1 2251-8517 764 General The Effects of Different Levels of Irrigation, Nitrogen and Plant Population on Yield, Yield Components and Dry Matter Remobilization of Corn at Climatical Conditions of Khuzestan lack S.h. naderi A. saidat S. A. Ayenehband A. Nour – Mohammadi G.H. Moosavi S.H. 1 1 2008 11 42 1 14 12 08 2008   In order to study the effects of different levels of irrigation, nitrogen and plant population on yield, yield components and reserved dry matter remobilization of seed corn (SC. 704 hybrid) a research was conducted at the experimental field in Khuzestan Natural Resources and Agricultural Science University in summer, 2004. This research was made based on three split-plot field experiments, RCBD. Each of the irrigation treatments implemented separately in each experiment have been as follows: Optimum irrigation, Moderate stress and Severe stress (irrigation after drainage 50%, 75% and 100% of available water based on 70%, 60% and 50% of field capacity, respectively). In each experiment three nitrogen levels consisting of 140(N 1 ), 180 (N 2 ) and 220(N 3 ) Kg N ha-1 were applied in main plots and subplots which consisted of three plant populations (D 1 =6, D 2= 7.5 and D 3= 9 plant m-2). There were three replications for each experiment. The results of the combined analysis of variance indicated that the effect of water deficiency stress, nitrogen and plant population on grain and biological yield was significant. With increasing severity of drought stress, the grain and biological yield decreased. The maximum grain yield was estimated to be 1017.04 gm -2 which was related to optimum irrigation treatment. Grain yield reduction was mainly due to reduction of grain per ear and 1000 seed weight. The increase of nitrogen consumption caused an increase in grain yield. The positive effect of nitrogen application on grain yield considerably decreased as a result of the increased water deficiency in soil. The response of grain yield to plant population was positive. The contrary to interaction effects of irrigation and nitrogen, and irrigation, nitrogen and plant population, the interaction effects of irrigation and plant population and also nitrogen and plant population on grain yield were significant. The results indicated that the difference between different levels of irrigation in the case of dry matter remobilization rate was significant. The least and the highest remobilization rate of reserved dry matter was related to optimum irrigation and drought moderate stress treatment, respectively. The efficiency and contribution of remobilization in grain yield increased in response to increasing severity of drought stress, but these traits significantly reduced as a result of nitrogen consumption. Remobilization rate and contribution of reserved materials to grain yield in the highest density (D3) were significantly more than other densities. According to the results of this study, under drought stress conditions, the decrease of inputs consumption, in addition to the decrease of costs, will be followed by the increasing efficiency use of the resources.
765 General Effects of Row Spacing and Planting Density on Growth Indices and Yield of Safflower, Local Variety of Isfahan “Koseh” in Summer Planting Pourhadian H. Khajehpour M.R. 1 1 2008 11 42 17 31 12 08 2008   Planting patterns through growth indices affect yield formation. To evaluate these effects on safflower, Koseh local variety of Isfahan, a field experiment was conducted in summer, 2004 at the Agricultural Research Station, Isfahan University of Technology. The experiment was performed using a randomized complete block design with a split plot layout and four replications. Main plots consisted of three row distances (20 and 30 cm flat and 45 cm on bed), and sub-plots included two planting densities (40 and 50 plant m-2). The experiment was planted on June 25. The results showed that p lant canopy closed sooner, leaf area duration (LAD) increased and plant dry matter weight, leaf area index (LAI) and crop growth rate (CGR) were higher up to the middle of seed development as row distance decreased. In addition, the highest relative growth rate (RGR) and net assimilation rate (NAR) were obtained in 20 cm row distance. The highest (3039 kg ha-1) and lowest (1930 kg ha-1) seed yields were obtained with 20 and 40 cm row distances, respectively. Plant density did not affect the rate of canopy closure, CGR, RGR, NAR and seed yield. But, maximum plant dry weight, higher LAI and lower LAD values were obtained with 50 plants m-2. The results obtained in this experiment indicate that 20 cm row distance with 50 plants m-2 might be appropriate for summer planting of safflower, a local variety of Isfahan, under similar conditions. 766 General Regeneration of Plantlets from Embryo Explants of Bunium persicum (Boiss.) B. Fedtsch Valizadeh M. Safarnejad A. Nematzadeh G.H. Kazemitabar S.K. 1 1 2008 11 42 33 38 12 08 2008   Parsi Zira, Bunium persicum (Boiss.) B. Fedtsch., which is called Mountainous or Black Zira, is one of the most important medicinal plants with high economic importance. Generally, there is a little information about in vitro culture of Bunium persicum. Fragmented embryo was used as an explant in Bunium persicum regeneration. In this method, a great callus induction and regeneration only on the same medium without any subculture occurred because of being young and having better interaction with medium, leading to reduction of tissue culture time, infection and chemical consumption. In this research, B5 media containing different concentrations of plant growth regulators, NAA and 2,4-D only or together with Kin, were used. The experiment was conducted using completely randomized design with 30 treatments and 10 replications per treatment. The highest callus number was obtained from the treatment containing 0.1 mg/l 2,4-D and 2 mg/l Kin or 1 mg/l NAA and 2 mg/l Kin. Regeneration occurred in some treatments without Kinetin, showing that Kinetin is not essential for Bunium persicum regeneration. The treatment containing 0.1 mg/l NAA and 4 mg/l Kin was the best one for regeneration. The best treatment for somatic embryogenesis was 2 mg/l 2,4-D. 767 General Multi-trait Selection for Screening Elite Genotypes of an F2 Rice Population Fazlalipour M. Rabiei B. Samizadeh Lahiji H. Rahim Soroush H. 1 1 2008 11 42 41 52 12 08 2008   Application of selection index for screening desired plants based on complex quantitative traits can be more effective than direct selection. This study was conducted using an F2 rice population consisting of 87 plants derived from a cross between two cultivars Gharib and IR28. The purpose was to establish suitable selection indices for increasing yield and its related traits in research farm of Rice Research Institute of Iran (RRII), Rasht, in 2005. Studied traits included the days from sowing, germinated grain to maturity (MD), plant height (PH), panicle length (PL), flag leaf length (FL), flag leaf width (FW), number of panicles per plant (PP), number of grains per panicle (GP), number of spikelets per panicle (SP), 100-grain weight (GW), grain yield per plant (GY), biomass (BM), harvest index (HI), grain length (GL) and grain breadth (GB). Among the studied traits, 100-grain weight (GW), biomass (BM) and harvest index (HI) (0.99) and flag leaf width (FW) (0.35) showed the highest and lowest broad-sense heritability, respectively. Path coefficient analysis revealed that BM, HI, GP had positive direct effects on GY. Calculation of five different selection indices based on optimum and base indices indicated that selection for BM, HI and GP using genotypic path coefficients and their heritability as economic values would be a suitable selection criterion for improving population. Moreover, this study showed that both optimum and base indices show the same genetic progress for the studied traits. Since evaluation of base index, is much easier than the optimum index, it is highly recommended. 768 General Evaluation of Salt Tolerance of Sugarcane (Saccharum officinarum L.) Genotypes Based on the Ability to Regulate Ion Uptake and Transport at Early Stage of Growth Soltani Huwyzeh M. Mirmohammady Maibody S.A.M. Arzani A. 1 1 2008 11 42 56 66 12 08 2008   Sugarcane is one of the most important sugar crops in the world. Because of semi-arid climate and salinity of its cultivation area in our country, increasing salt tolerance of sugarcane is signifying. To achieve this goal determining salt tolerant cultivars and understanding salinity mechanisms in sugarcane are very important. This study was conducted to evaluate 8 commercial and promising sugarcane cultivars at early stage of growth. A complete randomized design with three replicates and four salinity treatments (0, 0.25, 0.5, 0.75 % NaCl) was used in a hydroponics system. The effect of salinity on absorption, transport and accumulation of Na+, Cl- , K+ and Ca2+ ions in shoot and root was determined. At high level salt concentration, Cl- content in shoot and root increased. Result showed that sodium accumulation in sugarcane plants was more than potassium. By increasing salinity level, sodium uptake and its translocation to shoots increased reducing growth and dry matter yield of plants. With rising salt concentration from medium (0.5%) to high (0.75%), content of chloride in shoot and root of NCO-310 was constant showed that this cultivar had genetic ability to avoid Cl- uptake. CP82-1592 with lowest ratio of shoot / root chloride had minimum transport of Cl- to shoots. Also this cultivar had high content of Ca2+ in shoot and low Na+/Ca2+ ratio at all salinity levels. CP48-103 had low sodium in shoot and relatively low sodium in root. Thus it probably has genetic potential to avoid sodium uptake. At last, exclusion of Na+ and Cl- to older leaves and tillers was seen in CP82-1592 and CP72-2086 cultivars. According to results, to avoid once of absorption and transport, and exclusion of harmful Na+ and Cl- ions were mechanisms that could be used in salinity tolerance of sugarcane. 