JWSS - Journal of Water and Soil Science

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In order to evaluate the effect of row and plant spacings on the yield and yield components of three cultivars of forge sorghum, a field experiment was conducted in Isfahan University of Technology, Lavark, during spring, 2001. Experimental design was a split-factorial with three replications. Main plots consisted of three row spacings (45, 60, 75 cm) and subplots were combinations of three cultivars of forage sorghum(cultivars KFS1, IS722, IS3313) and three plant spacings (4, 6 and 8 cm). The results showed that the number of young and adult tillers, the number of leaf per square meter and shoot and leaf dry weight were influenced by row and plant spacings and significantly decreased with increasing row and plant spacings. Forage yield also decreased with increasing row and plant spacing. The highest dry forage yield was produced by 45 cm row spacing and 4 cm plant spacing. The KFS1 cultivar produced more forage yield than IS722 cultivar. The number of young and adult tiller per square meter and the number of leaf per square meter were significantly (p< 0.01) influenced by the interaction between row spacing and cultivar, row spacing and plant spacing and plant spacing and cultivar in two cuts. Shoot and leaf dry weight (kg/m²) was also significant (p< 0.01) influenced by the interaction between row spacing and cultivar, and between plant spacing and cultivar in the second cut. The density of 45 cm row spacing and 4 cm plant spacing produced the maximum forage yield.

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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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This study was carried out to evaluate the yield potential and other agronomic traits of nine genotypes of flax at two different spring planting dates: April 4 and May 5, 2003 and 2004, using a randomized complete block design with three replications at the Research Farm of Shahrekord University. The results showed that the effects of planting date and genotypes were significant on all of the traits, and the genotypes had a great genetic variation. On average, the range of number of seedlings/m2, maturity, plant height, yield/plant, seed yield and seed oil content of genotypes were 306 to 464, 93.3 to 105.1 days, 28.8 to 58.2cm, 0.274 to 0.569g, 995 to 1423 kg/ha and 32.88 to 34.83%, respectively. The lowest mean of plant height and the highest mean of seed yield/ha were observed for Kordestan local population. Late planting significantly decreased the number of seedlings/m2, days to maturity, plant height, yield/plant and seed yield/ha, while this increased seed oil content. Average of seed yield/plant and seed yield/ha in the first and second planting dates were, respectively 0.506 and 0.414g, and 1598 and 811 kg/ha. Significant interaction of genotype by planting date for seed yield/ha and seed oil content was mostly due to the variation in the reduction of seed yield and increasing or decreasing of seed oil content in some genotypes in the second planting date. The genotypes had a variation of 1358 to 1784 and 632 to 1088 kg/ha for seed yield in the first and second planting dates, respectively. The local population of Kordestan had the highest mean of seed yield in both years. The results of regression analysis and also the correlation coefficients showed that the number of seedlings/m2 and seed yield/plant had the most contribution to the seed yield variation. The trait of number of seeds/capsule and number of capsules/plant were the main and most important yield components affected on seed yield/plant and due to can be used as selection criteria in selection programs to improve seed yield.

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The effect of Rathayibacter tritici on the movement of Anguina tritici larva and nematode function as vector of ear rot bacterium was conducted in the laboratory (Agarose plates) and greenhouse conditions. The results showed that the contact of nematode larva with high concentration of bacterium or long duration of nematode-bacteria contact can decrease the movement and the efficiency of nematode function as the vector of the disease, and in some cases it resulted in the mortality of the nematode. No differences were detected in the mobility of larva in the concentrations less than 10² CFU and less than 0.5 hour of nematode-bacteria contact times and their controls (exposed to water alone). Movement of the nematodes appeared to be random under these conditions. It can be concluded that Rathayibacter tritici did not act as an attractant to Anguina tritici larva. These results suggest that the attachment of a large number of bacteria to nematode (as an essential vector of the bacterium) would induce nematode weakness and mortality. So it is possible that ear rot bacterium can parasite ear cockle nematode, or the nematode is a host for this bacterium .

