harvest index

To investigate the potential for increasing the yield and quality of sweet sorghum (Sorghum bicolor (L.) Moench) by utilizing nanochelates in low irrigation conditions.

This experiment was conducted using split plots with three repetitions over two years, 2016-2017 and 2017-2018. The irrigation regime was compared at two levels: 90% (normal irrigation) and 50% (deficient irrigation) of the field capacity in the main plots. Additionally, foliar spraying of Khazra iron nano chelate fertilizer was applied at five levels of 0, 2, 4, 6 and 8 per thousand in the secondary plots. At the end, the characteristics of leaf relative water content, photosynthesis and transpiration rate, mesophyll conductance, the amount of photosynthetic pigments chlorophyll a and b, carotenoids, biological yield, seed yield and harvest index were evaluated. Photosynthesis rate, transpiration rate and mesophyll conductance were measured using a photosynthesizer (model CI-304 made in America) during the flowering stage on the youngest fully opened leaf between 10 am and 2 pm. Chlorophyll a, b and carotenoid levels were measured through randomly sampling mature leaves and extracting them using acetone.

The interaction between irrigation and iron nano-fertilizer (INF) had a significant impact on transpiration rate, mesophilic conductance, chlorophyll b, carotenoid content, and grain yield at a 1% significance level, and on biological yield at a 5% significance level. The application of iron nano chelate helped alleviate the negative effects of water deficit on grain yield traits, biological performance, chlorophyll b and carotenoid pigments, transpiration rate and mesophilic conductance. The combined effects of irrigation and fertilizer on mesophilic conductivity showed that there was no significant difference between irrigation regimes at 50% and 90% of field capacity for any levels of iron fertilizer except at the 4 per thousand level. Similarly, when comparing  the interactive effects of water and fertilizer on transpiration rate and chlorophyll b characteristics of the plant, similar results were observed with mesophilic guidance. The use of 4 parts per thousand iron nano-fertilizer increased biological yield under 50% field capacity irrigation compared to the same irrigation without iron nano-fertilizer. Furthermore, grain yield in the 50% field capacity irrigation was 17% higher with iron nano-fertilizer application compared to without it.

The foliar application of nano-chelated iron fertilizer, combined with irrigation at 50% of field capacity and a concentration of 4 per thousand of this fertilizer, is considered the most effective treatment for sweet sorghum in regions with deficiently irrigated conditions.

Waterlogging stress is a common agricultural problem in many regions across the globe. Crop productivity is threatened primarily by waterlogging in rainfed areas. Plant growth and crop production is constrained severely by waterlogging in many regions around the world. Waterlogging significantly reduces the grain yield. Moreover, oil yield reduces mainly due to a significant decrese in grain yield under waterlogging stress condition. Waterlogging at different growth stages has different effects on crop growth and yield. In most crop plants, it was shown the different adverse effects of waterlogging on yield determination at the vegetative and reproductive stages. However, the effects of waterlogging stress at different growth stages on safflower under field conditions is not yet known.

In the current study, in order to study of the influence of waterlogging stress at different growth stages on the morphological traits and grain yield of safflower under field conditions, a field experiment was carried out during 2020-2021 growing season in a split plot arrangement in randomized complete blocks design using three replicates per treatment. The study site was located at the research farm of Shahid Chamran University of Ahvaz, Iran. The plants were grown in the filed to ensure the environmental conditions found in flooded soils. Three waterlogging treatments were applied to plants as main plots: Well-drained controls watered weekly, mild stress (waterlogged for 24 h) and severe stress (waterlogged for 48 h). Waterlogging treatments implemented at the vegetative and reproductive stages as sub plots. After the waterlogging period, waterlogging treatments were watered with sufficient water (80% field capacity) until the end of the experiment.

The waterlogging treatments at vegetative and reproductive stages significantly decreased biological yield, grain yield, number of sub-branches, branche number, capitulum number per plant, grain number per capitulum, grain number per plant, 1000-grain weight and oil yield. There was no significant difference between growth stages in terms of all traits except for capitulum number per plant and the number of sub-branches. The mild and severe waterlogging stress at both growth stages was led to a significant reduction in grain yield by 34 and 39%, respectively, compared to control. The waterlogging treatments at different growth stages differently reduced the grain yield. The maximum decrease was found when waterlogging occurred for 48 h at the reproductive stage. The reduction in the number of sub-branches was associated with capitulum number per plant and grain number per plant. Under waterlogged conditions, the reduction in capitulum number per plant was mainly due to the decrease in the number of sub-branches.

These findings indicate that safflower is more sensitive to waterlogging at the reproductive stage. The effect of waterlogging stress on grain and oil yield varied between two growth stages and waterlogging durations. Under waterlogging condition, grain yield loss occurred mainly due to a decrease in the number of sub-branches, branch number, capitulum number per plant, grain number per head and grain number per plant, which led to a significant decrease in grain yield and ultimately reducing the oil

Using practical, safe and cheap methods to produce healthy food and protect the environment is a necessity, and one of these solutions to solve the problem of chemical fertilizers consumption is to use the principles of sustainable agriculture. Biological and organic fertilizers play an effective role in increasing the yield of agricultural products by increasing the water holding capacity and also improving the biological properties of the soil and having essential nutrients. Biological and organic fertilizers are used as growth promoters with more efficiency than chemical fertilizers. Foliar spraying of nutrients can help in compensating the lack of nutrients absorbed through the roots or supplying the plant's need for these elements in the leaves. Also, by feeding through the leaves and foliar spraying, it can provide food to the plant in the shortest possible time, and this method is a suitable way to reduce the use of chemical fertilizers and reduce their environmental risks. In order to evaluate the effect of three types of organic fertilizers on the yield, yield components and seed oil percentage of Black Cumin (Nigella sativa L.) and the amount of some elements in soil, an experiment has been carried out at the research farm of the College of Aburaihan, University of Tehran, in the agricultural year 2019-2020.