769 General The Response of Safflower Genotypes, Local Variety Kouseh to Planting Date Heydaryzadeh P. Khajehpour M.R. 1 1 2008 11 42 69 79 12 08 2008   During the past years, safflower genotypes have been selected from local variety of Isfahan, named Kouseh. The response of these genotypes to planting date might be different. To determine this, performances of several genotypes selected from Kouseh plus Arak 2811 ) as check ( were studied at the Agricultural Research Station, Isfahan University of Technology in 2002-2004. The experiment was conducted using a split-plot arrangement within a randomized complete block design with three replications. Planting dates were considered as the main plots and subplots consisted of 22 genotypes of safflower. Number of days from planting to emergence was highest (18.0 days) in early spring planting and lowest (10.3 days) in late spring planting. Days from planting to head visible, flowering and physiological maturity were decreased with delay in planting from autumn to late spring. Days from planting to emergence, head visible and physiological maturity were not influenced by genotype. Genotypes C116 and DP29 had the highest (145.0) and genotype ISF28 the lowest (140.2) days from planting to flowering. Plant height, number of first and second degree branches, number of heads per first and second degree branches, number of seeds per head, 1000-seed weight and seed weight per plant reduced significantly with delay in planting from autumn to late spring. Genotypes C128 and DP7 had the highest (120.0 and 120.5 cm, respectively) and genotype DP9 the lowest (104.2 cm) plant height. Genotypes DP6 and DP9 had the highest (12.8) and the lowest (6.7) first degree branches per plant, respectively. Arak-2811 had the highest (16.9) and genotypes DP9 and DP5 the lowest (7.2 and 7.1, respectively) second degree branches per plant. Number of heads per first degree branches was not significantly affected by genotype. Arak-2811 and genotype C114 had the highest (12.8 and 12.2, respectively) and genotype DP9 the lowest (5.1) number of heads per second degree branches. Genotype DP7 had the highest (45.9) and genotype C111 had the lowest (28.0) number of seeds per head. Genotypes DP3 and C128 had the highest (34.2 g) and lowest (22.0 g) 1000-seed weight, respectively. Genotype DP25 had the highest (20.5 g) and genotypes DP29 and DP9 the lowest (9.9 and 10.0 g) seed weight per plant. Harvest index was not affected by planting date and genotype. The result of this study showed that safflower may yield more in fall planting under conditions similar to this experiment. Genotype DP25 might be recommended for this planting date, genotypes ISF66 and DP25 for early spring planting and genotypes DP7 and ISF14 for summer planting. 770 General Effect of Preharvest Chemical Desiccation on Harvest Time and Grain Quality in Rice (Oryza sativa L.) Modaraye Mashhoud M. Esfahany M. Nahvi M. 1 1 2008 11 42 81 90 12 08 2008   In order to reduce the rainfall damages on rice yield at harvest stage, a field experiment was conducted at Rice Research Institute of Iran, Rasht, in 2004 by using Sodium Chlorate as a chemical desiccant. Five seed moisture contents of Dorfak rice cultivar were considered as experimantal treatments [24 - 28% (M1), 22 - 24% (M2), 20 -22% (M3). 18 - 20% (M4) and control (M5= conventional harvesting)]. The experiment was carried out in a randomized complete block design with three replications and the effects of treatments on grain yield, head rice yield,seed germination rate and percentage, kernel breakage, kernel cracking, amylose content, gelatinization temperature and gel consistency were evaluated. Results showed that the whole plant and grain moisture contents were significantly reduced in all experimental treatments compared with control. M2 and M3 both cosiderably reduced the plant moisture content in which harvesting occurred 12 and 8 days respectively sooner than the control. In M1, due to high grain moisture and non - simultaneous grain filling in different tillers, many of panicles desiccated prior to maturity lost their quality. In M4, the crop harvested was only 2 days earlier than the control. Analysis of variance showed that there were no significant effects of treatments on evaluated traits. It seems that rice plant could be reliably desiccated by Sodium Chlorat and harvested earlier without any adverse effects on its quality and quantity. 771 General Evaluating the Response of Bread Wheat Genotypes to Weed Interference under Dryland Conditions Abdulahi A. Mohammadi R. 1 1 2008 11 42 93 102 12 08 2008   The response of bread wheat genotypes to weed interference was evaluated under dryland conditions. An experiment was conducted with 26 genotypes of bread wheat and two known cultivars, Sardari and Azar2, as checks in a strip plot (Split block) arrangement based on Randomized Complete Block Design (RCBD) with four replications in 2002-03 at Dryland Agricultural Research Institute, Srarood, Kermanshah. Weed-free and weedyconditions were assigned to horizontal factor with genotypes as vertical factor. Plant height, number of seeds per spike, number of spikes per square meter, grain yield, weed density and dry matter, and indices of Weed Interference Tolelance Index (WITI) and Competition Index (CI) were recorded. Mean comparison showed that genotypes 13, 1, 26 and 8 had higher grain yield than those of checks under both weed-free and weedy conditions. These genotypes also had higher WITI in comparison with the checks. According to CI values, genotypes No. 1, 9, 13, 26 and 27 including checks had a high potential of weed competition. Results of stepwise regression analysis based on WITI as the dependent variable indicated that the number of spike, plant height and number of seed per spike had positive and significant effects on WITI. On the wole, considering WITI and grain yield as two main attributes, genotypes 13, 26, 1 and 8 were selected as appropriate since they showed a high weed competitive ability and also produced higher grain yields under both weedy and weed-free conditions. 772 General Genetic Improvement in Grain Yield and Related Traits of Oat Cultivars Released in Canada During 1921 – 1997 Moradi M. Rezai A.M. Arzani A. 1 1 2008 11 42 105 111 12 08 2008   Evaluation of genetic improvement of grain yield and other traits in cultivars released in different years is useful to determine plant breeding impact on grain yield improvement, to define future selection criteria and to identify the desirable environment and traits for further assessment. This study was conducted to evaluate the genetic improvement for grain yield and other traits of twelve oat (Avena sativa L.) cultivars released in Canada during 1921- 1997, at Research Farm, College of Agriculture, Isfahan University of Technology, during 2001-3 in a randomized complete block design with three replications. The regression of mean grain yield on released year of the cultivars showed that the rate of increase in grain yield during a 76-year period is 32.63 kg h-1 year-1 or 0.63% per year. Breeding programmes have inereased harvest index, grain number per panicle and fertile tillers /m2. The effort of breeders in this period was to decrease plant height and days to heading. The other traits had small changes and showed no specific trends. In general the results of this study showed continous improvement of grain yield in this period. Genetic improvement of grain yield in evaluated cultivars closely correlated with harvest index. Therefore, most variation in grain yield of oats was due to variation in harvest index. Although much of the improvement in grain yield described here could be attributed to the increased harvest index, the scope for further improvement in this character may be limited. Further yield improvement of oats might be achieved by combining high biological yield with high harvest index. 773 General Assessment of Drought Tolorance in Different Breeding Lines of Wheat (Triticum aestivum L.) Yousofi Azar M. Rezai A.M. 1 1 2008 11 42 113 121 12 08 2008   This study was conducted at Research Farm of Isfahan University of Technology to evaluate drought tolerance potential of 23 F2:4 wheat lines derived from the cross of Virmarin (susceptible line) and Sardari (tolerant line). A randomized complete block design with three replications was used in each irrigation treatment (i.e. irrigation after 70±3 and 120±3 mm evaporation from class A pan for non-stress and stress conditions, respectively). Drought tolerance and susceptibility indices were calculated for yield, and principal components analysis was performed on the basis of indices. Rosielle and Hambline tolerance index and Fisher and Maurer stress susceptibility index had positive and significant correlation, but their correlations with drought yield and the first two principal components were negative. High value of these components indicates low sensitivity to drought. The first component had high and positive correlations with geometric mean productivity, stress tolerance index and harmonic mean. Lines number 4, 17, 11 and 14 with high yields in drought condition, showed high values for these indices. Line number 2 with high yield in non-stress condition and in spite of high sensitivity to stress, was a superior genotype based on these indices. 774 General A Study of Relationship between Grain Yield and Yield Component in Common Bean Cultivars (Phaseolus vulgaris L.) Sabokdast M. Khyalparast F. 1 1 2008 11 42 123 133 12 08 2008   This research was conducted in order to determine the relationship between grain yield and yield components, using 30 common bean varieties in a randomized complete block design with four replications at the Agricultural filed faculty of Agriculture,Tehran university In this study 18 traits were assessed on 10 random plants from each plot. The result showed that there were significant differences among varieties in terms of trait under study, indicating the existence of genetic variation among varieties. Also results showed that the grain yield had a positive and significant genotypic correlation with number of seed/pod, pod weight, number of pod/plant, biological yield, days to flowering and maturity. Stepwise regression analysis showed that the maximum variation in grain yield could be attributed to the number pod/plant, number seed/plant, 100 seed weight and pod length. The results of path analysis showed that the highest direct effect, being positive, was related to number seed/plant and the lowest direct effect, which was related to number pod/plant. Factor analysis resulted in three factors that accounted for 78/7% of total variation. The first factor accounted for 38.39% of total variation and was designated as yield and yield component factor. This factor is comprised of pod weight, biological yield, grain yield and number of pod/plant traits. 