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A field experiments was conducted at Sabzevar Agriculture & Natural Resources A field experiments was conducted to study the effect of zinc sulfate foliar application on yield and yield components of sunflower, Haysun-25 cultivar (Helianthus annuus L.) under drought stress at Sabzevar Agriculture & Natural Resources research center. This experiment was carried out (conducted, deleted) as split plot based on randomized complete block (RCB) design that main and subplot factors were drought stress levels [Non-stress, Moderate and High drought stress (6, 12 and 18 day’s irrigation interval, respectively] and foliar zinc applications (0, 5, 10 and 15‰), respectively. Foliar application of zinc was performed in 6 to 8 leaf stage of sunflower. Plant height, seeds per head, hollowness percentage seeds, 1000 seed weight, grain yield and biological yield were significantly affected by drought stress. Severe drought stress decreased plant height, seeds per head, 1000 seed weight and economic yield and increased percentage of empty seeds. The highest yield and yield components were related to foliar application with 15‰ concentration of zinc sulfate and the lowest one was related to the control. However, yield response to zinc sulfate foliar application was more in non-stress condition, but zinc sulfate with 15‰ led to decrease of negative effects of drought stress. Overall, the highest yield was obtained by spraying with concentration of 15‰ zinc sulfate and non-stress condition.

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Optimum leaf area index (LAI) is necessary to decrease in soil surface evaporation, to intercept maximum radiation and to increase in dry matter production and seed yield. In order to study the development of leaf area in canola (B. napus) and its relationship with seed yield, this experiment was conducted at agricultural research station of Gonbad during 2005-7. The experiment was a RCBD arranged in a split-plot in two conditions, i.e. supplemental irrigation and rain-fed. Five sowing dates (SD) (Nov. 6, Dec. 6, Jan. 4, Feb. 5 and Mar. 5) assigned as main plots and two cultivars (Hyola 401 and RGS003) as subplots. In all treatments, the number of leaves on main stem and LAI increased till the beginning of seed filling, and then decreased considerably due to sever shedding of leaves. LAI at the beginning of seed filling stage, varied from 6.1 in Nov. 6 to 3.1 at Mar. 5 SDs in supplemental irrigation conditions, and from 5.2 on Nov. 6 to 2.4 at Mar. 5 SDs in rain-fed conditions. The better early growth of Hyola401 compared to RGS003 cultivar caused that, in each year and conditions, LAI of Hyola401 was significantly more than RGS003 at the beginning of stem elongation and budding. The strong relationships between the number of leaves on main stem and LAI at different growth stages and seed yield, showed the positive effects of these traits on seed yield.

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Management of organic fertilizers in terms of environmental impact and crop yield is important, especially in arid and semiarid regions. The objectives of this work were to evaluate the effect of drought stress and organic fertilizer on some morphological and yield components of safflower. The experiment was conducted as a split-plot based on a randumaized complet block design with three drought stresses: irrigation at 35, 55 and 75% of ready available water (RAW) depletion comprising the main-plot, and four fertilization systems: non-application (control), application of 40 tons of compost ha-1, humic acid spraying (1.5 g per litr) and combining compost and humic acid as sub-plot that were applied with three replications. The experiment was conducted in 2013 at the Zabol University research farm in Zabol, south Iran. Drought stress reduced oil yield, chlorophyll fluorescence and membrane stability. Delays in irrigation by 75% RAW depletion reduced oil yield by 68.6% compared with the control. Organic fertilizer application increased oil content and oil yield, membrane stability, carbohydrates, peroxidase, catalase and guaiacol peroxidase activiteis. Integrated application of compost and humic acid increased oil yield by 99.7% over the control. Application of humic acid and compost can be combined to develop safflower cultivation in Sistan, especially in mild stress conditions.

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To evaluate the effects of nitrogen and water stress on allelopathic potential of sorghum (Sorghum bicolor) on the seed germination traits of safflower (Carthamus tinctorius), a factorial experiment was carried out in randomized complete design (CRD) with three replications in the greenhouse and laboratory, College of Agriculture, Shiraz University, Shiraz, Iran in 2012-13. Treatments included irrigation [Normal (I1) and water stress (I2)] and nitrogen [control (no nitrogen), Urea (200 kg N ha-1), Nitroxin (Azotobacter) and Nitrokara (Azospirillum and Azotobacter) inoculation per kg seeds]. Extracts were prepared from sorghum shoot resiude in 5, 10, 15 and 20 (W/V) and were applied to individual Petri dishes distilled water was used as control treatment. Also, foliar applications of extracts were applied in treatments under the greenhouse conditions and sorghum dried residues were also mixed with the soil in amounts of 0, 5, 10, 15, and 20 g after the first irrigation. Analysis of variance showed that interaction effects of sorghum extract type and its concentration had significant effects on all traits except relative water content. Safflower germination percentage reduced with increase in concentration. 5, 10 and 15% concentrations of Nitrokara under normal irrigation had 34, 22 and 12%, effects on allelopathy index of safflower respectively. Whereas concentration of 20% extract, decreased allelopathy index by 71%. The effects antagonist on length and dry weights of roots and shoots was observed when biofertilizer treatments (Nitroxin and Nitrokara) applied. In addition, more synergist effects were obtained when urea extract was appliedt under water stress. The results of foliar application revealed a decrease in CAT and POD activities in leaves of safflower when urea was usedunder water stress conditions. However, the lowest germination rate and primary growth of safflower was abserved when urea applied under water stress conditions.

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To study the effects of drought stress and salicylic acid and Chitosan spraying on safflower, an experiment was conducted as a split plot design as base of a randomized complete block design with three replications. The drought stress had 4 levels ascontrol and irrigation after 25, 50 and 75% of soil available water as main plots and sprayin of salicylic acid (0.424 grams per liter), chitosan solution (5 g per liter) and both of them that were considered as sub-plots. drought stress reduced the number of heads per plant, head diameter, stem diameter, number of leaves, seed weight, seed weight and increased the percentage of hollowness of the seed. Application of chitosan and salicylic acid increased the distance of the first branch from the ground, head diameter, stem diameter, number of leaves, flowers, root length and weight and yield components as number of seeds per head, seed weight per head, seed weight and unfilled seed percentage. It seems salicylic acid and chitosan spray can be sugested to develop boost crop cultivation and increase safflower yield in the province of Sistan.

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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.