فهرست مطالب شهرام رضوان

In order to investigate the effect of planting densities and different amounts of nitrogen on leaf greenness index and leaf area index, seed yield and oil yield, irrigation water productivity and nitrogen use efficiency in sunflower, an experiment was conducted as a split plot in the form of randomized complete blocks design with three replications in the research farm of Agriculture Institute in Semnan province in the spring of 2019. Plant density in four levels (4, 6, 8 and 10 plants per m2) as a main plot and the amount of nitrogen levels (0. 50, 100, 150 and 200 kg urea ha-1) as sub plot was considered. Leaf greenness index, plant height, 100-seed weight, seed nitrogen content and seed oil content were significantly affected by the simple effect of planting density, which decreased with increasing density of the above traits. Also, the nitrogen levels significantly affected the studied traits, so that with increasing the amount of nitrogen consumption, from control (0 kg urea ha-1) to 200 kg urea ha-1, the leaf greenness index increased by 15.3%. The highest amount of plant height, 100-seed weight and grain nitrogen were obtained in the treatment of 150 kg urea ha-1 and 14.13, 9.07 and 24.3% more than no application, respectively. Mean comparing the results of water use efficiency showed that at a density of four plants per m2 and an increase in nitrogen levels, along with increasing height and leaf area index, water use efficiency also increased, but higher levels of density led to smaller plant yield, less plant biomass and water efficiency were reduced. The highest nitrogen use efficiency was obtained in the density of 8 plants per m2 and no application of nitrogen fertilizer. Finally, maximum grain yield (4016 kg.ha-1) and oil yield (1827 kg.ha-1) were obtained by consuming 150 kg urea per ha-1 and density of 8 plants per m2.

The present study was conducted to evaluate the impact of potassium nano-fertilizers, fulvic acid, and chitosan on quantitative traits of sesame under different irrigation regimes. A field experiment was conducted in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. In this experiment irrigation regimes (full irrigation: non-stress, irrigation cut off at the beginning of seed formation inside the capsule: moderate stress and the beginning of flower structure formation: severe stress) as the main plot, and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application of chitosan (five g.ha-1) and fulvic acid (two kg.ha-1) in four levels were tested as sub-plots. The application of potassium nano-fertilizer along with fulvic acid and chitosan increased the photosynthetic pigments, seed yield, and oil and protein content, which was a significant increase under severe drought stress. Application of 1.5 per thousand potassium nano-fertilizer with chitosan under non-stress conditions resulted in the highest number of capsules per plant, seed yield, biological yield, oil yield, and protein yield. The highest oil and protein content (48.79 and 25.12%, respectively) were obtained using a combination of chitosan and fulvic acid under non-stress conditions. The highest seed yield (2249.2 kg.ha-1) was achieved in the application of chitosan along with 1.5 per thousand potassium nano-fertilizer under non-stress conditions.

This experiment works on the physiological, growth, and yield responses of sesame to the application of potassium nano-fertilizers, chitosan, and fulvic acid under drought stress in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. The experimental treatments include drought as the main plot (normal irrigation, irrigation cut offin 70 and 60 BBCH as moderate, and severe stress, respectively) and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application (control, chitosan, fulvic acid, and 50% of chitosan+ fulvic acid) as sub-plots.Application of potassium nano-fertilizer under normal and stress conditions significantly cuts chlorophyll b and total, leaf area index, number of capsules, 1000-seed weight, and oil percentage.The highest grain yield belongs to the application of 1.5 and 2.5 per thousand nano fertilizers, using fulvic acid alone or in combination with 50% chitosan (2516, 2277.5, 2506.6, and 2313.2 kg/ha, respectively). The highest oil content has been in 1.5 and 2.5 per thousand nano fertilizer application under normal irrigation, which has increased 13.2% and 15.4%, respectively. Foliar application of fulvic acid with nano potassium fertilizer (1.5 per thousand) under severe drought stress show the highest activity of antioxidant enzymes catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase. In general, the results show that the application of 1.5 per thousand nano potassium fertilizer and combined foliar application of chitosan and fulvic acid under severe drought by improving physiological traits, manage to modify the adverse effects of drought, increasing growth, yield, and quality indices of sesame.