775 General Factor Analysis for Quantitative Traits and Path Analysis for Grain Yield in Wheat Heidar B. Saeidi G.H. Sayed-Tabatabaei B.E. 1 1 2008 11 42 135 143 12 08 2008   In this study, factor analysis was conducted to determine the factors which contributed to the variation of quantitative traits and path analysis was performed to find the direct and indirect effects of yield components on grain yield in bread wheat. A doubled haploid population of 157 lines of wheat (Triticum aestivum L.) was evaluated for agronomic and morphological traits, using a randomized complete block design with three replications in 2003 and 2004. The results of factor analysis based on maximum likelihood indicated five factors explaining 80.4% and 73.9% of total variation in 2003 and 2004, respectively. The first factor in 2003 had 30.5% contribution to the total variation, strongly influenced by the traits of pollination date, heading date, flag leaf length and days to maturity. This factor also indicated the negative relationship among the yield components and the importance of relationship between grain yield and some morphological traits. The first factor in 2004 was more affected by grain weight/spike, grains/spike and 1000-grain weight, thus it was named as grain yield factor. The second and third factors in 2003 were considered as plant height and grain yield and in 2004 as maturity and plant height, respectively. The results of path analysis showed that grains/spike had the most direct and positive effects on grain yield in 2003 (1.33) and 2004 (0.87). Because of the negative and high indirect effects of grains/spike via fertile spikes/m2 and 1000-grains weight on grain yield, the correlation coefficient between grain yield and grains/spike was very low. There was not much difference between the phenotypic and genetic direct effects of spike/m2 on grain yield, indicating that their relationship was less affected by environmental conditions. In general, the results showed that grains/spike and spikes/m2 can be more efficient compared to 1000- grains weight for increasing grain yield and can be used as selection indices in breeding programs. Also, according to the results of factor analysis, selection based on the fourth factor including biological yield, spike/m2 and grain yield as selection index can be effective to improve grain yield in breeding programs. 776 General Effect of Supplemental Irrigation and Amount of Available Water on Yield, Yield Components and Physiological Characteristics of Two Rainfed Wheat Cultivars Tadayon M.R. Emam Y. 1 1 2008 11 42 145 156 12 08 2008   Photosynthesis and wheat grain yield responses to supplemental irrigation with different amount of applied water under dryland conditions were investigated. Therefore, a two-year field experiment was conducted research farm of College of Agriculture, Shiraz University during 2004-2005. Five levels of irrigation including dryland conditions, irrigation at stem elongation, booting, flowering and grain filling were main plots and two wheat cultivars: Agosta and Fin-15 were subplots, and three rates of nitrogen including zero, 40 and 80 kgha-1 were sub sub-plots. The results showed that in both years, photosynthetic rate, stomatal conductance, substomatal CO2 concentration and transpiration rate, were significantly higher under irrigation at stem elongation stage compared to other supplemental irrigation treatments. In all of the four supplemental irrigation treatments, photosynthetic rate, stomatal conductance, substomatal CO2 concentration and transpiration rate decreased with decreasing the amount of applied water to each plot. In both years, the highest grain yield was obtained from supplemental irrigation at stem elongation stage, and the lowest yield was harvested at dryland conditions. The highest photosynthetic parameters, yield and yield components were obtained from interaction of supplemental irrigation at stem elongation stage × Fin-15 and 80 kg N ha-1 in both years. The supplemental irrigation in 2004 and 2005 increased the grain yield 200 and 221 percent, respectively, compared to dryland conditions. Thus, supplemental irrigation at sensitive stem elongation stage could affect significantly wheat grain yield of rainfed wheat cultivars and provision of adequate water for a supplemental irrigation at the appropriate growth stage could double the grain yield of rainfed wheat. 777 General Assessment of Heterosis in Durum Wheat F1 Hybrids under Field Conditions Farahani E. Arzani A. 1 1 2008 11 42 159 170 12 08 2008   An experiment was conducted to investigate the heterosis in 12 F1 hybrids of durum wheat using agronomic and morphological traits. Parents were selected according to the estimated genetic distances based on the results of a two-year field experiment, which were then crossed to produce F1 hybrids. Twenty-three genotypes (including 11 parents and 12 hybrids) were evaluated using a randomized complete block design with three replications Research Farm of College of Agriculture, Isfahan University of Technology, located at Lavark, Najaf- Abad in 2003. Agronomic characteristics comprised days to 50% flowering, days to 50% pollination, days to maturity, plant height, spike length, grain weight per spike, number of grain per spike, number of spike per m2, 1000-grain weight, biological yield, grain yield and harvest index. The results of analysis of variance showed significant differences among parents F1 hybrids and parents vs. crosses for all the studied traits. Substantial differences in the level of heterosis for plant maturity were detected among the hybrids with the highest heterosis belonging to HPI40100×PI40099 and HEupoda6× Chahba88 hybrids. Furthermore, superior hybrids included HAltar84/Ald×Chahba88, HBuchen7×Chahba88 and HEupoda6×Mexi75/Vic possessing the highest heterosis for grain yield and grain yield components among 12 hybrids of the present experiment. Eventually, it is concluded that Eupoda6, Odin12, Altar84/Ald and 45063Karaj genotypes when crossed with Mexi75/Vic genotype as well as Buchen7 and Altar84/Ald genotypes when crossed with Chahba88 genotype produced superior F1 hybrids. 778 General Stability Analysis of Yield in Chickpea Genotypes by Additive Main Effects and Multiplicative Interaction (AMMI) Zali H. Sabaghpour S.H. Farshadfar E. Pezeshkpour P. Safikhani M. Sarparast R. Hashem Beygi A. 1 1 2008 11 42 173 180 12 08 2008   Presence of genotype × environment interaction necessitates evaluation of genotypes in a wide range of environments to find desirable genotypes. This study was carried out to determine the stability and adaptability of grain yield of 17 chickpea genotypes, in RCBD with four replications at Kermanshah, Lorestan, Ilam, Gachsaran and Gorgan Research Stations during two seasons (2003-2004). The genotype × environment interaction effect analyzed using the additive main effects and multiplicative interaction (AMMI) statistical model was significant at 1% level of probability. The sum of squares of G × E interaction was partitioned by AMMI model into four significant interaction principal component axes (IPCA). The first four principal component axes (IPCA 1, 2, 3 and 4) cumulatively contributed to 94% of total genotype by environment interaction. A biplot generated using genotypic and environmental scores of the first two AMMI components also showed that genotypes FLIP 97- 79, X95TH1 and FLIP 97- 114 were selected as stable genotypes, among which the genotype FLIP 97- 114 was outstanding for high yield stability. 779 General Comparison of Selection Indices for Yield and Related Traits of Barley under Nitrogen Stress and Non-Stress Conditions Emrani S.N. Rezai A.M. Arzani A. 1 1 2008 11 42 183 194 12 08 2008   The most desirable approach to improve characteristics such as yield with polygenic inheritance and genotype × environment interaction, is simultaneous selection using selection index based on related traits. This study was conducted Research Farm of Isfahan University of Technology, to compare selection indices for barley yield improvement under nitrogen stress and non stress conditions, using 49 F13 recombinant inbred lines derived from a cross between Azumamugi and Kanto Nakate Gold. A split plot design with randomized complete block layout in three replications was used. In non-stress condition 100 kg nitrogen per hectare as urea was used at early reproductive growth, stem elongation and grain filling stages. In stress condition, 50 kg nitrogen per hectare was only used at early vegetative growth stage. Smith-Hazel and Pesek-Baker indices based on 4 traits (days to heading, harvest index, growth rate and nitrogen harvest index) and also direct and correlated response of these traits were calculated. The result of response to selection and correlated response indicated that the selection based on higher harvest index and nitrogen harvest index under both conditions screens high yielding lines. Harvest index had high weight in both indices under stress and non stress conditions. Under both conditions and for Smith-Hazel and Pesek-Baker indices, growth rate had negative correlation coefficients. Therefore, the selection based on these indices, separates lines with lower growth rate. In this study, Smith-Hazel index had higher efficiency. 780 General Evaluation of Concentration and Time of Application of Gibberellic Acid and 2,4-D Isopropyl Ester on Some Fruit Characteristics in Navel Oranges and Clementine Mandarin Rastegar S. Rahemi M. 1 1 2008 11 42 197 206 12 08 2008   Navel oranges and Clementine mandarin are classified as early cultivars and when fruits are left on the trees, fruit firmness and juice content will decrease. Plant growth regulators have been used to improve fruit quality. Gibberellic acid (GA3) and 2,4-D isopropyl ester sprays were used to increase juice content ,peel firmness and delay senescence in Navel oranges and Clementine mandarin. Factorial experiments were arranged in a complete randomized block design with three replications and each block consisted of three trees. Chemicals were sprayed on the branches (north and south of each tree) with 10 liter sprayer to the point of run-off during fall of 2004 and 2005 ,in a commercial orchard in Jahrom in the south east of Fars province, Iran . In both years of study, GA3 at 100,150 and 200 mgl-l and isopropyl ester 2,4-D at 8,12 and 24 mgl-1 were sprayed on September 30 (diameter of Navel 64 mm and diameter of Clementine 46 mm), October 14 (diameter of Navel 69 mm and diameter of Clementine 48 mm ) and November 7 (diameter of Navel 70 mm and diameter of Clementine 50 mm) and fruits of Navel oranges and Clementine mandarin were harvested 45 and 35 days after last the spray treatment, respectively . The results of experiment revealed that Navel oranges responded better with second application (Oct.14, diameter 69 mm ) and Clementine mandarin with the first application (Sept.30, diameter 46 mm ). Juice content and fruit firmness at harvest increased. GA3 increased juice content even better than 2,4-D isopropyl ester but delayed senescence, 2,4-D was more effective in increasing fruit sizing in both cultivars. GA3 at 150 and 200 mgl-1 and 2,4-D at 24 mgl-1 when compared with the untreated resulted in highest juice content of fruits. 781 General Evaluation of Resistance of Rice to Leaf and Panicle Blast in Mazandaran Province Amanzadeh M. Moumeni A. Okhovat M. Javan. Nikkhah M.J. Khosravi V. 1 1 2008 11 42 209 219 12 08 2008   Blast, caused by Magnaprthe grisea, is often an important fungal disease in the production of rice in temperate and tropical areas including Iran. To determine reaction of rice cultivars against blast disease, 40 rice genotypes from Iran and other sources from Asia were selected. Four blast isolates from different races were used to test all rice genotypes in different greenhouse tests. In blast nursery, experiments were conducted in a Randomized Complete Block Design (RCBD) with three replications. In different experiments inoculated plant materials were evaluated for Infected Neck Number(INN), Neck Lesion Size(NLS), Infection Type(IT), Diseased Leaf Area(DLA), Area Under the Disease Progress Curve(AUDPC), Lesion Number(LN), and Sporulating Region Diameter(SRD). Most of the Iranian traditional cultivars together with CO-39 and C104-PKT showed susceptible reaction for AUDPC, IT, INN and NLS. Performance of improved cultivars from Iran, IRRI and NILs (except C104-PKT) was resistant. Some cultivars including Fujiminori, Onda , Hassan saraii were moderatly susceptible to leaf blast in blast nursery. All components of resistance in both growing stages in greenhouse and nursery tests were significantly correlated. In some cases such as cultivar Haraz different reaction was observed in seedling and flowering stages, indicating that genetics of resistance in two stages could be different. 