محمد رضا داداشی

The aim of present study was to investigate the effects of NPK chemical fertilizer management on parameters related to lodging, yield components, grain yield and NPK nutrient uptake in local rice cultivars. The experiment was conducted in farms located in Mazandaran province, Sari, during 2017 and 2018. The experiment was performed as split plot in a randomized complete block design with four replications. The different doses of fertilizer treatments at five levels including F1: N250P150K150, F2: N200P100K100, F3: N150P75K75, F4: N100P50K50, and F5: Control (N0P0K0) as main plot and local rice cultivars at two levels of Sang Tarom and Tarom Hashemi were considered as sub-plots. The results showed that the highest third and fourth internodes lodging index were observed in N250P150K150 and N200P100K100 treatments. Application of N200P100K100 treatment increased the number of fertile tillers per hill (13.25) and finally produced highest grain yield (4806 kg/ha-1), although there was no significant difference with N250P150K150 and N150P75K75 treatments. When the doses of NPK fertilizers increased, the concentration of NPK in grain and straw and as well as grain protein content also enhanced. There was no statistically significant difference between the two cultivars in terms of grain yield and concentration of N and K in plant, but the concentration of P in grain for Tarom Hashemi cultivar was about 8.9% higher than Sang Tarom. According to the findings of this study, the application of N150P75K75 treatment is a better option to improving the grain yield of rice cultivars along with a decrease in chemical fertilizers and subsequent reduced fertilizers costs and environmental damages.

In order to the effects of deterioration, accelerated aging and planting density on yield, yield components and seed characteristics of produced wheat seeds in Gonbad region, an experiment was conducted as factorial arrangements, based on completely block design with three replication at researcher station in 2017. Treatments were combination of three factors, i. E. leaf deterioration (without leaf deterioration, removing all leaves, removing all leaves except flag and Removal of all leaves except flag leaf and the leaf below), accelerated aging (without deterioration and deterioration for 72 hours at 45 centigrade in incubator) and plant density (350, 400 and 450 plants per square meter). The simple effected of removing leaves and accelerated aging and plant density were significant on yield and its components at 0.01 probability level. The yield and its components decreased with increased removal of the leaves, such the grain yield with leaves removal decreased from 4125 to 3670 kg/ha. There was significant deterioration among accelerated aging for studied traits. The seed yield was 3423 and 4244 kg/ha for accelerated and non accelerated treatments.

In order to evaluate the effects of drought stress on the yield and some biochemical characteristics of four Maiz hybrids in the Gorgan conditions, an experiment was conducted as a split split plot based on a randomized complete block design with three replicaitons during 2022. The main factor was drought stress at four levels (100, 75, 50 and 25% of water use) and the secondary factor was four maize hybrids (SC703, SC704, ZP548, BK50). The results of analysis of variance showed that the effects of drought stress and hybrid on all traits was significant (chlorophyll a, chlorophyll b, total chlorophyll (a+b), carotenoid, soluble sugar, proline, number of rows, number of seed in rows, thousand seed weight and grain yield). On the other hand, the interaction effects of drought stress × hybrid were also significant on all traits except proline and the number of rows. The results of mean comparison showed that the highest amount of proline (9.91 mol/g-1) and soluble sugar (30.2 mg/g-1) was obtained from the 25% water requirement. With increasing drought stress, the amount of chlorophyll a, chlorophyll b, total chlorophyll (a+b) and carotenoids decreased. Also, the highest seed yield (8450 kg/ha-1) was observed in hybrid Zp548 from 100% water requirement, but with 75% of water use (7934.3 kg/ ha-1) was in the same statistical group. At other levels of drought treatments, the highest seed yield was obtained from hybrid Zp548. Therefore, treatment of 75% water use and Sowing of ZP548 hybrid in Gorgan region is recommended.

In order to investigate irrigation management and the effects of different amounts of nitrogen fertilizer on hybrid corn SC704 experimental in the form of crushed plots in the form of complete randomized block design in three replications during two crop years 2015 and 2016 in Golestan province, in Katul was done. The main factor of irrigation cycle by day in four levels including 7, 14, 21 and 28 days and the secondary factor of nitrogen fertilizer in four levels included 60, 120, 180 and 240 kg.ha-1. The results of analysis of variance showed a significant effect between irrigation cycle and nitrogen on Weigh of 1000 grains, grain yield, seed nitrogen and biomass yield. The results showed that 28 days of irrigation reduced grain yield, seed nitrogen, seed phosphate and seed potassium compared to 7 to 14 days of irrigation. The increase in nitrogen fertilizer to 180 and 240 kg.ha-1 increased the yield of the grain by affecting the biological yield and yield components seed nitrogen, seed phosphate and seed potassium. However, nitrogen consumption in higher amounts under stress conditions (21 to 28 day Interval Irrigation) not only did not have a positive effect on yield, but also reduced grain yield by 180 to 240 kg.ha-1. The highest grain yield was obtained in the combination of 7 and 14 day irrigation treatment and nitrogen level of 240 to 180 kg.ha-1 and 12209, 11416, 10147 kg.ha-1. The results of the average comparison between the two years showed that the highest number of grains per corn was 583, the Number of grains per row as 40.3 and the Weigh of 1000 grains was 138.9 grams and seed nitrogen 3.991 µg.g-1 DW in the second year.