Wheat (Triticum aestivum L.) is one of the most important crops in the world as well as in Iran. It has experienced many improvements in terms of yield and quality traits during recent decades. Wheat, like energy, is known as a strategic commodity and is one of the important indicators of agriculture. This plant has the highest area under cultivation and production among other cereals in the world. Planting date is an important factor in crop production because meteorological parameters vary with changes in planting date. Delay in planting is one of the problems that is common in almost all wheat growing areas of Iran and is one of the main causes of reduced yields of wheat cultivars. Yield reduction rate varies depending on the delay in planting and cultivars, and the results of some experiments indicate that this amount sometimes reaches more than 35% of potential grain yield. Phenology and growth rate due to their effect on duration and the occurrence of different stages of development and the environmental conditions prevailing in each of these stages, are the key point of adaptation to various environmental conditions such as delayed planting date. This experiment was designed to identify the changes in yield and yield components and phenological stages of new bread wheat cultivars with different growth habits and to investigate the possibility of introducing cultivars compatible with delayed planting date in the region.

This research was conducted in two separate experiments based on a complete randomized block design with optimum planting date (6th November) and delayed planting date (6th December) on 10 new bread wheat cultivars with three replications on the research farm of the Seed and Plant Improvement Research Institute in Karaj in two years (2016-2018). The bread wheat cultivars include Pishgam, Heidari, Rakhshan, Sivand, Baharan, Sirvan, Parsi, Mehregan, Chamran 2 and Chamran. Yield and yield components such as number spike per m2, number of grain per spike, 1000-grain weight were measured at the end of the growing season to evaluate responses of the cultivars to the various planting dates. In addition, the phenological stage was recorded during the growing season.

Results indicated that delayed planting date from 15th Nov. to 15th Dec. caused a significant reduction on grain yield (from 7485 to 6066 kg.ha-1), number of spikes per m2 (from 698 to 605), number of grain per spike (from 28.5 to 25.8 seed), and 1000 grain weight (from 41.1 to 38.4 g). The interaction effects of planting date and cultivars were significant on grain yield and yield components. The highest and lowest grain yield belonged to Pishgam (7436 kg. ha-1) on optimum planting date and Chamran (5842 kg.ha-1) on delayed planting date, respectively. Delayed planting date reduced duration of planting to double ridge (from 736 to 641 GDD), planting to terminal spikelet (from 982 to 886 GDD), planting to anthesis (from 1608 to 1457 GDD) and planting to maturity (from 2456 to 2265 GDD).

Duration of different developmental stage is very important for the formation of yield components that determine the final grain yield. Although these stages are a genetic trait, but they are affected by plant growth conditions and environmental stresses, climatic factors, especially temperature and day length. Our research showed that delay in planting reduced grain yield by 18% compared to the optimum planting date because of the reduced number of spikes per m2 and vegetative and grain-filling periods.Based on the results, in cases of delayed planting date (unfavorable weather conditions, insufficient planting equipment, etc.) in Karaj region or similar climatic regions, early maturity cultivars such as Mehregan and Chamran 2 and moderate maturity cultivar like Sivand are recommended in order to minimize yield loss.

Sesamum, scientifically named Sesamum indicum L., is one of the oldest oilseed families and is adapted to warm and semi-warm regions and is known as the queen of oilseeds. The use of nanotechnology in the production of fertilizers results in optimal release and increased efficiency of absorption of nutrients in fertilizer which leads to significant economic and environmental benefits. Chitosan elicits stimulating defense mechanisms and is beneficial to plants, animals and humans and is environmentally friendly. Due to the fact that water stress and dehydration in Iran is always one of the most important agricultural problems and due to the importance of magnesium in photosynthesis of plants and also the use of different polymers such as chitosan to reduce the damage caused by stress, this study aimed to evaluate the effect of nano chitosan and magnesium application under water stress conditions on some sesame traits for sustainable agriculture development in Varamin region.