This experiment has been conducted as a factorial based on a randomized complete block design in three replications. The combination of factorial levels were in the form of nutrient fertilizer 1 factor in two levels of 300 kg.ha-1 and no application of nutrient fertilizer 1, nutrient fertilizer 2 factor in 2 levels of 2 lit.ha-1 and no application (spraying with distilled water) and nutrient fertilizer 3 factor in three levels of foliar application at the rate of one and two liters per hectare and no application.

The results showed that the use of nutrient fertilizer 1 alone resulted in higher plant dry weight. The use of organic fertilizers compared to the control treatment increased the capsule weight, seed yield, harvest index and seed oil percentage, and the lowest values of these traits belonged to the control treatment. The simultaneous application of nutrient fertilizer 1 and nutrient fertilizer 3 was effective in stimulating nitrogen absorption by the plant, and as a result, reduced the amount of soil nitrogen.

In general, it can be concluded that the application of organic fertilizers, especially the nutrient fertilizer 1, has had a favorable effect on the yield and growth characteristics of the plant.

The significant importance of identifying, studying, evaluating, and conserving native ecotypes of medicinal plants as part of human heritage, along with the collection of cultivated medicinal plants and the ecological assessment of their native ecotypes, makes the introduction of their compatible ecotypes to farmers a necessity. The purpose of this research was to investigate the ecotypes of common Dragon's head in the region in terms of performance and performance components.

In order to evaluate the features related to the yield and yield components of 49 ecotypes of Dragon's head collected from different regions of the country, a research in the form of a randomized complete block design with 3 replications. The most important traits measured were the number of capsules in the main and secondary stems, the number of seeds per flower cycle in the main and secondary stems, the number of seeds per plant, the weight of 1000 seeds, biological yield, dry herbage yield and seed yield per unit area and seed harvest index.

Based on the results of the mean comparison, the ecotypes from Alvar Bostanabad village with an average of 116.3 g/m2, Tabriz 4 with an average of 107.7 g/m2, and the local ecotype Kolavank 14 with an average of 101.7 g/m2 had the highest grain yield per unit area. These results indicate the high potential of these ecotypes for grain production and their adaptability to the climatic and soil conditions of the region. The high performance of these ecotypes may be attributed to their genetic characteristics, adaptability to environmental conditions, and appropriate agricultural management. Additionally, the ecotype from Param 2 in Haris and the Zanjan ecotype achieved the highest thousand-grain weights, with averages of 418.5 g and 385.5 g, respectively, among the studied ecotypes. This characteristic not only reflects the high quality of the grains produced by these ecotypes but may also positively impact the final quality of the products and their marketability. Thousand-grain weight is an important indicator in assessing grain quality and can assist farmers in selecting the best ecotypes for cultivation.

Based on the results of this research, the ecotypes from Alvar Bostanabad village, Tabriz 4, and Kolvanagh14 have been identified as the best options in terms of grain yield. These ecotypes, by providing the highest grain yield per unit area, demonstrate their high adaptability to the environmental and climatic conditions of the Tabriz region. Additionally, the ecotypes Tabriz 3, Leilab Varzeqan village, and Alvar Bostanabad village exhibited the highest performance in terms of dry biomass yield and yield components. These results emphasize that these ecotypes can be recognized not only for grain production but also as the most suitable and compatible options for cultivation in the city of Tabriz. Identifying these ecotypes can assist farmers in selecting the best varieties for cultivation, leading to improved agricultural performance and increased productivity in the region. Overall, this research can serve as a solid foundation for future studies and agricultural planning aimed at enhancing agricultural production in the Tabriz area.

In the last 50 years, global rice yield has continuously increased partly because of the increase in fertilizer use especially those containing the nitrogen (N) nutrient. Unfortunately, a large proportion of N is lost through surface run-off; nitrate leaching in groundwater; volatilization to the atmosphere, thus increasing greenhouse gas emissions; or denitrification by different microorganisms. In addition to N, planting space (PS) is another key factor in determining crop yield. It is well known that the panicle number per unit area (PN) plays an important role in determining yield and increasing the tiller number (TN) may be a feasible way to offset paddy yield (PY) losses (Liu et al., 2017). On the other hand, a high PN could lead to a yield reduction because of an excessive TN, increased ineffective tiller percentage, high spikelet sterility, and a reduced number of grains per panicle (Kabir et al., 2008). Therefore, the present study was designed and conducted to determine the best amount of N fertilizer and PS to optimize yield and yield components of the rice promising line of 965.

