grain yield

The aim of research is to investigate and compare the effects of different planting dates on the competitive ability of rapeseed cultivars against weeds, and to identify the best cultivar for expanding the cultivation area of rapeseed in the temperate and humid climate of Guilan. 

The experiment was carried out during two years (2021 to 2023) in Amlesh. In split plot factorial experiment, two weed interference conditions (full competition under natural weed community and weed free) were considered as main plots and four varieties of canola (RGS003, Delgan, Drago and Hayola4815) and three planting dates (6th of October, 26th of October and 15th of Novamber) as factorial arrangement in sub plots. 

The results of variance analysis showed a significant effect of weed, cultivar and planting date on seed yield, biological yield, number of pods per plant, and oil yield. The average comparison results showed that weed interference caused a decrease in seed yield by 10% (from 2631 kg.ha-1 to 2364 kg.ha-1) regardless of cultivar. The cultivar type and planting date had a significant effect on the biomass and density of weeds. Delgan and Drago cultivars had the highest seed yield in each weed interference conditions with average of 2650 and 2590 kg/ha. The effect of planting date on the reduction of seed yield in rapeseed cultivars was greater than that of weed interference. Weed-free treatments were significantly different from weedy treatments in terms number of silique per plant, number of seeds per silique, seed yield, biological yield, oil yield and protein yield.

The Delgan cultivar had higher seed and oil yield than other treatments in both weed interference conditions on the planting date of 26 October, which suggests that this cultivar can be used to produce adequate rapeseed yield in Guilan.

The purpose of this research was millet and soybean yield evaluation in monoculture and strip intercropping under weed-free and weed-infested conditions. 

Split-plot experiment based on randomized complete block design with three replications was conducted in 2021 and 2022. The main plots included weed-free and weed-infested treatments, and the subplots included six different patterns of millet (M) and soybean (S) strip intercropping, sole cropping of millet and sole cropping of soybean. Millet and soybean seed yield traits and LER, AYL, K, IA, CAI indices were investigated. 

The results of variance analysis showed that the effect of weed-infested, cropping system and interaction on grain yield of millet (p< 0.01) and soybean (p< 0.01) were significant. The highest grain yield of millet (1134/83 kg/ha) and soybean (1832/83 kg/ha) was obtained in the weed-free sole cropping treatment, and the lowest one in millet (355/16 kg/ha) was observed in the 2M2S intercropping weed-infested treatment and in soybean (440/22 kg/ha) was observed in the 2S4M intercropping under weed-infested treatment. The highest LER in the 2M4S intercropping under weed-infested condition was 1.85 in the average of two years. The maximum CAI in the average data of two years related to 2M4S intercropping in weed-free treatment. Also, the maximum IA was related to 2M4S intercropping in weed-infested condition. 

LER and CAI was greater than 1 in all intercropping patterns, which indicates the superiority of millet and soybean intercropping, compared to their sole cropping. The positive value of IA and AYL in all intercropping patterns indicated the beneficial effect of plants on each other and the advantage of their intercropping in weed-free and weed-infested conditions. 2M4S intercropping in weed-infested treatment increased millet and soybean grain yield per occupied area by 20% and 9.7% compared to the sole cropping of both plants in weed-free conditions, respectively.

The careless use of chemical fertilizers has led to numerous environmental issues. A key strategy to reduce reliance on chemical fertilizers and mitigate their adverse effects is the application of organic fertilizers.

The factorial experiment was conducted using a randomized complete block design (RCBD) with three replications during 2022. The first factor consisted of three levels of supplemental irrigation [no irrigation (control), one irrigation at 50% flowering stage, two irrigations at 50% flowering and 50% podding stages] and organic fertilizers at three levels [no application of organic fertilizer (control), application of vermicompost at 10 tons ha-1, application of cow manure at 20 tons ha-1]. 

The resultdns showed that in comparison to no irrigation, once and twice supplementary irrigation decreased the contribution of total plant in grain yield by 15.1% and 43.2%, respectively. When supplementary irrigation is applied once, as opposed to without irrigation, the digestible dry matter, total digestible nutrients, and net energy for lactation increase by 3.1, 2.4, and 2%, respectively, and when it is applied twice, the increases are 4.3, 5.1, and 4.2 percent, respectively. When compared to no-fertilizer conditions, the use of animal manure and vermicompost reduced the contribution of total plant in grain yield by 38.9% and 44.3%, respectively, while increasing dry matter intake by 3.9% and 14.1% and relative feed value by 3 and 14.2%. Additionally, under non-irrigated conditions, the use of vermicompost and animal manure increased grain yield by 99% and 106.8, respectively, over the absence of fertilizer. 

