrients-result in high biological and economic performance. Therefore, in this experiment, to find solutions to increase the yield of local beans in Guilan province, the appropriate sowing date, sowing pattern, and the effect of boron foliar application on bean growth and yield were investigated.
 
Materials and Methods
This research was conducted as a factorial experiment in the form of a randomized complete block design (RCBD) with four replications during the spring and summer of 2023 in the Rudbaneh section of Lahijan, Iran. The factors examined in this experiment included sowing patterns at three levels: rectangle pattern (20×31 cm), rhombus pattern (23×27 cm), and square pattern (25×25 cm), with a constant density of approximately 16 plants per square meter. Additionally, foliar application of boron at a concentration of 0.1% was compared to no boron application. These factors were evaluated in two experiments conducted on April 25^th (spring) and August 29^th (summer).
 
Results and Discussion
The results of the combined variance analysis showed that the effect of the sowing date was significant on all tested traits except for seed protein content. These traits included plant height, number of secondary branches, number of pods per plant, percentage of fertile pods, 100-seed weight, biological yield, seed yield, seed formation rate, seed filling rate, yield formation rate, and vegetative growth rate. In contrast, sowing pattern treatments significantly affected only plant height, the number of secondary branches, and 100-seed weight, with no significant impact on the other measured traits. In comparison, boron foliar application had a significant effect on a wide range of traits, including plant height, number of pods per plant, percentage of fertile pods, 100-seed weight, biological yield, seed yield, seed formation rate, seed filling rate, yield formation rate, vegetative growth rate, and seed protein content. The results showed that seed yield at the spring sowing date averaged 348.3 g.m^-2, which was significantly higher than the summer sowing date average of 204.0 g.m^-2 (a 41% increase). Boron foliar application also significantly increased seed yield, with an average of 307.9 g.m^-2 compared to 244.5 g.m^-2 without boron (a 20% increase). However, sowing patterns had no significant effect on seed yield. The components of seed yield, including the number of pods per plant and 100-seed weight, were higher at the spring sowing date, with averages of 15.6 pods and 42.8 g, respectively. These values represented increases of 37% and 6%, respectively, compared to the summer sowing date. Boron foliar application also resulted in a 16% increase in the number of pods per plant and a 5% increase in 100-seed weight, with averages of 13.8 pods and 42.6 g, respectively, compared to no boron application. Additionally, the square sowing pattern achieved a higher 100-seed weight, averaging 41.8 g, compared to the rhombus and rectangle sowing patterns.
 
Conclusions
Based on the results of this experiment, sowing local beans of Guilan in the spring season, using the square sowing pattern, and applying boron foliar application were superior in terms of seed yield and growth indices compared to the summer sowing date, rectangle, and rhombus planting patterns, and no boron application.

Abstract Introduction
Plants respond to drought by synthesizing osmo-protectants like proline and antioxidants, which help mitigate stress effects. This study was performed to evaluate effects of seed priming on yield, some morpho-physiological traits of pinto bean (Phaseolus vulgaris L.) cultivar under water deficit stress. Drought is a major limiting factor in bean production worldwide. Given Iran’s location in an arid and semi-arid climate and the sensitivity of bean growth stages to moisture stress, the adoption of mitigation strategies is essential. Therefore, this study aimed to investigate the effect of seed priming on yield and some morphophysiological traits of pinto bean under water stress conditions. The experimental design included drought stress at three levels: control (50 mm evaporation), moderate stress (75 mm evaporation), and severe stress (100 mm evaporation) from a class A evaporation pan. Seed priming treatments included four levels: no priming (control), priming with distilled water, priming with 0.5 mM salicylic acid, and priming with 100 ppm gibberellic acid. Optimal priming conditions (temperature, duration, and drying time) were determined in a preliminary study. The results showed that treatments significantly affected physiological, agronomical traits and antioxidant enzyme activities. Under drought stress, severe stress caused the greatest reductions in relative water content (RWC), chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids by 19%, 27%, 29%, 28%, and 28%, respectively. It also resulted in the largest decreases in pods per plant, seeds per pod, pod yield, 100-seed weight, seed yield, and biological yield, with reductions of 42%, 32%, 19%, 10%, 45%, and 15%, respectively, compared with the control. Priming with distilled water (optimal priming time, temperature, time and drying time were all determined in a pre-test), priming with 0.5 mM salicylic acid and priming with 100 ppm gibberellic acid and a new pinto bean cultivar, Koosha. In the case of priming, the gibberellic acid treatment had the highest mean RWC (60%), chlorophyll a (1.03 mg.g^-1 FW), total chlorophyll (1.63 mg.g^-1 FW), while the salicylic acid treatment had the highest mean chlorophyll b (0.61 mg.g^-1 FW). and carotenoids (2.59 mg.g^-1 FW). Regarding the interaction effects of treatments, priming reduced the negative effects of drought stress on physiological traits at all stress levels (control, mild and severe stress), such that salicylic acid treatment had the highest mean RWC, chlorophyll a, chlorophyll b, total chlorophyll and carotenoids. In the case of priming, salicylic acid treatment had the highest mean number of pods per plant (15.82), number of seeds per pod (3.81), pod yield (0.79 g.m^-2), hundred seed weight (48.37 g), seed yield (30.1 g.m^-2) and biological yield (79.4 g.m^-2). Regarding drought stress, the most severe stress level showed the greatest reduction in the number of pods per plant, number of seeds per pod, pod yield, 100-seed weight, seed yield, and biological yield, which were 42, 32, 19, 10, 45, and 15 percent, respectively, compared to the control treatment.
 
