seed yield

In recent years, population growth on the one hand and climate change on the other, have increased the need for higher agricultural production. With the expansion of cultivated areas and increasing use of chemical fertilizers, the health of the environment and humans has been jeopardized. Consequently, recent studies have begun on the type of fertilizers used, the best fertilizer composition, and how to use them. Various studies have shown that organic fertilizer can ensure the sustainability of agricultural systems’ production, sometimes as a replacement and most often as a supplement to chemical fertilizers. In conditions where climate change and the salinization of agricultural lands have had noticeable effects on the production of various crops, the need for resilient plants becomes more apparent. Quinoa (Chenopodium quinoa Willd.) is a crop that is resistant to environmental stresses and is nutritionally very rich, to the extent that its amino acid composition is compared to that of mother’s milk. The current research aims to investigate the effects of foliar application with seaweed extract on the growth and performance of different quinoa genotypes.

This research was conducted in the summer and autumn of 2020 at the educational and research farm of the Faculty of Agriculture and Natural Resources of the Islamic Azad University, Karaj unit. The study was carried out as a split-plot experiment (5×3), based on a randomized complete block design with three replications. The main factor in this research was the fertilizer factor, which included 3 treatments: control: (without foliar application with seaweed extract), foliar application with seaweed extract at a concentration of 10 percent, and foliar application with seaweed extract at a concentration of 20 percent, placed in the main plot. The other factor was the genotype of the quinoa plant, which included 5 genotypes: Giza1, Titicaca, Rosada, Kancolla, and Q12, placed in the subplot. At different stages of plant growth, traits such as seed saponin content, thousand seed weight, seed yield, days to physiological maturity, days to flowering, dry plant weight, fresh plant weight, stem diameter, inflorescence length, and plant height were measured.

The foliar application of seaweed extract had a significant effect on various traits, with a **1% significance level** for days to flowering, days to physiological maturity, inflorescence length, thousand seed weight, and seed saponin content, and a **5% significance level** for plant height. The simple effect of genotype was significant at the 1% level for all traits except for thousand seed weight. The interaction effect of foliar application × genotype was significant at the 5% level for days to flowering. The application of seaweed extract reduced the number of days to flowering by **3.8 days**, days to maturity by **4.8 days**, plant height by **5%**, and inflorescence length by **10%**. However, it had no significant effect on seed yield, as well as the fresh and dry weight of aerial parts. The highest seed yield was related to genotype Q12 (2477 kg.ha-1) and the highest thousand seed weight was related to the Giza 1 variety (2.47 g). Plant height showed a significant negative correlation with seed yield and thousand seed weight.

The use of seaweed fertilizer in the nutrition of different quinoa genotypes showed varying effects. However, the impact of this fertilizer in reducing the growth period of quinoa, which is one of the most important issues facing quinoa cultivation in our country, is very significant. The differences between the genotypes studied in this research were quite evident, but it seems that special attention should be paid to the purpose of quinoa cultivation when selecting the superior genotype. If the goal of quinoa cultivation is forage production, the Rosada genotype is recommended, otherwise, the Q12 genotype is advised.

Pulses, including red beans, are a significant source of protein in human nutrition. Increasing yield per unit area is one of the most important factors for increasing crop production. Todays the increase in crop yield occurred by the excessive use of chemical fertilizers, including nitrogen fertilizers, which caused environmental hazards and consequently human health. Humic acid is a natural organic polymer compound that results from the decay of soil organic matter, peat, lignin, etc., which can be used to increase the product and its quality. One of the important benefits of using humic acid is the ability to chelate various nutrients such as potassium and magnesium and other elements to overcome the lack of nutrients. Humic acid also creates more space for water to penetrate through physical modification and improved soil granulation. Plant density is another important agronomic factor that manipulates micro- environment and affects growth, development and yield of plants. Within certain limits, increase of plant population density declines the growth and yield per plant but the reverse occurs for yield per unit area. The optimum plant density to attain highest yield may vary with the genotype and agronomic factor. Therefore, the purpose of this research was to investigate the effect of sulphurous humic acid and plant density on growth and yield of red beans (Phaseolus vulgaris L.) cultivars (Ofogh, Dadfar and Yaghoot).

The experiment was conducted as a factorial based on a randomized complete blocks design with three replications in the Bojnord city located in north east of Iran during the year 2022. The experimental factors were: plant density at three levels (18, 25, and 40 plants per m2, sulfur-containing humic acid (0 (no application humic acid) 4 and 6 liters per hectare) and red bean (Phaseolus vulgaris L.) cultivars (Ofogh, Dadfar and Yaghoot). Humic acid treatments were applied in the stages of two to four leaves, before flowering and after pod formation, depending on the level of treatment.

The results showed that Yaghoot cultivar had the highest plant height (71 cm) while, Dadfar had the lowest plant height (40 cm) at all three plant densities. Yaghoot cultivar also had the highest seed number per pod (4.1) and seed yield (4450 kg.ha-1) with application of 6L per hectare humic acid while, Dadfar cultivar had the lowest seed per pot (2) and seed yield (766 kg.hac-1). Results showed the best cultivar was Yaghoot and then Ofogh due to growth traits. The best plant density was 40 plants per m2 and among the humic acid levels, application of 6 lit per hectare had the best results. In the absence of fertilization, the amount of total chlorophyll of cultivars Yaghoot and Ofogh was not affected by the density, However, increasing of humic acid significantly increased the amount of total chlorophyll in all three cultivars and the highest amount of chlorophyll obtained at the highest level of humic acid and plant densities 18 and 25 for Yaghoot and the density of 18 plants for Dadfar.