In order to evaluate limited water stress and foliar application of magnesium and chitosan on growth and yielding traits and oil content of two sesame varieties, an experiment was conducted as a split factorial based on completely randomized blocks designed with three replications in a research farm in the southern Varamin Province, Iran, during 2016-17 growing season. Irrigation cut-off based on BBCH scale in three-level included: normal irrigation, 65 BBCH (flowering), and irrigation cut-off in 75 BBCH (capsule maturity) as the main factors. Sub-plot included a combination of three factors: two genotypes Oltan and Dashtestan-2, foliar application of Mg-nano in two levels non-application and foliar application (2 g/L) in 65 BBCH stage and foliar application of chitosan in three levels: non-application, foliar application of 4.8 g/L in 65 BBCH stage and 6.4 g/L in 75 BBCH stage.

The results showed that the irrigation up to 65 BBCH caused a reducing 28.08, 20.8, 53.05, 54.04 and 23.10% in the average traits of number of capsules, 1000-grain weight, grain yield, LAI, and oil percentage content in compared to the normal irrigation treatment (control). The highest grain yield was achieved in the application of Mg-nano-fertilizer under normal irrigation in Dashtestan-2 variety with a mean of 1188.2 kg/ha, which 16.3% increased in compared to the control treatment. The highest oil percentage was observed in the application of Mg-nano under normal irrigation was in Dashtestan-2 variety with an average of 50.38%, which 3.5% increase in compared to the control treatment.The highest grain yield was achieved in the application of Mg-nano-fertilizer under normal irrigation in Dashtestan-2 variety with a mean of 1188.2 kg/ha, which 16.3% increased in compared to the control treatment. The highest oil percentage was observed in the application of Mg-nano under normal irrigation was in Dashtestan-2 variety with an average of 50.38%, which 3.5% increase in compared to the control treatment.

Finally, foliar application of Mg-nano and chitosan (4.8 g/L) under water stress conditions were able to compensate for damage and to modify the negative effects of stress.

To investigate the physiological responses of sesame cultivars to the application of nano magnesium and chitosan biopolymer under different irrigation regimes, a split factorial based on randomized complete block design has been conducted with three replicates between 2017 and 2018. The irrigation cut-off, based on BBCH scale, has served as the main factor (normal irrigation, irrigation up to 50% flowering, and seed ripening), with the sub factors including Oltan and Dashtestan-2 sesame cultivars, and nano magnesium (application and non-application) and chitosan (control, 4.8, and 6.4 g.L-1). The highest mean grain yield belongs to the application of 6.4 g.L-1 chitosan under normal irrigation with an average of 1235.1 kg.ha-1. Also, the highest total chlorophyll content is observed in Dashtestan-2 genotype under normal irrigation with a mean of 24.7 mg.g-1 FW and the lowest mean have been obtained in both genotypes under irrigation up to 65 BBCH with a mean of 17.21 and 17.46 mg.g-1 FW, respectively. Application of nano fertilizer in Oltan genotype under irrigation up to 65 BBCH increases the catalase activity by 41.11%, compared to the control treatment. The highest activity of ascorbate peroxidase has been achieved when not applying chitosan under irrigation conditions up to 65 BBCH. It has risen by 55.06%, compared to the control treatment. In general, the results show that irrigation up to 65 BBCH reduces grain yield, in turn alleviated by the negative effects of stress on magnesium and chitosan nanoparticles (9.93% and 27.46%, respectively). Based on the regression analysis results, four traits, namely chlorophyll b, total chlorophyll, proline, and catalase, enter the model that explains 42.11% of the total grain yield variations. Results of simple correlation between traits and regression analysis indicate the indirect effects of physiological traits on grain yield and among the studied parameters, photosynthetic pigments has been of high account in stress conditions.

Cumin (Cuminum cyminum L.) is one of the most important domestic herbs in Iran and is one of the earliest spices used by humans. Due to its characteristics such as short growing season, low water requirement, non-interruption of growth season with other agricultural products as well as high economic justification for other crops and export, it has found a special place in arid and semi-arid areas, including Sabzevar. Growth, yield and characteristics of medicinal plants are influenced by environmental factors such as temperature and light that can be varied by different sowing dates. Planting date is one of the most important factors in crop performance improvement and percentage of essential oil of cumin, which is resulted in weather parameters changes during the growing season and then in the production. In addition, the use of the adapted ecotype to the environmental conditions of the area plays a major role in achieving a proper performance. A high proportion of the total variation in yield is related to the interaction of genotype in planting history, which can greatly complicated the choice for a broad adaptation to different sowing dates. This research was carried out with aim of investigating the changes in yield of cumin ecotypes in different planting dates and determining the optimum planting time for this plant under Sabzevar climatic conditions.