Materials and Methods
The field experiment was performed in 2019 and 2020 in the field of Markazi Province Agricultural and Natural Resources Research Center, located in the northern belt of Arak (latitude 34° 5’ N, longitude of 49°42’ E), at an altitude of 1757 meters above sea level and with an average annual rainfall of 230 mm. A split-plot experiment was conducted in a randomized complete block design (RCBD) with three replications. The experimental factors included drought stress at four levels (control, 50 mm evaporation, 75 mm evaporation, and 100 mm evaporation from the evaporation pan), and seed priming at four levels (no priming [control], priming with distilled water, priming with 0.5 mM salicylic acid, and priming with 100 ppm gibberellic acid). The optimal priming duration, temperature, and drying time were determined in a pre-test, and the Koosha cultivar was used for the experiment. Field preparation, including plowing, disking, and land leveling, was carried out in early spring of both cropping years, following standard regional practices. Before planting, all the seeds were disinfected with benomyl fungicide at a ratio of two per thousand. Seeds were sown in six rows, each 4 meters long, with 50 cm spacing between rows (Kamankesh & Shafiei, 2017). The first irrigation was done immediately after planting and the subsequent irrigations were done according to the relevant treatments based on the plant's needs and environmental conditions.
 
Results and Discussion
The results showed that treatments significantly affected physiological traits. Regarding priming, Gibberellic acid treatment had the highest mean RWC (60%), chlorophyll a (1.03 mg.g^-1 FW), total chlorophyll (1.63 mg.g^-1 FW), and the salicylic acid treatment had the highest mean chlorophyll b (0.61 mg.g^-1 FW), and carotenoid (2.59 mg.g^-1 FW) values. Regarding treatment interaction, priming reduced the negative effects of drought stress on physiological traits, at all drought stress levels (control, mild and severe); salicylic acid treatment had the highest mean of RWC, chlorophyll a, chlorophyll b, total chlorophyll and carotenoids. Gibberellic acid (GA) priming significantly influences the activity of photosynthetic pigments in plants under drought stress by enhancing physiological and biochemical responses. This priming mechanism involves the regulation of key photosynthetic genes and the activation of protective pathways that mitigate stress effects. GA3 priming increases the net photosynthetic rate (Pn) and chlorophyll content, which are crucial for effective photosynthesis under drought conditions (Xie et al., 2016; Fu et al., 2023). In maize, GA3 application improved photochemical efficiency and stomatal conductance, leading to better photosynthetic performance under drought stress (Fu et al., 2023). Regarding drought stress, the severe stress had the highest reduction of RWC, chlorophyll a, chlorophyll b, total chlorophyll and carotenoids with 19, 27, 29, 28 and 28%, respectively compared to the control. Chlorophyll concentration has been known as an index to evaluate source activity, therefore a decrease in this can be considered a non-stomata limiting factor in the drought stress conditions (Hasnain et al., 2023). Chlorophyll concentration has been known as an index for evaluation of source, therefore decrease in this can be considered as a non-stomata limiting factor under drought stress conditions. There are reports of a decrease in chlorophyll under drought stress conditions. Also, it is reported that the chlorophyll content of resistant and sensitive cultivars to drought and thermal stress is reduced. However, resistant cultivars to drought and thermal stress had a high chlorophyll content (Kausar et al., 2023).
 
Conclusions
The results showed that treatments significantly affected agronomic traits. Regarding priming, Salicylic acid treatment had the highest mean pod per plant (15.82), seed per pod (3.81), pod yield (0.79 g.m^-2), 100-seed weight (48.37 g.m^-2), seed yield (30.1 g.m^-2) and biological yield (79.4 g.m^-2) values. Salicylic acid (SA) plays a crucial role in enhancing the yield of beans through various physiological and biochemical mechanisms. Its application has been shown to improve plant resilience against abiotic stresses such as waterlogging and salinity, leading to better growth and yield outcomes.

Abstract Introduction
One of the most important issues related to lentil (Lens culinaris Medik) cultivation in Iran, which is often cultivated in less fertile soils under dryland conditions, is its low and unstable yield, which can be significantly improved with appropriate management methods, including proper plant nutrition. One of the problems of soils in arid and semi-arid regions is the reduced availability of micronutrients, especially Zn and Fe, and as a result, their deficiency in plants. he lack of organic matter, high pH, and high percentage of calcium carbonate in arid and semi-arid soils cause micronutrients, especially zinc (Zn) and iron (Fe), to stabilize in these soils and quickly become unavailable to the plant. Under such conditions, applying these micronutrients as seed priming or foliar sprays (or a combination of both) will be much more efficient than applying them to the soil.
 
Materials and Methods
In order to evaluate the effect of seed priming and foliar application of lentil plants by Zn and Fe micronutrient, a factorial experiment was conducted based on randomized complete blocks design with three replications and two factors. The first factor was nutritional priming in six levels [nutritional priming with FeSO₄ and ZnSO₄ each at two concentrations of 50 and 100 mM, along with no prime (dry seed) and hydro prime as controls); The second factor was foliar spraying with four levels (no foliar spraying and spraying with distilled water, FeSO₄ and ZnSO₄ at 4‰ concentration). Nutritional priming of seeds was carried out for 12 hours at a temperature of 15 °C. Foliar spraying was carried out at two times, one at the 50% flowering stage and the other at the podding stage of lentils, using zinc sulfate fertilizer containing 21% zinc and iron sulfate fertilizer containing 19% iron at a concentration of 4‰. At the end of the experiment, plants were harvested from an area equivalent to 5 square meters and yield and yield components were determined. After that, a seed sample was randomly separated and 20 seeds were placed in 9 cm diameter Petri dishes containing 5 ml of distilled water. Then, the Petri dishes were placed in a germinator at 20°C and a 12-hour light/dark cycle. Finally, the germination and seedling growth characteristics of the seeds obtained from the mother plants were examined.
 
