JWSS - Journal of Water and Soil Science

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In this study 2510 records of reproductive traits from the mating of 879 ewes with 164 rams of Bakhtiari sheep breed, during 1989 to 1997, were used in order to estimate the effects of environmental factors on their reproductive performance.

The mean and standard errors of reproductive traits were as follows: conception rate, 0.9±0.01 number of lambs born per ewe exposed, 1.06±0.01 number of lambs born alive per ewe exposed, 1.01 ±0.0l, number of lambs weaned per ewe exposed, 0.93±0.01 litter size alive at birth, 1.10±0.01 litter size at weaning, 1.01±0.02 and number of lambs weaned per lambing ewe, 1.09±0.01. The effect of joining year was highly significant (P, 0.01) for all of the considered reproductive traits. Age of ewe at joining time was also a significant (P<0.05 and 0.01) source of variation for most of the reproductive traits. Maximum reproductive performance occurred for ewes of 4 to 5 years of age. Mating time was also a significant factor (P<0.05 and 0.01) for all of the reproductive traits. Maximum reproductive performance occurred for ewes mated during the first half of the mating season. Type of birth was a highly significant factor (P<0.0l) for the number of lambs alive and weaning traits. However, due to significant effects of environmental factors on considered traits, and in order to increase reproductive efficiency, one should improve environmental conditions (barn, management, feeding system and ... ) as well as organizing mating plan for the first half of the mating season and make a suitable age combination of ewe herd. In this combination, decreasing the percentage of ewes older than five years could benefit herd performance.

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In order to estimate the heritability of morphological characters of worker honey bee and honey yield, 30 queen-mothers were selected randomly from the apiary of Research Center of Animal Science and Natural Resources in Isfahan Province. From each queen-mother, five queen-daughters were reared and introduced to equalize colonies after natural mating of queens. Summer honey yield was measured, while fall honey production was calculated from area of sealed honey combs. The total honey was calculated by adding summer honey production to fall honey production. Morphological characters were measured under a stereo-dissecting microscope fitted with a calibrated micrometer reticle according to Ruttners method (1985).

 Heritabilities were estimated by intraclass correlation method. Heritabilities of summer, fall and total yearly honey yields were estimated to be 0.64, 0.51 and 0.30, respectively. Estimates of heritability of morphological characters for probscis length, tibia length, femur length, metatarsus length, metatarsus width, forewing length, forewing width, cubital index, hindwing length and number of hamuli were 0.64±0.08, 0.45±0.07, 0.50±0.07, 0.47±0.07, 0.33±0.06, 0.42±0.06, 0.89±0.10, 0.5±0.07, 0.94±0.10 and 0.45±0.07, respectively. It could be concluded that in order to increase honey yield in either season (summer or fall), selection must be based on the amount of honey yield in the corresponding season. Thus, heritabilities of forewing and hindwing lengths were high selection according to these morphological characters would, therefore, change the size of these characters.

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In this paper, a numerical solution is presented for one-dimensional unsaturated flows in the subsurface. Water flow in the subsurface, however, is highly nonlinear and in most cases, exact analytical solutions are impossible. The method of reference-operators has been used to formulate a discrete model of the continuum physical system. Many of the standard finite difference methods and also the finite volume method are special cases of the method of reference-operators. Unlike elementary finite difference methods, the method of reference-operators may by used to construct finite difference schemes on grids of arbitrary structure. A one-dimensional model was developed to predict the soil-water suction (negative pressure head) and water content in a vertical column of a layered soil. The model was verified against some available analytical solutions and experimental results and, in all cases, it showed good agreement.

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A field survey was carried out in Firoozabad Beneh (Pistacia mutica) Forest Station covering about 12000 hectares. Data were collected using combined random and systematic sampling methods to study the effect of altitude, dominant slope direction, sex and age of the host and plant canopy on rust severity caused by Pileolaria terebinthi.

The rust severity decreased with plant age and elevations above 2000 meters. Female trees were more susceptible to the pathogen than males. The slope direction and plant canopy had no effect on disease severity. There was a significant correlation between plant age and elevation with disease severity but not with plant canopy. Regression analyses indicated a linear regression between disease severity variables and dependent variables of age, sex, and elevation.