In general, it was concluded that humic acid and plant density have been able to have a positive effect on most of the growth traits and photosynthetic pigments of red bean plant. The best cultivar was Yaghoot variety and then Ofogh variety and the best plant density was 40 plants per square meter. Among the humic acid levels, the consumption of 6 liters per hectare had the best result. By observing the appropriate level of density, variety and humic acid, we will be able to harvest the maximum yield of red bean (Phaseolus vulgaris L.) cultivars (Ofogh, Dadfar and Yaghoot) in Bojnord region.

Sunflower as an oilseed crop is usually cultivated in a wide range of climatic conditions ranging from temperate to tropical and semi-arid regions. Seed yield and quality of sunflower is affected by the water deficit caused by climate change. Fatty acid composition of sunflower seeds depend on many factors including; genotype and weather conditions of the growing season. Oleic and linoleic acids are the most important unsaturated fatty acids, contributing more than 80% of total fatty acid content in sunflower oil (Díaz et al., 2012). Water deficit affect seed yield and oil quality characteristics of sunflower (Totsky and Lyakh, 2015). The high percentage of linoleic acid increases the quality of sunflower oil. Therefore, the current study aimed to investigate the changes in the chemical composition of sunflower oil under deficit irrigation conditions.

The experiment was carried out as split plot arrangements in randomized complete block design with three replications in 2019-2020. The experimental site was located Safiabad Agricultural and Natural Resources Research and Education Center, Dezful, Iran. Main plots consisted of three irrigation regimes including; full irrigation (control), moderate and severe deficit irrigation (50, 70 and 90% of available soil moisture, respectively), and sub plots consisted of six sunflower cultivars including; Oscar, Felix, Shakira, Savana, Labad and Monaliza.

The results showed that deficit irrigation had significant effect on seed yield and related traits and fatty acid composition of sunflower oil in comparision with control. At 90% level of deficit irrigation thousand seed weight, seed oil content, seed yield, oil yield, and harvest index decreased by 36, 24, 37, 50 and 11%, respectively in comparison with control. The highest seed protein content was 19.7% at 70% level of deficit irrigation. Oscar cultivar in control and cv. Shakira in 90% level of deficit irrigation showed the highest and lowest seed yield (5340 and 2670 kg.ha-1, respectively). Oscar cultivar maintained the highest oil yield (1610 kg.ha-1) while cv. Shakira had the lowest oil yield (900 kg.ha-1). Labad cultivar maintained the highest seed yield in 70% and 90% levels of deficit irrigation (4410 and 4280 kg.ha-1, respectively) when compared with control. Fatty acids composition of oil in sunflower cultivars, using gas chromatography method, identified four fatty acid compounds,, which included two saturated fatty acids: palmitic acid (C16:0) and stearic acid (C18:0), a mono-unsaturated fatty acid including oleic acid (C18:1) and a poly-unsaturated fatty acid, linoleic acid (C18:2), with a total of 96.6, 93.2 and 91.7% in the control, 70 and 90% levels of deficit irrigation, respectively. The results showed that, in the 90% level of deficit irrigation, palmitic and stearic fatty acids increased (by 17.6 and 25%, respectively) and oleic and linoleic fatty acids decreased (by 11.1 and 6.69, respectively). Among the sunflower cultivars, the highest Stearic acid (4.41%), oleic acid (42.6%) and linoleic acid (50.0%) contents were measured in cv. Oscar, cv. Savana and cv. Felix, respectively.

There was significant reduction unsaturated: saturated fatty acids under deficit irrigation levles when compared to control. Felix and Labad sunflower cultivars showed the lowest reduction in seed yield under water deficit conditions and identified as the suitable cultivars for weather conditions of the experiment site.

Soybean is an important oilseed crop that its oil has nutritional and high economic value. Soybean (Glycine max L.) is an annual, self-pollinating, diploid plant and is one of the most important oilsed plants in the world (Smith and Huyser, 1987). Evaluating of promising genotypes of soybean under different environmental conditions is essential for identifying and selecting superior genotypes with high and stable seed yield potential. Genotype × environment interaction effects are important and challenge in selection and release of new cultivars. Various methods have been introduced to evaluate the interaction effect, each of which examines the nature of the interaction effect from a specific point of view. The nonparametric statistics are suitable method with high efficiency to investigate the interaction effect of genotype × environment and provides useful information about the studied genotypes (Mehmet et al., 2019). The purpose of this experiment was to investigate genotype × environment interaction effect using some nonparametric statistics to identify soybean genotypes with high seed yield and yield stability under different environmental conditions.  

Thirteen promising soybean lines along with two cultivars Saba and Amir were evaluated using randomized complete block design with three replications in four experimental field stations including Karaj, Sari, Gorgan and Moghan in 2020–2021 growing seasons. Some nonparametric statistics were used to study yield stability of soybean genotypes. Plots were harvested at maturity and then seed yield was recorded for each genotype.

The results of combined analysis of variance indicated that year, location and genotype effect and genotype × year, gewnotype × location and genotype × year × location interaction effects were significant on seed yield. Cluster analysis based on the nonparametric stability statistics showed that there were three main clusters. According to mean rank of nonparametric stability parameters, Hamilton × Karbin, Hamilton×TMS and Sari × Charleston promising lines, and Saba cultivar with the lowest mean rank had seed yield stability. Also, the results indicated that the nonparametric statistics NPi(4) and RS were associated with mean seed yield and the dynamic concept of yield stability. Therefore, these methods were suitable for selecting high yielding soybean genotypes with seed yield stability. Sari × Charleston, Hamilton × Karbin and Hamilton × TMS promising lines with wide adaptation were selected as superior lines, for being released as new commercial cultivars. The results of cluster analysis showed that Gorgan and Sari locations located in the same group, which indicated these locations had high predictability and repeatability.

