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In order to study the effect of foliar application of zinc and iron on yield quantity and quality of canola (Brassica napus cv. Talaye) an experiment was conducted in Zarghan region of Fars in 2008- 2009 crop season. Iron and zinc solutions were sprayed twice (first in stem elongation and then in early flowering) treatments, including concentration of zinc sulfate in three levels: (0, 2, 4 gr lit-1) and Iron sulfate in three levels: (0, 2, 4 gr lit-1). This experiment was arranged as factorial using randomized complete block design in four replications. Significant interaction between zinc and iron foliar application was observed for grain yield, seed protein percentage and oil yield. Maximum grain yield (4905.3 kg ha-1), Seed protein percentage (37.7%) and oil yield (2124.5 kg ha-1) was obtained from foliar application of combined zinc and iron at 4 g lit-1. Increasing of zinc from 0 to 4 gr lit-1 significantly increased 1000 seed weight (from 4.24 to 4.69 gr), number of seed per pod (from 19.12 to 22.88), seed oil percentage (from 38.67 to 43.17) and seed zinc concentration (from 33.28 to 22.07 mg kg-1). Increasing iron from 0 to 4 gr lit-1 significantly increased 1000 seed weight (from 4.24 to 4.64 gr) and seed iron concentration (from 64.29 to 79.18 mg kg-1). Finally, with respect to this research, foliar application of zinc and iron sulfate together and twice, at 4 g lit-1 was suggested to get more quantity and quality of canola (Talaye) in Zarghan.

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Impact of three water deficit treatments in vegetative, flowering and grain filling stages along with optimum irrigation as control were evaluated on grain yield and agronomic characteristics of 8 sunflower cultivars (Hysun 33, Hysun 25, Farrokh, Record, Aravirski, Lakumka, Master and SHF 81-90) as a strip plot design with three replications in Khoy Agricultural and Natural Resources Research Station. Different water regimes had significant effect on growth period, plant height, stem and head diameter, seed yield and its component. Stem diameter, plant height and seed number per head were affected considerably by drought stress in vegetative stage, while head diameter by drought stress in flowering stage and growth period and seed weight by water deficit in seed filling stage. Water deficit in flowering and vegetative stages had the highest (38%) and lowest (25%) negative effect on grain yield, respectively, so flowering stage and vegetative stage established as the most sensitive and tolerant stages to water deficit, respectively. Farrokh hybrid with highest seed yield in different irrigation treatments (3686, 2856, 2256 and 2506 Kg/ha in control and water deficit in vegetative, flowering and grain filling stages, respectively) revealed as the most drought tolerant cultivator while Hysun33 lowest seed yield showed maximum drought sensitive.

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In order to comparison of antioxidant enzymes and proline roles in drought tolerance of rapeseed, an experiment was conducted at the research field of Yazd Agricultural and Natural Resources Research Center in 2011-2012. In this study, three commercial rapeseed genotypes (GKH2005, Opera and Okapi) were examined for response to irrigation treatments such as non-stress conditions (control) and withholding irrigation from stem elongation, flowering and silique formation stages in four separate experiments based on randomized complete block (RCB) design. The results indicated that proline accumulation, activity of catalase and proxidase enzyme and lipid peroxidation index (content of malondealdehyde) were higher in drought stress treatments, but these amounts were different in three rapeseed genotypes. Maximum activity of antioxidant enzymes and low content of malondealdehyde was observed in GKH2005 compared with others, in drought stress conditions. Between these genotypes, GKH2005 produced the highest seed yield under non-stress conditions and withholding irrigation from stem elongation, flowering and silique formation stages as 3110, 1450, 1773 and 2510 kg.ha-1, respectively. These results showed that role of antioxidant enzymes on reduction of lipid peroxidation and increasing the drought tolerance is more than proline. Also, an effective antioxidant system along with lower malondealdehyde and high silique number per secondary branch had the greatest role to productivity maintenance of Rapeseed under drought stress conditions

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In order to the evaluate the effect of planting dates on phenological traits, plant height, pods per plant and seed yield of rapeseed spring varieties, a split-split plot experiment based on randomized complete block design with four replications was conducted during 2 years at Agriculture Research Station of Baykola, Mazandaran, Iran. Treatments were planting dates (September 29, October 9, October 19, October 29 and November 8) as main plot and sub-plots were three cultivars ( Hyola401, Option500 and RGS003. All the traits were affected by planting date and variety. The mean values of seed yield of Hyola401, Option500 and RGS003 were 3274, 2898 and 3040 kg ha-1, respectively and Option500 and RGS003 had not statistically significant difference. Non significant interaction effects of planting dates and varieties for seed yield indicated that yield reduction of the varieties in late planting dates had similar trend and Hyola401 and Option500 had the most and the least seed yield, respectively. Seed yield reduction at late planting date was related to insufficient vegetative growth before flowering stage. Significant positive correlation between plant height and number of pods per plant was the main reason that in late planting date reduction of plant height imposed reduction of pods per plant and finally seed yield was decreased.