782 General Insecticidal Effects of Some Plant Extracts on Callosobruchus maculatus F. under Laboratory Condition and Laphigma exigua H. in Greenhouse Mahdavi Arab N. Ebadi R. Hatami B. Talebi Jahromi K.H. 1 1 2008 11 42 234 221 12 08 2008   In order to evaluate insecticidal potential of some botanical extracts, a factorial experiment of complete randomized design with three replications on Callosobruchus maculatus was adopted for a pilot experiment in the laboratory. Plant extracts were prepared from 22 plants with three solvents (Methanol, Acetone and N-Hexane) with 30% concentration. Experiments were carried out at 25˚C and 70 ± 5% RH under 16: 8 (D: L) conditions. Each unit of experiment was a petri dish covered with a filter paper and 1.5 ml of each treatment solution was poured in it and 25 insects were released. Mortality was recorded after 36 hours. In this experiment, each plant extract with more than 50% mortality on C. maculaus was selected for further laboratory screening. In this stage of experiment methanolic leaf extract of Teucrium polium (with 55.04 percent mortality), hexane extract of Sonchus oleraceus (with 54.64 percent mortality), acetonic leaf extract of Calotropis procera (with 53.6 percent mortality), methanolic extract of Fumaria parviflora (with 52.7 percent mortality), methanolic extract of Capsicum annuum (with 50.04 percent mortality), and acetonic extract of Thymus vulgaris (with 50 percent mortality) were selected. After carring out the pilot experiment, the effective extracts with five concentrations of 15, 22.4, 33.5, 50.2 and 75% and one control were evaluated on the C. maculaus. This experiment also was designed in the laboratory as a factorial experiment of complete randomized design with three replications and mortality was recorded after 36 hours. In the highest concentration (75%), extract of Fumaria parviflora and extract of Thymus vulgaris (with 88.3% mortality) and extract of Sonchus oleraceus (with 78.3%) had higher and lower percentage of mortality resectively. The LC50 values of effective extracts were calculated for C. maculaus after 36 hours of treatment with plant extracts. The results showed that C. maculatus with LC50 = 126.27 µl/ml has highest sensitivity against extract of Fumaria parviflora and has lower sensitivity against extract of Sonchus oleraceus with LC50 = 370.09 µl/ml in comparison to other extracts. Amongst the tested concentrations of plant extracts, 5 plant extracts with the concentrations that had the higher mortality on C. maculaus, were selected for experiment on Laphigma exigua in greenhouse. This experiment was carried out with complete randomized design with four replications. The acetonic leaf extract of Calotropis procera (with 57.5 %) caused the highest mortality and acetonic extract of Thymus vulgaris (with 27.5 %) caused the lowest mortality on L. exigua in comparison to other extracts. 783 General Optimization of Sterilizing Method of Larvae and Cyst of Heterodera Schachtii and the Possibility of their Application in Sugar Beet Seedlings in In vitro Condition Shadmehr A. Norouzi P. Garosi G.H. Yavari N. 1 1 2008 11 42 237 247 12 08 2008   In this research, after optimization of sterilizing cyst and larvae of second stage of Heterodera schachtii, the possibility of using nematode on seedlings of sugar beet (Beta vulgaris L.) in in vitro condition was studied for developing larvae to cyst. For this purpose, non sterile cysts were extracted from infected soil and hatched into zinc chloride solution with concentration of 0.5gl-1. Then, for preparation of sterile second stage larvae, several sterilizing treatments were used . Mean comparisons were performed between sterilized live larvae number by Duncan's method. Results showed that 70% ethanol for 1 minute followed by 5% sodium hypochlorite for 5 minutes and 0.1% sodium hypochlorite for 20 minutes were the best treatments for disinfecting cysts and larvae, respectively. In the next step, two nematode susceptible sugar beet varieties were applied to produce cyst from the larvae in in vitro culture. PGoB medium containing different hormonal compositions was used to produce hairy roots and inoculation of seedling with sterilized larvae. After nematode inoculation tests, were the stained cysts were observed under stereomicroscope and counted 40 days later. Five to twelve cysts were formed on the roots of each seedling from two varieties. As a result, it seems that this technique can be used for sugar beet germplasm evaluation to screen nematode resistant genotypes in in vitro controlled condition. 784 General Seasonal Population Fluctuation of Brachycaudus amygdalinus (Schout.) and Hyalopterus amygdali (Blanch.) on Almond Trees in Najafabad Region Ghorbali R. Seyedoleslami H. Rezwani A. Khajehali1 J. 1 1 2008 11 42 259 249 12 08 2008   Aphids are known as important pests of plants specially almond trees. Seasonal population fluctuation of two aphid species, Brachycaudus amygdalinus (Schout.) and Hyalopterus amygdali (Blanch.) were studied in 1999-2000 on almond trees in Najafabad area. Characteristics such as times of egg hatch, appearance, outbreak, spring migration to alternative hosts, migration from alternative hosts in fall, oviposition, number of eggs laid, damage degree, alternative, other primary hosts and some natural enemies were investigated. In early spring damage signs of B. amygdalinus were expressed on almond twigs as serious leaf curling followed by retarded growth of twigs and shortened internodes. Shortly after that H. amygdali colonized other leaves. For both species egg hatching was coincided in late winter however colonization and population increase of H. amygdalei were observed two weeks later than what was observed for B. amygdalinus. With the onset of warm season, both species moved from almonds to alternative hosts for aestivation. Gynoparae shortly followed by males appeared on alternative hosts in late summer and migrated to almonds. Oviparae produced by gynoparae mated with males and laid their eggs near the buds. 785 General Application of Fluorescent Pseudomonads in Biological Control of Rhizoctonia solani , Causal Agent of Colza Sarani SH.A. Sharifi Tehrani A. Ahmadzadeh M. Javan Nikkhah M. 1 1 2008 11 42 261 270 12 08 2008   Two hundred fifty seven bacterial isolates were collected from colza root and rhizosphere in Golestan, Mazandaran, Guilan and Tehran provinces. Antagonistic effect of bacterial isolates on Rhizoctonia solani, the causal agent of colza damping off, was studied using dual culture method. The results showed that, 60 isolates had the ability to inhibit the growth of R. solani on PDA medium. On the basis of the biochemical, physiological and morphological tests, isolates P1, P2 and P3 were identified as Pseudomonas fluorescens. Biocontrol mechanism studies showed that isolates produced antibiotics and volatile metabolites prevented the mycelial growth of the fungus. The isolates produced some of antimicrobial metabolites including hydrogen cyanide, protease and siderophore. Isolate P3 was more effective to inhibit the growth of the fungus in-vitro. The effect of isolates on disease reduction in comparison with control was significantly different. None of the isolates were able to prevent disease occurrence completely. Isolates applied as soil treatment had a significantly higher disease control as compared to seed treatment method. Isolate P3 had considerable effect on reduction disease in the greenhouse conditions. All isolates were capable of colonizing canola roots and so increased canola growth in free-causal agent conditions. 786 General Detection of Spiroplasma citri , the Causal Agent of Citrus Stubborn Disease in the Field Collected Leafhoppers in Southern Kerman Province Lori Z. Hosseini-Pour A. Massumi H. Rahimian H. 1 1 2008 11 42 273 281 12 08 2008   Citrus stubborn disease is caused by the helical mollicute Spiroplasma citri. The pathogen is naturally transmitted by sap feeding leafhopper vectors. In the present study attempts were made to detect S. citri in presumptive vectors. Leafhoppers were collected from various wild and cultivated plants in citrus growing areas in Jirfot. Fifteen leafhopper species were identified and 12 species were analyzed for the possibility of carrying S. citri with an antiserum prepared against a citrus strain of S. citri by indirect ELISA. S. citri was detected in leafhopper species by ELISA in Austroagallia sinuata, Psammotettix alienus, Circulifer haematoceps, Orosius albicinctus and Psamotettix striatus. However, S. citri was isolated only from the last three leafhopper species in LD10 medium. These leafhoppers were primarily captured from sesame fields. Therefore, these potential vectors and sesame farms may play a key role in the epidemiology of S. citri in the surveyed area. 787 General Factors Affecting Requests for Land Consolidation Projects in the Opinions of Experts in Kermanshah and Lenjanat Region in Isfahan Ahmadi A. Amini A.M. 1 1 2008 11 42 283 296 12 08 2008   The purpose of this research was to study factors on farmer’s request to land consolidation projects and also consolidation’ adventages in utilization units. The data of this study was collected through completing questionnaires and interviewing 34 experts connected with administrating of land consolidation projects in agricultural offices and service centers in Kermanshah township and Lenjanat region in Isfahan. Data was also collected through visiting some performed and performing projects. The results showed that in Kermanshah land consolidation improves the technology, farm management and land more than other production factors. In Lenjanat it improves technology and farm management in comparison with other factors. In both regions the aplicant villages of the projects have a larger ownership and more fragmentaed parcels than other villages. Moreover they have younger exploiters, more educated and less in number. It is also notworthy that these regions obtain more extention education, are nearer to agricultural offices, and have closer relation with extention agents. 