The results of this study, Sari × Charleston, Hamilton × Karbin and Hamilton × TMS promising lines were identified superior lines with high seed yield and yield stability. Therefore, these lines can be considered for further studies and as cndidates for release as new commercial soybean cultivars.

 Sesame is one of the oldest oilseed crops grown in tropical and sub-tropical regions of the world. Sesame production is constrained by susceptibility to capsule shattering and excessive pre- and post-harvest seed loss. Recently, new indehiscent sesame cultivars have been developed and introduced with the characteristics of indehiscent capsules at the ripening stage and resistance to capsule and seed shattering (Langham, 2001). More research is required to convince the local farming communities to adopt and grow these new indehiscent sesame cultivars and benfit from their promising productivity. Sesame cultivars vary in their adaptability to different growing conditions.  This experiment was conducted to to determine optimum sowing date window and irrigation interval for new indehiscent sesame cultivars.

 To study the effects of sowing dates and irrigation intevals on morphological traits and seed yield of new indehiscent sesame cultivars, a field experiment was carried out as strip-split plot arrangements in randomized complete block design with four replications in Shahid Rajaei Agro-Industrial Company in Dezful, Iran, in 2021 and 2022. First main factor consisted of three sowing dates (June 5, June 20 and July 5) and second main factor included were three irrigation regimes (irrigation after 8, 13 and 18 days). Sub plots consisted of three indehiscent (Chamran, Mohajer, Barkat) and one dehiscent (Schewin) sesame cultivars.

The results showed that morphological traits and seed yield significantly decreased in both years by increasing irrigation intervals. Irrigation intervals caused significant decrease in seed yield in both years. In 2021, the seed yield of all cultivars significantly decreased under irrigation after 13 and 18 days by 12% and 34%, respectively, when compared with irrigation after 8 days. Delayed sowing dates caused significant decrease in seed yield. In 2022, the seed yield of all cultivars significantly decreased in delayed sowing dates June 20 and July 5 by 16% and 9%, respectively, when compared to June 5. In 2021, cv. Barkat had the highest seed and oil yield (1730 and 821 kg.ha-1, respectively) in irrigation after 8 days, and June 5 sowing date. In 2022, cv. Barkat had the highest seed and oil yield (1400 and 694 kg.ha-1, respectively) in irrigation after 8 days, and June 20 sowing date. Indehiscent cv. Barkat and cv. Mohajer had the lowest seed and oil yield reduction and showed greater seed yield stability under longer irrigation intevals conditions and delayed sowing date, when compared with cv. Schwin. In addition, these two cultivars can adapt to environmental changes through minimizing the seed yield losses due to seed-shattering resistance under different irrigation intervals and sowing dates.

Overall, the results of this experiment showed that sowing dates from June 5 to June 20 as the optimal sowing date window and irrigation intervals between 8 to 13 days can be recommended as a suitable crop management package to improve sustainable sesame production in warm and dry agro-climatic conditions of kuzestan province, Iran. In addition, high seed and oil yield in indehiscent cv. Barkat and cv. Mohajer facilitate mechanization of growing and harvesting of sesame as a summer crop. This is very important for food security as well as reducing water consumption by replacing it with other summer crops with higher water consumption, especially in Khuzestan conditions.

In recent years, silicon (Si) fertilizer has attracted attention of farmers and researchers as a potential mitigator for adverse effect of drought stress, offering means to enhance the resilience and functional traits of agricultural crops. Numerous studies have demonstrated the positive effects of Si application in alleviating water deficiency, though most have utilized foliar spraying methods. Soil application (fertilization) may serve as a suitable alternative for utilizing this beneficial element (Mostofa et al., 2021). This study aimed to determine the beneficial role of silicon as a plant biostimulant through fertilization, reducing water stress effect and improving the biochemical and physiological characteristicsas well as yield of quinoa.

To investigate the physiological, biochemical, and yield responses of quinoa to silicon fertilization under drought stress conditions, a field experiment was conducted during the 2023–2024 growing season at the Gandoman research farm of Payame Noor University, Chaharmahal and Bakhtiari province, Iran. The experiment was carried out as split-plot arrangements in randomized complete block design with three replications. The experimental treatments included irrigation at four levels in the main plots (40%, 60%, 80%, and 100% field capacity; defined as severe, moderate, mild and full irrigation, respectively) and silicon fertilizer at four levels (0, 1, 2, and 3 l.ha-1) in the sub-plots. Analysis of variance was performed using SAS software and the means were compared using LSD test at the 5% probability level. Graphs were made using Excel software.

The results indicated that reducing irrigation levels led to a decrease in photosynthetic pigments, antioxidant enzyme activities, and seed yield, while the application of silicon fertilizer mitigated the negative effects of the drought stress. Under the 40% field capacity irrigation level, the chla, chlb, carotenoids and total chlorophyll content in the treatment with 3 l.ha-1 of silicon were higher by 103%, 52%, 117%, and 99%, respectively, compared to the control (without silicon). Additionally, the activity levels of catalase, superoxide dismutase, and peroxidase enzymes in the 3 l.ha-1 of silicon level were higher by 264%, 65%, and 176%, respectively, than in the control under the 40% field capacity irrigation condition. Moreover, in the 40% field capacity irrigation level, compared to the 100% field capacity level, the increase in relative water content of leaves, seed yield, and biomass in the treatment with 3 l.ha-1 of silicon was higher by 51%, 40%, and 9%, respectively, than the control without silicon application. Based on the results, the treatment with 40% field capacity and 3 l.ha-1 of silicon (equivalent to 1250 kg.ha-1) prevented more effectively the reduction in seed yield. Under the 40% field capacity treatment (severe drought stress), the highest proline content (1.56 µmol.g-1 FW) and soluble carbohydrate content (20.7 mg.g-1 FW) were observed with the application of 3 l.ha-1 of silicon.