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The present study was conducted to evaluate the yield and agronomic traits of commercial soybean genotypes and introduce the genotypes that are compatible with higher yield potential for both spring and summer cultivation seasons. This study was carried out in a split plot experiment based on randomized complete blocks with three replications during two cropping years, 2008-2009 and 2009-2010, in the field of agricultural and natural resources research center of Moghan. The main plot was the cultivation date in two levels of summer and spring cultivation and the subplot was 14 cultivars of soybean including Sahar, Linford, Hobbit × Williams, Davis× Williams, 032, DPX, Ronack, JK, BP, 033, Clarck,Williams, Zan and L17. A combined analysis of the grain yield over two years revealed that the effect of cultivation date, genotype and their interaction was significant at 1% probability level. Comparison of the two cultivation dates demonstrated the yield rates of 3642.1 and 2530.3 kg/ha for spring and summer cultivation, respectively. Zan and Linford varieties with yield rates of 4276 and 4105 kg/ha respectively over the spring cultivation and the cultivar of BP and L17 with yield rates of 2974 and 2920 kg/ha respectively over the summer cultivation had the highest yield among all cultivars.

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In order to study the effect of limited-irrigation stress on canola cultivars, an experiment was conducted in 2007-2008 at the Safiabad agricultural research center. The design was a split plot in a completely randomized block basis with three replications. Main plots were consisted of 4 levels of limited-irrigation, irrigation based on 60 mm cumulative evaporation (Control), withholding irrigation in flowering stage, withholding irrigation in pod initiation and irrigation withholding in grain filling period, and subplots were 5 canola cultivars (Hyola308, Hyola330, Hyola401, Hyola420 and RGS003). The mean comparison of interaction showed that the highest (3155.55 kg.ha-1) grain yield appointed to Hyola420 cultivar in optimum irrigation (control treatment), and the lowest (1491.66 kg.ha-1) belonged to RGS003 cultivar at withholding irrigation in pod initiation period. The maximum (161.42) number of pods observed on Hyola330 cultivar at optimum irrigation (irrigation after 60 mm cumulative evaporation), and the minimum (78.1) ones appointed to RGS003 cultivar at withholding irrigation in pod initiation period. Results showed that there was no significant difference among withholding irrigation, cultivars and the interaction effect of them for oil content. By considering the results of this experiment, withholding irrigation at flowering, pod initiation and grain filling periods leads to decrease grain yield by 24.72%, 14.33% and 11%, respectively. Reduction of grain yield due to the withholding irrigation during flowering, podding and grain filling stages was along with a decrease in the number of pods per plant and thousand seed weight. By considering the results of experiment, withholding irrigation in flowering stage has to be avoided.

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Humic acid as an organic acid produced by humus and other natural resources can improve nutrients absorption and seed yield. In order to study the effect of granular humic acid and foliar application of compost tea and vermiwash on nutrient absorption, chlorophyll content and seed yield of safflower (Carthamus tinctorius L.), an experiment was conducted as a factorial experiment based on randomized complete block design with three replications in agricultural research farm at Vali-e-Asr University of Rafsanjan. Treatments included of soil application of humic acid (0, 500, 1000 and 1500 kg ha-1) and foliar spraying of vermiwash 1:10, vermiwash 1:20, compost tea and distilled water as control. Results indicated that humic acid application had significant effect on the zinc, nitrogen and phosphorus content of shoot, chlorophyll index and seed yield. On the other hand, compost tea foliar application significantly influenced zinc and copper content of shoot, chlorophyll content and seed yield of safflower. It seems humic acid application (1500 kg.ha-1) in soil along with compost tea foliar application was the best treatment for producing of seed yield and higher nutrition absorption, chlorophyll content in safflower.

