فهرست مطالب

  • Volume:4 Issue:3, 2013
  • تاریخ انتشار: 1392/01/20
  • تعداد عناوین: 8
|
  • A. Khoshnam, H. Haydari Sharifabad, G.A. Afsharmanesh Pages 111-117

    In order to determine the optimum plant density and evaluate the effect of drought stress on yield and oil content of safflower, an experiment was conducted as a strip plot on the basis of a Randomized Complete Block Design with three replications at Jiroft and Kahnooj Agricultural Research Center, Iran in 2009-2010. The vertical factor was water deficit stress at four levels of irrigation withdrawal before flowering and pollination, at 50% flowering and 100% flowering, and full irrigation (control). The horizontal factor was plant density at four levels of 30, 35, 40 and 45 plants m-2. It was found that drought stress significantly affected seed yield, oil yield, oil percentage, seed number per head and stem diameter at 1% and 1000-seed weight at 5% probability level. The effect of plant density was significant on seed yield, oil yield, head number and floret weight at 5% and on seed number per head and stem diameter at 1% probability level. Out of the studied drought stress levels, the highest seed and oil yield was obtained from control (2634 and 1054 kg ha-1, respectively) and drought stress application at 100% flowering (2389 and 726 kg ha-1, respectively) and the lowest ones from drought stress application before flowering. In addition, as plant density was increased up to 40 plants m-2, seed and oil yields were increased up to 1792 and 801 kg ha-1, respectively and then, started to decrease.

    Keywords: safflower, drought stress, plant density, seed yield, oil yield
  • H. Madani, A.R. Pazoki, B. Esfahani Pages 119-124

    The present field study was carried out under the climatic conditions of Hamedan, Iran. It was a split-split-plot experiment based on a Randomized Complete Block Design with four replications. The experimental treatments included plant density of sweet sorghum cv. Pegah at three levels of 100 000, 200 000 and 400 000 plants ha-2, irrigation interval of 10 and 15 days and urea fertilization pattern at two levels of 100, 200 and 100 kg ha-1 urea fertilizer (46%) at sowing date and 45 and 65 days after sowing (N1) and the application of 100, 100 and 200 kg ha-1 urea fertilizer at sowing date and 45 and 65 days after sowing (N2). The studied traits included shoot dry weight, fresh forage yield and dry forage yield. It was found that urea fertilization pattern significantly affected fresh weight, dry weight, fresh forage yield and dry forage yield. Plant dry weight and fresh and dry forage yield were influenced by the interactions between treatments. The highest fresh forage yield (81.20 t ha-1) was obtained at the density of 400 000 plants ha-2 with the irrigation interval of 10 days and urea application pattern of N2.

    Keywords: sweet sorghum, plant density, irrigation interval, urea fertilization pattern, forage yield
  • S. Koorepaz Mahmoodabadi, B. Panahi, J. Agharahimi, A.R. Talaie Pages 125-128

    This study was aimed at determining the fatty and amino acids as well as protein content in three pistachio (Pistaciavera L.) cultivars including Ohadi, Mumtaz, and Ahmadaghaei in Kerman region, Iran. The amount and type of fatty acids, protein and the type of amino acids were measured. According to the results, the range of oil in the studied cultivars was 54.93–55.4% and the highest rate of fatty acids (60.2–64.8%) was related to Oleic acid. The amount of protein was 18.81–19.31%. There was a significant difference among cultivars for the amount of amino acids including Glycine, Tyrosine, Alanine, α-Aminobutric acid, Valine and Isoleucine.

    Keywords: Amino acid, Fatty acid, Pistaciavera, Kerman
  • M.H. Shirzadi, S.S. Hemayati Pages 129-134

    The current study was carried out to evaluate the variations of meteorological parameters of Jiroft Region, Iran (Lat. 28°35´ N., Long. 57°48´ E., Alt. 601 m.) during 1990-2010. After collecting the data, the linear correlation was estimated between the monthly average of different parameters related to temperature, moisture and other parameters with time. The results showed significant increase in mean minimum and maximum yearly temperature. The decrease in the difference of maximum and minimum temperature during July and the increase in the number of days with maximum daily temperature of ≥30°C implied the regional warming. The decrease in relative humidity in winter and spring was a response to the increased temperature which had led to the increase in total evaporation in summer and autumn. In total, the conditions of the region including the rising temperature, decreasing relative humidity, decreasing annual precipitation and increasing evaporation (especially in summer and autumn) indicate the gradual development of aridity in the region during recent years.