 

The experiment was laid out as a split-plot arrangement based on a randomized complete block design and three replications in the Rice Research Institute of Iran– Deputy of Mazandaran (Amol) in the cropping year of 2022. The main plots were pure N fertilizer with four amounts (0, 92, 115, and 138 kgN.ha-1 from the source of urea fertilizer and subplots were PS with three levels of 20×20, 25×25 (transplanting by hand), and 30×16 cm (Mechanized transplanting). The traits measured in this study included plant height (PH), shoot dry weight (SDW), Leaf area index (LAI), chlorophyll a (chl a), b (chl b), fertile tiller number per hill (FT), filled and unfilled grains number (FG and UG), thousand grain weight (TGW), biologic and paddy yield (BY and PY), harvest index (HI) and nitrogen agronomic efficiency (NAE). Data were analyzed using SAS software and the means were compared with the LSD test.

 

The results showed that with the increase amounts of N in the booting stage of rice plant, the PH and LAI markedly was higher from 1 to 35% than non-application of N. Also, the maximum LAI belonged to 20×20 and 30×16 cm of PS with 50.8 and 14.9% difference compared to 25×25 cm of PS, respectively. The highest SDW was obtained at 138 kgN.ha-1 and 20 ×20 cm PS with 34.7% and the highest amount of chl b and chl a+b belonged to 138 kgN.ha-1 amount of nitrogen fertilizer and 20×20 cm with 2.9 and 2.2 times increase compared to the zero amount of N at the same PS, respectively. The highest PY (10309 and 10998 kg.ha-1) and NAE (about 29.8 kg.kg-1) without significant difference in fertilizer amounts (115 and 138 kg N.ha-1) were recorded at 20×20 and 30×16 cm of PS, respectively. In total, two amounts of 138 kgN.ha-1 for 30×16 cm (Mechanized transplanting) and 115 kgN.ha-1 for 20×20 cm (transplanting by hand) are recommended to achieve the highest PY from rice promising line of 965 cultivation. Similarly, Moosavi et al. (2015) indicated that N application in the Khazar cultivar is associated with increased durability and development of leaf surface, photosynthetic activity, and plant growth rate, which leads to increased PY.

With the increase of N fertilizer amounts, the number of FG, TGW, and HI markedly increased. In total, two amounts of 138 and 115 kgN.ha-1 are recommended at the PS of 20×20 (hand transplanting) and 30×16 cm (mechanized transplanting) to achieve optimal yield of the promising rice line 965, respectively.

The production of oil, especially organic oil, from oilseed plants is important, so that oilseed plants occupy the second food reserves in the world after cereals. Sesame is an industrial plant that can be cultivated in arid and semi-arid regions, however, its growth and yield are limited by drought stress. Drought stress is considered as one of the most important factors limiting the performance of plants. Therefore, proper and principled management of agricultural inputs, including fertilizers, can partially reduce the negative effect of drought stress. This study aimed to examine the effects of chemical fertilizers, biofertilizers, and humic acid—applied individually and in combination—on the yield, yield components, and protein content of sesame grain under different irrigation regimes.

This research was carried out in the form of a split plot experiment based on the complete blocks design with three replications during the 2022 and 2023 at a research farm in Hormozgan province. The experimental treatments included irrigation regimes at three levels (irrigation after 40, 60 and 80% moisture discharge as main plots and fertilizer treatments at seven levels (control (F1), 100% need plant to phosphorus chemical fertilizer (F2), plant inoculation with arbuscular mycorrhizal fungus (F3), humic acid (F4), 50% chemical fertilizer+mycorrhiza (F5), 50% chemical fertilizer+humic acid (F6) and 50% chemical fertilizer+Mycorrhiza+humic acid (F7) was in sub-plots. In this experiment, agronomic characteristics, yield, yield components and grain protein of sesame were investigated.

The results showed that irrigation regimes and fertilizer treatments showed a significant effect on the studied characteristics of sesame. Irrigation at 80% moisture reduced the plant height, the number of sub-branches, the number of leaves, the number of capsules, the weight of 1000 grain, the biological yield, the grain yield and the harvest index by nearly 35, 50, 37, 48, 42, 52, 61 and 13% respectively compared to irrigation at 40%. Therefore, increasing the plant's access to water improved cell growth and division by increasing cell mass. It has been reported that there is a direct relationship between the increase of drought stress and the decrease of each of the growth characteristics of the plant, so that drought stress can cause damage to the growth characteristics and plant yield components, depending on the growth stage, which will reduce economic yield. On the contrary, irrigation after 80% treatment led to an increase in nitrogen and grain protein concentration compared to irrigation after 40%. In addition, among the fertilizer treatments, the F7 treatment resulted in an increase in growth characteristics, yield components, yield and nitrogen content of sesame grain. In this research, the individual application of mycorrhiza and humic acid could have more favorable growth characteristics than the application of 100% phosphorus chemical fertilizer or its non-application. Different mechanisms have been described for the effect of mycorrhizae on the growth characteristics of plants, such as increasing the absorption of nutrients, nitrogen, phosphorus, and low-use elements. Because in a mycorrhizal plant compared to a non-mycorrhizal plant, the creation of a wide hyphal network of fungi between the soil and the root provides a large surface for the absorption of nutrients. Humic acid is also able to improve the vegetative characteristics of plants by increasing the photosynthetic capacity, leaf water content and the metabolism of antioxidant compounds.

Increasing water availability, along with the combined application of reduced amounts of chemical fertilizers, mycorrhiza, and humic acid, resulted in improved quantitative and qualitative yield of sesame. The enhanced performance of the combined treatments compared to other fertilizer treatments can be attributed to the lack of organic matter in the region's soil. The best results were observed with the integrated treatment of mycorrhiza, humic acid, and chemical fertilizers, as it provided the plant with the most access to essential nutrients.