Maize cultivation is rapidly expanding in the world due to its high adaptability to different weather conditions, and it is an exceptional product that can be effectively used as feed and forage products to meet the ever-increasing needs of livestock. Low irrigation is an approach to increase water productivity with the view of increasing production per unit of water consumption. The research results show that water stress has a significant effect on the quantity and quality of forage. Lack of water is one of the important factors in reducing the level of corn, so this experiment was conducted in order to check the possibility of saving water consumption by using low irrigation method and choosing the best hybrid in low irrigation conditions.

In order to investigate the effects of low irrigation and different maize hybrids on the quantitative and qualitative traits of maize forage in the Gorgan region, an experiment was conducted in split plots arranged in a randomized complete block design with three replications in the Iraqi station of the Gorgan. Low irrigation was implemented in four levels in the main plots (100, 75, 50% and 25% of water requirement) and subplots in four levels (including hybrids SC703, SC704, ZP548 and BK50). To determine the amount of water consumption three days after each irrigation, the amount of moisture was determined by sampling the soil and immediately after reaching 40 to 60% usable moisture, irrigation was done. Irrigation was done as a drip using tapes, the distance between the nozzles was 20 cm and the amount of water output per nozzle was 2 liters per hour. Harvesting was done from the two middle lines by removing half a meter at the beginning of the row and weighed separately (leaf, stem, cob) in a separate laboratory, and their fresh weight was recorded and then placed in an oven with a temperature of 65 degrees Celsius for 72 hours, Then the dry weight was calculated. The samples of dry forage were sent to the laboratory of Forests and Ranges Organization (Tehran) and the amount of protein, fiber and other quality attributes of forage were measured by infrared spectrometry with PertenInformatic 8620. The data were analyzed using SAS 9.1.3 statistical software and the means were compared with the LSD test at the 5% probability level.

The results of analysis of variance showed that low irrigation effect was significant on all studied traits. Also, the effect of the studied hybrids on all the traits was significant except for insoluble fibers in acidic detergent and water-soluble carbohydrates. Also, the interaction effect of hybrid × low irrigation was significant only on forage yield (Total biomass, ear fresh weight, stem and leaf fresh weight, and total dry weight). The results of means comparison showed that the highest biomass yield was observed in the 100% water demand treatment, which was 7.2, 49, and 79.7% higher than the 75, 50, and 25% irrigation treatments, respectively. However, the highest water consumption efficiency with a significant difference compared to other levels was observed in the treatment of 75% water requirement (5.99 kg m-3). Also, with the increase of irrigation levels, the amount of crude protein, crude fiber, water-soluble carbohydrates and insoluble fibers in the neutral environment increased significantly, and among the studied hybrids, the SC703 hybrid had the highest forage yield (43692.4 kg ha-1).

Considering the shortage and high economic value of water, the reduction in rainfall and the occurrence of successive droughts in recent years, optimum use of water can allocate more land to irrigated cultivation in addition to achieving appropriate and economic performance. The results showed that the lack of water reduces all quantitative traits. Among the studied hybrids, SC703 had the highest forage yield per unit area. On the other hand, low irrigation treatment at the level of 75% of the total water requirement is recommended to achieve the highest water consumption efficiency in Gorgan region.

In order to investigate the effects of soil salinity, plant density and planting date on quantitative and qualitative yield of forage mustard forage, an experiment was conducted in 2016 at Gorgan Nemoone Farm Research Station as a split split plot in a randomized complete block with three replications. Main factor of soil salinity (2 and 10 dS/m), sub-factor of planting date (6 November, 21 November, 6 December, 21 December and 5 January) and sub sub-factor of plant density at three levels (208000, 277000 and 416000 plants Per hectare) was considered. The results showed the interactions of environment × planting date on all studied traits including fresh weight, dry weight, percentage of leaf protein, percentage of stem protein, percentage of pod protein, percentage of total protein, protein yield, percentage of leaf fibers, percentage of stem fibers, percentage of Pod fibers, percentage of total fibers, fiber yield and leaf proline concentration were significant. The interaction effect of environment × planting density was also significant on all the mentioned traits except leaf protein percentage and leaf proline concentration. Also, the interaction effect of planting date and planting density was not significant only on stem protein percentage and leaf proline concentration. In conclusion, it can be said that the cultivation of forage mustard on November 6 and 208000 plants per hectare will produce the highest fresh and dry weight of forage and protein yield, as well as the lowest amount of fiber.