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The population parameters of sweet potato white fly, Bemisia tabaci (Genn.) (Hom.: Aleyrodidae), which is an important pest of cotton fields, were studied during 2001. The infected leaves containing nymphs and pupae were collected from Darab, Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, Orsoiieh (Kerman), and Shooshtar cotton fields. Experiments were conducted in a growth chamber under 24±.2^ºC, 55%±3RH and 16:8 (L:D) photoperiod on cotton, a Gossypium hirsutum L. (Varamin 76 variety). The newly emerged populations of each locality were released into a large cage set on cotton plants separately. Population parameters of 40 mated females were calculated for each local population. Intrinsic rates of increase (r) for Darab, Qom, Saveh, Gonbad, Gorgan, Varamin, Garmsar, Orsoiieh and Shooshtar were 0.0401, 0.0719, 0.0750, 0.0602, .0682, 0.0774, 0.0876, 0.0751 and 0.0988, respectively. Doubling times (DT) were 17.26, 9.63, 9.24, 11.51, 10.16, 8.94, 7.91, 9.22 and 7.083 days, respectively, and mean generation times (T_c) were calculated to be 28.72, 28.9, 28.74, 28.3, 28.68, 27.53, 29.12, 28.21 and 26.84 days, respectively. Other population parameters such as finite rate of increase (λ), intrinsic birth rate (b), intrinsic death rate (d), and stable age distribution were also calculated. The results revealed that there were significant differences between population parameters in local populations. The parameter (r) was the least in Darab and the greatest in Shooshtar populations.

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The dissemination of Phytophthora spp. in the surface irrigation water was studied during 1993-94 in Marvdasht area and certain other parts of Fars province. Monthly the water samples were taken along 100Km of the Kor river 22Km up stream from the Doroudzan Dam to about 80Km down stream to Mardvdasht where Sivand and Kor rivers joined. The other sampling locations includede the Maeen river adjecent to the Dam, and the Sivand river from Dashte-Morghab to Mardasht. Few samples were also obtained from Shapour and Dalaky rivers and also from Yasouj and the Sisakht regions in Khkilueh and Boir Ahmad. The water temperature, pH and EC were measured and samples were assayed on the same day of the collection. The water sample was filtered through the two layers of the cheese cloth and about 1L was placed in a plastic container (30 × 20 Cm) 2-3C deep and 100 fresh citrus leaf disks (6mm dia) were also added and incubated at the room temprature. After 48hr, disks were collected, washed, blotted dry and plated on Phytophthora were collected, washed, blotted dry and plated on Phytophthora selective medium (PARPH). At least 50 disks were used in the 5 plates for each sample. The five to 8 boiled hemp seeds were placed on each growing colony and transferred to the distilled water, after 12hr for sporangium production. The Phytophthora species were idenified by their morphological characteristic and temperature requirement. Phytophthora spp. were present in the most rivers except the Shapour and Dalaky. The predominant species were non-popilate high temperature (above 35C) species mainly P. cryptogea and P. drechsleri. In some cases P. capcisi and the other unidentified species were also detected. Phytophthora spp. were present throughout the year but the lowest population was detected during winter months. The fluctuation of the phytophthora population and the other water microorganisms in the Kor river after shiraz petrochemical complex during the growing season was very high, but sometimes reduced to zero (perhaps due to the water pollution). No Phytophthora colonies were detected in the dam lake or in the most cases in the cement canals.

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The main objective of this article is to present the results of a study done about the social, economical, and farming characteristics of wheat farmers in Khuzestan province of Iran regarding adoption of low input sustainable agriculture (LISA). LISA practices have tended to reduce the use of fertilizer pesticides, and maximal tillage, but, rely more on crop rotation, crop residues, animal manure, green manure, leguminous, appropriate mechanical cultivation or minimal tillage to optimize soil and natural pest control activity. The research design was a descriptive and correlation surveying method. Wheat farmers in Ahvaz, Behbahan, and Dezful township of Iran who cultivated wheat by the use of irrigation in the year of 1379-80 were the target population for this study. A random sample of wheat farmers selected from three randomly selected township of Ahvaz, Behbahan, and Dezful township (N = 5529 , n = 359 ). The main results of the study indicated that correlation of level of education, wheat land, ownership land , income, social participation, social status, social norm, technical knowledge, LISA knowledge, with adoption LISA practices were significantly positive and the correlation of age, experience in agriculture, distance between farm and service centers with adoption LISA practices were significantly negative.