The findings suggest that supplemental irrigation and the use of organic fertilizers can significantly enhance the yield and quality of fodder in pea plants cultivated in rainfed conditions.

Wheat (Triticum aestivum L) is one of the most important cereal crops. A model is a tool that helps us interpret and understand the world we live in. Crop modeling, a branch of agricultural science, has been around for about 40 years, with the development of powerful and efficient computers playing a major role in its advancement. These models usually enable the determination of management options and can be used to explore a wide range of management strategies at low costs. Plant models have proven to be useful tools for estimating crop yield, integrating a comprehensive set of values under physiological conditions, and evaluating crop management options. One essential feature of simulation models is the accurate prediction of crop phenology. The key phenological stages required for simulating the physiological processes of growth and yield in wheat are as follows: Days from planting to emergence, days from emergence to tillering, days from tillering to stem elongation, days from stem elongation to booting, days from booting to heading, days from heading to anthesis, days from anthesis to physiological maturity, and days from physiological maturity to harvest. The aim of this research is to evaluate the SSM-Wheat model for predicting the phenological stages and yield of wheat.

The necessary information for simulating the phenological stages and yield of wheat was obtained from experimental data on 7 planting dates (November 1st, November 10th, November 20th, November 30th, December 10th, December 20th, and December 30th) and four bread wheat genotypes (line N9-93 and the varieties Araz, Taktaz, and Arman) over two cropping years, 2019-2020 and 2020-2021. Data on the phenological stages and yield of wheat were used to evaluate the model. Daily meteorological data (maximum and minimum temperatures, precipitation, and solar radiation) were collected and defined in the model. Soil characteristics parameters were considered based on the model's default data.

The evaluation of the SSM-Wheat model showed that this model accurately simulates the phenological stages, including days to emergence, days to stem elongation, days to heading, days to flowering, and days to physiological maturity, as well as grain yield across different planting dates and wheat varieties under the climatic conditions of Gonbad. However, the model did not accurately predict days to tillering, biological yield, and harvest index. The highest coefficients of determination (R²) were obtained for days to heading (0.79), days to flowering (0.77), and days to physiological maturity (0.92). Accurate prediction of crop phenology is a crucial feature of simulation models. Yield in crop simulation models is largely regulated by the timing of developmental stages. The poor prediction of biological yield and harvest index may be due to water stress and high temperatures during the grain-filling and maturity stages, which caused leaf drop and reduced biomass, leading to incomplete harvest by the combine. Delayed planting and low temperatures during the early growth stages in areas with very cold winters, due to inadequate plant establishment and growth to withstand autumn frosts, and high temperatures in hot and dry regions during the late growth stages, especially the grain-filling period, can reduce plant yield. Grain weight is a key component of final grain yield and is influenced by environmental stresses, particularly water stress.

The evaluation of the SSM-Wheat model showed that this model was acceptable in simulating phenological stages, including days to emergence, days to stem elongation, days to heading, days to flowering, days to physiological maturity, and grain yield across different planting dates and cultivars under the climatic conditions of Gonbad Kavous. However, the model poorly predicted days to tillering, biological yield, and harvest index. It seems necessary to revalidate and refine the model accuracy using data from diverse experiments, and if the results of this review are confirmed, to incorporate them into the model equations. Nevertheless, this model can be used in field management planning, such as selecting planting dates, suitable cultivars, analyzing crop yield, and its limitations. Obviously, models become effective only when applied with an analysis of physiological and ecological conditions, based on experimental measurements and observations from the system.

Safflower, scientifically known as Carthamus tinctorius L., is an annual plant belonging to the Asteraceae family. Today, with the development of high-yield varieties that produce substantial quantities of high-quality oil, safflower is recognized as one of the world's important oilseed crops. Given its strong resistance to salinity and ability to grow under rain-fed conditions, it is considered a drought-tolerant plant—an attribute that significantly enhances its value. Additionally, humic acid, as an organic compound, poses minimal harm to the environment. Additionally, through its hormone-like activity, it has many positive effects on various traits, including performance characteristics. The presence of micronutrients, especially Fe, enhances the plant's resistance to various biotic and abiotic stresses.

This study was conducted at the Ardabil Agricultural Research Center to evaluate the effect of two types of fertilizers (iron fertilizer and humic acid) on the yield and phenological traits of two safflower cultivars. This experiment was conducted as a split-plot design based on a completely randomized block design with three replications. The main factor included two safflower varieties named "Chini" and "Goldasht," while the sub-factor consisted of nine fertilizer levels. These fertilizer levels included one control level, two levels of 95% humic acid (two milligrams per liter and four milligrams per liter), two levels of 12% EDTA chelated iron (one milligram per liter and two milligrams per liter), and four combined levels of iron and humic acid fertilizers.