Over the past four decades, pod anormaly disorder has been one of the most important factors affecting soybean seed yield and production in Golestan province in Iran. To assess the role of crop management factors on soybean pod anormaly and seed yield, 80 soybean fields were selected randomly during 2018 and 2019 in Gorgan and Aliabad in Glestan province. Stepwise regression analysis showed that seed yield model (Yield = -442.5 + 6.9 X1 + 180.2 X2 + 866.2 X3) was determined with three factors of potassium fertilizer (X1), number of irrigation (X2) and insect pest management (X3). Potassium fertilizer, number of irrigation and insect pest management explained 19.2%, 18.7% and 62.1% of the yield gap components, respectively, and reflected the importance of these factors for increasing soybean seed yield. Among 80 soybean fields, 15 and 18 fields had full and partial pod anomaly disorder symptoms, respectively. The mean soybean seed yield for fields without and partial pod anomaly disorder was 3039 and 848 kg ha-1, respectively. The results of this study showed the importance of optimum insect pest management to prevent and control the incidence of soybean pod anomaly disorder in Goletan province in Iran.

Over the past four decades, pod anomaly disorder has been one of the most important factors affecting soybean seed yield and production in Golestan province in Iran (Payghamzadeh, 2017; Malek Shahkouei et al., 2019; Faraji et al., 2023). This conditions has led to disorders in the flower and pod system of the soybean plant which ultimately causes no or low pod set, modified of pods shape, stay-green plants, and so called by the farmers, fodder plants In fact, in the affected plants, a mechanism prevents the transfer of assimilates from leaves to seeds, hence the leaves remain green and the plants continue vegetative growth. In 2015, about 13765 hectares out of the total of 35107 hectares (about 39% of the soybean growing areas) suffered from this disorder. Due to luck of adequate quantitative information on the role of each of the factors in the incidence of this disorder and seed yield reduction, it would be necessary to investigate the effect of each of these factors on reduction of the soybean seed yield to enable farmers to overcome these limiting disorders by adopting appropriate crop management strategies.
 

In order to investigate the role of management factors affecting the seed yield and incidence of pod abnormality disorder in soybean, during the years 2018 and 2019, 80 soybean fields in the two cities of Gorgan and Aliabad, were determined and investigated. These fields included good, medium and poor fields and even seed production ones. Soybean variety cultivated in all investigated fields was Katul. During the growing season, the stages of development, including the date of planting, emergence, beginning and end of flowering, podding, seed filling, physiological maturity and harvest maturity were determined (Fehr et al., 1971). For data analysis, the collected information was normalized (SAS, 1997). To determine the yield model, qualitative variables were coded as zero and one. Then, the relationship between all quantitative and qualitative measured variables with yield was investigated through step wise regression method and data analysis was performed using the statistical method of yield comparison analysis (Soltani et al., 2009). Finally, using the yield model and parameter values, potential yield, yield gap and the contribution of each factor causing the yield gap were determined.
 

Out of 80 studied soybean fields, 47 fields had completely normal soybean plants and no pod anomaly disorder, 18 fields had moderate pod anomly disorder and 15 fields had completely affected by pod anomaly disorder. Mean seed yield in fields without disorder, with moderate disorder and complete disorder was 3039, 848 and 0 kg ha-1, respectively, indicating considerable sedd yield reduction of 72% and 100% in fields with moderate and complete disorder in comparison with fields without disorder. These results reflected the importance of pod anomaly disorder in reducing soybean seed yield. The seed yield model estimated the average and maximum seed yields as 2003 and 4792 kg ha-1, respectively. The estimated yield gap was 2789 kg ha-1 that with approperiate crop management particularly effective insect pest control, adequate potassium fertilizers application and adequate number of irrigations can be narrowed and even closed. The results of this two-year field study showed that under the conditions of Golestan province, it is possible to significantly increase soybean seed yield by application and adoption of appropriate crop management startegies and techniques.

In order to study the effect of deficit irrigation on antioxidant enzymes content, soluble carbohydrates, chlorophyll concentration and yield of two sweet corn cultivars a field experiment based on randomized complete block design (RCBD) arranged in factorial with three replications was conducted at the Education-Research Farm (With geographical position: 37°33' north, 59°11' east), Mashhad Branch, Islamic Azad University, Mashhad, Iran, during in cropping season 2018-2019. The experimental factors were included at three levels (0 (Full irrigation), 20 and 40% less than the irrigation requirement) and two sweet corn cultivars (Amylapop and Merit). The results showed that with increasing of deficit irrigation (increasing stress) content of catalase, peroxidase, superoxide dismutase enzymes and soluble carbohydrates increased. However, concentration of chlorophyll a, b and total, husked cob yield, dehusked cob yield and conservable grain yield decreased. The content of catalase, peroxidase, superoxide dismutase, husked cob yield, dehusked cob yield and conservable grain yield were higher in Amylapop cultivar than Merit. In general, the results of this research showed that the tested cultivars do not have the necessary stability under conditions. Therefore, applying the method of deficit irrigation in the studied cultivars it will be justified only if a 20 and 40 percent reduction in the amount of water used for this product is more beneficial than the reduction in yield.