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Genetic variation within and between five Iranian sheep populations including Sanjabi (SAN), Kordi Kordistan (KKO), Kordi Khorasan (KKH), Mehraban (MEH) and Moghani (MOG) was assessed using six microsatellite markers (McMA2, McMA26, MAF64, OarAE64, OarCP26 and OarFCB304). The PCR reactions were successfully perfomed with all primers except OarAE64. All locus-population combinations were at Hardy-Weinberg equilibrium except McMA2 in MOG population (P<0.005). Polymorphism criteria showed that the five studied loci were polymorphic in all populations. The lowest D_A genetic distance (0.234) was observed between KKH and KKO and the highest (0.388) between SAN and MOG populations. The dendrograms based on D_A distances were drawn using unweighted pair-group method using an arithmetic average (UPGMA) and neighbor-joining (NJ) method. KKO, KKH and SAN were grouped together at one cluster and MEH and MOG at another by both methods. The average expected heterozygosity for each populations (as interpopulation variation) ranged from 0.744 to 0.847 for KKH and MEH, respectively. The estimated time of divergence for two Kordi populations (KKO and KKH) was 445 years that complies with historical evidences. The findings of this research confirmed that microsatellite variation could be a useful tool for screening of investigating biodiversity among domestic animals.

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This paper investigates the effects of wheat production risk and other socio-economic factors on the probability of adopting new seed technologies. Also, the effects of production inputs and production conditions are examined on wheat production yield and risk. Moreover, the relative risk of new seed varieties will be examined under different scenarios. To carry out the study, farm-level data was collected from a sample of 187 wheat farms located in Fars province, and selected by multi stage random sampling method during the years 2001 and 2002. A generalized stochastic production function by a three-stage estimation procedure was used to determine the influential factors on the production yield and risk. The results showed that yield uncertainty could not be sufficiently explained by the level of input use in the cultivation of both wheat varieties. The comparison of two wheat varieties cultivation indicated that in the absence of suitable production conditions, on the average, the cultivation of new wheat varieties ensures greater yield than traditional wheat varieties, but involves greater risk, as measured by yield variance. Accordingly, the farmers’ risk aversion attitude could be a major factor inhibiting speedy diffusion of new wheat varieties, which besides having greater average yield than traditional wheat varieties, it has less production risk. The results indicated that the risk associated with seed has negative effect on the adoption of new seed technologies.

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Application of sewage sludge on the farmland as a source of crop nutrient had recently received considerable attention. Some management practices may be required to control the accumulation of toxic elements including Pb, Ni and Cd. Sequential extraction gives useful information on plant bioavailability of the elements. The objective of this study was to investigate the cumulative and residual effects of sewage sludge application on the chemical forms and mobility factor of Pb, Ni and Cd. Zero, 25, 50 and 100 Mg ha-1 of sewage sludge were applied for 1, 2 and 3 consecutive years in a split plot design, with three replications. Soil samples were taken from 0-20 cm at the end of the third year of application. Different chemical forms of Pb, Ni and Cd were measured. Results revealed that the soluble form (SOL) of Ni and Cd increased whereas Pb soluble form decreased with increasing levels and years of application. Exchangeable (EXC), carbonate (CAR) and organic (ORG) forms of the three elements increased as levels and years of application increased. Occluded (OCC) form decreased for Pb, Ni and increased for Cd. Residual form (RES) of Pb increased while that of Ni and Cd decreased. A gereral increase was observed for available (DTPA-extractable) concentration of Pb, Ni and Cd. Relative distributions of different chemical forms were in the following order: Pb: OCC > RES> ORG> CAR> EXC> SOL, Ni: RES> ORG> OCC> CAR>EXC> SOL and Cd: OCC> CAR> RES> ORG> EXC> SOL. The comparison of different forms of the metals showed the following orders: soluble Ni>Pb>Cd, exchangeable, carbonate and occluded Pb>Ni> Cd, organic and residual Ni> Pb>cd. Increasing the available (DTPA-extractable) concentration of the elements in such a calcareous soil showed that consecutive application of sewage sludge may increase the available (DTPA-extractable) concentration beyond critical levels. A significant corretation was observed between organic form and available (DTPA-extractable) concentration of the elements.