The results revealed a significant difference in performance traits between the two varieties, Chini and Goldasht. Observations showed that the Goldasht variety produced a significantly higher seed yield of 1,462.5 kg per hectare, compared to 1,403.3 kg per hectare for the Chini variety. Additionally, the second level of iron + second level of humic acid treatment showed significantly the highest yield, resulting in a 49% increase in seed yield compared to the control. Overall, the combined use of these two fertilizers is recommended. The Goldasht variety requires a shorter time for flowering and maturity compared to the Chini variety and matures earlier while also having a higher yield, making it preferable in this regard. For the traits of plant height and antioxidant activity, there is no significant difference among the cultivars. However, among the fertilizer levels, the second level of humic acid resulted in a height of 68.3 cm, and for antioxidant activity, the combination of the second level of humic acid and the second level of iron exhibited the highest activity at 84.5%. Overall, among the cultivars, 'Goldasht' and among the fertilizer levels, the treatment combining the second levels of iron and humic acid had the highest biological yield, the highest harvest index, oilseed yield, and seed yield.  Humic acid, due to its nitrogen-like effects and its richness in organic materials, leads to increased seed filling and higher thousand-grain weight. On the other hand, the application of iron helps to cleanse reactive oxygen species and improves the plant's sink performance, providing more seeds for filling.

The studies indicated that the Goldasht variety matures earlier and yields more than the Chini variety. Due to its longer growth period, the Chini variety is more susceptible to late-season challenges such as heat stress, pests, and bird damage, which can negatively affect yield. Therefore, the cultivation of the Goldasht variety is preferable in this context. In terms of physiological traits, the application of iron and humic acid fertilizers was found to enhance the stability and resilience of both varieties. The interaction between humic acid and iron proved beneficial for safflower health, promoting greater nutrient uptake, improved growth parameters, increased seed yield, and enhanced stress tolerance.

Water stress is one of the main limiting factors for global crop productivity in arid areas. A strategy to mitigate the pronounced water stress levels may entail the application of plant growth-promoting rhizobacteria (PGPRs), organic matter, and intercropping systems in arid regions. Among PGPRs, Pseudomonas and Azospirillum bacteria stand out for their remarkable capacity to enhance the availability of soil phosphorus (P) and nitrogen (N), respectively. Sufficient P and N uptake has been documented to improve plants' resilience to water stress through several mechanisms and, therefore, increase dry matter remobilization, grain yield in late-season severe water stress. The application of organic matter and intercropping systems emerges as alternative solutions for mitigating severe water stress levels, and consequently improving dry matter remobilization and grain yield of the intercropping members. Despite the above knowledge, there is a lack of information regarding the interaction between biological fertilizer, organic matter, and the triticale-chickpea intercropping system in mitigating the detrimental effects of water stress on triticale (× Triticosecale Wittmack). Therefore, this research was conducted to evaluate the impacts of PGPRs, sheep manure, and intercropped triticale with chickpea (1:1) on assimilate accumulation and translocation of triticale as two main traits for determining the triticale grain yield under the late-season deficit irrigation (water stress) in southern Iran (Fars province -Darab).

A split-factorial experiment based on randomized complete block design with three replications was implemented at the research field of the College of Agriculture and Natural Resources of Darab - Shiraz University in 2019-2020 growing season. Treatments were two levels of irrigation (Ir): [1- normal (IRN): irrigation based on the plant water requirement up to the physiological maturity stage (ZGS92) and 2- deficit irrigation (water stress - WS): irrigation based on the plant water requirement up to the milking stage] as the main plots. Three fertilizer sources (FS) [1- chemical: ( 50 kg P ha-1 + 150 kg N ha-1), 2- integrated: (25 Kg P ha-1 + 75 Kg N ha-1 + 20 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense) 3- bio-organic: 40 tons sheep manure ha-1 + inoculation with P.  fluorescens and A. brasilense] and two cropping systems (Cs) [1- monoculture of triticale, 2- intercropped triticale with chickpea (1:1)] were subjected as the sub-plots. The aboveground dry matter of the whole plant organs at the anthesis stage and the dry matter of the vegetative organs at maturity were measured, and the dry matter remobilization and its attributes were calculated as Barati and Ghadiri (2017) mentioned. Data were analyzed using SAS 9.1 software, and means were separated using the Duncan multiple range test at 5% probability level.