Overall, the results of this experiment demonstrated that drought stress led to reductions in photosynthetic pigments (chla, chlb, and carotenoids by 29%, 79%, and 38%, respectively, compared to the control), relative leaf water content (by 11% compared to the control), seed yield (by 49% compared to the control), and biomass (by 68% compared to the control). Under drought conditions, antioxidant enzyme activity, proline, and soluble carbohydrate content increased. Moreover, silicon fertilization mitigated the negative effects of drought stress. In conclusion, the results of this experiment showed that although drought stress led to reduction in physiological traits and seed yield, however, the application of silicon fertilizer significantly lessened the negative effects of drought stress.

Rapeseed is one of the major oilseed crops in the world. Increasing the seed yield and oil content of rapeseed is important for the production of rapeseed oil. The maximum seed yield is achieved in the optimal plant density. By reducing the plant density, it is partially compensated by the increase in number of secondary branches, biomass, while in high density, rapeseed plants are often prone to increase the incidence of disease (Rondanini et al., 2017). Determining the optimal density in crops depends on many factors such as plant type, soil fertility, available water and environmental conditions (Hiltbrunner et al., 2007). Rapeseed genotypes differ from each other in terms of the number of seeds per silique, the number of siliques per unit area, seed weight, and the number of secondary branches. The objective of the present experiment is to obtain this information and determine the appropriate plant density to obtain the highest seed yield and to identify the role of yield components in production and the relationships between them in new rapeseed cultivars.

The seedinging rate was determined based on the thousand seed weight of rapeseed cultivars using a fine seed machine and 1 kg., 2 kg, 4 kg and 8 kg.ha-1 seed were used. The rapeseed cultivars used were Architect, Rohan and Okapi. Factorial arrangement in randomized complete blocks design with three replications was used. The experiment was carried out in research farm of Fadak Agro-industry Company in Markazi province, Iran in 2021-22 and 2022-23 growing seasons. Phenological traits including days to flowering days to maturity, seed filling duration, seed filling fraction (the ratio of seed filling duration to the total growth duration from seeding to maturity) and plant height were measured and claculted. Seed yield and its component, including; number of secondary branches, thousand seed weight, number of silique.plant-1, number of seed.silique-1, were measured on randomly harvested 20 plants from each experimental plot and calculating the average. Seed yield was obtained with harvesting from 50 m2 in each plot. Seed oil content was measured using an NMR spectrometer (ISO 10565, 1998). Analysis of variance was performed using SAS 9.1 software, and relationship between traits was studied using Excell 2003 software. LSD test, at the 5% probability level, was used for means comparison.

Results showed that days to flowering varied from 198.7 to 205.8 days and had a decreasing trend with the increasing of seeding rate. The longest seed filling duration (30.5 days) was recorded for cv. Architect. The shortes seed filling duration (24.3 days) belonged to cv. Okapi at the seeding rate of 2 kg.ha-1. The 1000 seed weight of the cv. Architect, cv. Rohan and cv. Okapi were 5.22 g, 4.36 g and 3.39 g, respectively. With the increase of seeding rate, 1000 seed weight decreased from 4.56 g in 1 kg.ha-1 to 4.1 g in 8 kg.ha-1 seeding rates. The highest number of secondary branches in the cv. Architect was obtained at 1 and 2 kg.ha-1 seeding rates. The highest seed yield in cv. Architect (4731 kg.ha-1) was obtained in seeding rate of 4 kg.ha-1. The plant height decreased from 172 to 152.6 cm. with increasing seeding rate.The number of seed.silique-1 had a downward trend. With the increase in seeding rate, the seed oil content showed a significant upward trend. Seed yield significantly correlated with 1000 seed weight, number of secondary branches, plant height and seed oil content.

With the increase in seeding rate, seed oil content increased and this result can be related to the increase in the number of main stems with the increase seeding rate. Seed filling fraction (the ratio of seed filling duration to the total growth duration from seeding to maturity) and its positive and significant correlation with yield traits such as seed yield, 1000 seed weight and seed oil content showed that the long seed filling duration in addition to the early flowering is a desirable attributes. According to the results of this experiment, the optimum seeding rates for cv. Architect, cv. Rohan and cv. Okapi were 2, 4 and 8 kg.ha-1, respectively. In new rapeseed cultivars, cv. Architect and cv. Rohan, early flowering, longer seed filling duration and higher seed filling fraction may have important roles in achieving higher seed yield.

Basil with numerous medicinal characteristics is one of the most important plants of the mint family (Lamiaceae). Among the factors affecting the growth and development and the production of effective substances of medicinal and aromatic plants is water, which is more effective than other institutions for reduction. Research has shown that salicylic acid makes plants resistant to environmental stresses. Therefore, in order to investigate the effect of foliar spraying of salicylic acid on the quantitative and qualitative characteristics of basil plants under the influence of drought stress, an experiment was conducted in the form of split plots based on randomized complete block design in 3 replications in a private farm located in Mahdasht area of Karaj city in 1394-1395 and 1395-1396. Irrigation in 4 levels: I1: 100%, I2: 80%, I3: 60% and I4: 40%. The volume of water required in the main plots and salicylic acid in 5 levels: S1: No application (spraying solution with water net as control), S2: foliar spraying with a concentration of 50 μM, S3: 100 μM, S4: μM and S5: 200 μM were placed in the subplots. The results showed that the water deficit caused a decrease in the number of spikes per plant, the number of hazelnuts per plant, the number of seeds per hazelnut and the 100-seed weight, and the use of salicylic acid increased the number of spikes, the number of hazelnuts per plant and 100-seed weight. Under the influence of water deficit, biological and seed yield decreased and with increasing concentration of salicylic acid, biological and seed yield increased significantly. By increasing the concentration of salicylic acid in all humidity regimes, biological and seed yield also showed a significant increase. Also, the response of basil plant to salicylic acid under drought stress conditions was very significant compared to the conditions of supplying 100% of the plant's water needs (full irrigation). Finally, due to the adverse effect of drought stress on the growth and production of basil plant, it seems necessary to use salicylic acid to moderate drought stress.