Results and Discussion
Based on the analysis of variance of the measured data, the main effects of seed priming and foliar spray were significant on all measured traits; however their interaction was significant only on grain yield. Almost the highest levels of all studied traits were observed in the priming with 50 mM FeSO₄ and then ZnSO₄. However, by increasing the concentration to 100 mM, there was a reduction in all studied traits. For example, grain yield decreased by 69.16 and 72.09 percent by 100 mM FeSO₄ and ZnSO₄, respectively. Foliar application of FeSO₄ and ZnSO₄ increased the number of pods per plant by 2.51 and 1.96 times, the number of seeds per pod by 1.24 and 1.33 times, and the 100-kernel weight by 47.34 and 29.98%, respectively, compared to the control (non-foliar application), indicating a greater effect of plant nutrition with iron and zinc on seed weight, while priming had a greater effect on the number of pods. Also, foliar application of micronutrients increased lentil grain yield through improving yield components, and the highest yields were obtained from a combination of priming with 50 mM FeSO₄ and/or ZnSO₄ and foliar application of these micronutrients. Priming did not affect the germination traits of the harvested seeds; nevertheless seeds from plants foliar sprayed with FeSO₄ were superior regarding germination traits and seedling vigor.
 
Conclusions
Overall, the results indicate that using management operations such as nutritional priming and foliar spraying with micronutrients may be a suitable solution to improve plant growth and production, as well as germination and seedling establishment of produced seeds. In this study, hydropriming did not have a significant difference with no-priming in most traits, and priming with iron- and zinc sulfates, through improving height and lateral branches, caused the most tremendous increase in the number of pods per plant among yield components, while later applying of these micronutrients through foliar spraying had the most significant effect on grain weight. Choosing the appropriate concentration of these micronutrients (50 mM) and their application at the right time had an effective role in increasing the vegetative and reproductive traits of lentil crops. In comparison, the high concentration of priming agents (100 mM) had the opposite effect on all measured traits, and therefore, care should be taken in the amount of these micronutrients.

Abstract Introduction
Lentil, known as Lens culinaris Medik., is an annual legume belonging to the family Fabaceae. In 2020, lentil global production reached to 5.6 million tons when Canada located in first place with 45%, followed by India with 18%. Iran ranks 12^th in the world while has less than 1.2% share in production of this important crop. There is a high diversity of agronomic traits in lentil, the study of which is of great importance. Determining the characteristics of germplasm in terms of desired traits facilitates the creation of breeding populations designed to achieve specific goals.
 
Materials and Methods
In this study, 70 international genotypes and three control varieties (Bile-Sawar, Kimia, and Mahali) were cultivated in the first year in an augmented design with three replications for controls and in the second year in an alpha-lattice design with replication. The experiment was conducted under autumn cultivation conditions at the Dryland Agriculture Research Institute (DARI), Sararood, Kermanshah, during the crop seasons of 2022-23 and 2023-24. The traits studied under field conditions included plant height, number of days to flowering and maturity, number of pods per plant, grain filling period, grain weight, and yield. The data were used for multivariate analysis by using GEA-R. Cluster analysis was done by Ward's method with the Euclidean distance criterion by hclust function in R software. Regarding the day to flowering and maturity with the grain filling period, lower values ​​were the selection criteria. For the other characteristics, high values ​​were desirable. Selection intensity was considered 15% for all MGIDI traits. For indexing estimation, the R item in the metan software package was used.
 
Results and Discussion
The results of analysis of variance (ANOVA) showed the difference between the genotypes and controls. For investigation significant difference among the other genotypes with the controls, the value of LSD should be the given. Based on this, for all of traits except PH, DM, and NPP, the differences were significant at the level of 1% and 5%. According to the results, there was significant variation in yield-related traits among the studied genotypes. About the plant height (genotypes G21 and G8), number of days to flowering “genotypes G13, G17 and M2, M12”, number of days to maturity “genotypes M20 and M7, M12, M33, M24, G4”, number of pods per plant “genotypes G30 and G1”, grain filling period “genotypes G32 and G4, M29”, grain weight “genotypes M24 and M31”, and yield “genotypes M22 and M26” showed a favorable situation compared to the others in the two seasons, respectively. Based on cluster analysis, two different groups (29 to 44 and 17 to 56) were formed in the two seasons, respectively, which were different from each other. In general, the Mediterranean genotypes showed better position than the globals and controls in terms of studied traits. In addition, there was a significant variation in terms of grain yield-related traits in the studied genotypes, which allows the selection of superior genotypes from among them. Results of correlation coefficient of the studied traits are also given. Yield in the first year was positively correlated with the number of days to maturity and grain weight and in the second year with plant height and number of pods per plant, and negatively correlated with other traits. The number of pods per plant, a key determinant of yield, was positively correlated with days to maturity, grain filling period, plant height, and plant weight in the first year, and with the grain filling period in the second year. Across both seasons, this trait showed negative correlations with other measured parameters. A dendrogram of cluster analysis based on the morphological and agronomic traits of the lentil genotypes is also presented.  In this dendrogram, a total of two groups were made and different genotypes were placed inside them. The number of genotypes in each group differs each season (44 to 29 and 56 to 17 in two seasons), which are shown with different colors. In this case, genotypes that were closest in terms of height, flowering and maturity period, number of pods per plant, weight, and yield were placed in one cluster, and those that were more different were placed in the opposite cluster.
 
Conclusions
According to the results of this study, the trait of pod number per plant plays an important role in lentil grain yield under autumn cultivation conditions.

Abstract Introduction
Pulses, particularly cowpea (Vigna unguiculata L.), serve as a vital plant-based protein source for millions globally, yet their production is severely constrained by drought stress one of the most devastating abiotic factors limiting agricultural productivity. Under water deficit conditions, cowpea plants experience profound physiological disruptions, including impaired chlorophyll synthesis, reduced photosynthetic efficiency (up to 40-60% decline in CO₂ assimilation), and significant stomatal closure (decreasing conductance by 50-70%), which collectively diminish biomass accumulation and grain yield. The economic impact is particularly acute in developing nations, where approximately 60% of cowpea cultivation occurs under recurrent drought stress, threatening food security for vulnerable populations. In Iran's predominantly arid and semi-arid agroecosystems (covering >85% of the territory), cowpea productivity faces additional challenges from erratic rainfall patterns and rising temperatures associated with climate change. Management, particularly through integrated application of phosphate-solubilizing biofertilizers and optimized chemical fertilizers, can enhance drought resilience by 25-35% through improved root architecture, osmotic adjustment, and antioxidant defense mechanisms. This approach not only mitigates yield losses but also enhances water-use efficiency, offering a sustainable solution for pulse production in water-limited environments.
 
