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Showing 5 results for Type of Study: Applicable
Volume 1, Issue 1 (9-2014)
In order to investigate the effects of water deficit stress effects, different rates of nitrogen and plant density on remobilization, current photosynthesis and grain yield in oily sunflower var. Iroflor, an experiment was carried out in field Agriculture and Research center of West-Azerbaijan during 2011 and 2012 cropping seasons. The experimental was conducted as split-split-plot base on Randomized Complete Block Design (RCB) with 3 replications. The main factor was consisted irrigation treatment including optimum irrigation, moderate stress and sever stress which irrigation was done after depletion of 50%, 70% and 90% of available water, respectively. Three nitrogen levels of 100, 160 and 220 kg N haG1 were considered as sub plots and sub-sub plots consisted of three plant populations of 5.55, 6.66 and 8.33 plants m2. The results of combined analyzes showed that severe drought stress reduced the grain yield by 60% compared to the optimum irrigation condition. Comparison of two-year-mean revealed that severe drought stress in compared with optimum irrigation dry matter remobilization rate decreased about 30 percent. Also, severe drought stress led to 35% reduction of current photosynthesis efficiency in compared with optimum irrigation. In each level of nitrogen fertilizer, increasing plant population led to increase contribution of remobilization but current photosynthesis contribution decreased. Therefore, due to reduction of current photosynthesis rate in severe drought stress condition, contribution of current photosynthesis decreased so that increasing of (contribution of, deleted) remobilization contribution prevented reduction of seed yield.
Volume 1, Issue 1 (9-2014)
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.
Parviz Yadollahi, Mohammad R. Asgharipour, Nooralah Kheiri, Asghar Ghaderi,
Volume 1, Issue 2 (3-2015)
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.
Azadeh Khoram Ghahfarokhi, Asghar Rahimi, Benyamin Torabi, Shahab Maddah Hosseini,
Volume 2, Issue 1 (9-2015)
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.
Somaye Esmaili , Mahmoud Reza Tadayon , Ali Tadayyon , Mohammad Rafiee Alhossainy ,
Volume 3, Issue 1 (9-2016)
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%.