Along with nitrogen (N), light is one of the determining factors for the growth and yield of cereals, especially rice. Since few studies have been done regarding the interaction of these two factors on the growth and yield of rice; therefore, the current research was carried out with the aim of evaluating the effects of radiation reduction in different stages of growth on the yield and yield components of the high-yielding cultivar of Shiroodi in different amounts of N.

A field experiment was conducted at four different levels of N fertilizer with amounts of 0, 100, 200, 300 kg of urea per hectare, shading treatments including natural light, 70 and 40% natural light in the three stages of vegetative, reproductive and seed filling. The rice plots exposed to different radiations using shading nets. Experiment was laid out in split-split plot based randomized complete block design with three replications in 2017. At the harvest stage, various traits related to yield and yield components were measured.

The results showed that the amount of N, shading stage (S) and percentage (SP) as well as their interaction were statistically significant in terms of yield and yield components. Shading stress led to a sharp decrease in Shiroudi rice yield components such as the number of filled grains, the number and the length of panicle. The highest amount of yield (8910 kg/ha) was assigned to the treatment of 200 kg of N fertilizer and the treatment without shading stress. By comparison, in the condition of shading stress paddy yield decreased up to 35%. The results of the interaction between the S and SP also indicated that the highest yield per unit area was recorded when rice plant grown without light stress and the lowest yield (5000 kg/ha) was assigned to the light stress of 60% in the grain filling stage. The less incident radiation at the reproductive and grain filling stages markedly decreased the percentage of filled grain (17-50%), the 1000 seeds weight (7-12%) and the paddy yield (15-38%) of the rice plants.

According to the results of this research, despite the fact that the optimal amount of N fertilizer for the Shiroudi cultivar was calculated to be 200 kg urea/ha, but under shading conditions (30 and 60%), the treatment of 100 kg urea/ha resulted in better yield and yield components (about 10%) compared to those plots which received 200 kg urea/ha. The 50% increment of unfilled grain number in the panicle in the shading treatment at the seed filling stage indicates that the lower radiation incident in the grain filling stage is very critical. Therefore, the amount of reduction in rice yield (especially the Shiroudi cultivar) by shading stress depends on the growth stage, and the adverse effects of stress can be reduced with proper management of N nutrition.

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.

Legumes are a vital source of plant-based food, second only to cereals. Among them, Chickpea (Cicer arietinum L.) holds significant importance, particularly in semi-arid regions such as western Iran, where it is primarily cultivated under rainfed conditions. Chickpea is a valuable dietary component, particularly for low-income populations, as it is rich in protein (18-22%), unsaturated fatty acids (e.g. linoleic acid and oleic acid), and a good source of vitamins, such as riboflavin, niacin, thiamin, and folate (vitamin B9), and beta-carotene (a precursor of vitamin A) and minerals including calcium, magnesium, phosphorus, and potassium. In terms of total grain production in rainfed environments, chickpea ranks as the third most cultivated crop in Iran. Kermanshah province, with approximately 141,000 hectares dedicated to chickpea farming, leads in cultivation area. Despite this, the average yield of rainfed chickpea fields in Iran (480 kg/ha) lags significantly behind the global average (1,057 kg/ha). This disparity is primarily attributed to limited soil moisture and a lack of bioavailable nutrients. This study investigates the potential of iron, zinc, and boron chelates applied in both bulk and nanoparticle forms – to enhance chickpea grain yield and address nutritional deficiencies under rainfed conditions.

The experiment was conducted during the 2018-2019 growing season at the Agriculture and Natural Resources Campus of Razi University under rainfed conditions. A randomized complete block design with three replications was implemented. Fertilizer treatments were applied as foliar sprays in two growth stages: the beginning of vegetative growth and flowering. Treatments included bulk and nanoparticle chelates of iron, zinc, and boron at three concentrations (2, 4, and 8 g/l), their combinations and a control.

Soil analysis revealed deficiencies in bioavailable iron, zinc, and boron. The analysis of variance showed that both the type and concentration of fertilizers significantly affected grain yield and its components. All treatments, except boron fertilizer, caused a significant increase in grain yield compared to the control. The highest yield (814 kg/ha) was observed with the combined application of iron+zinc+boron at 8 g/l, resulting in 1,392 kg/ha grain yield and 3,287 kg/ha biomass.  Other notable results included combinations of iron + zinc + boron (1,196 kg/ha), iron + zinc (1,108 kg / ha), and bulk zinc alone (1,053 kg/ha). Increasing fertilizer concentration positively influenced plant height, the number of pods per plant, grains per pod, total grains per plant, and 100-grain weight. Among all treatments, the concentration of 8 g/l consistently yielded the most significant improvements. While nanoparticle fertilizers performed well, bulk forms of iron and zinc proved equally, if not more, effective in enhancing grain yield. However, bulk fertilizers were superior in increasing plant height.

The study concludes that while both bulk and nanoparticle fertilizers of iron and zinc improve chickpea yield under rainfed conditions, nanoparticle fertilizers did not demonstrate a clear advantage over bulk forms. However, regarding plant height increase, bulk iron and zinc fertilizers were particularly effective. Considering reports of the higher efficiency of nanoparticles in irrigated environments, further research is necessary to determine conditions where nanoparticles may outperform bulk fertilizers in rainfed systems.

