https://cr.guilan.ac.ir/ Cereal Research en daily 1 Wed, 21 Jan 2026 00:00:00 +0330 Wed, 21 Jan 2026 00:00:00 +0330 https://cr.guilan.ac.ir/article_9166.html IntroductionRice is a valuable food commodity in the world, most of which is produced and consumed in Asian countries, plays an important role in providing the required calories compared to other foods especially for Asian people. The importance of rice and its nutritional role in the world have made it a special place in the food security of consumer countries as a food supplier. This valuable cereal grain has experienced significant price fluctuations over the past years due to various factors, which has limited its availability to consumers, especially in poor countries. Since the strategic rice reserves in the world are limited, fluctuations and increases in rice prices are important. Therefore, governments, research and study centers, and rice producers should pay special attention to the trend of rice price changes. The objective of this review-analytical article was to evaluate the factors affecting the fluctuations in rice prices in the world in different periods from 1970 to 2025, as well as to study the trend of rice prices changes in the years when rice experienced the highest prices in the world. Research findingsThe results of this study showed that the highest rice prices were recorded during the crisis years of 2008, 2013, 2021, 2023 and 2024, the reasons of which can be considered a result of a combination of natural factors and social activities. On the one hand, climate hazards such as successive droughts (in 2006 and 2007), destructive storms (in 2007, and hurricane narcissus in 2013), abnormal cold (in 2008), and the El Niño phenomenon (in 2023 and 2024) were directly associated with a decrease in rice yields and supplies in key producing countries. On the other hand, several human and economic factors also played a role in exacerbating this crisis, including the increase in the prices of vital inputs such as oil, fertilizers and pesticides at critical times (2008 and 2021), geopolitical tensions such as the Russia-Ukraine war, and disruptions caused by the Covid-19 pandemic in the global supply chain. Meanwhile, the political reaction of some major producers, especially the imposition of export restrictions by India, the world’s largest rice exporter, as an aggravating factor, had a direct impact on the global market. In addition, the gradual impact of long-term structural factors such as the shift in consumption patterns towards protein has also added to the complexity of the demand equation. Therefore, it was the results of these multiple drivers that ultimately led to a reduction in global reserves and supply constraints, and consequently an increase in rice prices during these specific periods. Among the mentioned years, 2008 was the point of the price crisis in cereals, especially rice. Although rice prices have also increased after that, 2008 can be considered as the critical point of rice prices, which has experienced a price jump. ConclusionRice price have greatly fluctuated since 1970 and it’s trend have been upward. Drought, storms, floods, COVID-19, the Russia-Ukraine war, export bans, rising fuel prices, the dollar’s depreciation against the euro, and changes in the diets of developing countries and a greater preference for protein over grains can be identified as the most important natural, social, and economic factors affecting the reduction in rice yields and supply, and the increase in rice prices. Therefore, rice-importing countries, including Iran, should have appropriate and comprehensive planning to increase local rice production and reduce imports on the agenda. https://cr.guilan.ac.ir/article_9266.html IntroductionIn arid and semi-arid regions, drought stress particularly during the reproductive and late-season stages, often accompanied by high temperatures substantially reduces wheat yield. The use of early-maturing cultivars with shortened growth cycles, which complete development prior to the onset of stress, represents an effective strategy to mitigate these adverse effects. Evaluating the response of these cultivars to irrigation cutt-off during reproductive stages facilitates the identification of drought-tolerant genotypes. This study aimed to investigate the effects of drought stress on morphological, phenological, and functional traits of early-maturing near-isogenic wheat lines subjected to irrigation cutt-off during reproductive growth.Materials and methodsThe experiment was carried out in split-plot based on a randomized complete block design with three replications at the research field of Shahid Chamran University of Ahvaz, Ahvaz, Khuzestan province, Iran, in 