788 General Factors Influencing Farmers’ Attitudes Toward Participation in Water Users’ Associations (A Case Study in Khorasan-e-Razavi Province, Iran) Shahroudi A.A. Chizari M. 1 1 2008 11 42 299 312 12 08 2008   The purpose of this study was to investigate and analyze the factors affecting farmers’ attitudinal dimensions toward participation in Water Users’ Association (WUA) by comparing two groups of farmers in irrigation networks with WUA and without it. The methodological approach was a descriptive-correlational and causal-comparative study of the survey type. The target population in the study consisted of 2551 farmers of irrigation networks in Khorasan-e-Razavi Province, Iran. Using stratified random sampling technique, 335 participants were chosen. Data were collected through a questionnaire, and analyzed using SPSS, V.13. Content and face validity of the instrument were obtained by the faculty members of Agricultural Extension and Education, Agronomy and Irrigation Departments at Tarbiat Modarres University and also specialists board of Agricultural Jihad Organization and Regional Water Joint-stock Company in Khorasan-e-Razavi Province. The reliability analysis was conducted and cronbach’s alpha values for the various sections of instrument were estimated between 0.73 and 0.86. The descriptive findings of the study showed that the majority of farmers’ overall attitude with respect to participation in WUA was at a good level. The results obtained from Pearson correlation analysis indicated that there are significant and positive relationships between such variables as education level, size of irrigated cultivated landholding, annual income, extension contacts, social capital components, water users’ perceptions regarding irrigation networks status and farmers’ participation status concerning irrigation networks management with the farmers’ overall attitude toward participation in WUA. The result of stepwise multivariate regression analysis indicated that 61.1% (R2 = 0.611) of the variance in farmers’ attitudes with respect to participation in WUA could be explained by farmers’ behaviour regarding optimum farm water management, social participation, social confidence, water users’ perceptions regarding irrigation networks status, farmers’ participation status concerning irrigation networks management. Also, significant differences were found between the two respondent groups in irrigation networks with WUA and without it in relation to farmers’ attitudinal dimensions. 789 General Determination of the Most Suitable Stage-Discharge Relation at the Hydrometric Station of the Zayandehrud Regulatory Dam Vafakhah M. Shojaei G.h. 1 1 2008 11 42 315 322 13 08 2008   Continuous measurement of river discharge is a hard and expensive task in hydrology. To overcome this problem, the stage readings at hydrometric gauges are permanently taken and the discharge of any time at which the actual discharge is unavailable will be estimated through a relationship between discharge and stage. To study the stage-discharge relations and the capability of long-term data in establishing a permanent stage-discharge relationship, and also to determine the best time to measure the discharge of rivers, a study was conducted at the hydrometric station of the Zayandehrud regulatory dam using data from 1990 to 2003. The data were analyzed using simple regression analysis, the percentage of relative error and factor analysis. The results indicated that the best model to show the stage-discharge relation at the studied station is a power function model. Moreover, the model used for every year can only be used for that year. The results also showed that the most suitable times for the measurement of discharge are July, December and March. 790 General Comparison of Hydrological and Meteorological Methods for Daily Drought Monitoring: A Case Study, the 1998-2000 Drought Spell of Tehran , Iran Morid S. Paymozd S.h. 1 1 2008 11 42 325 333 13 08 2008   Application of meteorological indicators has extensive use in drought monitoring. However, hydrological indicators can also play an effective role in this task. In this research, one of the rare approaches in drought monitoring with hydrological indicators namely Chang method has been applied and assessed for the Tehran basin using daily time step. The results have been compared with the unique meteorological drought index, EDI (effective drought index) and show the capabilities of the hydrological method and its more sensivity to water resources deficit. For instance, application of these procedures for the 1998 to 2000 drought spell in Tehran province revealed that Change method declares 31.1 % of times in very severe drought whereas it is 3.7 in EDI. Because of applying different indicators (e.g. reservoir and ground storage), a combination of both procedures is an ideal approach for drought monitoring in which the water inputs to the system as well as storage and consumptions are considered. The applied methodology makes it Possible to distinguish droughts due to rainfall deficit from the ones, which are resulted from water resources miss management. 791 General Comparison of Flood Routing by Muskingum and Muskingum-Cunge Methods in Section of Lighvan River Moradi H.R. Vafakhah M. Akbari Baviel A. 1 1 2008 11 42 335 342 13 08 2008   Discharge routing as a mathematic process to forecast the changes of greatness, speed and form of flood wave is function of time in one or more points along drainage, canal or reservoir. Hydrologic and hydraulic methods are used to accomplish the flood routing. Although hydrologic method is less accurate than hydraulic methods but it is simpler to use in flood control and designing works with acceptable confidence. This study has been conducted for flood routing in Lighvan River from Lighvam hydrometric station to Hervy hydrometric station in eastern Azerbaijan Province in a distance the 12 Km. The discharge for different return periods (2, 10, 20, 50 and 100 years) was calculated by using upstream stations data. Then routing of every flood discharge was studied with different return periods by Muskingum and Muskingum-Cunge methods. Results showed significant difference between calculated discharges routing by two methods with discharge values to relate that return period in Hervy hydrometric station. The reasons of exist this different, is numerous for example mountain location this area and to exist sub drainage in between two stations and etc. 792 General Evaluation of EPM Model by Sediment Measurement in Reservoirs of Small Dams Hashemi S.A.A. Arab Khedri M. 1 1 2008 11 42 345 355 13 08 2008   In order to quantitatively evaluate the sediment yield in ungauged basins, it is necessary to use empirical models. The EPM model, as a model which is using in Iran, has sometimes been evaluated. Most evaluations have often been conducted by using river's sediment information and direct measurements of dam reservoir sedimentation have been less used, while the sediment measurement method on reservoir is more carefully. 9 small watersheds from Semnan province (Iran) were selected in this research. There is a small earth dam which have been built on the outlet of each watershed in the past years that them age is 10 years. These dams have not been weirs since they have been building to now. Therefore total of sediment yield volumes of each watershed are entrapped in the dam reservoirs. The volume of sediments deposited in reservoir were calculated by surveying. Sediment's apparent specific weights were measured in each reservoir and the volume of sediments transformed into sediments weight. By EPM model the volume and weight of sediment yield were estimated. Values of sediment yield measured in reservoirs were compared with estimated values by t-test. The results showed that at level 5%, there was not any significant difference between sediment yield values estimated in reservoirs by EPM model in comparison with values of volume and weight which were measured. But determination of performance and relative root mean square error showed that EPM model has low efficiency for estimation of sediment yield in the case study of watersheds. 793 General Estimating Maximum Air Temperature in Khoozestan Province Using NOAA Satellite Images Data and Artificial Neural Network Rahimi Khoob A. Behbahani S.M.R Nazarifar M.H. 1 1 2008 11 42 357 364 13 08 2008   Air temperature prediction models using satellite data are based on two variables of land surface temperature and vegetation cover index. These variables are obtained by atmospheric corrections in the values for the above data. Water vapor, ozone, and atmospheric aerosol optical depth are required for the atmospheric correction of visible bands. However, no measurements are available for these parameters in most locations of Iran. Using the common methods, land surface temperature can be measured accurately at 2 ° C. Given these limitations, efforts are made in this study to evaluate the accuracy of predicting maximum air temperature when uncorrected atmospheric data from the NOAA Satellite are used by a neural network. For this purpose, various neural network models were constructed from different combinations of data from 4 bands of NOAA satellite and 3 different geographical variables as inputs to the model in order to select the best model. The results showed that the best neural network was the one consisting of 6 neurons as the input layer (including 4 bands of NOAA satellite, day of the year, and altitude) and 19 neurons in the hidden layer. In this structure, about 91.4% of the results were found to be accurate at 3 ° C and the statistical criteria of R2, RMSE, and MBE were found to be 0.62, 1.7 ° C, and -0.01 ° C, respectively. 794 General Nitrogen Mineralization Potential in a Calcareous Soil Treated with Two Organic Fertilizer Lotfi Y. Nourbakhsh F. Afyuni M. 1 1 2008 11 42 367 377 13 08 2008   Organic fertilization has been practiced in Iran due to the shortage of soil organic matter. In recent years, attention has been payed to the organic fertilizers because their commercial production has recently started and demands for their application have increased. The objectives of this study were to investigate the effects of organic fertilizer type, rates and times of application on the N mineralization potential (NMP) in a calcareous soil (fine loamy, mixed, thermic, Typic Haplargid) in Isfahan region. The soil samples were collected from a previousely established field experiment. The experiment design was split plot with three replications. Each main plot was split into subplots receiving 1, 2 and 3 annual consecutive applications of cow manure and sewage sludge at the rates of 0, 25 and 100 Mg ha-1. The soil samples were taken from 0-15 cm depth, 6 months after the third application of the organic fertilizers. Nitrogen mineralization potential was measured by a long-term leaching-incubation procedure. Results indicated that NMP was similarly affected by cow manure and sewage sludge. Nitrogen mineralization potential in the treatments which received 100 Mg ha-1 organic fertilizers, was 4 and 1.7 times greater than that of control and 25 Mg ha-1 treatments, respectively. A significant increase was also observed in NMP in the treatments which received different times of application. The NMP in the three-year applied treatments was 5, 2.5 and 2.1 times greater than that of control, two- and one-year applied soils. Significant correlations were observed between NMP and corn yield (r=0.531**) and corn N uptake (r=0.568***). The product of NMP and N mineralization rate constant was also significantly correlated with corn yield (r=0.710***) and corn N uptake (r=0.734***). Different patterns were observed between the responses of total N and NMP in the treated soils. 