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Sewage sludge application on farmland as fertilizer is commonly practiced in many countries. Sewage sludge is rich in macro- and micro- nutrients. However, high concentration of heavy metals in sludge may cause pollution of soil, groundwater and human food chain because of uptake of toxic metals by crops. The objective of this study was to determine residual and cumulative effects of sewage sludge on concentration of Pb and Cd in soil and wheat. Different levels of 0, 25, 50 and 100 Mg ha^-1 of sewage sludge were applied to the soil for four years. To study the cumulative and residual effects of the sewage sludge, applications were repeated on three fourth of each plot in the second year, on one half of plots in the third year and in one fourth of plots in the fourth year. Wheat grown in the plots, after the fourth year, soil samples from the 0-20 cm depth of the different parts of the plots were taken and analyzed. Wheat was also harvested roots, stems and grains were separately analyzed for the heavy metal concentritons. Cumulative sewage sludge application increased OM, CEC, ECe, total and DTPA-extractable concentration of Pb and Cd in soil significantly (P≤ 0.05). Residual sewage sludge in the soil also increased CEC, total and DTPA-extractable concentration of Pb and Cd significantly. Single sludge applications at different rates increased the DTPA-extractable concentrations of heavy metals. In subsequent years with no further sludge application, DTPA–extractable metal concentrations in soil decreased continuously approaching the levels in the control. However, even after four years, DTPA-extractable concentration of Pb and Cd, were still significantly higher in plots which received more than 50 Mg ha^-1 sludge than control. DTPA-extractable concentrations of Pb was closely correlated with total concentrations. Sewage sludge increased concentration of Cd in roots and stems and Pb in grains significantly. Cumulative effects on concentrations of Pb in grains, and Cd in stems were more than residual effects. The results of this study show that cumulative and residual effects of sewage sludge application increased concentrations of heavy metals in soil and wheat.

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In vitro regeneration of four cultivars of carnation namely ‘Nelson’, ‘Impulse’, ‘Sagres’ and ‘Spitit’ through somatic embryogenesis was studied. MS culture medium was supplemented with 30 gl^-1 sucrose, 2 mgl^-1 2,4-D and 0.2 mgl^-1 BA and used for embryogenic callus formation. Somatic embryos were formed when embryogenic callus was transferred to MS medium without growth regulators containing 30 g/l^-1 sucrose alone or supplemented with different concentrations of mannitol (15, 30, 60, 90, 120 and 150 gl^-1). No somatic embryo was formed on culture media containing mannitol without sucrose. Number of somatic embryos produced from embryogenic calli significantly increased by adding mannitol to the culture media. Normal embryos formed on culture media containing high concentrations of mannitol (60, 90, 120 and 150 gl^-1) developed normally. About 95% of somatic embryos transferred to the1/2 MS culture medium containing 30 gl^-1 sucrose, germinated into plantlets. Plantlets also continued their growth under greenhouse conditions.

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In order to examine the responses of proso millet (Panicum miliaceum) to drought stress at different growth stages, four breeded genotypes and a local one of proso millet were selected and planted in a split-plot design with five irrigation treatments and three replications.This experiment was conducted in two locations, Birjand and Sarbisheh. Irrigation treatments included well - watered, drought stress at vegetative stage, ear emergence stage, seed filling stage and vegetative and seed filling stages which were considered as main- plots. The first five mentioned genotypes were considered as sub-plots. Drought stress. caused a great reduction in grain yield and WUE at ear emergence stage. This reduction represented itself in the number of seed per ear and the weight of seeds, but it didn’t have any effects on the number of ear. At ear emergence stage, the drought stress increased the floret death and loss of weight of seeds which resulted in the reduction in the harvest index of both ear per plant and seed per plant. Comparison of genotypes indicated that since K-C-M.4 had a greater number of ears and K-C-M.9 had heavier seeds that had higher grain yield. These two genotypes had the highest WUE and their harvest indices were relatively higher. Due to the salinity of water and infertility of soil in Birjand, the grain yield was lower compared with Sarbisheh. In summary, it can be said that genotype K-C-M.4 proved to be more suitable for both areas.