The results showed that the highest amount of assimilate remobilization occurred in integrated (2271.9 kg ha-1) and intercropped triticale (2188.4 kg ha-1) under IRN condition. Assimilate remobilization and assimilate remobilization efficiency decreased by deficit irrigation. However, these decrements were different in the two cropping systems. Intercropping triticale, as compared to its sole, showed a lower decrease in these traits (16.5% and 4.3%, respectively).  Furthermore, the smallest reductions in assimilate remobilization and assimilate remobilization efficiency due to deficit irrigation were observed in the bio-organic (16.0%) and integrated (2.3%) treatments, respectively. Grain yield showed a positive and linear relationship with assimilate remobilization in IRN and WS conditions (R2 = 0.65 and R2 = 0.95, respectively).

As a result, to enhance assimilate remobilization and subsequently increase triticale grain yield, triticale–chickpea intercropping combined with integrated fertilizer application is recommended under IRN conditions. In contrast, when deficit irrigation (water stress) is anticipated, a bio-organic fertilizer system and intercropped triticale are advisable.

The growing global population, coupled with the scarcity and limitations of food resources, has prompted researchers and agricultural professionals to seek more effective solutions for feeding millions of people, particularly in developing countries. Guar (Cyamopsis tetragonoloba L.) is an annual legume known for its tolerance to salinity and drought, making it a promising alternative crop for low-water plains. Determining the appropriate planting date and optimal plant density are crucial factors that contribute to the efficient use of environmental resources and achieving high yields.

This experiment was performed in the form of split plots based on a randomized complete block design with three replications in 1398 in Mohammadieh Agricultural Research Station, Birjand. Experimental factors include planting date in four levels (May 10, June 10, June 25 and July 10) as main plots and plant density in three levels (distances of 10, 20 and 30 cm between plants in a row) as plots Guar cultivar was a Pakistani mass that was prepared from Pakan Bazar Isfahan Company. For planting, the land was plotted after preparation so that each plot consists of 4 ridges 60 cm wide and 3 m long, and on each row of two rows was planted manually at a depth of five centimeters, and irrigation was carried out immediately. After reaching the final height of Guar plant and physiological maturity before final harvest, taking into account the marginal effect of five plants from each plot, they were randomly selected and the characteristics of plant height, number of sub-branches per plant, pod length, number of pods per plant, number pods per plant, 1000-seed weight, initial plant weight, plant weight without pods and pod weight were measured. The number of pods per square meter, plant yield, and biological yield were calculated after removing the marginal effects based on plants harvested from one square meter in the middle of each plot. Data were analyzed using SAS software (V9.1) and comparisons of means were performed by Duncan method at 5% level and graphs were drawn with Excel.

One of the most important fields of research on legumes is the study of different environmental conditions affecting their quantitative (biological) yield and economic performance. Therefore, studying and obtaining the best growing environment conditions that can lead to crop production with the highest economic yield is one of the most important goals in research related to the cultivation of legumes. The results of the present study showed that seed yield and its components were affected by planting date and with delay in planting, the amount of studied traits was significantly reduced, so that this decrease was more in the planting date of 10 July because the planting date late exposure of guava plants to adverse conditions such as lower temperature, more humidity and less day length at the end of the growing season and causes a decrease in grain yield. Also, in this experiment, planting density levels on the studied traits were significant, and according to the results of the experiment, it can be stated that with increasing plant density, the distribution of sources such as light, nutrients, and moisture between plants was more favorable. It led to an increase in grain yield and biological yield per unit area, so that the highest grain yield and biological yield were obtained at the highest density (10 cm distance between plants per row). Therefore, planting at higher plant densities will probably be economically justified.

Based on this research, it can be concluded that planting guar in early June with a spacing of 10 cm between plants yields the highest productivity and optimal crop components.

Wheat (Triticum aestivum L.) is one of the most important and widely consumed crops in the world. Changing the density towards an optimal density can alter the ratio of soil evaporation to plant transpiration in such a way that water use efficiency improves. One of the branches of crop science and crop physiology is crop modeling. Quantifying the growth and development of a crop in response to environmental conditions in a system is called modeling, which helps the user make better decisions about crop management. One of the simple models of crops is the SSM model, which provides a simple simulation for estimating yield and phenological stages of various crops. Models have the ability to be used with physiological and ecological analysis based on research and empirical observations. The aim of this experiment is to evaluate the SSM-Wheat model under different density conditions and late-season drought stress. 

This experiment was conducted in the cropping year 2021-2022 at the Gorgan Agricultural Research Station. The factorial experiment included factors such as plant density at six levels (200, 250, 300, 350, 400, and 450 seeds per square meter) and genotype at six levels (N-93-9, Taktaz, Araz, Arman, Kalateh, and Tirgan). In this study, the SSM-Wheat model was used to simulate the growth and development of bread wheat. The meteorological data file, including precipitation, total sunshine hours, average relative humidity, average temperature, and average maximum temperature, was collected daily and defined in the model. The parameters related to soil characteristics were considered from the base data of the model. To evaluate the model, the coefficient of determination (R2), root mean square error (RMSE), normalized root mean square error (nRMSE), and the 1:1 line were used. 