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In order to evaluate the effect of different nitrogen fertilizer levels on physiological traits, plant height, yield components, and seed yield of rapeseed genotypes a split-plot experiment based on a randomized complete block design with three replications was carried out at the Baykola Agriculture Research Station, Mazaandaran during 2010-11. Four levels of nitrogen, as urea fertilizer, including of 0, 70, 140 and 210 kg ha-1 were considered as main plots and four rapeseed genotypes including of L7, Zafar, RGS003 and Hyola401 were considered as subplots. The result of analysis of variance revealed that the traits, including number of days to flowering, number of days to end of flowering, number of days to maturity, plant height, siliques pods per plant, seeds per silique, seed yield and oil yield were significantly affected by nitrogen levels. Genotype effect was significant effect on all the traits except seeds per silique. Hyloa401 and Zafar respectively with 3831.2 and 3893.7 kg ha-1 of seed yield, and also 1638 and 1591 kg ha-1 of oil yield were classified at the same statistical group. Non significant interaction effects of nitrogen fertilizer application and genotypes were achieved for all of the studied traits, indicated that the trend of variation of these traits due to nitrogen levels were similar in all genotypes. A significant positive correlation of seed yield with the other studied the traits, except days to flowering, indicated that increasing of nitrogen level application made increasing of the traits and finally seed yield.

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Soybean is one of the most important oil production resources in the world. In order to study of genetic diversity and relationships among quantitative and qualitative traits of 14 soybean cultivars, an experiment was conducted as a randomaized complete block design with four replications in 2013 at the Agriculture Research Farm, Shirvan Higher Education Complex. 12 traits such as seed and components yield, protein and oil content were evaluated. The results showed that there were significant differences among genotypes for all traits except protein content, which indicates the existence of genetic variations between genotypes. Zane, Century and Clombus cultivars had the highest seed yield, although, the lowest yield was achieved in Habit cultivar. Results showed that seed yield was positively and significantly correlated with number of pods per plant, number of seeds per pod, number of seeds per plant,100 seed weight, oil content, protein content and harvest index and there were significant and negative correlation between seed yield with number of days from planting to flowering . The Zane cultivar had the highest oil content of 515.8 kg ha-1. Based on the stepwise regression and path analysis the grain yield of soybean cultivars were explained by the direct and indirect effects 100 seed weight, number of pods per plant, number of seeds per pod and number of seed per plant. Considering to the residual effects and the coefficient of determination (86.7 percent), the large proportion of the variation in seed yield of soybean were determined with these four traits of seed yield. Path analysis showed that the greater and lower direct positive effects on seed yield were related to 100-seed weight and seed number per plant, respectively. In general, Zane , Columbus and Cencurty cultivars due to their high oil and seed yields can be proposed cultiveting in North Khorasan.

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Studyign of soybean cultivars under abiotic stress conditions to improve their yield is important. This experiment was carried out as a strip plot based on a randomized complete block design with three replications in the Safiabad Argicultural Research Center. Vertical factor consisted of foure levels of irrigation (Irrigation after 50, 90, 130 and 170 mm evaporation from class A pan) and horizontal factor was 6 soybean genotypes (504, Katoul, Safiabadi, BP×Safiabadi, Migmat and Salend). Results showed that the effect of drought stress, genotypes and their interactions were significant on grain yield. The mean comparison of drought stress × genotype interaction showed that the highest grain yield (4522 Kg ha-1) achieved in irrigation after 50 mm evaporation from class A pan in Migmat and the lowest grain yield (1017 Kg ha-1) belonged to Katoul genotype with irrigation after 170 mm evaporation from class A pan. Pod number per plant decreased by 16%, 28% and 51% with increasing irrigation intervals to 90, 130 and 170 mm compared to irrigation after 50 mm evaporation. The treatments did not have any significant effect on the number of grain per pod. It is concluded that, irrigation after 50 mm evaporation from class A pan would be suitable for Migmat and BP×Safiabadi genotypes. Irrigation after 90 mm evaporation from class A pan appropriate for 504, Salend, Katoul and Safiabadi genotypes.

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In order to investigate the effects of boron, zinc and sulfur on quantitative and qualitative characteristics of rapeseed (Hyola 401 cultivar), an experiment was conducted at Rice Research Institute of Iran, Rasht province in 2011. A field experiment with completely randomized block design was performed with eight treatments in three replications. Treatments consisted of control, zinc was added as Zn 15% EDTA at the rate of 1.5 kg ha^−1 were applied to the soil, Boron was added as Borax at the rate of 1.5 kg ha^−1, sulfur treatment added at the rate 100 kg ha^-1 before of sowing, B+Zn, B+S, Zn+S and B+Zn+S. Maximum grain yield (4157.6 kg ha^-1) was obtained from S+B+Zn treatments that increased the seed yield by 48.7% compared to the control. Maximum and minimum oil content obtained from B+Zn+S (42.58%) and control (38.37%). Maximum protein (24.62%) was obtained from zinc fertilizer. The highest leaf boron, zinc and sulfur content were obtained in treatments B+Zn+S of 15.7, 26.38 and 577.4 mg kg^-1 respectively, and minimum nutrients content was obtained in control. Regards to the experiment results, the application of B+S fertilizer increased the seed yield and oil content and is suggested in Rasht reign conditions.