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Half diallel crosses of eight bread wheat cultivars were used to estimate the genetic parameters and types of genetic control for yield and yield components, and to determine the effects of environmental factors on these parameters. Parents and their F2 hybrids were grown in a randomized block design under irrigated and stressed (terminal drought) conditions. For all traits, except for number of spikelets per spike and number of grain per spike, the effect of environment (irrigated v.s stressed) and genotype by environment interaction were significant. The mean square of GCA for all characters was significant in both environments, except for number of fertile tillers in the irrigated condition and grain yield in the stressed conditions. The mean square of SCA was significant for plant height only in the irrigated condition, while for number of fertile tillers and grain yield it was significant in both conditions. The high significant ratios of GCA to SCA mean square indicated the importance of additive genetic effects on controlling plant height, spike length number of grain per spike in both environments and number of spikelets per spike in the stressed condition. The parameter estimation revealed partial dominance gene actions for plant height, spike length and grain per spike in both environments, and number of spikelets per spike in stressed environment, whereas over-dominance gene actions were observed for the other traits in one or both conditions.

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This research was conducted at Research Farm of Isfahan University of Technology to examine the relations among phonologic, morphologic and physiologic traits and their effects on grain yield of 20 oat (Avena sativa L.) genotypes. A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3, and 130±3 mm evaporation from class A pan). Grain yield had significant and positive correlations with harvest index and relative water content (RWC) in both irrigation treatments and with plant height at maturity in non-stress condition. Also, grain yield had significant and negative correlation with days to heading. Factor analyses resulted in three factors in each condition, which were named yield factor, phenologic factor and sink factor in both conditions. Based on stepwise regression, harvest index was the first character which entered the grain yield model in both conditions. At the next step, RWC and plant height entered the model, with harvest index explaining 66% and 64% of yield variation in stress and non-stress conditions, respectively. The results of path analysis in both conditions showed that harvest index had the highest positive direct effect on grain yield. The highest indirect negative effects through number of grain per panicle were obtained for the harvest index and panicle m-2 in stress and non-stress conditions, respectively.

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A total of 25 advanced rapeseed (Brassica napus L.) varieties were evaluated under cold weather conditions using Randomized Complete Block design (RCBD) with four replications in Dr. Nakhjavani Agricultural Research Station, 35 km North-East of Urmia the capital of West Azerbaijan province in 2000-2001. The results showed significant differences among the varieties (P ≥ 0.01) for all the phenological stages including days to germination, days to rosette completion, days to initiation of stem elongation, days to flowering initiation, pod formation stage and days to maturity. The spring varieties Sarigol (PF7045/91), Hyola 42 and SYN1 and autumnal varieties Alice, Eurol, Fornax, VDH 8003-98, Consul, Licord and Zarfam (Regent× Cobra), showed early maturity. On the other hand, Mohican, Olara, Colvert, L-1 and Akamar were late mature varieties. In fact, the most prolific varieties, DP.94.8, Zarfam (Regent ×Cobra) Cocktail, Consul and SLM046 (control variety) had the highest ability survive in the cold conditions and they completed their rosette stage sooner than the other varieties. There was positive and significant correlation between duration of pod formation stage and seed yield. Maturity date of varieties was positively and significantly correlated with harvest index, number of seed per pod, days to germination, days to rosette completion, days to stem elongation, days to flowering, and days to pod formation. Negative and significant correlations were found between days to maturity and duration of flowering and pod formation stages. It can be concluded that delay in initiation or completion of each growth stages could delay maturity of the rapeseed varieties.