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The identification of potato cultivars is a recurrent objective of potato research. The research is prompted by the increasing number of potato cultivars and the importance of seed purity. In developing a reliable method for identification of the imported potato cultivars and determining their genetic relationship, the capacity of 10 polymorphic simple sequence repeat markers (SSRs) was evaluated for the analysis of 28 commercial cultivars of potato. The number of alleles detected at different loci ranged from 3 to 10 alleles with a total of 57 for all loci and a mean of 5.7 alleles per locus. In the 28 potato cultivars analyzed, the number of heterozygous genotypes per locus varied between 6 to 28 with an average number of heterozygous genotypes per locus of 18, considering the 10 loci studied. Based on the resulting dendrogram of jacquard's similarity coefficient and UPGMA analysis, the potato cultivars were placed in two major groups. However, the results from similarity coefficient confirmed the close phylogenetic relationships among members in each cluster. The dendrogram derived from SSRs data clustered together Kenebek, Florida and Atlantic which are known as American potato cultivars, but Stanbuli, an old cultivar in Iran, was placed in concert with European cultivars. This finding might be an indication that this cultivar along with other unidentified cultivars, growing in local fields, has been introduced from European countries to Iran. The results obtained illustrate the appropriate utility of SSRs to assess genetic relationships of potato cultivars and develop a PCR- based tool for evaluation of potato seed purity.

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Many experiments have been carried out to alleviate the negative effect of drought stress and to obtain suitable growth under water deficient condition. Application of plant growth regulators (especially growth retardants) is one of the proposed methods. In a greenhouse experiment using a completely randomized block design with 4 replications at Kerman University Agricultural Department, the effect of 4 drought levels 25, 45, 65, 85 percent of field capacity and 3 different concentrations of chlormequat chloride 0, 1500, and 3000 mg/liter on some factors of winter barley cultivar Valfajr was investigated. Results indicated that increasing the cycocel concentration from 0 to 3000 milligram per liter leads to significant decrease in plant height. Relative water content affected by growth retardants was increased. Numbers of tillers and root and shoot dry weight, were also decreased because of applying cycocel in dry condition. The result also indicated that the root/shoot dry weight ratio, grain number per ear and ear number in dry condition without stress would increase using cycocel treatment.

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The effect of dietary protein level and feed restriction on performance, body temperature and hematological values was evaluated, using Ross 308 broiler chicks under heat stress. For this purpose, three dietary treatments were fed to broilers during 21 to 42 days of age. Two treatments consisted of diets with protein levels recommended by NRC, 1994 and 85% of NRC recommendation and were fed ad-lib during the experiment. The third treatment was a feed restriction group that was fed diet with protein level recommended by NRC, but chicks were deprived of feed for 6 hours during heat stress challenge. Birds had free access to water. Results indicated that lowering protein content or feed restriction had no significant effect on body weight gain (P>0.05). Feed restriction resulted in significantly decreased feed intake, improved feed conversion and energy efficiency ratio, and decreased body temperature after heat stress challenge at 24 and 32 days (P<0.05). Lowering protein of diet and feed restriction resulted in significantly decreased protein intake, improved protein efficiency ratio and increased hematocrit and blood uric acid (P<0.05). Sex had no significant effect on body temperature and hematological values (P>0.05). Heat stress significantly increased body temperature, hematocrit and glucose and uric acid values.

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Mayonnaise sauce is a nutritious food product with high caloric content, which is usually incorporated into other products as an ingredient. The product should be produced under hygienic conditions to avoid its physical and chemical deterioration along with microbial spoilage, which mostly happens due to the lack of thermal treatment. Mayonnaise is often stored for long periods at room temperature in large plastic containers before consumption. To carry out the investigation, samples of the sauce in large plastic containers and glass jars were obtained directly from a commercial producer. After preliminary quality examinations, they were allocated into 3 lots and stored at 5, 25 or 40^oC for up to 6 months. They were then subjected to physical, chemical, microbiological and organoleptic tests at monthly intervals. The results showed no significant microbial growth even when kept at higher temperatures. Significant chemical changes (autoxidation), however, occurred in both containers at temperatures close to 40^oC. Organoleptic examinations revealed significant changes, especially in color and emulsion stability, which were more evidenced for those stored at higher temperature. It was concluded that the storage of mayonnaise sauce in large plastic containers at higher temperatures should be avoided mostly due to deterioration through physical, chemical and organoleptic changes of the sauce.