In order to investigate the effect of planting date on quantitative and qualitative characteristics of different cumin populations, field experiment was conducted as split plots in a randomized complete block design with three replications in Sabzevar, Iran during 2016-2017. The factors included sowing date at three levels: 30 January, 20 February and 10 March, as well as different cumin ecotype in four levels of Sabzevar, Birjand, Kerman and Biyarjomand, respectively, assigned to the main plots and sub plots, respectively. Plant height, Umbel per plant, Seed per umbels, 1000- Seed yield, Biological yield, Essential oil yield and Essential oil percentage were measured and calculated accordingly. The treatments were run as an analysis of variance (ANOVA) to determine if significant differences existed among treatments means. Multiple comparison tests were performed for significant effects using the Duncan,s test.

The results showed that the highest number of umbels per plant, plant height, 1000-seed weight, seed yield and biological yield, as well as percentage of essential oil were obtained in the sowing date of January 30, and the delay in planting reduced the qualitative and quantitative characteristics of cumin. Among the studied ecotypes, Sabzevar ecotype had the highest number of umbrellas per plant, plant height, biological yield and essential oil percentage, as well as the highest number of seeds per umbels, seed yield and essential oil in Sabzevar ecotype and at sowing date of 30 January. It turned out that Sabzevar ecotype seems to have shown significant superiority to other ecotypes with higher potential performance in the studied environment. In this research, linear relationship between essential oil percentage and yield, as well as seed yield and essential oil yield were observed with 96% and 93%, respectively.

The optimum cumin’s planting date in one region causes reduction of the effects of non-biotic stresses during the growing season. The results of this experiment showed that in winter crop cultivation, seed yield and essential oil significantly decreased by delayed planting from January to March. In addition, Sabzevar ecotype in the study area had higher production potential. As for sowing date, the highest seed yield and essential oil were obtained in the first and second month of sowing. It seems that planting of cumin in the January increases the production potential due to increasing growth period and absorption of photosynthetic active radiation, as well as more effective use of plants from environmental factors.

In order to study the physiological responses of castor to foliar application of zinc nano-chelate and humic acid under limited irrigation, an experiment was conducted as split-factorial based on randomized complete block design with three replications in Damghan region during 2015-16 growing season. Irrigation as the main factor in three levels including normal irrigation (control), irrigation up to 75 BBCH (mild stress) and irrigation up to 65 BBCH (severe stress). Combination of spraying various concentrations of humic acid (non-application, application of recommended rate and two-fold recommended rate) and zinc nano-chelate (application and non-application) were as subplots of this experiment. The results showed that the effect of irrigation treatment, humic acid, and zinc nano-chelate were significant on the number of capsules, number of seeds, 100-seed weight, grain yield, oil percent, and chlorophyll content. Irrigation up to 65 BBCH resulted in a reduction of 11.9, 34.9, 24.2, 24.9, and 51.7 percent in 100-seed weight, grain yield, biological yield, percent and yield of oil compared to normal irrigation. With application of humic acid based on recommended amount obtained the highest grain yield (2098.8 kg.ha-1). Foliar application of zinc nano-chelate resulted in 14.4, 8.4 and 18.4 percent increase in the grain number, 100-seed weight, and grain yield. The highest oil content (45.4%) and oil yield (943.3 kg.ha-1) were obtained in the normal irrigation. The non-application of humic acid, as well as irrigation up to 65 BBCH, led to decrease in leaf chlorophyll content. The highest activity of superoxide dismutase enzyme was observed in non-application of zinc nano-chelate and two-fold consumption of humic acid under irrigation up to 65 BBCH conditions. The seed oil percent had a positive correlation with functional traits and total chlorophyll content and had a negative and significant correlation with antioxidant enzymes activity. Regression results showed that capsule number, 100-seed weight, grain yield, and oil yield were the main factors affecting seed oil percent. In general, the application of humic acid with recommended amounts and zinc nano-chelate led to improvement of growth and physiological traits and tolerance to limited irrigation in castor plant.