2024-2025 growing season. Irrigation treatments at three levels, including full irrigation (control), irrigation cut-off from the beginning of flowering to early dough stage (code 61-83 in BBCH scale) and irrigation cut-off from early dough stage to full grain maturity (code 83-92 in BBCH scale) was considered as main factor, and five bread wheat cultivars and near-isogenic lines, including Roshan, Mahdavi, Roshan’s near-isogenic line, Mahdavi’s near-isogenic line and Mehregan cultivar (control) as sub-factor. The measured traits included phenological traits (number of days to heading and days to maturity), morphological traits (plant height and peduncle length), yield components (spike weight, number of grains per main spike, spike weight and 1000-grain weight), as well as biological yield and harvest index which were measured at full maturity. To group the studied genotypes and traits, cluster analysis method was used and the respective dendrogram was drawn as a heat map using R-studio ver. 2023 software. Data analysis of variance was conducted using SAS ver. 9.1 software and comparison of means was performed using Duncan’s multiple range test at 5% probability level.Research findingsThe results of this study indicated that there was a significant difference between cultivars and near-isogenic lines for most of the evaluated traits. Irrigation cut-off at different growth stages significantly reduced the number and weight of grains per spike, 1000-grain weight, and days to maturity, ultimately leading to decreased grain yield across all cultivars and near-isogenic lines. However, greater reductions were obsberved in the cultivars compared with their corresponding near-isogenic lines. Under irrigation cut-off applied at the flowering stage, the grain yield of Roshan and it’s near-isogenic line, Mahdavi and it’s near-isogenic line, and Mehregan decreased by 33%, 38%, 29%, 29% and 20%, respectively, compared with full irrigation treatment. Corresponding reductions under irrigation cut-off treatment at the grain-filling stage were 12%, 15%, 15%, 15% and 8%, respectively. Grain yield in the Mahdavi cultivar and it’s near-isogenic line, as well as in Mehregan cultivar, was significantly higher than that of the Roshan cultivar and it’s near-isogenic line under all irrigation cut-off treatments. Across all irrigation cut-off treatments, the number of days from seed sowing to maturity in near-isogenic lines of Roshan and Mahdavi was 10 to 15 days fewer than their parental cultivars. This earliness likely contributed to reduced exposure to drought stress during critical reproductive stages, enhancing yield stability. Furthermore, irrigation cut-off during reproductive growth stages further truncated the reproductive cycle of both cultivars and near-isogenic lines by approximately three to five days compared with the full irrigation treatment.ConclusionOverall, the findings of this study showed that the the near-isogenic lines outperformed their parent cultivars in terms of yield and other agronomic traits. The near-isogenic line of Mahdavi, by employing an earliness strategy and shortening the time to flowering and maturity, achieved the highest grain yield under both full irrigation and cut-off irrigation treatments. Therefore, similar to the Mehregan cultivar, it is recommended for cultivation under mild water stress conditions in the Khuzestan region. https://cr.guilan.ac.ir/article_9427.html IntroductionWheat is one of the most important plant affecting human life due to various application. This plant is planted and harvested almost year-round across the globe due to high adaptability to various environmental conditions. Diverse management practices of farmers is caused the potential of the agricultural lands are often not optimally utilized, resulting in low yields per unit area. This issue is a significant problem in wheat fields that needs to be examined through field methods. The comparative performance analysis (CPA) method effectively estimates yield differences based on the potential of the land and the yield resulting from farmer’s management. This study was planned and implemented to investigate the yield gap and its contributing factors in the irrigated wheat fields of Azna county, Lorestan province, Iran, using the CPA method.Materials and methodsIn this study, data from 74 irrigated wheat farms in Azna county were used to estimate the yield gap and its contributing factors through the CPA method. The data from the wheat fields were collected using a questionnaire including farm characteristics (rural area, farmer experience and literacy, field area and rotation), planting operations (planting date, plowing, subsoiler, cultivator and trowel, disk and