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In order to study the effects of different levels of sulfur along with Thiobacillus and zinc on qualitative and quantitative growth of canola cv RGS003, a factorial experiment was conducted based on an RCBD with three replications at the Agricultural Research Station of Gonbad in 2013. The first factor was the application of sulfur with Thiobacillus at four levels, i.e. without sulfur and Thiobacillus (S0), 500 kg sulfur ha^-1 + 10 kg Thiobacillus ha^-1 (S1), 1000 kg sulfur ha^-1 + 20 kg Thiobacillus ha^-1 (S2) and 2000 kg sulfur ha^-1 + 40 kg Thiobacillus ha^-1 (S2). The second factor consisted of two levels of zinc: without zinc (control) and 20 kg zinc sulfate ha^-1. The results showed that all traits studied were significantly affected by sulfur with the exception of pod length. The effect of zinc was significant at 0.01 probability level of biological yield, seed yield, harvest index, straw yield, oil percent and oil yield. With an increase in application of sulfur mixed with Thiobacillus up to 1000 kg sulfur ha^-1 + 20 kg Thiobacillus ha^-1 (S2), all yield components increased except oil percent, but their further increase resulted in reduction of seed yield and yield components of canola cv RGS003. With the exception of oil content, the other traits studied were not affected by the interaction of sulfur by zinc.

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In order to evaluate the land equivalent ratio based on forage yield, oil content and some elements of peanut (Arachis hypogaea L.) grain in intercropping with corn (Zea mays L.), an experiment was carried out during 2013 and 2014 cropping seasons based on a randomized complete block design with three replications in the experimental field of Agricultural and Natural Resources Research and Education Center in Guilan province, Rasht, Iran. Sole cropping of corn and peanut, corn and peanut intercropping patterns with the ratio of 1:1, 2:1, 1:2 and 2:2 planting rows comprised the experimental treatments. The highest corn forage yield was obtained in corn-peanut intercropping pattern with the ratio of 2:1 planting rows. In this research, corn-peanut intercropping pattern with the ratio of 1:2 planting rows had superiority for forage yield, grain yield, oil and protein yield of peanut grain to other corn-peanut intercropping patterns. The lowest forage and grain yield of peanut was shown in corn-peanut intercropping pattern with the ratio of 2:2 planting rows. Results showed that forage and protein yield related to grain yield of peanut. There was a positive and significant correlation between oil and protein yield with grain yield of peanut. But, inversely relationship was shown between nitrogen and phosphorus content in peanut grain. Based on the results of this experiment, corn-peanut intercropping patterns with the ratio of 1:2 and 1:1 planting rows could be recommendable for peanut, grain yield and land equivalent ratio enhancement under climatic condition of the region, respectively.

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In order to evaluate the quantitative and qualitative yield of peanut (Arachis hypogaea L.) in response to starter nitrogen rates two separate experiments were performed in 2013 and 2014 cropping season as randomized complete block design with three replications, in experimental field of Agricultural and Natural Resources Research and Education Center of Guilan Province, Rasht, Iran. Four rates of nitrogen including of zero, 100, 150 and 200 kg/ha comprised the experimental treatment. The results of this research showed that with increment of starter nitrogen application, duration of developmental stages in peanut enhanced. The greatest pod (3561 kg/ha) and seed yield (1740 kg/ha) of peanut, grain oil (49.86 percent) and nitrogen content (3.91 percent), oil yield (867 kg/ha) and protein yield (426.5 kg/ha) were obtained at 100 kg N/ha level. Application of 150 kg N/ha showed superiority for pod number per plant (21.30) and grain number per pod (1.39). Also, application of 200 kg N/ha caused to enhance plant height (73.35 cm) and grain phosphorus content (0.437 ppm) in peanut. In addition, there was negative and significant correlation between grain yield and some traits such as day number to initial flowering, day number to the end of flowering and maturity. The correlation coefficient between grain yield and oil (r= 0.99^**) and protein yield (r= 0.89^**) was positive and significant. In this experiment, oil and protein yield of peanut per unit area mostly related to grain yield. In general, results showed that the application of starter nitrogen up to 100 kg/ha enhanced pod and grain yield of peanut and oil and protein yield in Guilan province climatic condition.

