Showing 47 results for Iran
H. Farhangfar, H. Naeemipour Younesi,
Volume 11, Issue 1 (4-2007)
Abstract
A total of 25,471 Iranian Holstein heifers distributed in 523 herds of 20 provinces were used to estimate heritability, genetic and phenotypic associations between a number of traits related to the production and reproduction performance. The Animal Breeding Centre of Iran collected the records studied in this research between 1991 and 2001. The traits associated with production were 305-day, 2x adjusted milk, fat yields and fat percentage and the traits associated with reproduction were age at first calving, number of services per conception, gestation period, calving interval as well as dry days as a separate trait. The heritability estimates were 0.31, 0.23, 0.31, 0.14, 0.03, 0.05, 0.10 and 0.01 for 305-day, 2x milk, fat yields, fat percentage, age at first calving, dry days, calving interval, gestation period and the number of services per conception, respectively. Milk yield was genetically correlated with age at the first calving (-0.14), dry days
(-0.31), calving interval (0.54), gestation period (0.01) and the number of insemination per conception (0.38). Fat yield had negative genetic correlations with age at first calving (-0.16), dry days (-0.23) while it was positively correlated with calving interval (0.44), gestation period (0.11) and the number of insemination per conception (0.20). Age at the first calving, dry days and gestation period had a positive genetic correlation with fat percenateg (0.03, 0.15 and 0.09 respectively) while calving interval and the number of insemination per conception were negatively correlated with fat percentage (-0.21 and -0.25 respectively).
H. Farhangfar, H. Rezaee,
Volume 11, Issue 40 (7-2007)
Abstract
A total of 179,460 monthly test-day milk records (thrice a day milking) obtained from 17,946 Iranian Holstein heifers distributed in 287 herds and calved from 1986 to 2001 were used to predict breeding value of animals. Monthly test-day milk production was analysed by applying a covariance function in which the effects of herd-year-season of production (HYSOP), age at test day (covariate), additive genetic and permanent environmental effects were included. Orthogonal legendre polynomials up to order 5 (quartic) were also implemented in the covariance model to take account of the genetic and environmental aspects of milk production variation over the course of the lactation. In the present research, breeding values of individual animals based upon 305-day and monthly test-day milk yields were compared. The results indicated that ranking of ten top sires, dams as well as progenies changed as the genetic evaluation of animals switched from the traditional (based on 305-day milk yield) to the new method that was based on the covariance function. Regression analysis of average breeding value of progenies on the first year of their calving showed that the amount of genetic trend obtained from the covariance function for 305-day milk yield was greater than that of the 305-day model (11.607 vs. 3.860 Kg/year) over the period of 16 years of calving. The phenotypic trend for lactation milk yield was 92.97 Kg per year which was statistically significant. This finding indicates that a large proportion of annual increase of milk production of Holstein heifers in Iran has been due to environmental rather than genetic improvement.
R. Sepehri, Gh. Tahmasebi, M. J. Jalali Zonoz,
Volume 11, Issue 41 (10-2007)
Abstract
During the honeybee breeding project in central Iran, sex alleles homozygoty and sex alleles number in the third generation of 364 colonies were studied in 2003. Sex alleles homozygoty was measured based on Ruttner (1988) and Tarpy and Page (2002) methods. The total area of worker brood area, stored pollen, and drone brood area were measured on the combs. The whole extracted honey weight and remaining honey in the combs were evaluated as honey production of colonies. Adult population was evaluated based on the number of full combs of adult honeybees. The results showed that sex alleles, average homozygoty and number in the colonies were 18.83% and 5.32 respectively. The results showed no significant correlation between homozygoty of sex alleles or sex alleles number and stored pollen ( P > 0.05 ) , but significant negative correlation between sex alleles homozygoty and colony population, total brood area and honey yield ( P < 0.01 ) was observed. So introduction of new sire colonies in the mating Isolated area is essential to prevent sex alleles homozygoty and also performance of honeybee colonies from decreasing.