Introduction :

Beans (Phaseolus vulgaris L.) are one of the most important sources of protein and minerals for humans, and their residues and straw are also rich in nutrients necessary for animal nutrition. This plant species plays an important role in sustainable agriculture due to its morphological characteristics and nitrogen fixation. Crop husbandry practices are very important in maximizing plant’s access to environmental factors and hence its yield potential. Among the most important crop management practices is weed management. Weed control practices such as using optimal planting density and weeding at the right time are more appropriate particularly in terms of minimizing pesticide applications and hence achieving sustainable agriculture. In addition to reducing the quantity and quality of grain yield of beans, weeds cause problems in planting, maintaining, and harvesting operations of this plant. It has been reported that the lack of weed management and control may cause grain yield reductions of  up to 83% in beans, as weeds  outcompete the weed crop in accessing water, nutrients, and light.

This research was conducted in Agriculture Center of Al-Mahdi town, Azna, Lorestan Province, west of Iran as a factorial experiment in randomized complete blocks design ith three replications in 2011. Experimental treatments included weeding factor at six levels of: 0 (no weeding), 14, 28, 42 and 56 days after crop emergence (DAE), and complete weeding during the growth period and the planting density at two levels: 40 and 50 plants/m2 of red beans (Sayyad cultivar(. The land had been left fallowed the year before planting. After moldboard-plowing and disc-harrowing the land, seeds were planted into a depth of 5 cm in plots of 3 × 3 m. Irrigation was carried out during the growing period of beans by flooding method, every 5 to 7 days according to the environmental conditions. Fertilizers were used as 100 kg ha-1 triple superphosphate and 50 kg/ha urea before planting and also at 50 kg ha-1 urea as top-dressing at the beginning of flowering. The evaluated traits included plant height (cm), days to physiological maturity, pods/plant, grains/m2, grains/pod, branches/plant, 100-grain weight (g), plant above-ground dry weight (g/m2), grain yield (g/m2), harvest index (%), yield loss due to weed competition (%). SAS statistical software was used to analyze the data and LSD test was used to compare means of main effects and interactions. 

Results and Discussion :

The effect of experimental factors on all measured traits in red beans (Sayyad cultivar( was significant. Among the weeding treatments, besides complete weeding, the most desirable values of measured traits including plant height, days to physiological maturity, pods/plant, 100-grain weight, plant above-ground dry mass, grain yield and yield loss due to weed competition were obtained in weeding at 28 DAE. However, the highest grains/pod and harvest index were obtained in weeding at 42 and 56 DAE, respectively. Increasing planting density increased the plant height, plant above-ground dry mass, grains/m2, and grain yield, despite decreasing the remaining traits. The interaction effect of planting density and weeding time were significant on branches/plant, grains/m2 and grain yield. The highest branches/plant (4.8) was obtained in weeding at 28 DAE and planting at 40 plants/m2, the highest grains/m2 (1815) and grain yield (3869 kg/ha) were observed when weeding was done in 28 DAE and planting was done in 40 plants/m2. The correlation coefficients of grain yield with grains/m2, 100-grains weight, pods/plant and grains/pod were 0.88**, 0.85**, 0.79** and 0.40*, respectively, indicating a greater role of grains/m2 in regulating grain yield than other yield components. Therefore, crop management practices toward appropriate time of weeding and planting density will guarantee a maximum grain yield of  bean, at leat when Sayyad cultivar is cultivated in Azna region.

Conclusions :

Our results suggested that weeding time and planting density are crucial in obtaining acceptable grain yield in red bean (Sayyad cultivar). With weeding at 28 DAE and planting at 50 plants/m2, it is possible to obtain 82% of grain yield obtainable in complete weeding and achieve the appropriate productivity of red bean cultivation in Azna.

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.

Wheat (Triticum aestivum L.) is one of the oldest and most widely used crops in the world and is the most important source of human food that grows in a wide range of climatic conditions in the world. In arid and semi-arid regions, water is the main limitation. Iran is a dry and semi-arid country with limited precipitations. Therefore, the mean annual rainfall in Iran is even less than one third of the global average. There are many solutions for sustainability in agriculture, one of which is the use of biological fertilizers. Among these biofertilizers are mycorrhizal fungi. The symbiotic relationship between the arbuscular mycorrhizal fungus and the roots of the host plant significantly increases the growth and absorption of plant nutrients. In this research, the aim is to investigate the effect of arbuscular mycorrhizal fungus on improving the yield, yield components, and chlorophyll index of wheat by applying water deficit stress through increasing the interval of irrigation cycles.

This factorial experiment was conducted based on a randomized complete block design in four replications in the research farm of the Azad Islamic University of Miandoab, northwestern Iran in  2021. The experimental factors included the application of arbuscular mycorrhiza fungus species in three levels, control (without inoculation), inoculation with Glomus mosseae and inoculation with Glomus intraradices and three levels of irrigation regimes (i.e. irrigation after every 6, 13 and 20 days). Seeds of Elvand wheat cultivar were inoculated with mycorrhizal fungus, then the inoculated seeds were immediately planted into a depth of 3. Before planting, 15 tons/ha of manure and 25 kig of nitrogen fertilizer in the form of urea were uniformly applied to the soil. During the growing season, 50 kg of nitrogen fertilizer in the form of urea was used during the two stages of stem growth and spike formation. To measure wheat grain yield components, 10 plants were harvested and to determine grain yield and plant above-ground dry mass, 0.25 m-2 was taken from each plot. In this way, after removing two rows from each side and half a meter from the beginning and end of all rows as a margin, sampling of experimental units was done. The evaluated traits included the spikes/plant, grains/spike, the thousand-grain weight, plant aboveground dry mass, grain yield, harvest index, and greenness index.