Plant nutrition is one of the most important environmental factors affecting the yield and yield components of crops such as soybean. This study was conducted to investigate the effect of nitrogen-fixing bacteria, humic acid and foliar application of micronutrients on yield and morpho-phenological traits of soybean (cv. Saman) in a factorial randomized complete block design with three replications at Gorgan agricultural research station in two cropping seasons (2019-2020). Experimental factors include foliar application of humic acid at two levels including fulvic and humic acid; Bacterial seed at three levels including bacterial seed, bacterial seed+Azospirillium, and control; and nutrient spraying was applied at four levels including cobalt, cobalt+molybdenum, cobalt+molybdenum+boron, and control. Based on the results, the simple effects was significant on the studied traits. The bacterial Rhizobium+Azospirillum and cobalt+molybdenum+boron treatments significantly increased the traits than control. The highest grain yield was observed under the humic acid (2750 kg/ha), bacterial seed+Azospirillum (2238 kg/ha) and cobalt+molybdenum+boron (2388 kg/ha). In general, the results of this study indicate the efficiency of nitrogen-fixing bacteria as well as foliar application of micronutrients in increasing soybean yield.

decres gap between actual yield and potencial yield (gap yield) is important way to incrace yield in unit. In order enhance yield, gap yield in any area determinted and factor participant be identified in gap yield in preduct crop plant. This investigation to order determination gap yield and limited factor to yield and contribution of each of them to soybean in Aliabad Katol area by using CPA method and boundary line analysis.

To carry out this study, Information on production management of 120 soybean farms in Aliabadabad district of Golestan province was collected in 2016. Management factors included field characteristics (area, previous crop, herbicides, previous crop, field position), seedbed preparation (type, number and time of tillage), sowing (amount of seed consumed, cultivar type, seed source, sowing date, Plant density), fertilizers and micronutrients (type of fertilizer, amount and timing of fertilizer application), pesticides (type and amount of herbicides and pesticides), use of biological control (Trichogram and Braun wasps), harvest (grain yield and harvest date). The yield was determined using CPA method and boundary line analysis.

The results showed that soybean yield potential in this region was 3921 kg / ha and soybean yield loss in Aliabad region was estimated at 30%. Delay in planting in this region was 8.4% of yield and suitable plant density of 15.5%, planting and seed consumption were 6.3% and 8.5% of seed yield, respectively. It was also found that not using herbicide before planting would decrease grain yield by 17.45%. According to the results, irrigation with 28.4% had the highest share in determining soybean production potential in the study area. The highest grain yield response to urea fertilizer application and irrigation was two-fold; increasing nitrogen up to 65 kg urea and 3 times irrigation increased grain yield and consuming greater than 65 kg ha-1 and more than 3 irrigation times. It did not change grain yield per hectare. The relationship between delay in planting and plant density with seed yield was dentate. 10-day delay in planting leads to increased yield, but yields maximum grain yield in fields that have 22 days past optimal sowing date.nsity with seed yield was dentate. 10-day delay in planting leads to increased yield, but yields maximum grain yield in fields that have 22 days past optimal sowing date.

In general, soybean yield in this area is related to resource limitation and crop management is second in importance, which can increase soybean production by 30% with proper irrigation and nitrogen use.

Natural biostimulants such as seaweed and humic acid may have positive effects on germination. Seaweed extract comprises high and low consumption elements, amino acids, plant growth regulators, and vitamins which increase root absorption and improve the quality and compounds of antioxidants. Humic acid is a mixture of sources such as soil, humus, oxidized lignite, coal and etc. Nutrients are essential for the growth and development of plants which are consumed in lower amounts. This current study was conducted to investigate the effects of biostimulants of seaweed and humic acid and some nutrients on seeding and other related traits in soybean. The current study showed that biostimulants of seaweed extract and humic acid and some nutrients had positive effects on germination.

In order to efficiency of different herbicides on weed control, forage yield, crop growth rate (CGR) of alfalfa (Medicago sativa L), an experiment with nine treatments based on randomized complete block design (RCBD) with three replications at the research field of Iranian Research Institute of Plant Protection located in Meshkindasht, Karaj, during 2014-2016 was conducted. The treatments consisted of Eradicane 4.1 g ai/ha (EPTC), Metribuzin 525 g ai/ha, 2,4-DB 1269 g ai/ha, 2,4-DB 1480 g ai/ha, Bentazon 144 g ai/ha, Imazethapyr 50 g ai/ha (with 200 ml Sitogit), Imazethapyr 100 g ai/ha (with 200 ml Sitogit), non-herbicide control (weedy) and whole-season weeding control (weed free). Among different herbicides, application of Imazethapyr (1L/ha) led to control of Flixweed (Descurania Sophia) and wild mustard (Sinapis arvensis) (control percentage more than 95%). The lowest percentage of dry weight reduction in both weeds (flixweed and wild mustard) was related to Eradicane herbicide, which was 42 and 41% in the first cutting and 40 and 35% in second cutting. The highest and lowest fresh and dry weight of alfalfa (qualitative forage yield in 5 cutting were observed weed free and application of Metribuzin herbicide treatments. Also, index of crop growth rate (CGR) was more in weed free and application of Imazethapyr herbicide (1L/ha) treatments. Therefore, weed control in alfalfa established, application of Imazethapyr herbicide (1L/ha) as post emergence (3-4 leaves of weeds) is recommended.