    Keywords: climatic change, meteorological parameters, time, linear correlation, Jiroft
  • M. Mehrpouyan, G.R. Nazariyan Pages 135-140

    To study the effect of irrigation deficit stress on photosynthesis, gas exchange and yield of four sunflower (Helianthus annuus L.) cultivars, a split-plot study experiment conducted at Agriculture and Natural Resources Research Station of Zanjan, Iran in 2009 on the basis of a Randomized Complete Block Design with three replications. The irrigation levels includdingfull irrigation (control) and water deficit stress at heading, flowering and grain filling stages were regarded as main plot and four hybrids including Master Lakomka, Azargol and Euroflour as the sub-plot. Analysis of variance showed that water deficit significantly influenced grain yield and decreased the yield of all four cultivars at all three stress stages compared to control. The highest grain yield was obtained from Azargol under optimum irrigation conditions. Stress at heading stage had the highest effect on yield and severely decreased it, so that it decreased the grain yield of Master, Lakomka, Azargol and Euroflour by 62, 52, 65 and 63%, respectively. In addition, stress level significantly affected physiological traits, so that irrigation deficit stress at heading decreased photosynthesis rate of Master, Lakomka, Azargol and Euroflour by 26, 27, 20 and 30%, stress at flowering decreased them by 42, 24, 22 and 39% and stress at grain filling stage decreased them by 34, 22, 16 and 25%, respectively. Stress at all three stages resulted in the loss of stomatal conductance of the studied cultivars and increased substomatal CO 2 concentration. In total, Azargol was superior to the other cultivars in terms of yield and photosynthesis attributes.

    Keywords: irrigation deficit, Azargol, stomatal conductance, photosynthesis rate, gas exchange
  • S.G.R. Mousavi, M.J. Seghatoleslami, R. Arefi Pages 141-149

    In order to study the effect of different levels of N fertilization and plant density on yield and yield components of grain sorghum cv. Sistan, an experiment was conducted in agricultural research farm of Zehak, Iran in 2009 as a split-plot experiment based on a Randomized Complete Block Design with three replications in which the main plot was dedicated to N fertilization (at four levels of 0, 75, 150 and 225 kg N ha-1) and the sub-plot to plant density (at four levels of 12, 15, 25 and 50 plants m-2). It was found that N fertilization levels significantly influenced all studied traits except panicle number per m2 and the changes in plant density affected all studied traits significantly. In addition, the interaction between N fertilization and plant density was significant for gain number per panicle, 1000-grain weight, grain yield, biological yield and harvest index. Means comparison of simple effects revealed that the application of N fertilizer up to 150 kg ha-1 increased grain number per panicle, harvest index and grain yield significantly. Furthermore, although the increase in plant density up to 50 plants m-2 resulted in the significant loss of 1000-grain weight, grain number per panicle and harvest index, it significantly improved grain yield owing to the significant increase in panicle number per m2. In total, it was found that if N fertilization sufficed, the increase in plant density would effectively improve economical yield of sorghum so that the highest grain yield of 2388.33 kg ha-1 was obtained from the treatment of 225 kg N ha-1 at the density of 50 plants m-2. Therefore, it is recommended to apply 225 kg N ha-1 and to use the density of 50 plants m-2 to realize optimum yield of grain sorghum cv. Sistan in Zabol region, Iran.

    Keywords: sorghum, nitrogen, plant density, yield, yield components
  • A. Sarmast Garousi, R. Mohammadian, M.R. Haj Seyyed Hadi, H. Noshad Pages 151-157

    Leaf area reduction affects the yield of crops by decreasing photosynthesizing area and whereby, affecting growth and development processes. Artificial defoliation is used to simulate the damages of different factors on leaves. The present study was carried out to determine the effects of different levels of defoliation at different vegetative growth stages on quantitative and qualitative yields of sugar beet and also, to determine the most sensitive growth stage to defoliation at Motahari Research Station of Sugar Beet Seed Institute (SBSI), Karaj, Iran in 2010. The study was carried out as a factorial experiment based on a Randomized Complete Block Design with four replications. Two factors were studied including growth stage at four levels (cotyledon until true two-leaf stage, about 12-leaf stage, about 37-leaf stage and about 55-leaf stage) and defoliation intensity at five levels (0, 25, 50, 75 and 100% defoliation). It was found that the highest effect of defoliation intensity on root yield was observed at 37-leaf stage, while the highest effect of defoliation on the loss of sugar percentage was observed at the end of growing season (57-leaf stage). In total, the greatest loss of white sugar yield was observed at 37 and 55-leaf stages. 100% defoliation at 37 and 55-leaf stages resulted in significant loss of white sugar yield compared to control. White sugar yield was decreased by 31% by 100% defoliation at 37-leaf stage and by 21% by 100% defoliation at 55-leaf stage. In addition, it was revealed that the increase in Na and amino-N due to the defoliation decreased coefficient of extraction and consequently, increased molasses percentage and decreased extractable sugar per-centage.

    Keywords: sugar beet, white sugar yield, defoliation, growth stage
  • Z. Haghighat, A. Ebadi, S. Khomari Pages 159-162

    The beneficial effect of seed priming at germination and early growth stages has been accepted by plant physiologists in improving these critical stages in many important crop plants. The influence of seed priming with polyethylene glycol (PEG), NaCl and salicylic acid (SA) on germination percentage, germination rate, plumule, radicle and seedling length and dry weight and vigour index of sorghum seedlings under salt stress with 4 levels (0, 40, 80 and 120 mMNaCl) was investigated. The experiment arranged as a completely randomized design with three replications. Priming with SA significantly improved germination and seedling growth characteristics such as final germination percentage, germination rate, vigour index and length of plumule, radicle and seedling except plumule, radicle and seedling dry weight. Increasing salinity levels affected severely all the above-mentioned parameters. No interaction between salinity and priming was observed.

    Keywords: germination, priming, sorghum, vigour