Results indicated that the effect of irrigation intervals and mycorrhiza fungus were significant for grains/spike, thousand-grain weight, grain yield, above-ground dry mass, harvest index, chlorophyll index, photosynthetic pigments and proline concentrations. G. mosseae species increased the grains/spike,  thousand-grain weight, above-ground dry mass, harvest index, and chlorophyll concentration compared to G. intraradices species by 5.21, 9.73, 8.86, 6.96 and 4.08% and increased the above-mentioned attributes compared to the control by 29.94, 30.28, 39.68, 27.90 and 21.43%, respectively. The highest spikes/plant, grain yield, chlorophyll index and concentration of chlorophyll a belonged to irrigation interval of 6 days and inoculation with G. mosseae species with 6.34, 612.45 g m-2, 62.89 SPAD unit, and 0.306 mg g-1 FW, respectively.  Prolongation of irrigation interval by creating water deficit stress caused the sterility of the spikes and significantly reduced the grains/spikes. The irrigation regime had a significant effect on the grain yield and by reducing the irrigation intervals, the grain yield was increased. The drought-induced decrease in grain yield stemmed from the decrease in green index, chlorophyll concentration, spikes/plant and grains/spike, leading to decrease in the harvest index. With increase in the irrigation interval, the concentration of chlorophyll a and b decreased, but the mycorrhizal inoculation led to significant increase in the concentration of chlorophyll a and b under water deficit stress. The plants inoculated with mycorrhizal fungus suffered less from water deficit stress than the non-colonized plants, and as a result, the concentration of proline increased less compared to the plants deprived from mycorrhizal fungus. According to these results, irrigation of wheat plants every 13 days and application of G. mosseae can produce the desirable grain yield, while decreasing water consumption for wheat production.  

Mycorrhizal fungus increased the plant's resistance to drought stress by improving the absorption of water and nutrients under water stress deficit. G. mosseae was more effective in increasing the resistance of wheat against water deficit stress and as a result, it increased the grain yield, yield components, chlorophyll index and chlorophyll concentration of wheat to a greater extent compared to G. intraradices. In order to make the best use of water resources and soil nutrients, irrigation of wheat should be done every 13 days and must be accompanied by inoculation with G. mosseae to achieve an acceptable grain yield.

Onion (Allium cepa L.) is a species of the Alliacea family. It is of great economic importance in Hormozgan province, Iran, which is ranked the second among the largest producers of onion in Iran in terms of cultivated area (8147 ha) (Agricultural statistics, 2021). Conventional Irrigation have undoubtedly helped in improving both bulb yield and quality of onion, but lately, it was arising many novel trends in Irrigation. Using of chitosan as an antiperspirant compound is one of these trends, as it can improve the water use efficiency (Geries et al., 2020). Chitosan is a member of the polysaccharides which is considered a useful natural polymer and is produced by alkaline N-deacetylation of chitin. Ahmed et al. (2019) reported that positive effect of chitosan nanoparticles on onion, as it significantly promoted seed germination and radical length under salt stress. The best treatment on germination was 0.3% of nano chitosan. Growth variables (plant height, leaf area, fresh and dry weights of the shoot and root) were increased significantly. Nevertheless, data on the utilization of chitosan for onion are meager in Iran. In this way, this study was carried to consider the impact of irrigation periods and chitosan as a biological elicitor on onion cultivar of Taki yellow, uniquely the adjustment in yield and quality properties.

This study was carried out at the private farm in Sohrabi village, Shamil district, Hormozgan province, Iran, conducted during 2020-2021 growing season. The experiment was carried out as autumn planting. This experiment was conducted as split-plot arrangement based on a complete randomized block design with 3 replications. Treatments were three irrigation periods and three doses of chitosan as main and sub plot, respectively. In this experiment 3 irrigation periods (such as two days, four days and six days) and 3 doses of chitosan (including zero, 1000 and 2000 ppm) with constant density of 63 plants m-2 yield and yield components (such as mean onion weight, length and diameter, onion shape index and dry matter content) and harvest index of onion were measured.

This study was conducted to assess the potential effects of irrigation periods and foliar spraying with chitosan, on the growth, yield quality of onion bulbs. In this experiment, nearly all measured traits were significantly (P<0.01) affected by irrigation periods and doses of chitosan. Results showed two forms of chitosan treatments (chitosan 1000 and 2000 ppm) were the most effective treatments for vegetative growth characters (plant height and Dry weight of shoot per plant), yield and its components (bulb dry matter %, bulb length, bulb diameter and total bulb yield) while chitosan at 0 ppm gives the highest values for harvest index in each irrigation periods. Also, results showed more irrigation (Two days) was the most effective treatments for vegetative growth characters, yield and its components. Therefore, according to these results, under deficit irrigation conditions, chitosan can reduce the effects of drought stress on onion more than No foliar application. In this regard, Shamekh, Jafari & Abdollahi (2021) the effect of proline, chitosan and its derivatives on photosynthetic pigments, chlorophyll fluorescence indices, qualitative characteristics and yield of greenhouse tomato (Lycopersicon esculentum Mill.) under deficit irrigation conditions and these researchers reported in their studies that under deficit irrigation conditions, chitosan and its derivatives can reduce the effects of drought stress on tomatoes more efficiently than proline.