The aim of present study was to investigate life cycle assessment of Iranian rice cultivars production affected by NPK chemical fertilizers using management. The experiment was conducted in farms located in Mazandaran province, Sari, during 2017 and 2018. The experiment was performed as split plot in a randomized complete block design with four replications. The different doses of fertilizer treatments at five levels including F1: 250 kg N ha-1 + 150 kg P ha-1 + 150 kg K ha-1 (N250P150K150), F2: 200 kg N ha-1 + 100 kg P ha-1 + 100 kg K ha-1 (N200P100K100), F3: 150 kg N ha-1 + 75 kg P ha-1 + 75 kg K ha-1 (N150P75K75), F4: 100 kg N ha-1 + 50 kg P ha-1 + 50 kg K ha-1 (N100P50K50), and F5: Control or no application of fertilizer treatments (N0P0K0) as main plot and local rice cultivars at two levels of Sang Tarom and Tarom Hashemi were considered as sub-plots. The results showed that an average amount of cumulative energy demand and cumulative exergy demand was 11549.78 and 13443.08 MJ, respectively that with increase of nitrogen consumption, both indices showed a decreasing trend. The average ecological footprint was 1190.80 m2a which CO2 emissions had shown the highest effect on the ecological footprint. The average of the impact categories of abiotic depletion was equals 12.44 kg Sb eq, acidification (3.15 kg SO2 eq), eutrophiction (2.33 kg PO4 eq), malodorous air (7295733 m3 air), freshwater sediment ecotoxicity (75.79 kg 1,4 DB eq), marine sediment ecotoxicity (116.11 kg 1,4 DB eq) that all of which decreased with increasing nitrogen consumption. The average global warming potential (GWP) 20a and GWP 500a were 399.20 and 382.97 kg CO2 eq, respectively. Two indicators of human toxicity and terrestrial ecotoxicity in the three periods of 20, 100 and 500 years shows increasing amounts equal 0.42% and 140.70% during 20a to 500a, respectively. All pollutants released into the air and the water demonstrated a decreasing trend with increasing nitrogen amounts. The emission of nitrate into soil, metals into the soil, and chemical oxygen demand showed a decreasing trend with increasing nitrogen levels. By group comparing between different levels of nitrogen at splitting levels, it can be stated that the main cause of variations in the amount of pollutants was the higher output (yield) compared to inputs. Indeed, nitrogen uptake in four developmental stages has resulted in maximum plant use, resulting in increased yield and emission reduction per unit area. Therefore, reducing the emission of pollutants by increasing nitrogen consumption can be due to increase of yield. According to the findings of this study, the application of N150P75K75 treatment is a better option to improving the yield of rice cultivars along with a decrease in chemical fertilizers and subsequent reduced fertilizers costs and environmental damages.

In order to determine the effect of foliar application of micronutrient fertilizers and humic acid consumption on the yield and yield components of sesame in the delayed planting date, an experiment was conducted in the research farm of Iraqi Mahalle station in the crop year of 2022. This research was carried out as a completely randomized block design with 9 treatments in 3 replications in the research farm of the Iraqi Mahalle. In each plot, 5 rows were planted, the distance between rows was 40 cm and the distance between replications was 3 meters. The studied traits included plant height, harvest index, seed yield, thousand seed weight and biological yield. The results obtained from this study showed that the treatment with humic acid + micronutrient, control and control + irrigation fertilizer + humic acid fertilizer had the highest biological performance, and the lowest biological performance was related to humic acid irrigation fertilizer and irrigation fertilizer + micronutrient. Also, the weight of one thousand seeds in the control group and the eighth treatment was significantly lower compared to other treatments. These results show that the use of micronutrient fertilizers and humic acid could significantly increase the weight of a thousand seeds. Finally, the seed yield was significantly higher in control, control + humic acid seed, and control + humic acid seed + micronutrient than other treatments. These results show that application of humic acid has better effects on grain yield than other treatments.