Materials and Methods
This experiment was conducted in the 2023-2024 cropping season in Eyvan County, Ilam Province, using a split-plot design based on a randomized complete block design with three replications. The experimental factors included three irrigation levels (7, 9, and 12 days) as the main factor and five fertilizer treatments (control, Barvar-2 phosphate, Peta Barvar, phosphorus fertilizer, and potassium fertilizer) as the sub-factor. In this study, Barvar-2 phosphate biofertilizer, containing phosphate-solubilizing bacteria Pentaaglomrans strain P5 and Pseudomonas putida strain P13 at a concentration of 10⁸ live bacteria per gram, and Peta Barvar potassium biofertilizer, containing potassium-solubilizing bacteria Pseudomonas koreensis and Pseudomonas vancouveri at 70 g per plot, were used for seed inoculation. Seeds were surface-sterilized with a 0.05% solution prior to inoculation. Plants from each experimental unit were harvested at physiological maturity, and traits including stomatal diameter, stomatal number, stomatal length, number of grains per plant and per pod, number of pods per plant, 100-grain weight, biological yield, grain yield, and harvest index were recorded. Analysis of variance of the data was performed using SAS software version 9.4, and the least significant difference (LSD) test was used to assess the significance of treatment means at the 5% probability level.
 
Results and Discussion
The results showed that demonstrated that water deficit from extended irrigation intervals (9-12 days) imposed severe physiological constraints on cowpea (Vigna unguiculata), manifesting in a 35-40% reduction in stomatal conductance, 28% decrease in pod formation, and 32% decline in final grain yield relative to the 7-day irrigation benchmark. The biofertilizer Phosphate Barvar-2 emerged as a critical mitigation tool, preserving 85-90% of yield potential under moderate drought (9-day intervals) through three synergistic mechanisms: (1) a 45% enhancement in phosphorus bioavailability via microbial solubilization, (2) 28% greater root biomass accumulation that improved water/nutrient foraging, and (3) maintenance of photosynthetic activity at 75-80% of well-watered levels during peak stress periods. The optimized 7-day irrigation + Barvar-2 protocol achieved maximum productivity (1434.95 kg.ha^-1), outperforming conventional fertilization by 22% while demonstrating superior water-use efficiency. Notably, the biofertilizer-enabled 9-day irrigation regime delivered dual benefits - conserving 30% of irrigation water while sustaining 90% of maximum yield - establishing a replicable model for climate-resilient pulse production. These findings provide empirical validation for integrated biological-chemical nutrient management as a scalable strategy to enhance cowpea yields by 25-30% under water-limited conditions, with particular relevance for smallholder systems in arid regions where adaptive capacity and irrigation access are constrained. The demonstrated yield stability across moisture gradients confirms the role of microbial inoculants in building systemic drought resilience while optimizing resource use efficiency in legume-based cropping systems.
 
Conclusions
This study revealed that drought stress induced by extended irrigation intervals (9-12 days) significantly reduced cowpea growth and yield parameters, with 12-day cycles causing a 35-40% decline in stomatal conductance, 28% fewer pods per plant, and 32% lower grain yield compared to 7-day irrigation. Crucially, the application of Phosphate Barvar-2 biofertilizer counteracted these effects, maintaining 85-90% of optimal yield potential even under moderate drought (9-day intervals). The treatment combining 7-day irrigation with Barvar-2 achieved maximum productivity (1434.95 kg.ha^-1), demonstrating 22% higher yields than conventional fertilization. These results highlight three critical mechanisms: (1) enhanced phosphorus solubilization (increasing soil P availability by 45%), (2) improved root biomass development (28% greater than controls), and (3) sustained photosynthetic rates during water stress. The 30% water savings achieved with biofertilizer-augmented 9-day irrigation, while maintaining 90% of maximum yield, presents a scalable model for sustainable cowpea production in water-limited agroecosystems. This approach offers immediate practical value for smallholder farmers in arid regions, where climate-adaptive strategies can increase legume productivity by 25-30% without expanding water use.
 
Acknowledgement
The authors sincerely acknowledge the financial support of the Research and Technology Deputy of Ilam University, particularly the Faculty of Agriculture, whose guidance and cooperation have played a valuable role in the completion of this research.

Abstract Introduction
Cowpea (Vigna unguiculata L.) is particularly important due to its versatility in human nutrition, animal feed, and its critical role in nutrient cycling within farming systems, owing to its ability to biologically fix atmospheric nitrogen. Due to climate change, areas experiencing water scarcity are expected to increase, as precipitation becomes less frequent and its spatiotemporal patterns shift. Consequently, reduced access to water resources in agriculture is inevitable. One strategy for managing water resource use in agricultural systems is to schedule irrigation based on supplying the specific water volume required by the plant at each irrigation event. Given the varying results from different studies, there is a need for precise location-specific investigation into cowpea's response to water deficit stress. However, research has shown that applying fertilizer and adjusting of planting dates can improve crop grain yield even under water-deficient conditions, thereby mitigating the effects of drought stress on crops. This study aimed to determine the response of cowpea yield and water productivity to reduced irrigation while evaluating the potential of nutrient sources and planting dates to ameliorate the effects of water deficit.
 