its number, planting method, fungicide, variety, seed quantity, amount, type, method and time of spreading nitrogen, phosphorus and potash fertilizers, amount and type of livestock manure), maintenance operations (type, irrigation frequency, irrigation in autumn and its number, first irrigation in spring, amount, time and method of top-dress nitrogen fertilizer, pest and weed control), and harvesting operations ((harvest date and length of wheat growth period). Topographic (aspect, slope and elevation of wheat fields) and soil information (organic matter, pH, available phosphorus and potassium, total nitrogen and soil texture) for each wheat field were also obtained from the GIS-prepared layers based on their geographical locations. To determine the yield model (output), the relationship between all measured variables and yield was examined using stepwise regression analysis with SAS software. Finally, using the derived production equation, the yield gap and its contributing factors, along with the share of each, were identified.Research findingsThe results of this study showed that the minimum and maximum observed yield of wheat fields were 2500 and 8500 kg.ha-1, respectively, with the average of 5943 kg.ha-1. Also, the average, minimum and maximum yield estimated by the model were 5906.62, 3248.22 and 11289.24 kg.ha-1, respectively, and the total yield gap was 5382.62 kg.ha-1. The correlation coefficient between the estimated yield and the actual yield of farmers was 0.81, and the residual root mean square (RMSE) and the coefficient of variation (CV) of the model were obtained 842.71 kg.ha-1 and 14.27%, respectively. The analysis of the factors contributing to the yield gap indicated the role of six variables, including low organic matter content in the soil (26.8%), lack of row planting (3.60%), low seed usage (10.96%), reduced number of irrigations in the fall (18.88%), reduced amounts of nitrogen applied as Top-dressing fertilizer (17.28%), and untimely harvesting (22.43%) in creating the yield gap in the irrigated wheat fields in Azna county.ConclusionThis study confirms the acceptable capability of the CPA method in estimating the yield gap and the factors affecting it in the wheat fields of Azna County. The results showed that with timely, targeted, and intelligent management, the yield gap can be reduced by approximately 48%, thereby significantly increasing wheat production. Implementing appropriate crop rotation, managing wheat and other crop residues, using animal manure, promoting the use of row planters and providing them to farmers, managing seedbed preparation, selecting suitable varieties, and strongly recommending fall irrigation, soil testing to determine appropriate nitrogen fertilizer levels, and distributing it according to the growth stages of wheat, along with precise planning to avoid overlap in spring crop cultivation with wheat harvesting and timely entry of harvesting machinery into wheat fields are recommended to reduce the yield gap based on the influencing factors. https://cr.guilan.ac.ir/article_9265.html IntroductionPearl millet (Pennisetum glaucum L.) is one of the most important crops in warm and arid regions, playing a key role in food security across arid and semi-arid areas of the world. Due to climate change and increasing environmental fluctuations, the need to develop high-yielding and stable hybrids has become more crucial than ever. Given the nature of cross-pollination and high heterosis potential, the development of hybrid cultivars is the main breeding strategy in pearl millet. Hybrid varieties of pearl millet can significantly enhance both yield and stability under diverse agro-climatic conditions. However, environmental variability causes differential genotypic responses, making it essential to assess genotype–environment (G × E) interactions for selecting superior hybrids in different climate regions. The objective of this study was to evaluate the stability of promising pearl millet hybrids and to identify stable, high-yielding, and well-adapted hybrids for the target regions.Materials and methodsThe plant materials consisted of eleven promising pearl millet hybrids along with the check cultivar ‘Mehran’. The experiment was conducted in a randomized complete block design (RCBD) with three replications across eight environments (four locations, Karaj, Birjand, Isfahan and Zabol, during two cropping seasons, 2022 and 2023). The traits evaluated included days to 50% flowering, plant height, panicle length, panicle diameter, number of tillers, 1000-grain weight, and grain yield. Statistical analyses were performed using SAS software, and mean comparisons were conducted using Duncan’s multiple range test at 0.05 