The results of the model, using statistics based on the differences between simulated and observed values, including the coefficient of determination, root mean square error, normalized root mean square error, and the 1:1 line, showed that the model was able to accurately estimate the main phenological stages of days to emergence, days to flowering, and days to physiological maturity. The highest coefficient of determination was obtained for days to emergence, days to physiological maturity, and days to flowering, at 0.97, 0.77, and 0.71, respectively. The root mean square error (RMSE) for these traits was 2.8, 4.9, and 8.8, respectively. However, the traits "days to tillering" and "days to stem elongation" were estimated with lower accuracy, with a coefficient of determination and RMSE of 0.44 and 15.2 for days to tillering, and 0.17 and 6.8 for days to stem elongation, respectively. The results suggest that with an increase in maximum, minimum, and average temperature, and annual precipitation, the number of days required to reach each phenological stage decreases, which is logical. The maximum and minimum model-predicted values for grain yield were 410.4 and 547.6 grams per square meter, respectively, with a mean of 467.8 grams per square meter. The coefficient of determination and root mean square error for grain yield were 0.63 and 35.3, respectively. The distribution of simulated and observed points for the main phenological stages of days to emergence, days to flowering, and days to physiological maturity, as well as grain yield, fell within the 1:1 line range, indicating the model's high accuracy in predicting yield.

In general, the  results showed that the SSM-Wheat model was useful in simulating the main stages of wheat phenology and its performance under different conditions in different cultivars. The evaluation of the model using statistical indices of the coefficient of determination and root mean square error also confirmed the model's strength. Overall, the present study confirmed that SSM-Wheat is a simple, robust, and transparent model suitable for agricultural applications aimed at improving technical decision-making in crop management. In general, according to the results obtained for the SSM-Wheat model, it can be used for correct management in terms of the density and suitable cultivars of wheat cultivation in the field and its performance analysis in Gonbad Kavus weather conditions.

 Lentil is a plant that has been considered a valuable source of protein, and this issue, as well as the plant's ability to grow in poor soils and different environmental conditions, and its ability to coexist with growth-promoting and nitrogen-fixing bacteria, have led to this plant surviving as an agricultural species to this day and being cultivated in different parts of the world. In this regard, the present study was conducted to investigate the effect of biological and chemical fertilizers on the growth and yield of rainfed lentil (Lens culinaris).

 This experiment was conducted in a factorial arrangement based on a randomized complete block design with three replications in 2019. The first factor includes Nitragin biofertilizer (control and application of Nitragin), the second factor includes Barvar 2 biofertilizer (control and application of Barvar 2) and the third factor includes urea and triple superphosphate fertilizers (control and application of 35, 70 and 100 % of recommended chemical fertilizers).

Based on the observed results, the use of Nitragin and Barvar 2 biofertilizers increased the number of pods in the plant, and the combined use of these two biofertilizers increased the average of these traits more than their separate use. Using of 35% of the recommended chemical fertilizers at all levels of Nitragin and Barvar 2 had the highest grain and biological yield of lentils compared to other levels of chemical fertilizers (up to 57%). On the other hand, with the increasing use of chemical fertilizers, the grain and biological yield of lentils decreased. Finally, the results of this research determined that the combined application of biological fertilizers + 35% of the recommended chemical fertilizers is the most favorable treatment for biomass production and grain yield in lentils under rain-fed conditions.

The combined application of biofertilizers + 35% of recommended chemical fertilizers was the best nutritional treatment for lentil production under rainfed conditions. The use of biofertilizers Nitrazhin and Barvar 2, in addition to improving crop production, can significantly reduce the use of chemical fertilizers, which is in line with the goals of sustainable agriculture.

Nowadays, due to environmental considerations and water deficit, the use of humic acid along with phosphate-solubilizing bacteria (through various mechanisms including the production of siderophores and increased phosphorus uptake by plants) leads to a significant improvement in the physical, chemical, and biological properties of the soil, and increases the yield of crops. This research was done, in order to investigate the effect of drought stress and some fertilizer sources, including biofertilizer and humic acid, on some morphological and physiological characteristics of pinto beans under drought stress conditions. 

A factorial experiment was carried out based on randomized complete block design with two factors and three replications in the Aghblag region (38º 21' 31" N latitude, 47º 39' 53" E longitude). The first factor was irrigation in two levels of full irrigation (100% of field capacity; FC) and deficit irrigation (70% FC), and the second factor was different sources of fertilizers in 6 levels (chemical P(150 kg/ha), biological P (100 g/ha Phosphate Barvar2), 50% chemical P+biological P, chemical P+humic acid (10 l/ ha), biological P+humic acid, 50% chemical P+biological P+humic acid). 

