A Habashi, A Mousavi, M Kaviani, S Khoshkam, A Rostami,
Volume 12, Issue 46 (1-2009)
Abstract
Date palm (Phoenix dactylifera L.) is propagated traditionally through offshoots or suckers, which usually appear at or below the ground level surrounding the stem base. However, there are many problems associated with this system. Offshoots are produced in limited number and vegetative propagation through them is slow, laborious, time consuming and expensive. The present study was conducted to determine the best micropropagation protocol for date palm in Kebab, Estameran, Piarom, and Berehi cultivars. The shoot apical meristem from two to three-year-old offshoots was used as source of explants. They were cultured in callus initiation medium, containing different concentrations of 2,4-D (40, 60, 80 and 100 mgl-1), NAA (10 and 20 mgl-1) and 2ip (3 and 5 mgl-1). All cultivars produced high percentage of callus with good quality in a matter of callus friability and color in 100 mgL-1 2,4-D, 20 mgL-1 NAA, and 3 mgL-1 2ip. Kabkab cultivar was superior for callus production (87.25%) in comparison with other cultivars. The calli were then transferred to a proliferation medium and then transferred to somatic embryogenesis medium containing different concentrations of Kinetin (2, 4 and 6 mgL-1), BAP (2, 4 and 6 mgL-1), and NAA (0.1, 0.5 and 1 mgL-1). Somatic embryogenesis was observed in MS medium supplemented with 2 mgL-1 kinetin, 2 mgL-1 BAP, and 0.1 mgL-1 NAA. Kabkab and Estameran cultivars showed higher somatic embryogenesis in comparison with other two cultivars. The somatic embryos were then transferred to MS medium without hormones under light, where they produced shoots and roots. Abbriviations: 2,4-D- 2,4-dichlorophenoxiaceticacid 2ip-N6(2-isopentenyl)adenine NAA-Naphthalene acetic Acid BAP-6-Benzylaminopurine MS-Murashige and skoog (1962).
S. Azadi, S. Soltani Kopaei, M. Faramarzi, A. Soltani Tudeshki, S. Pourmanafi,
Volume 19, Issue 72 (8-2015)
Abstract
The Palmer Drought Severity Index (PDSI), which uses hydrometeorological variables to solve a simple water balance equation in the soil and considers the drought or wet conditions as dynamic phenomena, is used for the assessment of drought conditions in many parts of the world. The main goal of this study was to assess the PDSI based on its original assumptions, its regionalized status, using the outputs of already calibrated and validated SWAT model in central regions of Iran. The PDSI was assessed through five methods: 1) original Palmer Index without calibration in which the climate coefficients and the severity equation were derived for Kansas and central Iowa 2) original Palmer Index in which the coefficients of severity equations were adjusted 3) the Palmer Index with the calibration of equations in central areas of Iran 4) the Palmer Index using the soil moisture and potential evapotranspiration from SWAT model and 5) the Palmer Index using the soil moisture, potential evapotranspiration and runoff from SWAT model. The evaluation was conducted for 17 major basins covering the entire country with a monthly time step for the period 1990-2002. Then, using all five methods, the severity of the drought for 160 sub basins located in central Iran was calculated and evaluated. The results of this study indicated that method 4 provides more acceptable results. Also, the results of this research showed these methods clearly demonstrated (1992) as the wettest year and (2001) as the driest year. The approach used in this study is applicable to regional calibration of Palmer Index and the outputs of other hydrological models.
N. Salamati, H. Dehghanisanij, L. Behbahani,
Volume 23, Issue 1 (6-2019)
Abstract
In order to investigate the effect of water quantity in subsurface drip irrigation on water use efficiency of palm yield and yield components, and determining suitable irrigation treatments for three different date cultivars, a split plot experiment design in a randomized complete block design with three replications were applied for three cropping years (2013-2016), at Behbahan Agricultural Research Station. The applied irrigation water in three levels based on 75, 100 and 125 percent of water requirement in the main plots and three cultivars of Kabkab, Khasi and Zahidi dates were compared in sub plots. The irrigation level of 75% with 0.646 kg of dates per 1 cubic meter of water in terms of water use efficiency as compared to the other two levels of irrigation showed a significant superiority. The Khasi cultivar with 83.9 pips and 29.2929 fruits in the cluster ranked first. The irrigation level of 125% with 11.1% were higher in fruit moisture, and 100% and 75% irrigation levels with 9.6% and 7.8% moisture content were the next. The irrigation level of 125% for Kabkab cultivar with a volume of 11.1 cubic centimeters were ranked first. Optimizing water use and reducing it to 10606 cubic meters per hectare in irrigation level of 75% water treatment will save water consumption. If the basis for comparing the amount of water used in 100% water treatment is considered, then the use of subtropical drip irrigation reduces water consumption by 2509.6 and 5019.2 cubic meters per hectare, respectively, compared to 100 and 125% water requirements.
F. Saniesales, S. Soltani, R. Modarres,
Volume 25, Issue 2 (9-2021)
Abstract
Several indices are used for drought identification and quantification. In this paper, the new Standardized Palmer Drought index (SPDI) was introduced and then the drought condition of Chaharmahal-Va-Bakhtiari Province was studied using this index. For this study, 11 synoptic, climatology, and evaporation meteorology stations were selected. Essential information in this investigation includes monthly temperature, monthly precipitation, and soil moisture measurement. To estimate SPDI, moisture departure, was first calculated on a monthly time scale. Then, converted to cumulative moisture departure values in different time scales including 3, 6, 9, 12, and 24 months. The best statistical distribution (GEV) was then fitted to cumulative departure. These values were then standardized to have the SPDI. The results showed that, as soil moisture affects SPDI estimation, it will be more valid for analyzing and monitoring drought conditions, especially for agricultural drought. Also, the results showed that 2000, 2001, and 2008 years were the driest time in this Province from 1988 to 2012. Moreover, drought frequency was found out in the western half of the Province more than in the other parts.