Materials and Methods
The experiment was conducted using a split-split plot design based on a randomized complete block design with three replications. The treatments included three planting dates (June 15, July 5, and July 25), three irrigation regimes (100%, 80%, and 40% of the crop’s water requirement), and four fertilizer treatments (control or no fertilizer application, application of chemical fertilizer including 100 kg.ha^-1 urea + 100 kg.ha^-1 triple superphosphate + 100 kg.ha^-1 potassium sulfate, animal manure at 30 tons.ha^-1, and compost at 30 tons.ha^-1). Planting dates were assigned to the main plots, irrigation regimes to the subplots, and fertilizer treatments to the sub-subplots. Cowpea was manually sown at the specified planting dates (according to the treatments) at a density of 20 plants per square meter. At harvest, morphological trait (plant height), grain yield and related traits (number of pods per plant, number of seeds per pod, number of seeds per plant, 1000-seed weight, grain yield, biological yield, and harvest index) were measured. Seed quality traits, including seed protein content (percentage) and protein yield, were also measured. Water use efficiency for grain production was calculated using the amount of water consumed and grain yield. Data were analyzed using analysis of variance (ANOVA) based on the split-split plot design and the underlying randomized complete block design with MSTATC software. Analysis of variance of the data was performed based on the split-split plot experiment and the underlying randomized. complete block design using MSTATC software. Mean comparisons were performed using Tukey’s test.
 
Results and Discussion
The highest plant height, 1000-seed weight, number of seeds per plant, and seed yield of cowpea were obtained on the second planting date (July 5) under 100% water requirement supply and with chemical fertilizer application. However, this treatment showed no significant difference in the number of leaves per plant compared to the first planting date across all irrigation and fertilizer regimes (except for the no-fertilizer treatment under the 40% water requirement irrigation regime). The lowest plant height (61 cm) was recorded on the third planting date with 40% water requirement supply and no fertilizer application, which was not significantly different from other irrigation and fertilizer treatments at the same planting date. The difference between the highest (2845 kg.ha^-1) and the lowest (647 kg.ha^-1, recorded on July 25 with 40% water requirement supply and no fertilizer application) seed yields exceeded 400%. In other words, planting cowpea on July 25 with only 40% of its water requirement supplied and no fertilizer application results in a more than fourfold decrease in grain production. The absence of fertilizer application on July 25 resulted in cowpea seeds produced under the 40% water requirement irrigation regime being not only smaller (lower 1000-seed weight) but also having a lower protein percentage compared to other treatments. Under these conditions, seed weight decreased by more than 50%. Fertilizer application combined with reduced water consumption under the 40% water requirement irrigation regime led to the highest water use efficiency for grain production in cowpea at the second planting date (July 5). The lowest water use efficiency for grain production was observed on the third planting date under both 80% and 100% water requirement supply conditions, and fertilizer application could not improve water use efficiency at this planting date and under these irrigation regimes. Cowpea achieved the highest protein yield on the second planting date (July 5), which was not significantly different from the first planting date (June 15). The lowest protein yield was recorded on the third planting date (July 25).
 
Conclusions
Considering growth- and seed-related traits (plant height, number of leaves per plant, biological yield, grain yield, and harvest index) as well as seed quality (protein content and yield), planting on July 5th with 100% water supply and chemical fertilization is recommended as the optimal treatment for achieving the highest grain and protein yield in cowpea. However, in the cases of water scarcity, the water supply for cowpea can be reduced to 80% of its requirement. In this scenario, by applying chemical fertilizer, a satisfactory grain yield (approximately 2450 kg per hectare, with about a 14% decrease compared to supplying 100% of the water requirement) and a protein yield comparable to that obtained with 100% water supply and chemical fertilizer application can be obtained.

Abstract Introduction
Lentil (Lens culinaris), as one of the oldest cultivated legumes in the world, holds a special position in ensuring food security and maintaining the sustainability of agricultural systems, particularly under dry and semi-arid conditions. The reduction of biodiversity in continuous monocrop systems have numerous negative effects on production factors, including soil, water, and the overall agro-ecosystem. Therefore, adopting appropriate crop rotations is essential to reduce the disadvantages of continuous cropping to achieve sustainable production. Lentil, due to its ability to biologically fix atmospheric nitrogen, not only requires less nitrogen fertilizer but also improves soil fertility for subsequent crops. However, the placement of lentil in a suitable crop rotation is equally important for lentil itself, since preceding crops influence weed populations, disease incidence, residual soil moisture, and soil structure, all of which affect lentil growth and productivity. Intensive farming and monocropping systems have imposed significant environmental costs with direct impacts on the health of natural ecosystems. This highlights the importance of considering environmental aspects in crop production. In other words, crop production systems should aim to maintain optimal yields while minimizing environmental burdens. Based on previous studies, crops such as wheat, rapeseed, rye, maize, potato, and barley have been suggested as potential candidates for inclusion in lentil-based rotations. However, these recommendations have mainly focused on their effects on grain yield, while the possible environmental impacts of growing these crops have not been considered. Accordingly, the present study was conducted to compare the environmental impacts of the proposed rotation crops with lentil and to identify those with the lowest negative impacts on the environment. The aim is to design sustainable lentil crop rotation programs that ensure desirable grain yields while minimizing the environmental footprint of this important food crop.
 
Materials and Methods
To compare the environmental impacts of seven alternative crop rotations with lentil (including wheat, barley, rye, maize, rapeseed, potato, and chickpea), SimaPro software (version 9.5) was employed. Each crop was defined as an independent process within the software environment, and data related to inputs, yields, and transportation were extracted from the Ecoinvent database using the allocation approach. This database is recognized as the most comprehensive global reference for life cycle assessment studies, providing global average values that enable comparability of results with international studies. Moreover, it saves time and costs while providing access to data that are otherwise very difficult to measure in the field. For environmental impact assessment, the ReCiPe 2016 Endpoint (v1.08) method was applied. This method aggregates a wide range of impacts into three endpoint categories: human health, ecosystem quality, and resource consumption. Such aggregation facilitates easier interpretation of results and decision-making while offering a comprehensive and integrated view of environmental performance. To quantitatively compare the impacts of each rotation option, the data were processed using the relative normalization method. In this method, the impact value of each crop within a category is expressed as a percentage relative to the highest value in that category. This provides a clear visual way to identify alternatives with the highest and lowest environmental impacts. Finally, an inventory of emissions and the impact values of each crop across the three categories was compiled, forming the basis for selecting the most sustainable lentil rotation option.
 