795 General Simulation of Runoff, Sediment and Soil Erosion by EUROSEM Model in Sulijan Sub- basin, North Karun Watershed Jalalian A. Amirpour Robat M. Ghorbani B. Ayoubi S.h. 1 1 2008 11 42 379 391 13 08 2008   Soil erosion is one of the most threatening issues for crop production and environmental qualities, especially for soil and water resources. Appropriate knowledge about total soil loss and runoff is valuable in order to perform soil and water conservation practices in watersheds. EUROSEM, "a single event, dynamic and distributed model," was developed to simulate soil loss, sediment transportation and deposition by rill and interrill processes. This study was conducted to evaluate EUROSEM model in order to simulate soil loss and runoff in Sulijan sub-basin, which covered 20 ha, from Charmah-Bakhtari province. The sub-basin was divided in to 19 homogeneous elements using topographic, land use, plant cover, slope and channel properties throughout it. Soil, plant cover, land surface and climate characteristics were measured and evaluated by field observations and laboratory measurements. Actual soil loss and runoff for studied events were determined by direct measurement in the field. After sensitivity analysis, calibration and validation steps were carried out to simulate runoff and soil loss. The results of sensitivity analysis showed that the EUROSEM model for predicting runoff was more sensitive to hydraulic conductivity, capillary drive and initial soil moisture. On the other hand the model for predicting soil loss was more sensitive to Manning's coefficient and soil cohesion. The results showed that the EUROSEM model was able to simulate well the total runoff, peak of runoff discharge, total soil loss and time for the peak of soil loss discharge. But that could not simulate well the peak of soil loss discharge and time for the peak of runoff. Although it seems that EUROSEM is able to predict soil loss and runoff partially well in individual events, it is necessary to evaluate the efficiency of the models for different basins with varieties of soil, plant cover and climatic properties. 796 General Qualitative, Quantitative and Economic Land Suitability Evaluation for Wheat, Maize and Sesame Production in Mehran Plain, Ilam Province Jalalian A. Rostaminia M. Ayoubi S.h. Amini A.M. 1 1 2008 11 42 393 403 13 08 2008   Extension of cultivation areas becomes gradually impossible due to ever-increasing population growth and urban area development in Iran. Therefore, it is very important to use the existing cultivated lands more efficiently. Land suitability evaluation makes the sustainable use of the lands feasible. The objective of this study was qualitative, quantitative and economic suitability evaluation of irrigated croplands for wheat, maize and sesame in Mehran plain, Ilam Province. Soil survey in the field, laboratory analysis of the soil samples, qualitative, quantitative and economic evaluation were different successive stages of this research. In qualitative evaluation, climatic, topographic and soil suitability classes were determined according to the degree of the matching with plant requirements, by parametric (square root) method. Quantitative and economic evaluations were done based on observed, potential and marginal yield analysis. Results of the qualitative land evaluation showed that most of the land units were classified moderately suitable for given crops because of soil limitations. Qualitatively, most of the land units were classified in the same classes as, or in lower classes than quantitative suitability classes for wheat and maize production, due to high management level at the farms. Whereas quantitative classes of sesame were determined lower than qualitative classes induced by low management level for this crop. Economic land suitability classification showed that the wheat production was the most economic land utilization type. Results of the economic assessment suggested that the cultivation of wheat in rotation with sesame would produce the most income for different units and could be increased in future using improvement in management level in the study area for sesame cultivation. 797 General Kinetics of Nitrogen Mineralization in Soils Amended with Compost, Vermicompost and Cattle Manure Soodaee Mashaee S. Aliasgharzade N. Ostan S.h. 1 1 2008 11 42 405 414 13 08 2008   Understanding nitrogen mineralization from different organic sources should be a key factor in developing efficient prediction of the need for nitrogen fertilization with minimal negative environmental impact. In order to investigate nitrogen mineralization rate in soils amended with compost, vermicompost and cattle manure, an experiment was done as factorial in a randomized complete block design in three replications. Four treatments (compost, vermicompost, cattle manure and soil alone), two temperature levels (8 and 25 0C) and two moisture levels (50% and 85% FC) were used for the 90 - day incubation study. Ammonium and nitrate were measured by spectrophotometer method. Results indicated that the mixed first-and zero-order kinetics model is the best model for our data. Cattle manure treatment had the highest Nmin at 25 0C (87.78 mgN/kg equal to 14.54% Ntotal) and the least value (23.62 mgN/kg equal to 4.62% Ntotal) was obtained for the compost treatment at 8 0C. N0k (nitrogen availability index) for treatments was in the following order: Cattle manure>Vermicompost >Compost. With increasing the temperature and moisture, N mineralization increased. Also Nmin positively correlated with N0 (r =0.583*), and N0k (r =0.834**). 798 General Modeling Phytoremediation of Soils Polluted with Cadmium and Lead Khodaverdiloo H. Homaee M. 1 1 2008 11 42 417 426 13 08 2008 799 General Determination of Some of Labile C Pools as Soil Quality Index Yoosefi M. Shariatmadari H. Hajabbasi M.A. 1 1 2008 11 42 429 439 13 08 2008   Adopting proper agricultural management and conserving soil organic matter are important components of sustainable agriculture. Soil organic matter content is a key attribute in soil quality. Labile organic matter pools can be considered as suitable indicators of soil quality that are very sensitive to changes in soil management practices. This research was carried out to investigate some organic carbon labile pools as an indicator evaluating the effects of different managements on some quality parameters of two calcareous soils. The study was conducted in 2 locations: 1- plots that receiving 0 (C1), 25 (C2), 50 (C3) and 100 (C4) Mg/ha of manure for five years successively with a cropping rotation of wheat –corn every year and plots under three cropping rotations (C5, C6 and C7) at Lavark experimental farm and 2- inquiry research station of Fozveh at different plots with three different cropping rotations (C8, C9 and C10) with a given cropping history recorded for the last 5 years. Soil samples were taken from the center of each plot and the depths of 0-5 cm and 5-15 cm. Their organic carbon, hot water soluble carbohydrate, particulate organic matter (POM), organic carbon and hot water soluble carbohydrate of POM, mean weight diameter of water stable aggregates were determined. Different managements consisting of different levels of manure and types of cropping rotation had significant effects on the soil characteristics measured. The greateast amount of carbohydrate and aggregate stability was obtained in the plots of 100 Mg/ha of manure in Lavak and in alfalfa plots in Fozveh station. Also, the results showed that aggregate stability has a better correlation with hot water soluble carbohydrate in comparison with other soil organic pools. Therefore, the carbohydrate extracted by hot water may be used as an index to assess the impacts of different agricultural management systems on soil quality. 800 General Study of Genetic Diversity of Sinorhizobium Bacteria Using PCR / RFLP 16S-23S rDNA Technique Karimi E. Lakzian A. Khavazi K. Asgharzadeh A. Haghnia G.H. 1 1 2008 11 42 441 449 13 08 2008   It is important to investigate the genetic diversity and evaluate symbiotic effectiveness of the indigenous rhizobial population. It helps understand the responses of indigenous isolates to different rhizobial inoculants. In spite of the importance of bacterial diversity, there are a few scientific reports about it in Iranian soils. Genetic diversity of 150 isolates of Sinorhizobium isolated from Hamadan soils was studied by using PCR / RFLP 16S-23S rDNA technique. The results showed that all isolates clustered in three different groups. Group (I) formed 122 isolates and they were quite similar to Sinorhizobium meliloti from viewpoint of genetic characteristics. Twenty five isolates were clustered in Group (II) and they belonged to Sinorhizobium medicae. Group (III) had two isolates and they were new species and quite different from the other groups. Shannon diversity index was different within eleven different land units (Medium gradient mountains, Level lands, Plateau, Foot slopes, Depressions and Composite land) and there was a correlation between Shannon index and some soil properties. Difference in Similarity index showed that Sinorhizobium groups in each land unit were different. 801 General Tillage and Tractor Effects on Bulk Density, Cone Index and Structural Stability of a Sandy Loam Soil Bayat H. Mahbobi A.A. Hajabbasi M.A. Mosaddeghi M.R. 1 1 2008 11 42 451 461 13 08 2008   Tillage is one of the important managing factors that can destroy or improve soil structure. Soil structure is affected by the machines and shape of the wheels. Field experiments were conducted at Hamadan Agricultural Research Station on a coarse loamy mixed mesic Calcixerolic Xerocrepts soil to measure and evaluate the effects of tillage and wheel-induced compaction on selected soil physical properties. Treatments included tillage methods (Moldboard Plow and Chisel Plow, (MP, CP)) performed using three customary tractors in Iran [John Deer (J), Romany (R) and Massey Ferguson ( MF) ]. Traffic zone and non traffic zone were other treatments. A split-plot design with three replications was used in a completely randomized arrangement of treatments. Soil samples were taken at the end of wheat growth season in traffic and non- traffic zone and from four layers and compared for bulk density (BD), cone index (CI), and mean weight diameter (MWD). The influence of both tillage methods on BD in most soil depths was not significant, meanwhile, BD was higher in the deeper layers. Wheel traffic did not affect BD significantly, but its effect decreased by increasing the depth. Commonly, conservation tillage increased structural stability as evaluated by MWD. Cone index illustrated the same trend as for BD, with some variation because of it higher sensitivity, so it was significantly was increased in CP rather than in MP for the traffic zone. Such a difference was not observed in non-traffic zone. The CI was also significantly increased in traffic zone compared with non-traffic zone. J significantly increased CI in two first layer in comparing with MF, but there was not significant difference between J and R. The MWD was increased by chisel plow in non-traffic zone and this increment was significant in fourth soil layer (22.5- 30 cm). Wheel traffic caused the increase of MWD in the second layer and significant difference was not observed in other layers. Overall, R caused less destruction in soil structure and tillage methods changed some of soil physical properties. 