In order to study the grain yield attributes of sesame in the presence of nutritional treatments and different irrigation regimes, a factorial split-plot experiment was conducted based on randomized complete block design with three replications in Shahed University of Tehran, Iran during 2015-2016. The treatments included irrigation regimes (full irrigation and irrigation up to 65 and 75 BBCH scales), three types of nitrogen fertilizers (nitroxin, urea, and the combination of nitroxin and 50% urea) and four levels of potassium fertilizer (non-fertilized as control, spraying and soil application of potassium nano-chelate and potassium dioxide). The triple interaction effect of irrigation × nitrogen × potassium was significant on plant height, the number of lateral branches, capsules, seeds per capsule, and grain yield. The highest grain yield was obtained from plants irrigated up to 50% of seed ripening (75 BBCH) in the absence of application of potassium and use of nitroxin with an average of 1340.5 kg ha-1 leading to 35% increase, compared to the control treatment. In addition, the grain yield was positively and significantly correlated with stem diameter, plant dry weight, number of capsules and seeds per capsule, and 1000-seed weight. A weak correlation was observed among the morphological traits. Further, there was no significant correlation between morphological and yield attributes. Based on the results of stepwise regression, the maximum grain yield difference was related to the total number of capsules, 1000-seed weight, and number of seeds per capsule, together explaining 98.8% of the grain yield changes.

In order to study the relationship between quantitative and qualitative traits with sesame grain yield in nutrient treatments as chemical, biological and nano fertilizers and drought stress, an experiment was conducted as factorial split plot based on randomized complete block design with three repetitions. The experiment factors including irrigation regimes, irrigation withholding at different stages of development based on BBCH, full irrigation and irrigation up 65 and 75 BBCH, three nitrogen fertilizers as nitroxin, urea and combination with nitroxin and 50 % urea and four combinations of potassium fertilizer, as non-fertilized as control, spraying and soil application of potassium nano-chelate (2 ppt and 2 kg.ha-1 respectively) and potassium dioxide (2 l.ha-1). The highest grain yield was obtained in irrigation up to 50 % seed ripping in non-application of potassium and use of nitroxin with average of 1340.5 kg.ha-1 that about 35 % increased the average of this trait compared to the control treatment. The grain yield was positively and significantly correlated with stem diameter, plant dry weight, number of capsules, number of seeds per capsule, 1000-seed weight and oil percentage and yield. There was no significant correlation between morphological and yield traits. The results of stepwise regression showed that the maximum grain yield difference can be attributed to the total number of capsules, 1000 seed weight, number of seeds per capsule, oil yield and oil percentage which explained 91.1 % of the grain yield changes. The application of potassium nano- chelate in irrigation withholding at 50 % seed ripening (equivalent to 75 BBCH) and using of nitroxin bio-fertilizer had the highest grain yield in second cultivation after wheat and is suitable for dry and semi-arid climates.

In order to evaluate the effects of chemical, biological and nano fertilizers on the yield and quality traits (oil and protein) of sesame seeds in irrigation withholding conditions an experiment was conducted as a split plot factorial based on completely randomized blocks design with three replications at Shahed University during 2015-2016 growing season. Irrigation withholding levels (full irrigation (control) and irrigation withholding at 75 and 85 BBCH (Codes of phonological stages that are equivalent to 50% of flowering and seed ripening respectively) were assigned as main plot and different nitrogen combinations (Nitroxin, urea, and a mix of 50% Nitroxin plus urea), various combinations of potassium (no use, nano-potassium foliar application (2 per thousand), irrigated use of potassium dioxide (2 L ha−1) and soil application of nano-potassium (2 kg ha−1) were allocated in the subplots. The highest number of per-plant capsules (19.26 numbers) was observed with irrigation up to 50% seed ripening and the use of urea together with potassium nano chelate foliar application. The greatest grain yield and protein content and yield were obtained in irrigation up to 50% seed ripening in the absence of potassium fertilizer and nitroxin usage (1340.5, 276.53 kg ha−1 and 5-20 percent, respectively). The oil yield was utmost in irrigation up to 50% flowering and foliar application of potassium nano chelate together with the mixed system of 50% urea fertilizer plus nitroxin with average values of 47.96% and 550.46 kg ha−1, respectively. The use of nitroxin as a nano-bio-fertilizer and foliar application of chelated nano