In order to evaluate the effects of deficit irrigation on the yield and water productivity of grain corn in the climatic conditions of Gorgan,an experiment was conducted using split plots in the form of a randomized complete block design in three replicates at the Araghi Mahaleh Research Station of Gorgan, in 2021. The main factor was irrigation treatments at four levels (100% (control), 75%, 50%, and 25% of corn water requirement) and was done based on soil sampling for moisture determination and use of drip irrigation by tape, and the secondary factor consisted of four corn varieties (SC703, SC704, ZP548, BK50). The results of the analysis of variance showed that the effect of irrigation factor was significant (p< 1%) on the examined traits, except the number of rows in the ear. The effect of cultivars on all traits (number of rows per ear, days until earing, plant height, number of seeds per row, weight of 1000 seeds, length of ear, dry weight of stem and leaves, dry weight of cob wood, grain yield, yield, water productivity, and leaf proline) was also significant (p< 1%). Additionally, interaction of deficit-irrigation and cultivars on the traits of the number of rows of seeds, weight of 1000 seeds and seed yield was significant. Comparing the averages showed that the highest seed yield (7722 kg/ha) was observed in the control treatment and the seed yield of the 75%, 50% and 25% treatments compared to the control was 6.8%, 52.4%, and 82% less, respectively. ZP548 hybrid had the highest seed yield (5576 kg/ha) and the highest amount of proline was obtained from the 25% water demand treatment (9.91 μmol/g). The highest water productivity was observed in the 75% treatment (1.07 kg/m3). Considering the large volume of water saving (2258 m3/ha) in this treatment, irrigation is recommended based on 75% of water requirement and cultivation of ZP548 variety in Gorgan region.

In order to investigate the effect of seed decay, plant density and defoliation on morphological, yield and yield components of bread cultivar, an experiment in the cropping years 2016-17 and 2017-2017, in Galikesh city of Golestan province with a longitude of 26 degrees and 55 minutes, Latitude 16 degrees and 37 minutes and altitude 200 meters above sea level. The experiment was a factorial randomized complete block design with three replications. Experimental treatments included two levels of seed decay including decayed (control) and decayed seeds (72 hours at 45 ° C), three density levels including 350, 400 and 450 seeds per m2 and decolonization at four levels including removal of all leaves, removal of all Leaves except flag leaf and delete all leaves except flag leaf and before, without leaf removal (control). The simple effects of accelerated leaf removal and accelerated aging and wheat seed density on yield and its components were significant at the level of one percent. The results showed that seed degradation significantly reduced biological yield, 1000-seed weight, number of spikes per square meter, 1000-seed weight, grain yield and harvest index. The highest biological yield, 1000-seed weight, number of spikes per square meter, number of seeds per spike, 1000-seed weight, grain yield and harvest index were obtained at a density of 450 seeds per square meter, which can be expressed as the desired density for this cultivar. Decolorization significantly reduced biological yield, number of spikes per square meter, number of seeds per spike, grain yield, biological yield and harvest index.

In order to investigate the effects of nitrogen rate and time of irrigation on the grain yield and grain yield components of wheat, one experimental as split plot was carried out as split plot design based on randomized complete block design with four replications in research farm of Aliabad Katoul Emam Khomeini agriculture high school during 2018-2019 and 2019-2020. Irrigation time was in main plot (no irrigation, irrigation at stage 33 zadoks, irrigation at stage 70 zadoks) and nitrogen rate was in sub plot (zero, 57.5 kg N/ha, 115 kg N/ha from urea source). Significant interaction wasn’t observed between irrigation treatments and nitrogen rates in almost all traits. The highest yield was obtained by using a supplementary irrigation in stage 70 of Zadox and consumption of 115 kg of pure nitrogen. Grain yield had a positive correlation with biological yield, spike length, spike weight, number of seeds per spike and seed weight per spike. Factor analysis revealed that the first two factors explained 74.5% of the total variation. The results of stepwise regression analysis showed that only the spike weight trait entered the model and alone justified 80.7% of the grain yield variation.

In order to evaluate the effect of chemical and biological fertilizers on crop and physiological characteristics of wheat, pearl cultivar was applied in experimental form in the form of complete randomized randomized blocks with three replications in Nokandeh city of Golestan province. Experimental factors include nitrogen supply sources at four levels of nitrogen (12 g/100 kg seed), Azospirillum (12 g/100 kg seed), urea (200 kg/ ha-1) and an equal combination of three sources (33% Azotobacter + 33% Azospirillum + 33% urea) and phosphorus-supplying sources at the level of three levels of triple superphosphate (100 kg / ha), fertile phosphate 2 (12g/100 kg seed) and equal combination of two sources (50% triple superphosphate + 50% fertile phosphate 2)) Was with the control.  The results of analysis of variance showed that nitrogen and biological fertilizers had a significant effect on all traits except the weight of one thousand seeds at the level of one percent probability. The results showed that the highest plant height, biological yield, spike length, number of seeds per spike, grain yield, flowering and care protein, chlorophyll b and total fertilizer treatment combined the three sources of nitrogen supply (33% Azotobacter + 33% of Azospirillum + 33% Urea). High levels of leaf area index, spike and chlorophyll a were obtained with Azotobacter treatment. In summary, the results of this study showed that using the right combination of biofertilizers and nitrogen fertilizers can reduce the use of chemical fertilizers and therefore be consistent with agricultural goals.

