Showing 4 results for Panahi
H. Hokmabadi, K. Arzani, Y. Dehghani-Shooraki, B. Panahi,
Volume 7, Issue 4 (winter 2004)
Abstract
To determine the effects of salinity and boron excess in irrigation water on relative growth rate (RGR), net assimilation rate on a leaf weight basis (NAR), and leaf weight ratio (LWR) of pistachio, three pistachio rootstocks (Badami -Zarand, Sarakhs and Ghazvini) were used. Rootstocks were grown in soil in eight-liter polyethylene pots. Sodium chloride treatments were 0, 75,150 and 225 mM NaCl and boron treatments were 0, 20 and 40mg liter-1. Treatments were applied to the one-year old pistachio rootstock seedlings in three-day intervals with irrigation water. Some plants were randomly selected and destructively harvested before (day 0) and after applying treatments (30 and 60 days after treatments started). Growth and physiological characters were then measured as follows: number of leaves, leaf area, plant height and root length, fresh and dry weights of stem, root and leaf, proline accumulation in the leaf, total chlorophyll, and leaf relative water content (RWC). Results indicated that relative growth rate decreased with time for all treatments and in all rootstocks. Salt treatment significantly reduced both RGR and NAR, whereas LWR showed no significant differences. In all rootstocks, NAR, but not LWR, was significantly correlated with RGR, indicating that NAR was an important factor underlying the salinity-induced differences in RGR among the pistachio rootstocks. Salinity did not affect leaf water potential (ψ), chlorophyll content, and Fv:Fm ratio but increased NaCl concentration and time correspondingly increased proline accumulation in leaves. In addition, Ghazvini rootstock accumulated more proline compared to other rootstocks and was more resistant to salinity treatments. Different boron treatments did not show any significant effect on growth rate nor on measured parameters after two months of exposure to treatments.
F. Kamiab, A. Vesvaei, A. Ebadiand, B. Panahi,
Volume 11, Issue 41 (fall 2007)
Abstract
This research was conducted in order to select male genotypes of pistachio with good performance. The study was performed on 10 genotypes in regard to their flowering time, pollen quantity and quality. The results indicated that flowering times of P1, P2 genotypes were simultaneous with Kallehghochi P3, P4, P5 genotypes with Ahmad Aghaii P6 and P7 genotypes with Ohadi and P8, P9, P10 genotypes with Akbari. Inflorescence weight showed big differences between them, ranging from 4.5gr for P6 to 1.66gr for P8. The amount of pollen per inflorescence also showed big difference, ranging from 71mg for P2 and 267mg for P5. In order to determine the percentage of pollen germination, a medium consisting of sucrose, agar and boric acid was used. The percentage of pollen germination also showed big difference, ranging from 30%for P3 and P4 and 85% for P10. Stored pollen at 4°C temperature showed 30% germination after one month and 0% germination after three months. The results also indicated that the percentage of pollen germination in culture medium without boric acid was lower, compared with other treatments. The viability of pollens collected from cutting inflorescences kept in water bottle was higher than that obtained from dried inflorescences maintained in room condition.
A.r Hosseinpur, M.r Panahi,
Volume 14, Issue 52 (sumer 2010)
Abstract
Potassium (K) fixation by phyllosilicates clay minerals is a very important process influencing the availability of K for plants. Information about K fixation is limited in Hamadan soils. The objectives of this research were to determine potassium fixation capacity (PFC) and potassium fixation index (PFI) of 10 surface soils of Hamadan province and the correlation of these parameters with soil charge characteristics. Potassium fixation capacity was obtained using six different levels of added K as KCl and three wetting and drying cycles. Also charge characteristics of soils were determined. Tetrahedral CEC of soils was determined after saturation of samples with LiCl and heating at 300 oC to reduce octahedral charge near zero. The results showed that tetrahedral and octahedral CEC ranged from 4.6 to 16.0 and 0.8 to 4.9 cmolckg-1 respectively. Mineral and organic portion CEC ranged from 6.1 to 20.9 and 0.97 to 9.7 cmolckg-1 respectively. The amount of PFC increased with increasing added K. Mean amount of PFC ranged from 58.2 to 175.03 mgkg-1. Potassium fixation index ranged from 0.23 to 0.67. The results of correlation studies indicated that PFI were significantly correlated with octahedral CEC, mineral and organic portion CEC, total CEC, exchangeable and nonexchangeable K. The results of this research showed that PFI very different in soils. So that this parameter should be consider in K soil testing.
S. Salehi, Sh. Esmael Zade, Gh. Panahi, K. Esmaili,
Volume 22, Issue 4 (Winter 2019)
Abstract
The effect of the uplift force in the hydraulics structures is against stability. So, determining and controlling this force can be very important. One of the ways to achieve this purpose is to decrease this force by using the hole drains; in this way, we can build perpendicular pipes with different diameters, leading to the durability of the structure. Therefore, an experimental model of concrete dam was constructed in the hydraulic laboratory. The dam's model was divided into five sections by using 4-hole drains with a thickness equal to the dam's foundation. By running experiments with the maximum water level at the upstream, dam hole drains were opened in their position. Hydraulic potential was estimated by using the Piezometer built in the flume body. Finally, by opening some hole drains, the uplift force was calculated from the equipotential lines. Therefore, the best case (which had the minimum force) was determined, which was a/L=0.4, to create the most proper hole drain in the dam foundation. (a: distance of drain to heel and L: length of the dam's foundation). To place the hole drain in this position, by applying the zero potential in this position, the up lift force was increased