Results and Discussion
Except for the effect of rye on water consumption in dryland ecosystems (which was negative), the impacts of other crops (as well as the other categories for rye) were positive. The negative value associated with rye cultivation indicates an overall favorable effect of this crop in terms of water use, as it avoids higher water consumption compared with other cropping options in the domains of water use and dryland ecosystems. According to the results, rye and barley caused the greatest environmental damage in terms of human health, while rapeseed and potato had the lowest impacts and were therefore the most favorable crops in this respect. The difference between rye and potato and rapeseed in the human health category was 48% and 65%, respectively. In addition, rye, rapeseed, and barley exerted the most negative environmental impacts on ecosystems, whereas potato had the lowest impact in this category. The findings of the present study demonstrated that all the examined crops had their greatest environmental impacts on human health, as this category accounted for the largest share of environmental effects across all crops. Following human health, the ecosystem category was the second most affected, while the impacts on the resources category were negligible. Therefore, it can be concluded that in assessing the environmental impacts of rye, barley, rapeseed, potato, maize, and wheat in rotation with lentil, particular attention should be given to their effects on human health.
 
Conclusions
The greatest environmental impact of the crops proposed for rotation with lentil was observed in the human health category, while their impacts related to resource consumption were minimal. Among the studied crops, rye and barley imposed the highest burdens on human health, whereas rapeseed and potato had the lowest impacts. Therefore, to reduce the environmental load in lentil-based crop rotations, it is recommended to avoid including rye and barley as much as possible, and instead to incorporate rapeseed and potato. Accordingly, a four-year environmentally sustainable rotation plan can be suggested as rapeseed–lentil–potato–lentil.

Abstract Introduction
Legumes hold a special position in sustainable agriculture and the global cropping pattern. These plants, by establishing symbiosis with nitrogen-fixing bacteria of the genus Rhizobium, are capable of converting atmospheric molecular nitrogen into a form absorbable by the plant. This characteristic, while reducing dependence on nitrogenous chemical fertilizers, leads to improved soil fertility and increased productivity in crop rotation. Among legumes, cowpea (Vigna unguiculata L.) is of particular importance due to its unique physiological and nutritional characteristics. This species, traditionally cultivated in arid and semi-arid regions such as northern Khuzestan, is an ideal option for cultivation under climate change conditions due to its favorable adaptation to environmental stresses (drought and heat). The high nutritional value of this crop (18-32% protein and essential amino acids) has made it a cost-effective substitute for animal protein sources. Plant hormones, as key signaling molecules, play a decisive role in modulating physiological processes and enhancing the performance efficiency of plants. Auxins, particularly indole-3-acetic acid (IAA), are effective in nitrogen fixation through increasing cell dimensions, vascular differentiation, and nodulation. Cytokinins also determine final yield by stimulating cell division, inhibiting leaf senescence, and regulating the transfer of photosynthetic materials to storage organs. The interaction of these two hormones in regulating the source-sink ratio and allocation of photosynthates to seeds is of particular importance. The innovation of this research lies in investigating the interactive effects of different levels of auxin and cytokinin on the morpho-physiological characteristics and yield of cowpea cultivars (Mashhad, Mahali, and Arabic) under the climatic conditions of Dezful. Despite scattered studies on the individual effects of these hormones, there is no comprehensive information regarding the optimal concentrations for their combined application and the differential response of cultivars. This research is designed with the aim of quantifying the growth and reproductive responses of cultivars to the combined application of auxin and cytokinin and identifying the best cultivar-hormone combination for sustainable yield increase.
 
Materials and Methods
This research was conducted during two crop years (2021-2022) at the Safiabad Agricultural and Natural Resources Research Center in Dezful. The experiment was designed as a factorial split-plot arrangement based on a randomized complete block design with three replications. Main plots consisted of three cowpea cultivars (Mashhad, Mahali, and Arabic), and sub-plots included factorial combinations of three auxin concentrations (0, 200, and 400 mg.L^-1) and three cytokinin concentrations (0, 100, and 200 mg.L^-1). Each experimental plot comprised 10 planting rows, 10 meters long, with a row spacing of 75 cm and a plant spacing of 20 cm.
Hormone foliar application was performed at the beginning of the flowering stage (60 days after planting). Measured traits included grain yield, biological yield, number of branches per plant, number of pods per plant, pod length, number of seeds per pod, and 100-seed weight. Combined analysis of variance for the data from two crop years was performed considering the year effect as a random factor and the effects of cultivar, auxin, cytokinin, and their interactions as fixed factors. Means were compared using Duncan's multiple range test at a five percent probability level using SAS software (version 9.2). Correlation coefficients between traits were calculated using Pearson's method in SPSS software (version 26), and graphs were drawn using Excel software (version 2013).
 