The effects of transplanting and direct-seeding on agronomic traits and white sugar yield of sugar beet were studied in a split-plot experiment based on randomize complete blocks with three replications two regions of Miandoab and Bokan in 2016.  Treatments were three planting date (25 March, 8 and 18 April) and two planting systems (transplanting and direct-seeding .(Planting systems were assigned in the main plot and planting date in the subplots. The difference between direct and transplanting systems in terms of leaf area index, sugar extraction coefficient, root yield, white sugar yield and molasses sugar percentage were significant at 1% and sugar content and sugar yield at the 5% probability levels. The effect of sowing time on leaf area index, dry matter yield, sugar extraction coefficient, root yield, white sugar yield and sugar content of molasses were significant at 1%, and sugar content and sugar yield at 5% probability levels. The interaction effect of sowing time and planting system was significant on leaf area index, dry matter yield, sugar extraction coefficient, and root yield, white sugar yield at 1% and on sugar content at 5% probability levels. The transplanting system reduced the amount of molasses sugar by 32.41% compared to the direct planting system and the lowest percentages of molasses sugar were attributed to 25th of March planting date.  In the present study the highest leaf area index, dry matter yield, and sugar content, sugar extraction coefficient, root yield, and white sugar yield were allocated to the 25th of March planting date and transplanting system.

In order To evaluate the effect of yield and components yield of cotton as direct seeding and transplanting systems in Gorgan climatic conditions a randomized complete block study with four replications on Amirabad area of Gorgan in 2016-2017. Experimental treatments were included different sowing methods at seven levels (direct seed sowing at a distance on the row 20 cm at 65,000 plant. ha-1, single planting at 20 and 40 cm, and 65 and 32.5 plant.ha-1, two-plant seedling transplanting. 40 cm density 65 thousand plants.ha-1, single plant transplanting for two lines at 31 and 61 cm and 65 and 32.5 thousand plant.ha-1 and two types of single plant transplanting for 61 lines Cm was 65,000 plants.ha-1). The results of the experiment showed that the planting method treatment affected all the above parameters except the phonological stages. Comparison of mean data showed that transplanting system increased the number of open bolls and total bolls, plant dry weight, fiber weight of one plant and boll, and fiber yield. However, the highest plant height and the number of closed bolls were obtained from direct planting system. Also, the highest mean fiber yield 3595/154 kg.ha-1) was obtained from single plant transplanting system for single planting of 40 cm with a density of 32500 plants. ha-1, which increased fiber yield by 23/40٪ compared to the direct planting system.

Climate change has made it difficult to access water resources. Therefore, induction of water stress tolerance in seeds production can make a great revolution in agriculture by achieving optimal yield and potential seeds, while reducing water consumption. This research was conductedwith aime of evaluation the physiological potential of cotton seeds obtained from different irrigation treatments in order to cotton seeds reproduction for farm of Golestan province in water stress exposure. The experiment was done in splite plot factorial in complete block design with three replications during 1396-97 crop- season. Main plot includes of 4 irrigation levels including rainfed, 33, 66 and 100% of field capacity and the sub-factor also includes the seed resources treatments in 5 sub-plots including control (supplyment of seeds from sales centers) and 4 seed levels obtained from different levels of irrigation (rainfed, , 66 and 100% of crop capacity) were considered.The results showed that the effects of number of being in water stress exposure for seeds on physiological characteristics and yield of plants were significantly different. In 33% water stress exposure, S22seed resources had the lowest and the most starch and carbohydrate solution,36.62 and 65.97 mgFw-1. So, 33% FC irrigation was not water-deficiency stress for S22. Decreasing in leaf area of S23 seed treatments in the double water stress exposure in rainfed and 100% FC conditions indicates that both rainfed and heavy irrigation are stressful for S23.

The majority of the country's oil consumption comes from foreign sources. Therefore, the development of oilseed crops is critical. Safflower has a special status among oilseed grains adapted to the country's conditions, and it is ecologically compatible with many agricultural lands in the country. Research has shown that planting date and plant density significantly affect the yield and yield components of crops. Over the past few years and in different Iran regions, several cultivars have been isolated from safflower, which may vary in response to planting date and plant density. Therefore, this study was conducted to study and determine the most suitable planting date and plant density for the advanced safflower cultivars and their effect on grain yield, forage, oil, and yield components in the Gonbad-e Kavus area.

This study was conducted with two separate factorial experiments (the first experiment on 30th of November and the second on 20th of December) in a randomized complete block design with four replications at the Agricultural and Natural Resources Research Station of Gonbad-e-Kavus in two seasons of 2013-14 and 2014-15. In each experiment, two sowing densities of 20 and 40 plants per square meter (10 and 20 cm plant distance on the row) and four advanced safflower cultivars included: Golmehr, Soffeh, Padideh, and Goldasht, were combined as factorial and formed eight treatments. Seeds of the mentioned cultivars were prepared from the Golestan Agricultural and Natural Resources Research and Education Center. The row spacing was fixed at 25 cm for all treatments. SAS software was used to analyze the data, and the mean comparison of the data with SPSS software was performed as the least significant difference (LSD) test.