D. Safaee, S.m. Okhovat, G.h. Hedjaroude , H. Younesi,
Volume 12, Issue 43 (4-2008)
Abstract
In order to diagnose form species of Bipolaris involving root and crown rot of wheat plants and determine their distribution, frequency and disease severity, 410 wheat fields (W. Fs.) in different regions of Kermanshah province were sampled at seedling, tillering and heading stages during three crop years (1997– 2000). Also 90 W. Fs. (30 per year) in different regions of the province were chosen randomly to estimate percentage of infected wheat plants. For the isolation of the fungi from tissues of root, subcrown internodes, crown and foot, the tissues were surface sterilized and placed on culture media. The results showed that there were some root and crown rots in the most regions of the province and the percentage of diseased plants was 0-24%, whose average was 3.2%. Forty three isolates belonging to form genus Bipolaris were isolated including form species B. sorokinina, B. cynodontis and B. spicifera. All three form species were pathogenic under greenhouse conditions. Disease severity and frequency of B. sorokinina were more than the others. Disease severity of B. cynodontis and B. spicifera was the same and their differences compared with the control were significant.
E. Zare, A.h. Chizari, Gh.r Pykani,
Volume 12, Issue 43 (4-2008)
Abstract
Malmquist index computed by data envelopment analysis approach was used to estimate the total factor productivity (TFP) growth in cotton production in Iran during 1983-2001. By dividing this index in the two components, technological change and technical efficiency change, two major factors of productivity growth in cotton production were analyzed. Data was obtained from production cost system and other statistical sources provided by ministry of Jahad-e-Agriculture. Results indicated that TFP growth in cotton crop was positive (0.8% per annum) for the period of this study .This figure was different in different provinces of Iran. Maximum growth rate was 6.2% in Fars province and was negative in Kerman, Mazanderan and Golestan provinces. In comparison, technical efficiency growth was more than technological change during 1983-2001.
H. Mehrabi Basharabadi,
Volume 12, Issue 44 (7-2008)
Abstract
Kerman province is the largest producer of greenhouse cucumber and tomato in Iran. This paper calculates the interest rate of return (IRR) and return period of investment (RPI) in vegetable, cut flowers and strawberry in greenhouse and compares them with vegetable grown outdoors. To do the study, a random sample of 309 farmers was selected in the province of Kerman in 2005. Results showed that IRR for vegetable, cut flowers and strawberry in greenhouse was about 20, 14 and 23 respectively, and it was 45/8 percentage per year for vegetable outdoors. RPI for vegetable, cut flowers and strawberry in greenhouse was about 8, 29, and 7 years, respectively. Vegetables Production under greenhouse produces more employment opportunities, has better yields, higher price and efficient use of factors, but it has lower IRR, higher production cost, higher pesticide residue and is more capital intensive in comparison with outdoor production. Improvement of greenhouse credits, enlargement of metal greenhouses, research on yield and development of greenhouses at region 5 are the important policy-making implications of this paper.
M. Nasr Esfahani, B. Ansari Pour,
Volume 12, Issue 45 (10-2008)
Abstract
Pink root-rot disease caused by Pyrenochaeta terrestris is one of the serious diseases of onion fields in Iran and the world. The use of resistant cultivars might be a good alternative as suggested on the basis of the screening at the near end of growing season. The susceptibility assessment of 43 Iranian onion clones in glass-house condition in Isfahan for the last two successive years i.e. 2003-04 indicated that, the clones react independently with various degrees of resistance to the pink root-rot disease and with a high significant effect. The scoring scale was of 0-3 to determine the susceptibility and/or resistance of the clones to the disease, out of which, the two clones, Ramhormoz-Saffiabad and Balochestan-Sarbaz were the most susceptible clones to the pink root-rot disease, and were placed in 2-3 (0-3) scale. But most of the clones were placed in the scoring scale 1-2 (0-3) indicating that they are in the ranges of tolerance. This could be why they still exist and could tolerate the disease and remain safe. The third and/or the resistant clones are those clones that were placed in the scoring scale of 0-1 (0-3), i.e. Naishabor-Ishaghabad, Sarri-Local, Loosha-Golden, Zanjan-Ghotigheseh, Shahrood- local, Azarbayejan-East, Shahrood-Lasjerd, Kashan-White, Yazd-Marvdasht, Azarshahr-Red and Boshehr-Local, respectively. In fact, the two clones Naishabor-Ishaghabad and Sarri-local are the most resistant ones to the pink root-rot disease of onion in these tests. These results indicate that there are certain clones which can be considered in breeding programs and/or cultivations.