According to the results, the seficit irrigation led to a decrease in plant height, stem diameter, number of leaves and leaf weight, while the fertilizer treatment, especially 50% chemical P+biological P+humic acid caused to increase in plant height, number of leaves, number of seeds and 100-seed weight. Seed protein increased in the treatments with chemical and biological fertilizers at the same time (by 19% with humic acid and 12% without humic acid) compared to the control. In general, with the combination of bio-fertilizer and humic acid, and using half of the chemical fertilizer, the highest seed yield (19.54 g/plant) was obtained in deficit irrigation. 

Therefore, to maintain the quality and yield of pinto bean at 70% FC, the half of chemical P+biological P+humic acid is recommended.

 To assess the impact of water scarcity and the use of biological and chemical fertilizers on the physiological traits and seed yield of the medicinal plant Lallemantia iberica Fischer & C.A. Meyer, a field experiment was conducted as a split-plot based on a randomized complete block design with three replicates.

 Different levels of irrigation (I1, I2, I3, and I4, representing irrigation after 70, 100, 130, and 160 mm of evaporation from a class A pan, respectively) were assigned to the main plots, while different fertilizer treatments (ammonium phosphate chemical fertilizer, Azoto Fertilizer 1 + Phosphate fertilizer 2, and vermicompost) were applied to the sub-plots.

Application of fertilizer treatments improved the physiological performance and reduced leaf temperature, leading to an increase in the growth and grain yield of dragon head. However, the extent of this increase depended on the type of fertilizer used. The application of both ammonium phosphate and biofertilizer at all irrigation levels led to an increase in the relative water content of leaves, leaf chlorophyll index, grain and biological yields. The impact of using ammonium phosphate fertilizer to enhance the physiological efficiency of plants under optimal and mild drought stress conditions was much obvious. However, in cases of severe water stress, the impact of biofertilizers on improving physiological efficiency and growth of plants was more pronounced.

This result demonstrates the positive impact of biofertilizers on enhancing the grain yield of dragon head plants under severe drought stress.

 Low temperatures is one of the factors limiting the growth and production of plants. To mitigate the destructive effects of cold stress, the use of salicylic acid can be beneficial.

 Factorial experiment was designed and conducted in a randomized complete block design with three replications in the research greenhouse of the Molecular Breeding Center at Faculty of Agriculture, University of Tabriz. Cold stress was applied at temperature degrees of 25, 8, and 4°C during the rosette stage, followed by salicylic acid spraying with concentrations of 1 and 2 mM, and water spraying a week before the cold stress application. Physiological traits were assessed after cold stress, while morphological traits were evaluated during the flowering stage.

The interaction of cold stress and salicylic acid significantly influenced plant height and number of leaves. Chlorophyll content index, number of branches and flowers, fresh weight of flowers, fresh and dry weight of the plant were affected by both cold stress and salicylic acid spraying. The dry weight of inflorescences was altered solely due to cold stress, while the seed yield of purple coneflower was affected by salicylic acid application. Chlorophyll index was measured one week after applying cold stress in the rosette stage and morphological traits in the flowering stage.

One effective method to alleviate the impact of chilling stress is the use of salicylic acid. Spraying salicylic acid, particularly at a 2 mM, enhanced the morphological, physiological, and grain yield characteristics of purple coneflower under cold stress.

This research was carried out to investigate the growth characteristics, yield components and yield of lentil (Lens culinaris Medik.) in intercropping with barley (Hordeum vulgare L.). 

The experiment was conducted in a complete block design with three replications and five treatments at research farm of Faculty of Agriculture, University of Tabriz at 2017. Cropping patterns based on replacement series. Barley was considered the main crop and lentil as a sub-crop. The cropping pattern included: monoculture of barely and lentil and intercropping of these two species with the ratio of 1:1, 3:1 and 5:3. During this experiment, morphological traits, yield components, and yield of lentil and barley were measured. 

Plant height, number of tillers, grains per spike, 1000 grains weight, biological yield in barley and plant height, branches per plant and pods per plant in lentil plants were affected by intercropping. In all cropping patterns, the Land equivalent ratio (1:1 1.96, 2:1 1.94, 5:3 1.74), which indicates the relative benefit of intercropping compared to monoculture. The mean of relative crowded coefficient in the different intercropping patterns showed that lentil with a value of 1.054 is a stronger competitor than barley. The relative value for all three patterns of intercropping (1:1 5.44, 2:1 5.38T 5:3 5.30), which indicates the economic benefit of intercropping compared to the monoculture of barley and lentil. 