The obtained results indicated that foliar application with chitosan had an important role in promoting and improving plant vegetative growth, and this led to improve in yield and yield components of onion in higher irrigation periods (four days and six days). The examination inferred that using chitosan to deliver highest yield in good quality with great the economic benefit was gotten from foliar application at 2000 ppm.

Drought has been a significant crisis in Iran in recent years. In Lorestan province, as in many other regions of the country, in addition to reducing the amount of rainfall, its inappropriate distribution and intensity also hurt the crops, including wheat, in rainy conditions. The introduction of cultivars adapted to the rainy conditions of cold regions is being developed, but choosing the most suitable cultivar for each region will help the economy of farmers in the region while increasing production. To investigate the response of rainfed wheat cultivars to anti-transpirant and biofertilizers, a split-factorial experiment was conducted in a randomized complete block design with four replications during two growing seasons of 2016-2017 and 2017-2018. The first factor, wheat cultivars (Azar 2, Ohadi, and Baran), was assigned to main plots, and the anti-transpirant (application and non-application of atrazine) and nitrogen biofertilizers (non-application, application of Azospirillum brasilense, and application of Azotobacter chroococcum) were arranged factorially in subplots. The aim of this study was to investigate the effects of biofertilizer application and the anti-transpirant atrazine on three rainfed wheat cultivars. In the first year, the Ohadi cultivar with the application of atrazine and Azotobacter showed the highest grain yield (2420 kg ha-1) and biological yield (7595 kg ha-1) among the studied cultivars. In contrast, the Azar 2 cultivar without atrazine application but with Azotobacter application had the lowest grain yield and biological yield (2000 and 7000 kg ha-1, respectively). In the second year, the Baran cultivar with atrazine application and without biofertilizer application produced the highest grain yield and biological yield (2765 and 8465 kg ha-1, respectively). The Azar 2 cultivar, which was inoculated with Azospirillum without atrazine application, showed the lowest grain yield and biological yield (2083 and 7083 kg ha-1, respectively). The results showed that the application of biofertilizers led to an increase in grain protein content. On the other hand, the use of the antitranspirant atrazine decreased the activity of peroxidase and polyphenol oxidase enzymes in the aerial parts. Considering these findings and the climatic conditions of Lorestan province, the cultivation of Ohadi and Baran cultivars, along with the simultaneous application of atrazine and biofertilizers, is recommended.

The purpose of this experiment was to study the trend of yield fluctuations and related traits in released wheat cultivars in Iran from 1968 to 2016.

This experiment was conducted with 16 wheat cultivars based on a Randomized Complete Block Design with three replications at Shirvan Higher Education Complex in North Khorasan during the 2018-2019 and 2019-2020 growing seasons.

The findings indicated that the Iranian cultivars released do not have significant differences in terms of the number of seeds per spike, plant height, spike length, biological yield and gluten percentage, but grain yield, harvest index, 1000-seeds weight and protein percentage have improved by 61.84, 63.54, 62.37 and 14.4%, respectively, during the last 48 years. Additionally, wheat breeding in Iran has progressed towards single-spike formation. Path analysis showed that the plant height, biological yield, number of fertile tillers/m2 and harvest index explain more than 96% of yield changes and that traits such as the harvest index and number of fertile tillers are considered the most important traits in increasing and decreasing grain yield in Iranian wheat.

According to the results of the causality analysis, it can be concluded that the selection for grain yield, based on other traits and without considering the relationships between them, may not provide accurate results. It is necessary to obtain a correct understanding of the role of the relationships between traits in breeding programs to increase selection efficiency.

Optimizing the consumption rate of nitrogen fertilizers is one of the important management strategies to improve performance. This experiment was carried out to investigate the effects of nitrogen stress and levels on the morphological characteristics and agronomic traits of rice.

An experiment was conducted in the form of split plots in a randomized complete block design with four replications in 2009 & 2010 at the research farm located in Amol. Nitrogen levels were considered the main factor at three levels (46, 69, 92 kg N/ha-1 from urea source) and the sub-factor included four levels of stress or lack of nitrogen consumption (T1= stress at the full clustering stage, T2= stress at the emergence of the initial cluster stage, T3= stress at the tillering stage, and T4= stress at the transplanting stage).

 The results demonstrated that the number of full panicles per panicle, 1000-seed weight, grain yield, and harvest index were higher in 2009 than in 2010. Grain yield in the first year (450.25 g/m2) was higher than that of the second year (395.1 g/m2). The maximum harvest index was also obtained in 2009 with nitrogen stress at the full clustering stage.

Therefore, the application of 69 kg of nitrogen per hectare in installments can be recommended to produce the highest grain yield.

Due to the extensive climate changes and environmental pollution, along with the heavy use of toxins and chemical fertilizers in industrial farming, addressing topics concerning sustainable agriculture is deemed essential in today's world. A key strategy for sustainable plant cultivation involves enhancing diversity by practicing intercropping. This technique aids in erosion control, soil and water protection, nitrogen biological fixation, boosting both the quantity and quality of yields, and managing weed growth.