probability level. For combined analysis of variance, genotype and location were considered as fixed factors, while year was treated as a random factor. Stability analyses were performed using the Lin and Binns method, rank-based stability parameters, and the GGE biplot model to identify stable and high-yielding hybrids.Research findingsCombined analysis of variance and comparison of means revealed significant genetic variability among the pearl millet hybrids for all studied traits. Moreover, the effects of environment and genotype × environment interaction were significant (P<0.01) on all measured traits including grain yield. The results indicated that the studied genotypes exhibited both crossover and non-crossover types of interactions. Comparison of grain yield of the studied hybrids showed that hybrids H794 and H824 with 8.41 and 7.81 t.ha⁻¹, respectively, produced the highest grain yield. The results of the stability analysis across eight environments based on the three methods (rank-based, superiority index, and GGE-biplot) demonstrated that two promising hybrids H794 and H824 had the higher grain yield and stability across all studied environments.ConclusionThis study clearly demonstrated the potential of exploiting heterosis in pearl millet to replace obsolete cultivars with modern high-yielding hybrids. All evaluated hybrids outperformed the check cultivar ‘Mehran’, indicating their superiority for yield improvement. Introducing these promising hybrids could significantly enhance the national average grain yield of pearl millet. Moreover, considering the ongoing water scarcity crisis in the country, the dissemination of high-yielding and drought-efficient hybrids could encourage farmers to cultivate this low-water-requirement crop. https://cr.guilan.ac.ir/article_9439.html IntroductionCereals such as maize, rice and wheat constitute major crop groups and serve as essential nutritional sources for a large portion of the global population. These crops hold significant international importance and, as central components of human diets, play a decisive role in ensuring global food security. Moreover, particularly in arid and semi-arid regions, cereals are recognized as primary providers of carbohydrates and proteins. The production of these staple crops faces numerous challenges: abiotic stresses such as drought, salinity, heat and cold can substantially reduce their yield and performance. Among these factors, salt stress stands out as one of the major barriers to cereal crop production. The key question addressed here is: How can cereals perceive environmental stimuli and, via intricate regulatory networks, activate their defense pathways to cope with such stresses?Research findingsThe plant (including cereal) response to salt stress typically unfolds in two distinct phases: initially, osmotic stress; subsequently, ionic toxicity followed by secondary stresses such as oxidative stress and nutritional imbalances. At the physiological level, plants confront salt stress by utilizing efficient systems for ion uptake and distribution, maintaining osmotic balance and accumulating protective compounds. At the biochemical level, activation of antioxidant systems and synthesis of compatible solutes such as proline—are among the principal strategies to mitigate oxidative damage triggered by salinity. On the molecular level, complex networks of transcription factors and functional genes (for example, NHX1, HKT1, SOS and P5CS) coordinate the salt‐stress response. Key signaling pathways including the MAPK cascade and the SOS (Salt-Overly Sensitive) pathway play central roles in transducing the stress signal and initiating defense responses. The identification of quantitative trait loci (QTLs) associated with salt tolerance and candidate genes has advanced our understanding of the genetic basis of this trait. Since salt tolerance is a quantitative (polygenic) trait controlled by multiple genes, its molecular processes are regulated via extensive regulatory networks comprising transcription factors and functional genes. Pathways such as MAPK and SOS have been widely studied in cereals, and the present findings draw on research specific to those crops; for example, in rice the SOS1, SOS2 and SOS3 genes enhance salt tolerance by mediating sodium efflux from the cytosol, thereby preventing ionic toxicity. Additionally, the accumulation of protective compounds (e.g., proline) and activation of antioxidant defenses are critically involved in maintaining cellular integrity under saline conditions.ConclusionConsidering the polygenic nature of salt tolerance, it is imperative to conduct genetic studies and identify relevant QTLs and key genes. Ultimately, the integration of