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Sustainability of livestock production systems (LPSs) is of prime importance to the needs of human beings. From a sustainability point of view, an LPS is sustainable when it is environmentally nondestructive, economically viable and socially provides appropriate quality of life for producer and the whole community. Iran LPS is primarily based on traditional production systems. Therefore, an important issue for animal production in this country is the question of sustainability of traditional LPSs.The aim of this paper was to investigate and compare the sustainability of traditional LPSs in Firouzabad County. Three dimensions of sustainability were considered. Survey research was used to reach this purpose. Therefore, 300 livestock producers in “Nomadic”, “Semi-nomadic” and “Village- based” system were interviewed. Respondents were selected by a multi-stage cluster random sampling method. Face validity was confirmed by experts and the questionnaires were subjected to reliability testing using data collected in the pilot study. Findings showed that all three LPSs were unsustainable with regard to social, economical, and technico-environmental dimensions. Comparison of LPSs showed that Village-based LPS was from social dimension relatively sustainable and technically and environmentally unsustainable. While nomadic LPS was from social dimension relatively unsustainable and technically and environmentally sustainable.

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  Erosion features map is one of the basic maps in erosion and sediment studies considered important in watershed management programs. For preparing soil erosion features map (1:250000 scale), a study was conducted in Jajroud sub-basin of Tehran, Iran. Working unit maps were prepared from integrating: A) plant cover, geology and slope B) land-use, geology and slope C) land-use, rocks sensitivity to erosion and slope and D) land-use, rocks sensitivity to erosion and land units. Working unit maps obtained from integrating layers were compared with three other maps consisting of working units maps according to E) land units F) rocks sensitivity to erosion units and G) image photomorphic units. Erosion features intensities in 314 control points were controlled and erosion features ground truth map was prepared by Thiessen method and using satellite imagery. Erosion features map was crossed with different working unit maps. Results showed that D map was better than A, B and C maps with regard to economic considerations. Accuracy was 53.0 and 42.9% for methods of land unit and rock sensitivity which resulted in the maps not suitable for differentiating soil erosion features. Root Mean Squared Error of working units showed that the error of land unit and rock sensitivity methods was more than image interpretation and integrated layers methods. The highest coefficient of variation was related to land unit and rock sensitivity to erosion methods and was the least for image interpretation and integrated layers methods. The greatest precision, therefore, was related to image interpretation and integrated layers methods. In general, working unit map of image interpretation was the best method for preparing soil erosion features map.

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A total of 1256 records associated with body weight and Cashmere at different ages (birth and 3 and 9 months) obtained from 754 Cashmere goats were used to estimate the genetic parameters in southern Khorasan province during 2000- 2003. A set of univariate animal models including additive and maternal genetic effects and maternal permanent environmental effects as well as the fixed effects of year and month of birth, sex, birth type and dam age (linear and quadratic covariates) and kid age (linear and quadratic covariates) was fitted. Co/variance components were estimated by restricted maximum likelihood procedure using Powel algorithm in DFREML software. For the body weight at 0, 3 and 9 months, models two, one and three were recognized as the appropriate models. For these models, direct heritability estimates were found to be 0.09, 0.11 and 0.09, respectively. For birth weight and weight at month 9, the magnitude of c² and h²_m were 0.18 and 0.00, respectively. For average daily gains during 0-3 and 3-9 months of age, direct heritability based on the model one was 0.16 and 0.05, respectively. Direct heritability of Cashmere was found to be 0.02. Applying repeatability model, the estimates of heritability and repeatability of Cashmere were 0.16 and 0.53, respectively. Genetic trends for birth weight (0.0175kg/year) and weight at month 9 (0.02065kg/year) were positive and non-significant. A negative non-significant statistical genetic trend (-0.00537kg/year) was found for Cashmere during the period of time.

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The growing season climatic parameters, especially rainfall, play the main role to predict the yield production. Therefore, the main objective of this research was to find out some possible relations among meteorology parameters and drought indexes with the yield using classical statistical methods. To achieve the objective, ten meteorological parameters and twelve drought indexes were evaluated in terms of normality and their mutual influences. Then the correlation analysis between the barley yield and the climatic parameters and drought indexes was performed. The results of this study showed that among the drought indexes, Nguyen Index, Transeau Index, Rainfall Anomaly Index and Standardized Precipitation Index (SPI24) are more effective for prediction of barely yield. It was also found that the multivariate regression is better than the univariate regression models. Finally, all the obtained regression models were ranked based on statistical indexes(R,RMSE and MBE). This study showed that the multivariate regression model including wind speed, sunshine, temperature summation more than 10, precipitation and Nguyen index is the best model for prediction yield production in Miane. Average wind speed and Nguyen index were recognized to be the most effective parameters for yield production in the model.