To investigate the impact of humic acid on the yield of wheat and lentil in both sole and intercropping systems under dryland conditions, an experiment was conducted during the 2018-2019 growing season in Qahavand city, Hamedan, Iran. The experiment followed a factorial design based on randomized complete blocks design with three replications. The factors included different cropping patterns at four levels: wheat sole crop, lentil sole crop, strip intercropping with 6 rows of wheat and 3 rows of lentil (6W:3L), and strip intercropping with 12 rows of wheat and 6 rows of lentil (12W:6L). Additionally, humic acid was applied at three levels (0, 6, and 12 kg.ha-1). Yields, yield components, and land equivalent ratio were measured and evaluated.

The results indicated significant effects of intercropping on various parameters in both wheat and lentil crops. In wheat, intercropping influenced traits such as seeds per spike, spikes per square meter, 1000 seed weight, grain yield, biological yield, harvest index, and protein percentage. For lentil, intercropping impacted the number of pods per plant, 1000 seed weight, grain yield, biological yield, protein yield, and harvest index. Additionally, the application of humic acid significantly affected most traits, except for the lentil harvest index. The interaction between the intercropping and humic acid influenced wheat grain yield, 1000-seed weight of lentil, lentil grain and biological yield, and the total yield of lentil and wheat. The land equivalent ratio (LER) in all intercropping treatments was greater than 1, indicating the benefits of wheat and lentil intercropping over sole cropping.

The application of 12 kg.ha-1 of humic acid resulted in increased yields and yield components for both wheat and lentil crops, along with a higher land equivalent ratio ( LER) index. The intercropping of 6 rows of wheat and 3 rows of lentil (6W:3L), combined with this application, is optimal for achieving maximum yield and benefits in the intercropping of wheat and lentil.Keywords: Cereal, harvest index, land equivalent ratio, organic fertilizer, pulses

Zinc and iron are essential micronutrients for plant and human growth, due to the lack of these elements in important plants such as wheat, it is necessary to evaluate any method to optimize the production and quality of this product and achieve self-sufficiency. In order to investigate the role of zinc and iron elements in improving the yield of dryland wheat, a factorial experiment of three factors was carried out in the form of a randomized complete block design with three replications in the agricultural year of 1401-02 at Gonbad Agricultural Research Station. The experimental factors include micronutrient elements (iron chelate 6 per thousand, zinc chelate 4 per thousand and control) in the form of foliar spraying at different growth times (pinching, stemming and seed filling) and two varieties of dry wheat (Asman and Paya). In this study, yield traits and seed yield components, biological yield, harvest index, greenness index, canopy temperature, leakage of electrolytes from the cell membrane, plant height, spike length, peduncle length and measurement of phenological stages based on Zadox, number of days until spike emergence, The number of days to maturity and calculation of day-growth degree were studied. The results showed that the two cultivars Aseman and Paya had significant differences on grain yield and harvest index, number of spikes, spike length, peduncle length, height, number of days until spike emergence, number of days until ripening and day-growth degree. Foliar treatment (iron, zinc and control) caused a significant increase in spikes per square meter compared to the control, but it did not affect grain yield, harvest index and other traits. The interaction effect of cultivar treatments at the time of foliar application had a significant effect on seed yield, biological yield and the number of spikes per square meter, and the highest amount of seed yield was obtained in the stemming stage of Paya cultivar with an average of 730 kg/ha. In general, it can be concluded that in the conditions of drought stress (rainfall less than 250 mm), the application of zinc and iron did not have a significant effect on grain yield and other traits, and the lack of moisture has reduced the development and growth of cells in dryland wheat cultivars.

This research was conducted in order to investigate the effect of foliar application of micronutrients on the yield and some physiological traits of new corn hybrids during 2016and 2017 in Safiabad Dezful research farm. This experiment was performed as a split plot based on a randomized complete block design in four replications. The main treatment includes foliar application of micronutrients in the eight-leaf stages and the time of full emergence of plant organs in the control levels, Fe, Mn, Zn, Fe+Mn, Fe+Zn, Mn+Zn, Mn+Zn+Fe and hybrid levels (single cross) including 637 (45/1-2z25), hybrid 637 (45/1-2z2), hybrid 670 (mol7), hybrid 701(mx11z18/1), hybrid 677 (1/64/018z35), hybrid702 (2/12/15/3-1) and hybridimbin (mx11z18/2) were considered as secondary treatment. The results of variance analysis showed the simple effect of micronutrient elements and hybrid on leaf area index, number of seeds per cob, 100 grain weight, grain yield, biological yield, harvest index and seed nitrogen percentage at the probability level of one percent and the interaction effect of micronutrient elements in hybrid on the grain yield was significant at the 1% probability level. The highest index of leaf area and biological yield in the second year was obtained from the combined foliar application of iron, manganese and zinc. The highest seed yield (14.61 ton/ha) was obtained in the second year with the combined application of iron, manganese and zinc in hybrid 670, which increased by 45% compared to the control treatment in hybrid 702. According to the above results, it is recommended to spray the three micronutrient elements iron, manganese and zinc in two times of eight leaves and the time of full appearance of the plant organs to increase the yield and improve the physiological characteristics of hybrid corn 670 in the conditions of the region.