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In order to evaluate the effect of different levels of humic acid on some quantitative and qualitative traits of cotton a factorial field experiment in a randomized complete block design with three replications was conducted in Kashan under salinity soil condition in 2013.Treatments included three cotton cultivars of Varamin, Line 43200 and Khordad as first factor, and six foliar ‌treatment included without humic acid and chemical fertilizer‌ (T₁), without humic acid with chemical fertilizer (T₂), 3 l/ha humic acid without chemical fertilizer (T₃), 1 l/ha humic acid with chemical fertilizer (T₄), 3 l/ha humic acid with chemical fertilizer (T₅), and 6 l/ha humic acid with chemical fertilizer (T₆).The results showed that humic acid significantly increased oil and protein content, yield, seed yield, fiber yield and 1000 seeds weight. In T₅ treatment, gin, lint, and grain yields, 1000-grain weight, and oil content increased by 32.74%, 31%, 33.69%, 5.32%, and 2.7%, respectively. Using 3 liters of humic acid without the application of chemical fertilizer increased seed protein yield by 63.4%.

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In order to determine the appropriate sowing dates, seed rates and their interaction effects on yield and yield components, oil and protein contents of soybean variety Sari, a split-plot experiment based on a randomized complete blocks design with four replications was carried out at Qaemshahr Gharakeil Agriculture Research Station in 2009. Five sowing dates including 15^th May, 31^th May, 15^th June, 1^th July and 16^th July were considered as main plots and three different seed rates including 60, 75 and 90 kg ha^-1 as the sub-plots. The results showed that all of yield components were affected by sowing dates and also seed rates had a significant effect on the number of pods per plant. Although due to increasing seed rates, yield components, such as pods per plant were decreased, but because of the increasing number of plants per square meters, seed yield not decreased significantly. Therefore for economically saving 60 kg ha^-1 of seed rates will be preferred. In this study high mean value of seed yield, biological yield and 1000-seed weight was achieved in first sowing date and all of the yield component characters were decreased in late sowing dates. Harvest index was increased in late sowing dates and it was not significantly affected by seed rates. Sowing dates and seed rates had not significant effects on oil and protein percentages, but due to significant effects of sowing dates on seed yield, oil and protein yields were significantly affected by sowing dates. In this study higher seed yield was belonged 60 kg ha^-1 of seed rate in first and second sowing dates which have not significant statistically differed.

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In order to evaluate the effects of zinc foliar application, Rhizobium inculation and phosphorus solublizing bacteria on soybean cv. Katul an experiment was carried out as a factorial arrangement, in an RCBD with three replications at Deland (Golestan province) in 2015. The factors comprised of zinc spraying at three levels (without spraying, 1.5 and 3 g L^-1 zinc sulfate), inoculation with R. japanicum at two levels (with and without inoculation), and inoculated with phosphorus solublizing bacteria at two levels (with and without inoculation). The results revealed that the effects of phosphor solublizing bacteria were significant for plant height, stem diameter, number lateral branches, pod length, number of seeds per pod, number of pods per plant, 1000 seed weight, grain yield and oil per cent. Seed inoculation with Rhizobium significantly affected all trails studied with the exception of protein content and pod length, Zinc significantly affected grain yield, oil and protein content. The seed yield of psb treatment had significantly higher yield (2954 kg/ha) compared to seed yield (2752 kg/ha) of non-incolation. Also, spraying with zinc at 3g/li had significantly higher yield (2990 kg/ha) than that of without sprying yield (2648 kg/ha).

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A field experiment was carried out to study the yield, quality and some morphological traits responses of spring canola (Brassica napus L.) to boron application and sowing date, in Ramin Agriculture and Natural Resources University of Khuzestan in 2013-2014. The experiment was carried out as a split plots design in basis of RCBD with three replications. Planting dates (18 November, 3 December, 17 December and 30 December) and boron application treatments (control, 10 kg B.ha^-1 incorporated with soil, boron spraying at 6 leaf stage and budding stages) were investigated as main and sub plots, respectively. Planting dates and boron application had significant effects on morphological traits, yield and quality of canola. The interaction effect of sowing date and boron on grain number per siliquie was significant. Late planting caused to significant decreased yield and its components. However, boron application incorporated with soil caused to compensate the negative effect of late planting. Generally, the highest grain yield (4579.7 kg.ha^-1) was obtained from sowing at 18 November and 10 kg boron.ha^-1 incorporated with soil, and lowest grain yield was obtained from planting at 30 December and without boron application. Delayed planting result in lowering morphological traits including plant height and branching. Delayed planting also caused by decreased grain oil and leaf N percentage, and increased grain N percentage. Boron application caused by significant plant boron content, but had no significant on grain oil ad N, and leaf N content. Also, boron application, in the experiment had no significant effect on alleviation of yield loss due to delayed canola sowing.