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Cucumber cultivars, grown in greenhouse in the Jiroft region, were surveyed for the relative incidence of Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus-2 (WMV-2), Cucumber mosaic virus (CMV) and Tomato spotted wilt virus (TSWV) from 2001 to 2004. Samples from 1294 plants representing different cultivars were analysed by Enzyme-linked immunosorbent assay (ELISA) and Dot immunobinding assay (DIBA). The data showed that green-house cucumbers are infected by CMV, ZYMV, TSWV and WMV-2. However, ZYMV was the most prevalent virus. Mixed infection including double and triple infection was identified in some samples. Transmission of aphid-borne viruses (CMV, ZYMV and WMV-2) by Aphis gossypii, A. fabae, A. craccivora and Myzus persicae revealed that ZYMV is most efficiently vectored by these aphids and, A. craccivora transmitted these viruses with more than 60% efficiency. In addition, WMV-2 was not transmitted by A. gossypii. In RT-PCR, ZYMV infection was confirmed by amplifying a PCR product of the predicated size 458 bp, using total RNA extracted from infected plants. All ZYMV infected samples reacted with monoclonal antibodies (705-1, 705-2 and 705-4) in TAS-ELISA test. These results showed that ZYMV isolate collected from Jiroft belongs to group A, cluster 1 or 2. In electron microscopy study, normal length of ZYMV flexuous particles in partial purified preparation was calculated as 790 nm. The molecular weight of coat protein of ZYMV was estimated at 36 KDa., using SDS-PAGE and western blotting. This is the first report of these viruses in greenhouse grown cucumber in the Jiroft region.

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To determine the preheating effect on frozen French - fries quality, four potato cultivars: Agria, Marfona, Auozonia & Auola were selected from Faridan region in Isfahan province & transferred to cold storage at temp.=5+0.5°C and RH=85-90%. At first, some physico – chemical characteristics of potato tubers such as specific gravity and dry matter content were measured by A.O.A.C methods. Also reducing sugar contents were analyzed by “High Performance Liquid Chromatography” (HPLC). The potato strips were blanched in hot water at different condition: 70°C - 4 min, 70 °C 10 min, 95 °C - 2min and then deep - fat fried at temperature 175°C for 2 minutes. Product quality properties such as texture, color and oil absorption were determined by standard methods. The data were analyzed using a factorial experiment in a completely randomized design, and average comparisons were made by by Duncan's multiple range test (p < 0.01). The results showed that blanching at 70 °C for 10 minutes markedly improved the quality parameters. Treatment at 95 °C – 2 min did not have any significant effect on Hunter Lab color parameters compared with 70 °C – 10 min. treatment, but the texture was significantly different. The oil absorption increased in strips blanched at 95 °C for 2 minutes. The samples blanched at 70 °C – 4 min had no significant effect on the product quality. In conculsion, Agria &Auola cultivars were more suitable for manufacturing French - fries than the other two varieties.

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A feeding trail was conducted to evaluate the effects of diets contaminated with Aflatoxin B1 (AFB1) on the performance and blood enzymes of broiler chickens. In a randomized complete-block design with 4 blocks and 4 treatments, 112 day-old male broiler chicks were divided into 16 groups, 7 chicks per. Treatments consisted of three levels of AFB1 in starter diet (0.4, 0.8, and 1.2 ppm) along with a control group (no AFB1). Feed intake and body weight gain were recorded on a weekly basis. On days 7, 14, 21, and 28, one bird from each replicate was weighed, and killed to collect the blood samples, and to weigh its proventriculus, gizzard, duodenum and pancreas, heart, liver, spleen, bursa of fabricius, and brain. Feeding AFB1 significantly decreased feed intake and body weight gain and increased relative weight of liver (p<0.05). Relative weight of brain decreased on day 7 and then showed a significant increase by day 28 (p<0.05). AFB1 significantly (P<0.05) increased serum activity of aspartate amino transferase (AST) and alanine amino transferase (ALT) and decreased serum activity of lactate dehydrogenase (LDH) enzymes. Generally, this study demonstrated that, alongside other negative effects, AFB1 could also have adverse effect on the brain of broilers.