A. Taghavi, Gh. Tahmasbi, A. A. Talebi, A. Zarnegar, A. Monfared, H. Nazarian,
Volume 12, Issue 45 (10-2008)
Abstract
The species diversity of bumblebees was investigated in two provinces, Tehran (Fasham, Zayegan) and Qazvin (Alamut, Wikan) in central Alborz during 2005-2006. Three casts of queen, worker and male bumblebees were collected during spring and summer in six dates in the two mentioned regions. Sampling of adult bees in Wikan was done from 26 July 2006 until 19 September 2006, and in Zayegan from 24 May 2006 to 17 September 2006. In sum, eleven species were collected of which eight species were common in the two regions. Data of different species casts at two regions were analyzed by Excel ver. 6 and Ecological Methodology ver. 6. 1. 2 soft wares. Species diversity of two regions was determined and compared with three indices of Simpson, Shannon-Weiner and Brillion, and evenness was calculated with indices of Simpson, Camargo and Esmit-Willson. Species richness of two regions was compared in research. The obtained results showed species diversity, evenness and species richness were more observable in Wikan compared with Zayegan. Consequently, Wikan in comparison with Zayegan was more sustainable. Similarity of two regions was 0/46, showing many differences in terms of the kinds. Also, there were 8 similar species in the two areas.
A Vaezi, H Bahrami, H Sadeghi, M Mahdian,
Volume 13, Issue 49 (10-2009)
Abstract
Proper evaluation of soil erodibility factor is very important in assessment of soil erosion. In this study, soil erodibility factor (K) was assessed in a zone, 900 km2 in area in Hashtrood, located in a semi-arid region in north west of Iran. Soil erodibility factor was measured at the unit plots under natural rainfall events in 36 different lands in the study area from March 2005 to March 2007. Results indicated that the measured soil erodibility factor K is on average 8.77 times lower than the nomograph-based values in the study area. To achieve a new nomograph, correlation between measured soil erodibility and soil physicochemical properties was studied. Based on the results, soil erodibility factor negatively correlated with coarse sand, clay, organic matter, lime, aggregate stability and permeability, while its correlation with very fine sand and silt was positive. Results of principal component analysis of soil properties and multi-regression analysis showed that the soil erodibility factor is significantly (R2 = 0.92, P < 0.001) related to soil permeability, aggregate stability, lime and coarse sand. A new nomograph with a R2 of 92% was developed based on these properties to easily estimate soil erodibility factor in the study area. The soil erodibility factor can be reliably estimated using the nomograph in all regions with the soil and rain properties similar to those in the study area.
Sh Ghergherechi, F Khormali, Sh Ayoubi,
Volume 14, Issue 51 (4-2010)
Abstract
Gypsum is the most common sulfate mineral in soils of arid and semi-arid regions. Two hundred million hectares of the earth’s surface and about 28 million hectares of Iranian arid soils are covered by gypsiferous soils. The studied soils consist of alluvial plane and eolian plains in northern Iran. Soils were classified as Haplocambids, Aquisalids and Endoaquepts. In this study, genesis, formation and development of gypsum in soils were investigated. Study area includes different geomorphic surfaces from the upper watershed to alluvial plains. Gypsum crystals without considering their size, shape, arrangement are determined as pedogenic. In the weakly-developed horizons, in aridic moisture regimes, formation of euhedral pedogenic gypsum crystals and incomplete infilling of voids was dominant. In the well-developed soils, in xeric moisture regime, gypsum crystals are oriented and the perpendicular in arrangement of crystals along pores is dominants. Gypsum crystals occur in different shapes such as lenticular, tabular, and rosette-like and fan arrangement. Origin of gypsum in weakly-developed soils was weathered gypsiferous marls in upper Atrak basin. The source of gypsum in the soils with shallow ground water is high content of sulfate dissolved in soil solutions. In horizons affected by fluctuation of ground water contaning sulphur, euhedral tabular shape is dominant. In well-developed soils, based on Snowball morphology, gypsum is classified as stage II nodule. Results showed that there is no relationship between formation of the snowball morphology, b-fabric and kind of diagnostic horizons (A, B and C).
M Bashiri Seghale, S.h.r Sadeghi, A.s Rangavar ,
Volume 14, Issue 52 (7-2010)
Abstract
Erosion plots are basically used for studying erosion processes and many related problems. However, the possibility to extend the results of experimental plots to surrounding watersheds is rarely taken into account. In the present study, an attempt was made to study on the accuracy of soil erosion plots in estimation of runoff and sediment yield from small watersheds. Towards this attempt, 12 experimental plots with length of 2, 5, 10, 15, 20 and 25 meter were installed on two north and south facing slopes in Sanganeh watershed, northeastern Razavi Khorasan Province with an area of ca. 1 ha. The performance of the plots in estimation of runoff and sediment was controlled by data collected at the main outlet associated with 12 storm events occurred during November 2006 to June 2007. The results showed that the accuracy of plot estimates on sediment and runoff improved while the plot length increased. The optimal length for estimation of sediment and runoff parameters was found to be equal to average slope length and more than 20m.