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Rose is one of the most important ornamental shrubs of the world because of its durability, long period of flowering, different cultivars and its beauty. The rose aphid, Macrosiphum rosae is the most important pest of the rose which causes significant economic damage annually. In order to compare four rose cultivars including Black Magic, Caramba, Noa and Good Life, and a wild rose, Nastaran, infested with rose aphid, a split-plot in time experiment was arranged in randomized complete block design layout with three replications, in Isfahan (Iran) from February 2004 to March 2005. The infestation levels of roses with the rose aphid and its seasonal fluctuations were determined by weekly sampling. Analysis of data showed that there are significant differences (P<0.01) between cultivars. Noa (with pink flowers) has the highest infestation of rose aphid (with average 23.12  ± 0.036 aphids) and Caramba (with yellow flowers) has the lowest infestation (with average 6.46  ± 0.036 aphids). The wild rose, Nastaran, showed low infestation (with average 8.76  ± 0.036) as well. Different sampling times also showed significant differences (P<0.01). There was a significant interaction (P<0.01) between cultivars and sampling date, such that reactions of cultivars to aphid (nymphs, adults and total) were not similar in different sampling dates. Seasonal fluctuations of the rose aphid showed two peaks in a year, in May and December. Activity of the rose aphid in spring which coincides with rapid growth and tenderness of rose foliage causes severe fading and inhibiting of floral opening.

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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.

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Remote sensing has been considered as an appropriate tool for temporal monitoring of some natural phenomena. Ardestan Region is prone to land degradation and masked by sand sheets, sand dunes, clay flats, desert pavement and different kinds of salt crust due to dry climate. To study the trends of land degradation in last three decades, four satellite data sets of Landsat MSS, Landsat TM, Landsat ETM+ and IRS acquired in 1976, 1990, 2001 and 2008, respectively were analyzed. The time series analysis revealed that the bare clayflats have decreased and clayflats with vegetation cover have expanded over 32 years. During this period, the areas which are covered by gravel have decreased 13 percent and both the area covered by salt crusts and aeolians have extended 2 percent. Puffy grounds have developed by 2001 but their magnitudes have decreased between 2001 and 2008 as they have been masked by the moving sand ripples. Reduction of 13 percent of sand sheets between 1990 and 2008 indicates that soil conservation practices have efficiently controlled land degradation and desertification in the area.

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One of the most important issues in trickle irrigation design is investigating the emitter's characteristics, the effect of factors on flow rate, and finally appropriate emitter selection. Therefore, in this study nine types of pressure compensating emitters with codes of A, B, C, D, E, F, G, M and N, made based on trickle irrigation physical model were tested and the effects of four different water temperatures (13, 23, 33 and 43°C) with different pressure ranges (between zero and 1.2 times more than the maximum pressure) on the emitters were evaluated. All experiments were carried out based on ISO 9261 standard and IRISI 6775 standard of the Institute of Standards & Industrial Research of Iran. The obtained results at all the tested temperatures, no emitter has x more than 0.2 and all emitters were pressure compensating types. The effect of temperature on the flow rates of models F, M and N was significant at 95% confidence level. Increase in temperature showed an increase in the flow rates of the above mentioned models.

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Few investigations have been carried out on the ability of different plants to take up non-exchangeable potassium (K). The objective of this investigation was to examine the ability of different alfalfa cultivars to absorb K from phlogopite. An experiment was carried out with a completely randomized design with 3 alfalfa cultivars including Pickseed 2065 (MF), Rehnani (R) and Hamadani (H) grown in a quartz sand medium containing <53 micron sized phlogopite under complete and K-free nutrient solutions for a period of 6 months. During the growth period, the shoot was harvested 4 times. At the end of the experiment, the root was also separated from the growth medium and collected. Plant samples were extracted using the dry ash method and their K concentration was determined. Under the K-free nutrient solution, the highest shoot and root K concentration and uptake were found for the MF cultivar. The shoot and root K concentration in this cultivar were respectively 1.6 and 1.5 times higher than those in the R cultivar and 1.8 times greater than those in the H cultivar. The K uptake in the shoot and root of the MF cultivar was respectively 1.6 and 1.9 times higher than that of the H cultivar and 1.6 and 1.5 times higher than that of the R cultivar. Thus, in addition to other parameters, the type of plant variety should be taken into account when K requirement is evaluated.