802 General Soil Phosphorus Forms in Four Toposequences of Isfahan and Shahrekord Regions Dehghan R. Shariatmadari H. Khademi H. 1 1 2008 11 42 463 472 13 08 2008   Studying soil phosphorus fractions is useful in understanding soil pedogenesis as well as soil fertility. In this reseach, 20 soil samples were taken from different depths of 0-30 and 30-60 cm of upper-slope, mid-slope and lower-slope positions of four toposequences in arid (Jei and Ziar in Isfahan) and semiarid (Farokhshahr and Shahrekord) regions. In each toposequence, the soil depth was relatively low at the upper-slope position and increased toward the lower-slope. The soils in upper-slope and mid-slope were under scarce native vegetation where the soil in lower-slope was under farming activities. Soil phosphorus (P) fractionation was carried out using sequential extraction. The total soil phosphorus was in the range of 302-1135 with an average of 715 mg/kg. About 65-89% of total phosphorus were inorganic, and 11-35% organic. The amount of inorganic and organic P in the soil samples was in the range of 204-897 with an average of 571, and 70-238 with an average of 114 mg/kg, respectively. The amount of total, inorganic and organic P increased from upper-slope toward the arable lands and decreased from topsoil to subsoil in all toposequences. In the studied soils, apatite ( Ca10-P ), aluminum phosphates(Al-P), octacalcium phosphates( Ca8-P ), iron phosphates (Fe-P), iron oxides occluded phosphates( OC-P ) and dicalcium phosphates( Ca2-P ) were the major constituents of the soil inorganic phosphates, respectively. 803 General Kinetics of Changes in Extractable Phosphorus in Some Soils of Hamadan Tahmaseby F. Hosseinpur A.R. 1 1 2008 11 42 475 488 13 08 2008   Soil properties play a significant role in phosphorus (P) sorption. Information about P sorption is limited in Hamadan soils. The objectives of this research were to study the P sorption in twelve soils of Hamadan, assess the capability of different kinetics equations describing P sorption and correlate the P sorption characteristics with the soil properties. The soils were fertilized with 200 mg P kg-1 as KH2PO4. Fertilized soil was incubated at 25±1 ˚C for 2520 h. The incubated samples at 1, 2, 4, 8, 24, 48, 72, 96, 120, 144, 168, 240, 336, 504, 672, 840, 1008, 1176, 1344, 1512, 1680, 1848, 2016, 2186, 2352, 2520 hours after P addition were extracted by two extractants. The soil phosphorous was extracted by 0.5 M sodium bicarbonate (Olsen solution) or by AB-DTPA. Zero order, first order, simplified Elovich equation, parabolic diffusion law and power function equations were fitted on the experimental data. The results showed that P sorption was initially rapid followed by a slow phase. The amounts of P sorption after 2520 h, ranged from 162.7 to 253.84 and 193.37 to 235.11 mg kg-1 for the Olsen and AB-DTPA methods, respectively. Regarding to higher determination coefficient and lower standard error, Elovich and power function equations were suitable to describe P sorption kinetics. Rate constants of the Elovich and power function equations ranged from 0.036 to 0.49 and 0.157 to 0.304 mg kg-1h-1 for Olsen and from 0.074 to 0.76 and 0.184 to 0.382 mg kg-1h-1 for AB-DTPA. The trend of the data implied a discontinuity in slope at 336 h, as two region models might better satisfy the trend of the data in to two range ( 0 to 336 and 336 to 2500 hr). At the first section, the P sorption could be describe by simplified Elovich, power function and parabolic diffusion law kinetics equations. Rate constants in these equations varied among the soils. At the second section, kinetics equations could not describe the P sorption. The results of this study indicated that P sorption rates varied among the soils and Fe , Al and CaCo3 affected on P sorption kinetics. 804 General Phosphorus Release Kinetics and the Correlation Between Kinetics Models Constants and Soil Properties and Plant Indices in some Hamadan Soils Biabanaki F.S. Hosseinpur A.R. 1 1 2008 11 42 491 503 13 08 2008   Phosphorus (P) after nitrogen limits agricultural production in most region of the world. Information about P release rate is limited in Hamadan soils. The objective of this research was to study P release in 10 soils from Hamadan province by successive extraction with 0.5 M NaHCO over a period of 1752 h and the correlation of P release characteristics with soil properties and corn plant (Zea mays) indices. The results showed that soil P release began with a fast initial reaction, followed by a slow secondary reaction until 1752 h. The amounts of soil P released after 1752 h ranged from 309 to 586 mg kg-1. The cumulative P release was evaluated by six kinetics equations. Statistical analysis showed that phosphorus release kinetics were described by parabolic diffusion law, first order and power function equations. The correlation study indicated that soil P release coefficients such as rate constant of first order, parabolic diffusion law, power function equations, P released after 168 and 1752 h were significantly correlated with some soil properties such as Olsen-P, calcium carbonate equivalent, sand and silt. The correlation studies between plant indices and constants of kinetics equation showed that rate constant of first order equation was not significantly correlated with plant indices. Equation constants of parabolic diffusion law, power function and P release after 1752 h were significantly correlated with plant indices. The results of this research indicated that release rate of P is different in soils and is an important factor in supplying available P to plants. 805 General Application of Steel Making Slag and Converter Sludge in Farm Manure Enrichment for Corn Nutrition in Greenhouse Conditions Melali A. R. Shariatmadari H. 1 1 2008 11 42 505 513 13 08 2008   Application of slag and converter sludge, major by-products of Esfahan Zob Ahan factory, to enrich two organic amendments for corn nutrition, was investigated. Farm manure and its vermicompost mixed with different rates of slag and sludge were incubated in 3 Kg pots at field capacity moisture and home temperature for three months. The applied rates of slag and sludge were 0, 5 and 10 percent (w/w) of pure iron from these compounds to the organic amendments. Iron sulfate with the above ratios was also examined for comparison. Sub-samples of the incubated materials were taken after 0, 10, 25, 45, 65 and 90 days of incubation and examined for DTPA extractable Fe, Mn, Zn and Cu. After the incubation, the enriched amendments were applied to a soil sample to grow corn. Three Kg soil samples, taken from Chah Anari experimental farm, Esfahan University of Technology, were mixed with 17 gr of the amendments (50 ton/ha) placed in 3 Kg pots. In each pot two corn seeds (single cross 704) were planted and after 70 days crop yield and concentration of Fe, Mn, Zn, Cu in the plant tissues were determined. Results showed that the use of iron sulfate strongly increased DTPA extractable Fe and Mn of the amendments. In enrichment by converter sludge, the best result was obtained in the mixture of 10 percent pure iron with the vermicompost on 60 days of incubation. Treatment of 5 percent pure iron from slag mixed with the manure increased DTPA extractable Fe and Mn with the time, but the 10 percent treatment was not much effective in this regard. The highest rates of iron uptake by the plants occurred in the iron sulfate and 10 percent converter sludge treatments, respectively however, the highest rate of the plant Mn uptake was observed in 5 percent iron from converter sludge mixed with vermicompost. In general, 10 percent pure iron from converter sludge was the most effective enrichment treatment, increasing the plant uptake of Fe, Mn, Zn and Cu micronutrients. 806 General Phytoremediation of Cyanide-Polluted Soils by Non-woody Plants Taebi A. Jeirani K. Mirlohi A. Zadeh Bafghi A.R. 1 1 2008 11 42 515 523 13 08 2008   Some industrial processes, such as plating and gold mining, utilize cyanide, which entering in their effluents. Because cyanide compounds are toxic contaminants, the waste-containing cyanide must be treated before discharge in the environment. Several methods are available for cyanide removal or detoxification. Natural degradation, alkaline chlorination, and oxidation with hydrogen peroxide are the most common methods in full-scale plants. Because of technical and economical concerns related to these methods, biological treatment processes have recently come under consideration. In phytoremediation, plants potential for pollutant removal is used. The main objective of present study is to investigate feasibility and potential of phytoremediation of cyanide-polluted soils by non-woody plants. The experiments carried out in this study were a completely random factorial design procedure, with three replications. Three non-woody plants: sorghum (as a cyanogenic cereal plant) and fescues with and free of endophyte (as grasses), were examined. Analysis of variance of the data obtained on soil cyanide reduction and cyanide accumulation in plants showed that phytoremediation is a suitable technique for low concentration of cyanide-polluted soils. Besides, it was been found that sorghum has a better soil cyanide removal efficiency than fescues, so that a significant portion of soil cyanide will accumulate in sorghum tissues. 807 General Impacts of Converting Rangelands to Cultivated Land on Physical and Chemical Properties of Soils in West and Southwest of Isfahan Hajabbasi M.A. Besalatpour A. Melali A.R. 1 1 2008 11 42 525 534 13 08 2008   Applying of intensive cultivation especially in marginal and sensitive regions, after conversion of rangelands to cropland farms, commonly causes reduction in soil quality, and thus an increase in soil degradation, erosion and runoff. This study was conducted to evaluate the land use change effects on some soil physical and chemical properties such as mean weight diameter (MWD), soil organic matter (SOM), bulk density (BD) and saturated electrical conductivity (ECe). For the experiment, soil samples were collected from 8 regions (rangeland and cultivated range) from west and southwest of Isfahan. Samples were taken from two soil layers 0-15 and 15-30 cm. Results showed that after conversion of range to cultivated lands, in some regions, SOM content was increased about 39% but in some regions decreased about 26%. This is due to the initial conditions of the regions. The ECe also increased by 41% due to this conversion. However, no changes were observed to the MWD, BD and pH in different treatments. Although there were little change to the physical and chemical properties of soil as a result of this conversion, those properties which were changed, could have a degradation effect and lower the soil quality. 