Results and Discussion
The results showed that the combined application of auxin 400 mg.L^-1 and cytokinin 200 mg.L^-1 resulted in superior performance in most traits compared to control treatments and individual hormone applications. The highest number of seeds per pod (12.7), pod length (16.7 cm), number of branches (14), and grain yield (2346 kg.ha^-1) were observed in the Mashhad cultivar, while the highest number of pods per plant (45.6) and biological yield (5226 kg.ha^-1) were observed in the Mahali cultivar under the same treatment. On average, hormone application caused a 24% increase in grain yield, with the Mashhad cultivar showing the greatest response. Combined analysis of variance showed that the three-way interaction (cultivar × auxin × cytokinin) was significant for biological yield, number of branches, number of pods per plant, and 100-seed weight. Two-way interactions were significant for grain yield, pod length, and number of seeds per pod. The highest grain yield (2346 kg.ha^-1) was obtained from the treatment of Mashhad cultivar with auxin 400 mg.L^-1 and cytokinin 200 mg.L^-1 (V1A2C2). This treatment also resulted in maximum biological yield (5661 kg.ha^-1), number of branches (12.8), number of pods per plant (45.6), pod length (16.0 cm), and number of seeds per pod (12.7). The lowest values were observed in the control treatment of the Arabic cultivar. It appears that the application of auxin and cytokinin, by improving hormonal balance, increasing photosynthetic efficiency, and optimizing source-sink relationships, has led to increased pod formation, improved seed growth, and ultimately enhanced yield. Correlation analysis showed a significant positive correlation between grain yield and biological yield (r = 0.75) and between the number of pods per plant and biological yield (r = 0.72). Pod length had a very strong correlation with the number of seeds per pod (r = 0.88) and 100-seed weight (r = 0.89).
 
Conclusions
The results indicated that the combined foliar application of the plant hormones auxin and cytokinin had a significant effect on improving the morphological traits, yield components, and grain yield of cowpea. The Mashhad cultivar showed the greatest positive response to hormone application, and the treatment of auxin 400 mg.L^-1 along with cytokinin 200 mg.L^-1 on this cultivar was identified as the most effective combination for maximizing yield impact. Therefore, the combined application of these hormones at the mentioned concentrations on high-potential cultivars like Mashhad can be recommended as an effective strategy to enhance cowpea productivity in regions similar to the climatic conditions of northern Khuzestan province.
 
Acknowledgement
The authors express their gratitude to the Safiabad Agricultural and Natural Resources Research Center in Dezful for their support in conducting this research.

Abstract Introduction
Legumes are the second most important group of cultivated crops after cereals, accounting for approximately 27% of global plant production. According to statistics from the Ministry of Agriculture Jihad, the average yield of rainfed lentil in Iran is 485 kg.ha⁻^¹. Globally, lentil is cultivated on more than five million hectares, with a total production exceeding 5.6 million tons and an average yield of 1,305 kg.ha⁻^¹. The lentil crop (Lens culinaris Medik.), after chickpea (Cicer arietinum L.), ranks second in terms of cultivated area in Iran, covering approximately 132,034 hectares, more than 90% of which is grown under rainfed conditions. Seed germination is one of the earliest physiological processes in plants. This process has numerous implications for the development of post-germination traits, ecological niche occupation, and the geographical distribution of plant species. Seed germination begins with water uptake and is completed by the emergence of the radicle. In most species, the radicle emerges first, and the seed is therefore considered germinated. According to the definition of the International Seed Testing Association (ISTA, 2009), seed vigour is the sum of seed characteristics that determine the potential level of activity and performance of seed germination and seedling emergence of an individual seed or a seed lot. This study aimed to compare and select superior lentil genotypes based on germination indices, stress tolerance, and seed viability, in order to identify those with better establishment, higher adaptability, and potential for high yield under field conditions.
 
Materials and Methods
To compare and select the best genotypes in terms of germination traits and growth indices, an experiment was conducted as a completely randomized design (CRD) with four replications in the laboratory of the Department of Agronomy, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili. The experimental treatments consisted of 12 promising lentil genotypes, including Varzeqan 6, Varzeqan 7, Nir D, Nir C, Boukan Karim Beigi, Naqadeh Mosalman, Khalkhal Sheikh Janlou, Mohagharloo, Namin B, Pardis, Bilesavar, and Sana. It should be noted that the seeds used in this study were obtained from the local seed populations of the Agricultural Research, Education, and Natural Resources Center of Ardabil Province. Sowing operations were carried out immediately after confirming the viability and health of the received seeds. For the experiment, 48 Petri dishes with a diameter of 9 cm and a depth of 1.6 cm were prepared. Twenty-five seeds from each genotype were placed in each Petri dish containing filter paper, with four replications, and five milliliters of distilled water were added to each dish. The Petri dishes were then transferred to a germinator set at 25 °C. Counting of germinated seeds began 24 hours after transfer to the germinator and was performed three times a day (every 8 hours) for 14 days. Seeds were considered germinated when the radicle had emerged at least 2 mm from the seed coat. Germination indices were calculated using the Germin software. Seed vigour of the genotypes was assessed using accelerated aging and electrical conductivity tests, and finally, the Seed vigour index was determined. At the end of the fourteenth day, to measure radicle and plumule lengths as well as fresh and dry weights of seedlings, ten seedlings were randomly selected from each Petri dish and evaluated. Statistical analysis of the data was performed using SPSS software (version 16), and mean comparisons were conducted using Duncan’s multiple range test at the 5% probability level. Figures and graphs were prepared using Microsoft Excel.
 
Results and Discussion
The Pardis genotype exhibited the highest germination percentage (98%), whereas the Nir C genotype showed the lowest germination percentage and germination rate (75% and 0.023 seeds per day, respectively). To determine seed vigour, accelerated aging and electrical conductivity tests were applied, followed by evaluation of the seed vigour index relationship. Under the accelerated aging test, the lowest reduction in germination percentage (10%) was observed in the Pardis and Nir C genotypes, while the highest reduction in germination percentage (25%) was obtained in the Mohagherloo genotype. The electrical conductivity test indicated that the Sana genotype, due to greater leakage of solutes from the seeds, had the highest electrical conductivity (68.98 µS.cm⁻¹.g⁻¹), whereas the Nir D and Varzeghan 7 genotypes showed lower electrical conductivity values (26.37 and 26.84 µS.cm⁻¹.g⁻¹, respectively). The Sana genotype was classified as having weak vigour, while the Nir D and Varzeghan 7 genotypes were categorized as genotypes with good vigour. The highest vigour index (671.60) and radicle length (4.74 cm) were observed in the Sana genotype. The Bukan–Karim Beigi genotype had the highest seedling dry weight (0.064 g).
 