A. H. Gharehsheikhloo , M. R. Vahabi , H. R. Karimzadeh ,
Volume 14, Issue 53 (10-2010)
Abstract
In order to classify and determine the plant communities in Karkas mountainsides, central Iran, quantitative data of 46 environmental characteristics including climate (12 characteristics), soil (26 characteristics), geology and physiology (8 characteristics), were analyzed based on partial Euclidean distance indicator using minimum variation method. The results showed the clustered separation of studied sites at 68% similarity level with three different growth places. Of these 46 factors, 24 factors (8 climate characteristics and 16 soil characteristics) were effective in this classification at 95% certainty level. Only 24 of these 46 factors were effective in this classification at 95% certainty level. These 24 effective factors were divided into 8 climate and 16 soil characteristics. In another classification, combinational percentage index of 17 plant species were investigated as an effective factor in separating growth place and determining the plant communities. Result of cluster classification indicated that the studied sites cold be classified to 3 habitats.
M. J. Nazemosadat, H. Ghaedamini Asadabadi,
Volume 15, Issue 55 (4-2011)
Abstract
The Madden Julian oscillation (MJO) is known as the primary mode of large-scale inter-seasonal variability in tropical regions, affectimg equatorial and sub-tropical climates. This study investigated the effects of the MJO on the occurrence of wet and dry spells in Fars province, central southern part of Iran, during November-April. Monthly precipitation data of nine stations spread over various parts of the province was analyzed during 1979-2005. Using two well-known MJO indices: MK and WH, the positive and negative phases of the MJO phases (enhanced and suppressed convective activity over the equatorial Indonesian region, respectively) were identified for monthly and seasonal scales. Precipitation-MJO composites were then constructed for the opposite phases. It was shown that for all the considered stations, seasonal precipitation during negative MJO phase was significantly greater (from about 2.5 to 6.0 folds) than the corresponding values during the positive phase. Moreover, the applied statistical tests proved that the frequency of wet or dry events was related to the prevalence of negative or positive MJO phase, respectively. As the positive MJO phase was engulfed, the probability of dry events varied from 60% to 84%. On the other hand, the probability of wet events was found to vary from 60% to 76% during the MJO negative phase.
M. R. Shoaibi Nobariyan, H. Torabi Golsefidi, Sabereh Darbandi,
Volume 18, Issue 70 (3-2015)
Abstract
CEC of the soil is the exchange sites of organic and inorganic soil colloids. Modeling and Estimation of CEC is a useful indicator for fertility. The new alternative approaches for estimating CEC are indirect methods based on intelligent models. In this research in order to estimate CEC, 485 soil samples were prepared from two regions, chaparsar (Mazandaran in northern Iran) and Bostanabad (North of West Azarbaijan, Iran).In this paper introduces the application of genetic programming. Input parameters that are percent Clay, Organic Carbon and Silt, evaluate using genetic programming, neural network and Neural Inference Systems-Fuzzy models. The results indicate a good ability to intelligent models for CEC Estimation According to indices used in this study. Genetic programming model with a root mean square error of 1.78 and coefficient of determination 0.95 compared to other models have been more efficient and is able to provide satisfactory results, Also are the explicit solutions that reflect the relationship between input an output variable, was presented based on genetic programming. This preferred the genetic programming model adds the other models. Stepwise regression analysis to determine the contribution of each of the parameters indicated in the CEC that organic materials having Most coefficient of variation of 84% is justified CEC and clay and silt, respectively, with a correlation coefficient of 10% and 6% respectively.
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.
. A. A. Sabziparvar1, S. Ebrahimzadeh2, M. Khodamoradpour3,
Volume 21, Issue 4 (2-2018)
Abstract
The most important factor in determining crop water requirement is estimation of evapotranspiration (ET). Majority of the methodsestimate ET apply series of relatively complex formula,which is then used to determine crop evapotranspiration (ETc). The parameters used in aforesaid methods are: Solar radiation, wind speed, humidity, etc. Unfortunately, in Iran and many countries, long-term records of these parameters are not readily available. The purpose of this study is to calculate the Selianinov Hydrothermic Index that merely requires daily temperature and precipitation data in order to determine correlation coefficients (r) versus ET and Crop Water Requirement (CWR) of some agricultural crops of Iran. First, the Selianinov index is calculated from daily precipitation and temperature during the growth season. Further, the results are correlated against both ETc and CWR. The model results indicate inverse (negative) strong exponential and polynomial relations between the dependent and independent variables. Coefficient of determination (R2) for polynomial equations (on average 0.84) in all crops was better than exponential equations (on average 0.72). Correlation between Selianinov index and CWR indicates that coefficient of determination in both equations was close together (0.83 for polynomial equations and 0.82 for exponential equations).