According to the Land Equivalent Ratio and Total Relative Value, the 1:1 intercropping pattern was superior to other patterns and was more beneficial than other intercropping patterns. In this intercropping pattern, the lentil is a stronger competitor more than barley.

Weed competition is considered as the most important factor in yield reduction in direct-seeded rice. In integrated weed management, the use of high seed rate and cultivars, in addition to herbicide application, can help to reduce weed biomass in direct-seeded rice.

An experiment was conducted using a factorial design based on a randomized complete block design (RCBD) with three replications in 2021 in Shosh (Mianab district). The first factor included four seed rates (90, 120, 150, and 180 kg/ha), the second factor comprised three rice cultivars (Anberbo, Sherodi, and Zighami), and the third factor was herbicide treatment (application of Bispyribac-sodium herbicide and no herbicide application).

The study results indicated that increasing the seed rate led to a decrease in the total biomass of weeds. Under conditions of herbicide application and a seed rate of 180 kg/ha, the lowest weed biomass was recorded (56 g/m2). Conversely, with a seed rate of 90 kg/ha and no herbicide application, the highest biomass was observed (296 g/m2). The total biomass of weeds was also lower in Sherodi than in zighami and Anberbo. The grain yield results also indicated that the Sherodi cultivar had the highest grain yield (4351 kg/ha) under herbicide application, while the Anbarbo cultivar had the lowest grain yield (755 kg/ha) under no herbicide conditions. The grain yield of the Sherodi cultivar in the seed rate treatments of 150 and 180 kg/ha was the highest compared to the other cultivars, with yields of 3658 and 3440 kg/ha, respectively.

The findings of this study indicate that the integrated weed management program would benefit from using the Sherodi cultivar and seed rate of 150 kg/ha. It is suggested to achieve optimal yield and reduce weed biomass and reduce production costs in in Direct seeded rice.

Considering the important role of intercropping in achieving high yield and increasing the stability of agricultural systems, this research was conducted in order to determine the most suitable pattern of mixed cultivation of broad beans and green beans and to investigate its effect on the growth and performance of urban green beans. 

The field experiment was carried out as a randomized complete block design (RCBD) with six treatments and four replications at the research farm of the University of Tabriz, Faculty of Agriculture during 2015 growing season. Treatments were included sole planting of broad beans and Balangu and four patterns of intercropping systems including (100:20, 100:40, 100:60, and 100:80 rate of faba bean and Balangu. 

The results showed that the sole cultivation of Balanghu had the highest biological performance and seed yield, which was significantly different from other treatments related to mixed cropping patterns. In all intercropping treatments, the ratio of land equality and total relative value was greater than one, which indicates the superiority of mixed cropping over pure cropping. 

According to the obtained results, the mixed cultivation of 80% Balanghu + 100% faba beans with the highest LER (1.48) and RVT (1.45) is the best cultivation pattern due to the optimal use of available resources.

In current research, we goaled to assess the effect of application of 24-epibrassinolide, spermine, and silicon on the growth and yield of Paya maize cultivar (SC715) under water stress.

An experiment was performed as split plots in a randomized complete block design with four replications during 2021 season at the Agricultural Research Station of Tabriz Branch, Islamic Azad University. The main plot was three irrigation regimes of well-watered, water-stressed, and interrupted irrigated conditions at the flowering and the seed filling stages, and sub plot was eight spraying treatments of double distilled water, 24-epibrassinolide (0.1 mg L−1), spermine (25 mg L−1), and silicon (7 mg L−1), 24-epibrassinolide (0.1 mg L−1) + spermine (25 mg L−1), 24-epibrassinolide (0.1 mg L−1) + silicon (7 mg L−1), spermine (25 mg L−1) + silicon (7 mg L−1), and 24-epibrassinolide (0.1 mg L−1) + spermine (25 mg L−1) + silicon (7 mg L−1).

Water deficit stress reduced grain yield and its components. The dual and triad applications of 24-epibrassinolide (0.1 mg L−1), spermine (25 mg L−1), and silicon (7 mg L−1) significantly increased the plant height, ear height, grain yield, and its components. Among grain yield with 100-grain weights, No. grain per/ear, ear height and ear diameter were positive correlation. Principal component analysis of agro-morphological traits under various water deficit stresses indicated that applications of 24-epibrassinolide (0.1 mg L−1) + silicon (7 mg L−1) had more impacts on grain yield (12.08%), 100-grain weights (5.91%), No. grain per/ear (3.21%), ear height (7.30%).

Overall, the dual and triad applications enhanced the plant's drought tolerance and improved plant height (9.10%) and grain yield (10.23%) of maize under water deficit stress.

The objectives of this study were evaluation of radiation absorption and use efficiency, and finally grain yield of Safflower and Lathyrus in intercropping system under dryland farming. 