To survey the effects of hand weeding and different densities of dragoon’s head on yield and yield components, a field experiment was conducted in the 2015-2016, at the research station of the faculty of agriculture, university of Tabriz. The experiment was a two-factor factorial in the basis of a randomized complete block design with three replications. The experimental factors included: different planting densities and weed control. The interaction of experimental factors on all studied traits were significant. Chenopodium album L., Amaranthus retroflexus L., and Asperugo procumbens L., were the predominant weeds of dragon’s head and that’s had the highest number and dry weight in density of eight plants per m2. In weeding conditions, increasing the plant density to 24 plants.m-2 reduced the number and dry weight of weeds and increased biological yield of dragon’s head (17.7%). Density of 16 plants per m2 in weed control condition, due to high grain and biological yields, number of capsules and seeds per plant and 1000-seeds weight (25.5 g), had a high harvest index. Among the studied traits, the number of seeds per plant showed the highest positive correlation with yield and harvest index. The Dragoon’s Head produced significant yields even when weeds were not controlled, especially at densities of 8 and 16 plants.m-2. Therefore, the density of 24 plant.m-2 and hand weeding can be considered as agronomic and managerial strategies in control of weeds and the density of 16 and 24 plants.m-2 as the optimal density to increasing the production of dragon’s head.

Weeds are one of the most important factors that reduce the growth and yield of plants, and weed control is one of the most important managements in farms. Various methods have been reported to control weeds. In order to control weeds, farmers have to use herbicides with destructive biological effects. The use of high concentrations of herbicides increases the resistance of various weeds and endangers the health of the environment. Weeds are controlled by manual, agronomic and chemical methods. Although weed management by methods such as weeding and the use of herbicides are effective in controlling weeds, these methods are uneconomical and cause environmental pollution. Therefore, it is necessary to use an alternate method to control weeds. According to the mentioned topics, the purpose of this study is to investigate the effect of integrated and agronomic management of weeds in spring safflower fields and the yield and yield components of safflower seeds (Carthamus tinctorius L.) in Kalibar city in East Azerbaijan.

In this study, the effect of integrated and agronomic management of weed control on the yield of safflower oil seed and medicinal plant was carried out in four replications based on a randomized complete block design. In this study, experimental treatments include the application of various weed control methods at 9 levels, including 1. Complete weeding of weeds during the entire safflower growth period (control), 2. Straw and stubble mulch of wheat (three tons/ha), 3. V. villosa (density of 50 plants per square meter), planting distance on the row 10 cm and between rows 20 cm, 4. V. ervilia cover plant (density of 50 plants per square meter), planting distance on the row 10 cm and between rows 20 cm, 5. Application of 100 % trifluralin herbicide (2.5 L/ha) before planting, 6. Application of 100% haloxyfop – R-Methyl herbicide (1 L/ha) in the five-leaf stage of weeds and narrow leaf plants, 7. Application of 50% trifluralin herbicide (1.25 L/ha) along with straw and stubble mulch before planting, 8. Application of 50% haloxyfop – R-Methyl herbicide (0.5 L/ha) along with straw and stubble mulch in the five-leaf stage of weeds of narrow leaf plants, 9. Lack of control of weeds. Weeds were present throughout the growth period (uncontrollable evidence). Analysis of the variance of the measured traits was done in the form of randomized complete block design with four replications. Before analysis of variance, establishing the assumptions of normality of distribution of deviations, uniformity of within-treatment variances and summability of block and treatment effects were checked and confirmed by Tukey 's test. Comparison of the average traits was done using Duncan's test at the five percent probability level. SPSS and Excel software were used for statistical analyzes and graphs.

According to the findings of this study, the highest yield of safflower seed was achieved in the complete weeding of weeds, which was not significantly different from trifluralin herbicide + straw mulch and wheat stubble. Trifluralin herbicide treatments + straw mulch and wheat stubble and complete weeding caused an increase of 119% and 128.6% respectively in safflower seed yield. The application of mulch alone increased the yield of safflower seed by 62.5%, but the cover plant of safflower, the cover plant of cowpea and the herbicide haloxyfop – R-Methyl had no significant effect on the yield of safflower seed. The weed control treatments increased the grain yield by increasing the number of seeds produced, but the 1000-seed weight was not affected by the weed control treatments.

The highest increase in the number of seeds per plant (34.3%), the number of seeds per plant (97.8%) and the yield of seeds (119.%) was obtained in the treatment of trifluralin herbicide + straw and stubble mulch of wheat. These results show that trifluralin herbicide + straw and stubble mulch of wheat were the most effective among the non-mechanical weed control treatments of safflower field. The results showed that the seed yield with 128.6% and the number of seeds per plant with 110% changes showed the greatest response to weed control treatments. The results showed that using straw and stubble mulch can reduce the use of chemical pesticides in weed control. According to the results of weed control, it has had a significant effect on reducing the density and biomass of weeds.