A. Vali, F. Roustaei,
Volume 21, Issue 4 (2-2018)
Abstract
Wind erosion is the most important geomorphic process and the main cause of the landscape change in arid and semi-arid areas. This paper focuses on the Dust Storm Index (DSI) with the aim of monitoring wind erosion in Central Iran using meteorology data. The trend of standardized DSI and its three factors which are sever dust storm, moderate dust storm and local dust events were studied using Man-Kendal non-parametric test. It was found that wind erosion is accelerating in recent years. Compared to primary 20 years (1965-1985) DSI rate has been three times more than 30 years ago (1985-2014). The central and southern parts of Central Iran show the highest severity of wind erosion and the severity of DSI decreases by approaching the north. Therefore, considering the sensitivity of these areas, in addition to taking into account prevention programs, they should also be considered in regeneration and control programs.
F. Amiri, T. Tabatabaie, S. Valipour,
Volume 22, Issue 1 (6-2018)
Abstract
The purpose of this paper was to assess the groundwater quality near Qaemshahr landfill site using the Iran Water Quality Index for Groundwater Resources-Conventional Parameters (IRWQIGC). In this study, samples were taken from 11 wells with three replications in February 2015 and water quality was assessed by evaluating nitrate, fecal coliform, electrical conductivity (EC), pH, total hardness, sodium absorption ratio, biological oxygen demand, phosphate, chemical oxygen demand, and dissolved oxygen parameters with the standard measuring methods; also, the quality of ground water was determined using the IRWQIGC. Statistical description of the parameters was performed using the SPSS software. Spatial extension mapping parameters were drawn using geostatistics extension with the ArcGIS software. The results of water quality assessment revealed that 0.15% of the area was classified as bad, 98.85% as relatively poor, and 1% as middle in terms of quality. The results of spatial dispersion also revealed that water quality from the South to the North and North East was reduced. Evaluating the changes in water quality near landfill sites showed that 2149.56 square meters of total area had a relatively poor potential for the region’s groundwater recharge.
S. Pourhossein, S. Soltani,
Volume 22, Issue 2 (9-2018)
Abstract
Bhalme & Mooley Drought index is one of common indices used in drought studies. Due to the fact that drought indices can have different sensitivities to different region conditions and the length of data recorded, 62 synoptic and climatological stations were selected within a homogonous region to study this index advantages and to assess the effect of climate, precipitation regime, and data record on the index. The best results were found for the humid climate. Also, this index had acceptable results for semi- mediterranean regimes regarding all different time scales,; however the situation was different for Mediterranean regimes, showing the best results for the time scales simultaneous with the precipitation period. From the data record point of view, the best results were estimated during the first 31- years of the common period which has correspondence with the results of the 36-year period.
S. Jahanbakhsh Asl, B. Sari Saraf, T. Raziei, A. Parandeh Khouzani,
Volume 23, Issue 4 (12-2019)
Abstract
In this study, the temporal and spatial variation of snow depth over the mountainous region of Zagros, in the western Iran, for the period 1979–2010 was investigated for the cold season when the probability of snow occurrences was high. For this purpose, daily gridded snow depth data relative to Era-Interim/land were retrieved from the European Centre for Medium-Range Weather Forecasts (ECMWF) and used for spatiotemporal analysis of snow in the region. Furthermore, monthly maximum, minimum and mean air temperature relative to the weather stations distributed over the region were also used to investigate the relationship between snow depth and air temperature variability in the region. In each grid point, the rate of temporal changes in the snow depth was estimated using the Sen’s slope estimator, while the modified Mann-Kendall Test was applied to assess if the change identified was statistically significant. The results showed that in almost all of the studied months, especially February and March, the snow depth was significantly reduced in the region, which was statistically significant at 5% significant level. Unlike the observed statistically significant decreasing trend in the depth snow in the region, a significant increase in the maximum, minimum and average temperature was observed for all the studied months and the stations. The result suggested that the observed decrease in the snow depth in the region was related to the increasing trend in the temperature during the study period, which could be attributed to the global warming and climate change.