physiological, genetic and molecular findings into breeding programmers coupled with the use of genomic approaches is indispensable for the development of novel cereal varieties that are salt-tolerant and exhibit stable performance under saline conditions. https://cr.guilan.ac.ir/article_9464.html IntroductionSalinity is recognized as one of the most detrimental abiotic stresses, severely affecting the growth and productivity of agricultural crops and posing a significant threat to global food security. Given the time-consuming and costly nature of physically restoring saline ecosystems, the development of salt-tolerant cultivars in strategic cereals such as rice, wheat, and maize is considered a sustainable and cost-effective approach to address this challenge. This review aims to explore recent advances in understanding the mechanisms of salinity tolerance and to introduce modern breeding tools that can accelerate the development of such cultivars.Research findingsStudies indicate that salinity tolerance mechanisms particularly osmotic adjustment vary significantly among plant species. For instance, barley exhibits higher tolerance due to its superior osmotic regulation capacity, whereas sensitive species like maize are more limited in this regard. At the molecular level, the identification of numerous quantitative trait loci (QTLs) and functional genes (e.g., SOS1, HKT1, and NHX1) involved in ion homeostasis and the accumulation of protective compounds has opened new avenues for molecular breeding. Although conventional breeding methods have achieved some success in developing salt-tolerant varieties, they are often inefficient, time-intensive, and environmentally dependent. Moreover, phenotypic evaluation of salinity tolerance under field conditions may not always reflect actual plant performance, highlighting the urgent need for standardized and reliable assessment methods. A major challenge lies in the simultaneous and stable introgression of multiple effective genes / QTLs into elite genetic backgrounds, as salinity tolerance is a complex quantitative trait. Relying on one or a few individual genes is insufficient to achieve durable resistance under field conditions.ConclusionModern plant breeding tools such as marker-assisted selection (MAS), genome-wide association studies (GWAS), and especially omics technologies (transcriptomics, proteomics, and metabolomics), along with genome editing, have revolutionized the identification and transfer of desirable genes. These technologies enable precise and rapid gene pyramiding and the simultaneous transfer of multiple salinity-resistance alleles. https://cr.guilan.ac.ir/article_9527.html Comprehensive abstract Introduction Rice (Oryza sativa) is a strategic agricultural crop that plays a pivotal role in food security and livelihoods in Iran and worldwide. In this context, a comprehensive assessment of greenhouse gas emissions from rice cultivation systems is essential for achieving sustainable production and Carbon footprint serves as an indicator for estimating both direct and indirect greenhouse gas emissions.Aligned with global efforts to mitigate climate change, the role of traditional knowledge systems in carbon management has increasingly garnered attention. The objective of this study was to investigate the carbon footprint of rice cultivation and the associated Traditional knowledge related to its influencing factors in Gilan Province during the 2022 cropping year. Materials and Methods A mixed-methods design was applied, integrating quantitative and qualitative approaches. The CF was calculated for three farm sizes (<0.5 ha, 0.5–1 ha, >1 ha) using life cycle assessment based on Intergovernmental Panel on Climate Change guidelines. Traditional knowledge was explored through an ethnographic method and analyzed with coding in MAXQDA 2020. Data normality was assessed using the Shapiro-Wilk test, and due to the non-normal distribution of some data, non-parametric Kruskal-Wallis tests was conducted using SPSS software. For pairwise comparisons, Dunn’s post-hoc test with Bonferroni correction was applied at a 5% significance level. Research findings The average CF of rice production was 1.23 kg CO₂eq/kg.year. Although no statistically significant differences were observed among farm sizes, larger farms tended to have slightly lower CF values. The mean global warming potential of the system was 3031 kg CO₂eq/ha.year. Irrigation practices and methane emissions during the growing season accounted for approximately 64% of total emissions, while nitrogen-based fertilizers and associated N₂O emissions contributed about 10%. Additional sources included fuel, labor, and seed inputs. Farmers recognized Traditional knowledge as