Oilseeds are among the most important sources of energy all over the world. Soybean (Glycine max L.) is an important crop and its oil has nutritional and high economic value. As an annual, self-pollinating, diploid plant belonging to the Leguminosae pea family, soybean falls into the most important oil plants in the world, containing 18-22% oil and 40-50% protein, depending on the genotype and environmental factors. Soybean has been the food of Asian people, especially China, for centuries, and Chinese people consume it along with rice as their main food. The United States of America is the largest producer of soybeans and produces almost two-thirds of the world's crop. Improving seed yield is always a major goal in soybean breeding programs. The economic performance of soybeans can be increased by using new and high-yield varieties. It is essential to evaluate promising advanced soybean genotypes under different environmental conditions for identifying and selecting superior genotypes with high and stable yield potential. Genotype × environment interaction effects are important limiting factors in the introduction of new cultivars. The genotype × environment interaction is a major challenge in the study of quantitative characters because it reduces yield stability in different environments and complicates the interpretation of genetic experiments, making predictions difficult. Therefore, it is crucial to know the type and nature of the interaction effect and reach the verities that have the least role in creating interaction effects. Various methods have been introduced to evaluate the interaction effect, each of which examines the nature of the interaction effect from a specific point of view. The GGE-biplot graphic method is a technique with suitable efficiency to investigate the genotype × environment interaction effect and provides good information about the studied genotypes and environments graphically. This study aimed to investigate the genotype × environment interaction effect using the GGE-biplot graphic method to evaluate genotypes, environments, and relationships between genotypes and environments. Finally, this research seeks to identify stable soybean genotypes with high grain yields under different environmental conditions.

In total, 27 new soybean lines along with Saba and Amir cultivars were evaluated under different environmental conditions in a randomized complete block design with three replications in four experimental field stations (Karaj, Gorgan, Sari, and Moghan) during the 2022 cropping season. The plots consisted of four rows of 5 m in length with 50 cm spacing between the rows. The GGE biplot statistical method (the genotype effect + genotype × environment interaction) was used to study the stability of genotypes in the studied environments. Plants were harvested at maturity, and then the seed yield was recorded for each genotype at each test environment.

The results of the combined analysis of variance indicated that the effects of environments (E), genotypes (G), and genotype × environment (G×E) interaction were significant for seed yield, suggesting that the genotypes responded differently in the studied environmental conditions, making the stability analysis possible. The results of the genotype × environment interaction analysis using the GGE-biplot method indicated that the two first and second principal components of the GGE-biplot explained 84.8% of the total seed yield variation, indicating the high validity of the biplot in explaining the variations of genotypes and the genotype × environment interaction (G + GE). This study identified two mega-environments, the first of which included Gorgan and Mughan, and the second mega-environment included Sari and Karaj. Based on the polygon view of the biplot, the genotype G1 in Sari and Karaj environments, and the genotypes G21 and G22 in Gorgan and Moghan environments were superior genotypes with high specific adaptation. The results of the average environment coordinate biplot showed that the G1, G22, G5, and G9 genotypes produced the highest seed yield, respectively. On the other hand, the G28, G25, G16, and G19 genotypes produced the lowest seed yield, respectively. Based on the hypothetical ideal genotype biplot, the G22, G5, G16, G12, G14, and G9 genotypes were better than the other genotypes for seed yield and stability and showed high general adaptation to all environments. Moreover, the Karaj and Moghan environments were the nearest environments to the ideal environment with the highest discriminating ability and representativeness. Therefore, the Karaj and Moghan environments can be used as a suitable test location for selecting superior soybean genotypes.

Based on the results of this study, the G22, G5, G16, G12, G14, and G9 genotypes are superior for seed yield and stability in this study. Therefore, these hybrids can be used for further testing, including adaptation tests. Besides, the results show that the Karaj and Moghan environments can be used as suitable test locations for selecting superior soybean genotypes. Generally, our results demonstrate the efficiency of the GGE-biplot graphical method to investigate the G × E interaction effect and provide good information about the studied genotypes and environments.

The purpose of this experiment was to evaluate the flora, damage and determine the critical period of weed control in Camelina plant.

This experiment was conducted in the crop year 1402-1401 in the form of a randomized complete block design, which included two groups in three experimental treatments; The first group includes weed interference treatments from the beginning of the growing season to the end of the 2-leaf, 4-leaf, 6-leaf, 8-leaf growth stages, the beginning of flowering, the beginning of fruiting, and then manual weeding of weeds, and the second group of non-interference treatments. Weeds included manual weeding of grasses from the beginning of the growing season to the end of the 2-leaf, 4-leaf, 6-leaf, 8-leaf growth stages, the beginning of flowering, the beginning of fruiting, and then no weed control). The results of this research showed that by reducing the leaf area index of camellia plant and consequently reducing the production of dry matter produced due to the competition of weeds, the yield and performance components were also affected. The highest number of pods per plant was obtained in weed interference treatments up to 2 and 4 leaves, and the least number of pods per plant was obtained in the stages of interference until the beginning of flowering, mid-podding and harvest. The highest number of seeds per pod and the weight of 1000 seeds were obtained in the interference treatment until two leaves of Camelina plant and the least in the interference treatments until the beginning of fruiting. Also, the results showed that increasing the length of the weed-free period (weed control period) increased grain yield and biological yield.

Optimum sowing date is very important and it is one of the important factors for maximizing yield production. Although chemical fertilizers provide plant nutrients faster, to increase the quality of products, especially medicinal and aromatic plants, the use of organic fertilizers is better. The purpose of this research was to Investigate the effect of planting date and different amounts of farmyard manure on nitrogen crop efficiency, nitrogen absorption efficiency, nitrogen utilization physiological efficiency, nitrogen harvesting index and seed yield The experiment was carried out in the form of split plots based on a completely randomized block design in three replications in the research farm Campus of Agriculture and Natural Resources, Razi University in 2021. Experimental treatments included farmyard manure as the main factor (0, 10, 20, and 30 ton ha-1) and sowing date (April 4, April 24, and May 14) as a sub factor. The results showed that sowing date, farmyard manure and their interaction had a significant effect on all evaluated traits. The increase in farmyard manure decreased nitrogen capture efficiency (NCE), nitrogen physiological efficiency (NUE), nitrogen agronomic efficiency (ANUE) and nitrogen harvesting index (NHI). By increasing farmyard manure application from 0 to 30 ton ha-1, NCE, ANUE, NUE and NHI decreased 50.23, 54.55, 73.16 and 61.65, respectively. Based on the results, the sowing date of April 4th, accompanied by the application of 30 ton ha-1 of farmyard manure, was the best treatment in this experiment.