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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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In this study wholesale prices of selected crops, namely, tomato, onion and potatoes in Fars province were predicted for various time horizons by using common methods of forecasting and artificial neural networks (ANN). Monthly data from September 1998 to June 2005 period were obtained from Ministry of Jihad-e Agriculture. For comparing different methods data selected from September 1998 to December 2004 were utilized, and latest six - month data were mainly used to monitor the power of prediction. The MAE, MSE and MAPE criteria were used for comparing the ability of different forecasting methods. Results of this study showed that ANN had the lowest error in prediction of prices for one - to three - month periods, but for six - month prediction, all forecasting methods were not statistically different.

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Sedimentation and consolidation of cohesive sediments near the dam body can cause many problems such as clogging the bottom outlets and entering the sediments into the hydropower intakes. Flushing of these sediments through the bottom outlet will be successful only if the hydraulic conditions are designed according to the physical and mechanical properties of consolidated sediments. During the past decades many researches have been conducted on the distribution of non cohesive sediments in the reservoir, yet little information is available for cohesive sediments. Therefore the main purpose of this study is to conduct a physical model study to investigate the process of sedimentation and consolidation of cohesive sediments in the dam reservoir. The experimental tests were conducted in a settling column test with a height of 3.8 m and diameter of 0.3m. The sediment samples were collected from the Dez dam reservoir since it is predicted that in less than 5 years the sediment will reach to such an elevation that can enter into the hydropower intakes. The obtained results show that there is a an algorithmic relationship between the time and changing of the sediment concentration during the sedimentation and self-weight consolidation processes. This process can be divided into four separate phases. It is also of note that in this paper the effective stress-void ratio and coefficient of permeability – void ratio relationship were obtained as a power relationship, which are in agreement with the results obtained by other investigators. These relationships can be used as primary data in the mathematical model of sedimentation and consolidation.

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A computer model (SprinklerMod) was developed to simulate hydraulics of sprinkler irrigation systems. The objective of this paper is to describe mathematical background of this model for simulating pressures and discharges of sprinklers along the laterals. The model is capable of designing two types of laterals: laterals with fixed sprinklers and laterals with portable sprinklers. The model shows the simulation results in the forms of tables and graphs. Laterals with one or two diameters on uniform or non-uniform slopes can be designed. The model provides graphical presentation of percentage of sprinkler pressure variations for different lateral inside diameters. The Hazen- Williams equation was used for the calculation of friction losses. The required input parameters for lateral simulation are lateral type, desired sprinkler operating discharge and pressure head, spacing between sprinklers, distance of first sprinkler from lateral inlet, number of sprinklers operating on the lateral, riser height, Hazen- Williams pipe friction coefficient and lateral longitudinal slope or field elevations at each of the sprinklers on the lateral. Laterals are simulated such that average sprinkler pressures and discharges become equal to the values requested by the designer. Iterative procedures were implemented to simulate sprinkler pressures and discharges on laterals and the Newton- Raphson iterative method was used for calculating pressure of each of the sprinklers on the laterals with portable sprinklers. In order to evaluate the model, some example results of the model were compared with classical design results. Since there is no formula for the calculation of the required lateral inlet pressure in classical design of laterals with portable sprinklers in the scientific references, a new formula was developed. Averages of absolute percentage of variations of lateral inlet pressures for laterals with fixed sprinklers and with one or two-size diameters ranged from 0.3 to 0.7 percent, respectively. This value for laterals with portable sprinklers was 0.1 percent.