This experiment was conducted as a randomized complete block design with three replications and five treatments at Razi University during 2018-2019. The experimental treatments included monoculture of Safflower, monoculture of Lathyrus, and three intercropping arrangements (25:75, 50:50, and 75:25 ratios of Safflower and Lathyrus, respectively). 

The leaf area index and radiation absorption in intercropping compared to monoculture increased by 19.3% and 50.7%, respectively. The maximum crop growth rate and relative growth ration of safflower in the conditions of intercropping than monoculture improved by 10.2% and 16.8%, respectively. The total dry matter accumulation in intercropping was higher by 7% compared to monoculture. In the conditions of intercropping, the light use efficiency was improved compared to monoculture. the highest grain yield of safflower was observed in monoculture, which of course was not significantly different with the treatment of 25:75 ratio and 50:50 treatment of safflower and Lathyrus.  

Among the tested arrangements in this study, replacement intercropping of Safflower and Lathyrus with a ratio of 50:50 was superior in terms of growth indicators and yield, and was the most suitable arrangement of intercropping in the present experiment.

This study was conducted to evaluate the effect of biofertilizer application on the performance of barley common cultivars and new line in the Tabriz plain.

The experiment was conducted in the lands of Mamaghn County, East Azerbaijan Province. Experimental factors include: biofertilizer treatment and cultivars. Materials and Methods The interaction of cultivar and biofertilizer had a significant effect on barley grain yield. The highest seed yield was obtained with 5.9 tons per hectare in the new promising line and with Barvar 2 biofertilizer application.In the new promising line and Jolghe cultivar, with the use of Barvar 2 bifertilizer, an increase in grain yield was observed by 36.6% and 55.2%, respectively. Therefore, Barvar 2 fertilizer caused a significant increase in barley grain yield, especially the new promising line. The number of seeds and weight of 1000 seeds of new promising (yield components) showed a better response to the application of Barvar 2 biofertilizer. This new line had more leaf area index, chlorophyll content index and number of days to maturity compared to the other two cultivars, so it had more photosynthetic capacity to produce yield.

Using Barvar 2 biofertilizer in the new promised and improved lines increased the yield in the Tabriz plain, but it did not show an effect on the yield of the native cultivar, so the use of Barvar 2 biofertilizer for the new promising line can increase the yield of barley seeds.

The use of chemical fertilizers has created environmental problems. Therefore, the application of organic fertilizers can be considered a suitable solution to maintain soil fertility and increase fertilizer productivity.

To investigate the effect of organic and chemical fertilizers on the growth and field performance of faba bean (Vicia faba L.), an experiment was conducted with a randomized Complete Block Design (RCB) with three replications in 2021 at the research farm of the Faculty of Agriculture at Tabriz University. In this experiment, the treatments included four different sources of fertilizers, including the application of nitrogenous chemical fertilizer in the form of urea (50 kg ha-1), leaf mould (5 tons ha-1), farmyard manure (8 tons ha-1), vermicompost (5 tons ha-1) and control.

The highest chlorophyll index, plant height, number of pods per plant, 100-grain weight, grain yield, and biomass were obtained from urea fertilizer application treatment which was not significantly superior to other treatments. in terms of leaf area index and the number of leaves per plant, the application of farmyard manure was significantly superior to other treatments.

In order to produce more biomass and grain yield in faba bean, two treatments of urea and farmyard manure were identified as the most favorable nutritional treatments. The application of farmyard manure at a rate of 8 tons ha-1, in addition improving crop production, can replace the application of nitrogenous chemical fertilizers.

Investigating the stability and compatibility of a genotype in different environmental conditions in order to introduce it for planting in specific and known environmental conditions in multi-breeding programs is one of the basic needs and to achieve sustainable production in order to achieve sustainable self-sufficiency in It is necessary to produce strategic products, especially wheat.

Methods & Materials: 

In the present study, in order to investigate the stability and identify high-yielding and compatible genotypes, the yield of 32 lines of recombinant inbred from the crossing of two cultivars Roshan and Superhead in the form of a randomized complete block design with three replications in six The region (Tabriz, Ahar, Ardabil, Faghan, Shabestar and Urmia) were investigated for two years.

The results of the present study showed that there was a significant difference between the locations in terms of performance. Also, the difference between genotypes, as well as the interaction effect of genotype × year, genotype × location, and the interaction effect of genotype × year × location were significant, which indicated the difference between the performance of genotypes in different environments, which indicated the necessity of stability analysis.

According to the relative alignment of the results obtained from different methods, it can be stated that in this research, lines 10, 12, 31 and the Roshan variety were recognized as the most stable genotypes and line 51 as the most unstable line and It was recognized as special for unfavorable areas.