In order to investigate the effect of biofertilizers application on agronomic characteristics and yield of corn cultivars this study was conductedin Borujerd region of  Lorestan Province in 2023. This experiment was done factorially based on a completely randomized block design with three replications. The experimental factors included three fertilizer application levels (control, humax, nitroxin and humax + nitroxin) and corn cultivars (KSC400, KSC201 and KSC410). The results showed that the effect of fertilizer and cultivars on plant height, ear height from the soil surface, leaf length, stem diameter, ear length, number of seed rows in an ear, number of seeds in an ear row, number of seeds in an ear, 100 grain weight, seed yield, dry matter yield and harvest index were significant. The interaction effect of treatments wassignificant on the plant height, ear height from the soil surface, number of seeds in a row of ears, number of seeds in an ear, weight of , 100 grain weight, seed yield and dry matter yield. KSC410 was the better cultivar and the highest growth rate and grain yield components belonged to this cultivar. The integrated application of humax and nitroxin fertilizer had the highest efficiency in increasing the growth and  yield.  KSC410 cultivar with the integrated application of nitroxin and humax had themaximum values of plant height (231 cm), cob height from the soil surface (111 cm), and seed numbers per cob (601). The highest hundred grain weight, grain yield and biological yieldobtained from the mentioned treatments. these values were 34 g, 9216 and 30256 kg ha-1, respectively. Based on the results of this study, in order to achieve the highest corn yield in Borujerd region of  Lorestan Province, KSC410 can be used with the integrated application of nitroxin and humax fertilizer.

Studies have shown that the use of some compounds whose importance is often neglected by researchers and farmers can have a significant effect on the growth and yield of plants and increase the amount of essential oil production in medicinal plants. Therefore, this research was conducted with the aim of investigating the effects of Selenium and Silicon foliar application and zeolite soil application on the yield and components of seed yield and the percentage and yield essential oil of Fennel (Foeniculum vulgare Miller.).

 This experiment was carried out in the form of a split split plot (twice chopped) based on a randomized complete block design with three replications at the Khosrowshahr Agricultural and Natural Resources Research Center in the 2019 crop year. The first factor included foliar spraying of calcium (zero and 4 gr/L) and the second factor included foliar spraying of selenium (zero and 4 gr/L) in the main and secondary plots, respectively, and the third factor was the application of zeolite (zero, 5 and 10 tons/ha) were placed in sub-sub-plots. In the full ripening stage, plants were harvested from one square meter of each plot and the dry matter of the whole plant, number of seeds per umbels, number of seeds per plant, 1000-seed weight, seed yield, percentage and essential oil yield were measured.

The results showed that the seed yield increased with the application of these treatments, which resulted in an increase in the yield of fennel essential oil per unit area. Based on the results of the average data comparison, the use of all three compounds of zeolite, selenium and silicon caused a significant increase in the yield of fennel essential oil and increased this attribute by 24, 23.1, and 22.5 percent, respectively. Silicon and selenium increased the yield of essential oil by increasing the seed yield. In addition, zeolite had a positive effect on seed yield through the number of seeds, while silicon and selenium increased both characteristics of yield components, including 1000-seed weight and number of seeds.

Finally, the yield of fennel essential oil was affected by the use of zeolite, selenium and silicon. In most cases, all three compounds were effective on the evaluated traits, and therefore, it can be concluded that these three compounds were effective in increasing the yield and yield components of fennel with different mechanisms. Therefore, it can be concluded that these three compounds work through different mechanisms to enhance the yield and quality of fennel essential oil, positioning them as effective tools in sustainable agriculture and the optimization of medicinal plant production.

One method for selecting high-yielding cultivars is selection based on physiological traits. Investigating the seed growth and filling process and its effect on seed weight is among the basic research in breeding programs. The speed and period of grain filling are important traits affecting grain yield in wheat, which are affected by environmental conditions. Selection based on traits such as seed filling speed and period can be a good physiological criterion for cultivar evaluation. This research aimed to evaluate the yield, speed, and period of grain-filling in bread wheat genotypes under end-of-the-season drought stress conditions and to identify superior genotypes.

In this research, 18 bread wheat genotypes along with two control varieties were obtained from the Ardabil Agricultural Research Station and Natural Resources. An experiment was conducted in a completely randomized block design with three replicates in two conditions of full irrigation and drought stress at the end of the season in the Ardabil Agricultural Research Station. In the field, the genotypes were cultivated inside each plot of 4 × 3 m with a distance of 20 cm between lines and a density of 400 seeds/m2. Genotypes were cultivated in the research station in the fall of 2019. In stress conditions, irrigation was not applied from flowering to seed maturity, while irrigation was carried out three times (early flowering, mid-seed setting, and late seed setting) from flowering to physiological maturity in stress-free conditions. Grain yield traits, grain filling speed, maximum grain dry weight, length of grain filling period, and effective grain filling period were measured in this study.