effective in reducing CF, particularly through organic fertilizer management (50%), mechanization (40%), and seed practices (10%). Conclusion Mitigating the CF of rice production in Gilan requires an integrated strategy that merges formal scientific approaches with Traditional knowledge. Priority measures include transforming irrigation practices, optimizing fertilizer application, promoting local rice cultivars, and combining farmers’ experiential knowledge with energy-efficient mechanization. https://cr.guilan.ac.ir/article_9546.html Introduction: The projected 60% increase in global food demand by 2050, along with growing limitations on water and nitrogen resources, highlights the urgent need to optimize input use in strategic crops such as rice. As a major irrigated cereal with high water requirements, rice production faces rising challenges related to water scarcity, low nitrogen use efficiency, and environmental concerns stemming from excessive fertilizer application. Effective irrigation and fertilization management—especially through distinguishing between green water (soil moisture from rainfall) and blue water (surface and groundwater withdrawals)—is essential for improving resource use efficiency. Process-based models like ORYZA2000 provide powerful tools for analyzing these management strategies. As a validated model widely used for rice systems, ORYZA2000 supports the evaluation of scenarios aimed at increasing productivity while reducing dependence on limited water resources under changing climatic conditions. Research Methodology: This study was conducted over two consecutive growing seasons at the experimental farm of the National Rice Research Institute in Rasht, Iran. A split-plot arrangement within a randomized complete block design with three replications was used, with 16 treatment combinations. Irrigation treatments included continuous flooding and irrigation 1, 3, and 5 days after surface water disappearance, while nitrogen levels consisted of 0, 60, 90, and 120 kg ha⁻¹. The hybrid cultivar ‘Bahar,’ known for its high yield potential and adaptability to Gilan’s climate, was grown. Field measurements of grain yield, biomass, leaf area index, and nitrogen uptake were used to calibrate and validate the ORYZA2000 model. Outputs from water balance simulations were then used to estimate green and blue water productivity indices and major water balance components. Findings: The highest grain yield (7.2 t ha⁻¹) occurred under irrigation 3 days after water disappearance combined with 120 kg N ha⁻¹. The ORYZA2000 model showed strong performance in simulating grain yield (NRMSE = 7–12%), biomass (NRMSE = 6–12%), total nitrogen (NRMSE = 8–15%), grain nitrogen (NRMSE = 9–10%), and leaf area index (NRMSE = 14–29%). For all variables except leaf area index, the model efficiency (EF) exceeded 0.65, and coefficients of determination (R² > 0.70) indicated a good match between simulated and observed data. Across two years, the highest simulated water productivity indices were also obtained from the I3N4 treatment (irrigation 3 days after water disappearance + 120 kg N), including irrigation water productivity (WPI = 1.32), irrigation plus rainfall productivity (WPI+R = 0.84), transpiration productivity (WPT = 2.0), evapotranspiration productivity (WPET = 1.12), and evapotranspiration plus percolation productivity (WPETQ = 0.89). Separation of indices into green and blue components showed that this treatment provided the highest values for most blue and green water productivity indices. However, green water productivity (WPg) and green water transpiration productivity (WPTg) were highest under I4N4 (irrigation 5 days after water disappearance + 120 kg N) and I1N4 (continuous flooding + 120 kg N), respectively. Conclusion: Combined irrigation and nitrogen management plays a crucial role in enhancing rice yield and water productivity. The ORYZA2000 model demonstrated strong accuracy in simulating management scenarios and water balance components, making it a valuable decision-support tool for water and fertilizer management in rice systems. Incorporating the distinction between green and blue water further supports strategies to reduce irrigation demand and increase overall productivity under water-limited conditions. The model identified the most efficient irrigation-nitrogen combination for maximizing both blue and green water productivity. This is particularly important where irrigation water is dominant; for example, alternate wetting and drying with a three-day interval plus 120 kg N ha⁻¹ was the most effective treatment. These findings can guide resource optimization strategies at both farm and policy levels under varying levels of dependence on water sources