The results showed that the effects of planting date on the branch number plant-1, grain yield, oil percentage, forage ash, and the dry matter intake were significant. The influences of sowing density on branch number plant-1, 1000-seed weight, and oil percentage were significant. There were significant differences among the cultivars according to the branch number plant-1, and safflower seed oil percentage. The mean comparison of data showed that the highest branch number plant-1, grain yield, forage ash, and the dry matter intake were observed in the first planting date, and the delayed sowing decreased these traits significantly, while oil percentage showed a significant increase. Increasing the sowing density induced the branch number plant-1, 1000-seed weight, and oil percentage significantly. The forage yield showed a positive significant with grain yield and crude protein.

In terms of safflower planting date, it was observed that the first planting, due to suitable climatic conditions and longer growing period, had better results in the branch number plant-1, boll number plant-1, oil content, forage ash, and dry matter intake traits. With increasing plant density, branch number plant-1, 100-seed weight, and oil percentage decreased significantly, so due to the importance of oil content, 20 plants per square meter is recommended. According to this study's results, the Soffeh cultivar could be used for the earlier sowings, but there was no significant difference in grain yield among the cultivars with delayed sowing. So, four studied cultivars Golmehr, Soffeh, Padideh, and Goldasht, could be cultivated under the delayed planting date conditions, and it is suggested that selection of safflower cultivar should be made according to the purposes of safflower planting (forage, oil, or seed breeding).

 In order to evaluate the influence of nitrogen fertilizer and sowing dates on agronomic characteristics, yield component and seed yield of rapeseed cultivar RGS003, two field experiments (separate) were carried out base on a randomized complete blocks design with three replications in 2014-15 and 2015-16 during growth seasons in research field of Islamic Azad University, Gorgan Branch. First experiment (November 9) and Second experiment (December 9), was performed, each one in 7 nitrogen levels (50, 75, 100, 125, 150, 175 and 200 kgN.ha-1). The analysis of variance results showed that sowing date and nitrogen fertilizer had significant effect at p<0.01 for pod per plant, seed per pod, 1000weight, biological yield, seed yield and harvest index. Highest (3128 kg.ha-1) and lowest (2414.95 kg.ha-1) seed yield was observed in 200 and 50 kgN.ha-1) treatments respectively. In two year, seed yield, biological yield and harvest index reduction at second sowing date was related to insufficient vegetative growth before flowering stage. Under present experimental conditions, planting on November 9 and usage of 175 and 200 kgN.ha-1 can be recommended as an appropriate date for obtaining the highest seed yield.

in oIn order to investigate the quantitative and qualitative response of autumn rapeseed cultivars to nitroxin biological fertilizer in drought stress conditions, a split plot factorial experiment was conducted based on complete randomized blocks design with 4 replications in the research farm of Agricultural Research and Training Center And the natural resources of Bojnourd city in 2015-2016 and 2016-2017. Factors were: drought stress at three levels (low, medium and serve) as the main plot and Nitroxin application (non-inoculation, inoculating with nitroxin), 3 rapeseed cultivar Natalie, Okapi and Neptune in factorial arrangment as the sub plot. Severe stress reduced the plant height (62.5%), the number of laterl branches (76.3%), the number of pods per plant (45.56%), the number of seeds per pod (1.3%), and the weight of 1000 seeds (11.52%), seed yield (19.2%), seed oil percentage (5.5%) and seed oil yield (90.45%) compared to low stress conditions. Maximum plant height (156 cm) and number of laterl branches (8.1), seed number in pods (24.8) and weight of one thousand seeds (3.44 gr) were observed in Neptune cultivar, grain yield (2062 kg.ha-1) and seed oil yield (933 kg.ha-1) in Natali cultivar and protein yield (321 kg.ha-1) in Natalie and Neptune cultivars. Overall, the results showed that the Natali was more tolerant to drought stress than other cultivars. Nitroxin also increased the tolerance of rapeseed to drought stress.

In this study, different genotypes of faba bean were evaluated for Tolerance index and biochemical compounds under drought stress. 21 Genotypes of faba bean were studied based on RCBD design with three replications in two irrigation treatments (including normal irrigation and drought stress) during two cropping years (2018-2019) at Gorgan Agricultural Research Station. Based on the potential (Yp) and stress (Ys) yields, drought tolerance including Stress Tolerance Index (STI), Tolerance Index (TOL), Stress Susceptibility index (SSI), Mean Productivity (MP), Geometric Mean Productivity (GMP), Yield Index (YI) and Yield Stability Index (YSI), stress Susceptibility Percentage Index (SSPI) were calculated for each genotype. According to data combined analysis, drought stress has significant effect on all studied traits. In drought stress, seed hull tannin, Endosperm tannin, and starch were 31.5, 19.7 and 1.96% more than normal conditions, respectively. Genotype×drought interaction showed the G-faba-66, G-faba-65, G-faba-62, G-faba-294, G-faba-292, G-faba-523, G-faba-525, and G-faba-20 genotypes in normal irrigation and the G-faba-67, G-faba-66, G-faba-75, G-faba-72, G-faba-65, and G-faba-62 genotypes in drought stress had the highest seed yield. G-faba-65 genotype showed the highest resistance to drought stress based on Tolerance index and biochemical compounds content.