The results of variance analysis for the evaluated traits showed a significant difference between environments and between genotypes in all evaluated traits. The genotype × environment interaction effect was also significant for all mentioned traits. The significance of the difference between genotypes indicates genetic diversity between the studied cultivars. Moreover, the significance of the interaction effect showed that the studied genotypes did not behave the same in two environments without and with stress. The seed-filling rate of all genotypes decreased under drought-stress conditions. The average seed-filling rates were 1.20 and 1.37 mg per day in the stressed and non-stressed environments, respectively. The length of the grain-filling period and the effective grain-filling period decreased with increasing the grain-filling speed. The length of the seed-filling period in the stressed environment was shorter by 2.31 days on average. The effective length and period of seed filling were directly related to the seed dry weight. The average yield of genotypes under stress conditions (594 g/m2) declined significantly compared to the non-stress environment (768 g/m2). On average, the length of the seed-filling period in the stressed environment (34.90 days) was shorter than that in the non-stressed environment (37.21 days). The greatest decrease in the effective length of seed filling was observed in genotype 5 (5.30 days). The longest seed-filling periods were recorded for genotypes 14 (41 days) and 12 (40.44 days) in stress conditions, and genotype No. 13 (43.21 days) in non-stress conditions. Genotype 3 showed the shortest seed-filling period in both stress and non-stress conditions. The correlation coefficients showed a negative and significant correlation between the speed and the effective period of seed filling in the stress (r = -0.358**) and non-stress (r = -0.404**) environments. A cluster analysis of the genotypes grouped them into three and four clusters in the stress and non-stress environments, respectively. The heat map of the distribution of genotypes grouped them into three clusters based on the traits studied in the stressful environment. Genotypes 19, 18, 3, 10, and 1 were in the first group, with a short effective seed-filling period and a higher filling speed, which was desirable due to the relatively better yield. The second group included genotypes 7, 4, 9, 17, 6, 5, and 8, with lower seed yields and short effective seed-filling periods. Finally, genotypes 13, 12, 2, 14, 11, 20, 15, and 16 were included in the third group, with lower values of speed and maximum seed weight and higher values  of effective seed-filling periods. Members of this group showed relatively good yields, which could be attributed to the length and long effective seed-filling period. Considering the importance of grain-filling processes to reach the desired grain weight, selection to increase the grain-filling speed and the effective long filling period can lead to more yields in stressful conditions.

A significant variation in traits was observed among the studied genotypes, indicating the existence of appropriate genetic diversity in the studied plant material. End-of-season drought stress negatively affected the final grain weight by reducing the speed and period of grain filling, eventually lowering the yield. In such conditions, selecting genotypes with higher seed-filling speeds can lead to the selection of drought-tolerant genotypes. However, the speed of seed filling and the effective period of seed filling alone cannot guarantee a high yield, and other factors affecting yield should be considered in the selection of drought-tolerant genotypes.

Agriculture has always struggled with weeds throughout history and has achieved considerable progress in this regard. Humans started fighting weeds by hand and also by using animals, and now they continue this way mainly through mechanical and chemical methods. Weeds not only reduce the production of crops and increase the cost of agricultural products, but also cause problems to the public in various ways. Weeds compete with agricultural plants to receive nutrients, soil moisture and sunlight and lead to a decrease in the yield of agricultural plants. Manual weed control is time-consuming and expensive. Chemical weed control method is one of the important methods used in weed control. but these herbicides can have a serious impact on the environment. Non-chemical weed control such as the use of mulch and cover plants are the preferred methods for weed control. Considering the importance of weed control and the existence of few studies on the comparison of different L. iberica weed control methods, this experiment was conducted with the aim of comparing the effect of different weed control methods in L. iberica fields. The field experiment was carried out in the research farm of the Faculty of Agriculture of Tabriz University, located eight kilometers east of Tabriz. According to meteorological maps, the climate of this region is classified as steppe and semi-arid. The height of this area is 1360 meters above sea level, and the latitude and longitude are 17°46′ east and 5°38′ north, respectively. The experimental design used in this study was a split plot based on a randomized complete block design with three replications. In this experiment, two levels of herbicides (use and non-use of Treflan herbicide) were placed in the main plots and the pure cultivation treatments of infected and weed-free L. iberica and cultivation along with the use of mulch and cover plants were placed in the secondary plots. In the process of the plants after removing the marginal effect, the number of 10 plants from each plot was taken as a sample and the number of flower cycles in the main and secondary branches, the number of nodes of the main and secondary branches and the number of leaves of the main branch were determined and then their average was determined. Calculated and recorded. Also, harvest index and soil moisture after harvest were calculated.Weed contamination caused a decrease in the biological yield per unit area and the yield index of the Dragon’s head plant. Based on the results of the variance analysis table of traits related to the medicinal plant L. iberica, the simple effect of treflan herbicide on grain yield per unit area at the level of one percent probability and on the biological yield per unit area at the probability level of five percent and in the rest of the traits was insignificant. Also, the simple effect of weed management methods, as well as the mutual effect of Treflan herbicide and management methods on all measured traits was significant at the 1% probability level. By using mulch of straw and stubble as well as the cover plant Vicia villosa, the number of seeds in the capsule of L. iberica plants infected with weed increased significantly compared to the pure cultivation of this plant. Weed contamination reduced the number of seeds per plant and the use of straw and stubble mulch and cover plants increased the number of seeds per plant infected with weeds. With weed infestation, the weight of 1,000 seeds decreased, and the weight of 1,000 seeds increased with the use of Treflan herbicide and weed management methods. Seed yield per unit area in plants grown under weed interference conditions was significantly lower than weed-free treatments. Conclusions Weed infestation decreased the number of seeds per capsule, number of seeds per plant, seed yield per plant, weight of 1000 seeds, biological yield per plant and biological yield per plant area of L. iberica. Among the management methods applied in this experiment, the use of straw and stubble mulch and the treatment of the cover plant V. villosa along with the use of the herbicide Treflan had the greatest effect in increasing the yield and yield components of L. iberica.