Conclusions
According to the results, the highest germination percentage was observed in the Pardis genotype, while the Nir C genotype showed a lower germination percentage and germination rate. Since the seed vigour index alone is not sufficient to predict actual seed performance, accelerated aging and electrical conductivity tests were conducted. After the accelerated aging test, the lowest reduction in germination percentage (10%) was observed in the Pardis and Nir C genotypes, whereas the highest reduction in germination percentage (25%) was observed in the Mohagherloo genotype, indicating that the vigour of the Mohagherloo genotype decreased under high temperature and humidity conditions. The electrical conductivity test, which measures the extent of electrolyte leakage from seeds into water, showed that the Mohagherloo genotype had relatively weak seed vigour. Based on germination percentage and seedling growth (seed vigour index), the highest seed vigour was observed in the Bilesavar genotype, and the highest seedling dry weight was recorded in the Bukan Karim Beigi genotype. Due to the direct effect of the seed vigour index on seedling length, the Bilesavar genotype exhibited the greatest radicle length. Therefore, the Nir D, Varzeghan 6, Varzeghan 7, and Nir C genotypes can be recommended for further studies under the Ardabil climatic conditions; however, to confirm these results, both greenhouse and field evaluations are also required.

Abstract Introduction
Chickpea (Cicer arietinum L.) serves as a vital source of dietary protein and plays a crucial role in sustainable crop rotations within the Iranian agricultural system. Its productivity in dryland conditions is predominantly constrained by suboptimal sowing dates and inadequate nutrient management, leading to significant yield gaps. In recent years, bio-fertilizers have emerged as a promising ecological strategy to improve crop growth, soil health, and resource use efficiency. However, the performance of these microbial inoculants is highly context-dependent and influenced by agronomic practices, particularly sowing date. Despite this, the interactions between sowing dates and specific bio-fertilizer formulations under the variable climatic conditions of Iran's rain-fed ecosystems remain poorly understood. Therefore, this two-year field study was conducted to evaluate the efficacy of various commercial bio-fertilizers applied as seed treatments on the growth, yield, and water productivity of rain-fed chickpea, with a focus on comparing autumn and spring sowing dates.
 
Materials and Methods
A two-year field study (2023-2025) was conducted in Maragheh, East Azerbaijan province, using a split-plot arrangement within a randomized complete block design with three replications. The main plots were assigned to two sowing dates (autumn and spring), and the sub-plots to five seed treatments: Non-inoculated control, Probio96, Bioguard, MycoSupre Plus, and Humic acid. Following land preparation with a combined tiller, chickpea seeds (cv. Ana) were inoculated and sown at a density of 40 seeds.m⁻² on plots measuring 30×5 m in rotation with wheat, using a three-axis ASKE seeder with a 17.5-53 cm row arrangement. Weed control was performed manually. At flowering, plant density, root volume, dry root weight, root nodule weight, and plant height were measured. At physiological maturity, whole plots were hand-harvested to determine 100-seed weight, biological yield, grain yield, harvest index, and rainwater productivity.
 
Results and Discussion
Combined analysis of variance revealed that the main effect of sowing date was significant (p≤0.01) for all studied traits except plant establishment and 100-grain weight. Autumn sowing consistently and significantly enhanced root system development, resulting in higher root dry weight (2.97 g.plant⁻¹ in Year 1) and root nodule weight compared to spring sowing across both years. This superior root architecture under autumn sowing translated directly into improved agronomic performance, culminating in significantly higher mean grain yield (1084 kg.ha⁻¹) and rainwater productivity (2.84 kg.mm⁻¹). The main effect of year was also highly significant (p≤0.01) for key traits, reflecting the substantial impact of inter-annual environmental variability. The performance of bio-fertilizer treatments was profoundly influenced by these year-to-year fluctuations and their interactions with the sowing date. Among them, Bioguard, a consortium of Trichoderma and Bacillus velezensis, achieved the peak performance under optimal conditions (autumn sowing in the favorable Year 1), yielding the highest grain yield (1084 kg.ha⁻¹) and biological yield (2337 kg.ha⁻¹). However, its efficacy was highly unstable, showing the most drastic decline in the stressful Year 2 under spring sowing, where it produced the lowest yield (405 kg.ha⁻¹), even underperforming the control. This highlights its high sensitivity to environmental stress. In contrast, MycoSupre Plus, a complex formulation containing mycorrhizal fungi, Azotobacter, and Pseudomonas, demonstrated greater stability across contrasting years. While it did not reach the absolute peak yield of Bioguard in the optimal year, it provided consistent and reliable improvements in root volume, plant height, and final yield in both autumn and spring sowings, establishing it as a lower-risk option. Probio96, based on Bacillus velezensis, had a limited impact on root biomass but registered the highest harvest index (46.8%), indicating a superior efficiency in partitioning photosynthetic assimilates towards grain production rather than vegetative growth. Significant two-way (Year × Sowing Date, Sowing Date × Bio-fertilizer) and three-way (Year × Sowing Date × Bio-fertilizer) interactions were observed for most traits, including root volume, grain yield, and rainwater productivity. These interactions underscore the complex interplay between management practices and the environment. For instance, in spring sowing under stressful conditions, the untreated control sometimes showed better plant establishment than some bio-fertilizers, suggesting that the inoculated microbes could pose an additional osmotic stress on germinating seeds when environmental conditions were already adverse.
 
Conclusions
The choice of bio-fertilizer should be tailored to specific environmental conditions, including seasonal climate and sowing date. Integrating autumn sowing with bio-fertilizers that possess stable mechanisms of action, particularly MycoSupre Plus, is recommended as an effective strategy for achieving both high yield and production stability in rain-fed chickpea systems.