808 General Investigating the Accuracy and Precision of Some Methods of Soil Erosion Features Mapping Mohammadi Torkashvand A. Nikkami D. 1 1 2008 11 42 537 549 13 08 2008   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. 809 General Geomorphological Characteristics of Claypan and Their Impacts on Land Degradation Using GIS Techniques. A Case Study: Rodasht Area (Esfahan-Iran) Naderi Khorasgani M. Karimi A. 1 1 2008 11 42 551 563 13 08 2008   This research was carried out to study the impacts of geomorphologic characteristics of claypan on land use and land degradation. Databank of the study area was constructed and digital terrain model of claypan was prepared. By using GIS techniques spatial distributions of the subsurface drainage network, sediment transportation index and wetness index were calculated. The results indicate that the depth to the claypan is between 0 (where the pan is exposed at the surface) to 605 cm. There are several depressions in the claypan which are filled by new sediments. Each depression has a catchment which is charged by the drainage water of its attributed lands. While a depression drains naturally or synthetically, the attributed soils over the depression are in non saline or moderate salinity condition otherwise, a marshland, a waterlogging area or a salt crust zone develops over there. The results also indicated that soil surface salinity is a function of depth to claypan and drainage condition of area. The trends of salinity extension are different for closed and open catchments and the depth to the claypan could be estimated using electrical conductivity. The results also show that analysis of microtopography of soil surface and soil stratification should be considered for designing irrigation and drainage networks. 810 General Comparision of Different Methods of Gypsum Determination in Selected Soils from Isfahan Yaghmaeian Mahabadi N. Givi J. 1 1 2008 11 42 565 576 13 08 2008   Gypsum affects many physical, chemical and mineralogical properties which in turn influences management, classification and sutability of the soils. This is the reason why accurate measurement of gypsum in soil is very important. In most of the soil science laboratories, the method of acetone ,in spite of its too much limitation, is being used as a standard method. The purpose of this research was to compare different gypsum determination methods and to find the most suitable one. The study areas include Jafarabad of Borkhar and Sepahanshahr.Soil samples were collected from different horizons of the studied profiles and seven samples with a wide range of gypsum content were selected. Gypsum content of the soil samples were determined by methods of acetone, sodium carbonate, resin, calcium and magnesium difference, diluted extracted sulfate, ammonium carbonate, sodium citrate and hydrochloric acid. To calculate the recovery percentage of the methods, after adding a certain amount of gypsum with known purity percentage to the soil samples, gypsum content was determined again by above mentioned eight methods. To evaluate the suitability of the methods, in addition to the recovery percentage of the methods, coefficient of variability and extent of proximity of the regression line to the 1:1 line were used. The results revealed that among the used methods, the method of sodium carbonate is the most accurate one. Resin method is ranked as the second best method and can be used in non-saline soils as another accurate method for determination of gypsum content. Sodium citrate and hydrochloric acid methods for different amounts of gypsum and ammonium carbonate method for gypsum content up to 30% are third in rank as far as their accuracy is concerned. Acetone, calcium magnesium difference and diluted extracted sulfate methods are not sufficiently accurate, because of low solubility of gypsum in water which is used as an extractant. In general, the most important determinant of accuracy of the methods is extractants of the gypsum among which the sodium carbonate has the highest efficiency. 811 General Effects of Soil Compaction Due to Wheel Traffic on Corn Growth and Yield Moalemi Ore A. Karparvarfard S.H. 1 1 2008 11 42 579 594 13 08 2008   This study was undertaken to investigate the effects of soil compaction due to wheel traffic on corn growth and yield, in summer 2004 and 2005 at the Badjgah Research Station, Shiraz University located in North West of Shiraz, Iran. The treatments consisted of axial load in two levels and wheel traffic location treatments at four levels, including none, between rows, on rows and on entire plot area. The corn growth rate, root density and yield were not significantly influenced by axial load, but they were significantly affected by wheel traffic in all plots. Corn yield with wheel traffic on entire plot area averaged 3.97 Mg/ha which was significantly lower than the yields with the other treatments which averaged 6.65 Mg/ha with no traffic. 812 General Tree-Ring Growth Response of Common Ash ( Fraxinus excelsior L.) to Climatic Variables Using Multiple Regressions Jalilvand H. 1 1 2008 11 42 597 609 13 08 2008   This study was down in Forest Park of Noor. In order to determination of tree ring response to climatic variations, 35 cores were taken from dominant natural stand of common ash (Fraxinus excelsior L.). The guide of this study was finding which climatic variables are effective in the ring width growth of ash in current growing year and previous years (one, two and three years before current growing year) by multiple regression models at the North of IR-Iran. Totally, 85 annually, monthly seasons and seasonal growth climatic variations of precipitation, temperature, heat index, evapotranspiration and water balance were analyzed. The best multiple regression models were explained 83 percent of total variance of the growth of common ash. The results show that the growth of common ash was related to the previous year's climatic variations than that of the current year. The most effective role of climatic variations was due to the first and second preceding years (55%). Evapotranspiration of July and September, and precipitation of May in the second and precipitation of March in the third previous years, all were positively affected the growth of this species. This study revealed that ash is interested in warmer condition on early and middle of seasonal growth in present of available humid, and precipitation in the months of early growing season (Ordibehesht-Khordad of two previous years). 813 General Investigation on the Plant Biodiversity in the Forestation Area of Needle Leaves Species (Case study: Kohsarkande- Mazandaran) Mohammadnejad Kiasari S.H. Akbarzade M. Jafari B. 1 1 2008 11 42 611 625 13 08 2008   The research design of elimination trail has performed in the form of randomized completely blocks design with 3 replications and 8 treatments ( species of needleleaves) in Kohsarkande forests of Neka, Mazandaran(North of Iran). For investigation of the plant biodiversity the treatments of needleleaves in this elimination trail, the aforestation of hard woods(Maple) and the bare area were selected. For determination of characteristics of top soil(0-10cm), a total of 24 samples of treatments were taken(per treatment 3 samples) and topsoil chemical properties such as EC, pH, T.N.V, caso4, P, K and organic matter were analized. To determin of plant biodiversity in these treatments Simpson´s index, N2 Hill´s index, Mc Arthur´s index and Shannon-Wiener function were used and for determination of species richness of these treatments Margalef ´s index and Menhinick´s index were employed. The results of this research showed that the treatments of the bare area, Cryptomeria japonica and Pinus pinaster with minimal survival and at least litter covering percentage have the highest biodiversity of plant covering on the floor of these treatments. The treatments of Pinus teada and the aforestation of hard woods(Maple) with maximum survival and the highest litter covering percentage have the lowest biodiversity of the plant covering on the floor of these treatments. 814 General Inventorying and Mapping of Natural Forest Stands of Zanjan Province Using Landsat ETM+ Image Data Bonyad A.E. Hajyghaderi T. 1 1 2008 11 42 627 638 13 08 2008 The natural forest and range stands of Zanjan province are located in mountainous areas. Inventorying and mapping of natural forest and range stands in mountainous areas are difficult and costly. Satellite data are suitable for this purpose. The Landsat ETM+ image data of 2002 are used for classification and mapping of natural forest stands in Zanjan province. For the purpose of data reduction and principal components extraction, the principal components analysis (PCA) was used. Just the scores of the first three PCs (PCA1، PCA2 and PCA3 (that accounted for 76.67 percent of the total variance were considered as new images for future analysis. A raster geographic information system (RGIS) database file was prepared and involved 7 ETM+ bands, 3 principle component analysis, 9 factor analysis and 8 vegetation indexes of image data. The correlation coefficients of 27 image layers and optimum index factors (OIF) of selected images were computed and 12 groups were found suitable for natural forest and range stands. Maximum liklelihood classification (MLC) method was used in this study. In order to test the accuracy of map, kappa index of agreement was calculated. The highest KIP belonged to three λ3, λ4, λ5 Landsat image bands with KIP = 0.86. The highest OIF belonged to three PCA3, FA2 and MIR with value of 233.44 and lower OIF belonged to three λ4, λ5, λ7 with value of 83.63. The overall, user’s and producer’s accuracy rates were 88.45, 73.69 and 70.23 percent respectively. The results of the study show that the Landsat ETM+ image data were appropriate for classification and mapping of natural forest and range stands in Zanjan province. 815 General Study of Annual Gonadic Development in Great Sturgeon ( Huso huso ) Cultured in Brackish Water Hedayati S.A.A. Yavari V. Bahmani M. Alizadeh M. Kazemi R. Hallajian A. 1 1 2008 11 42 641 649 13 08 2008   Great sturgeon is one of the most economically important species. However, in recent years overfishing, illegal fishing, etc., have resulted in severe declines in the stocks of this species. For conservation, stock of this species, determination of gonadal situation and its gonadal growth exchanges is very important. This paper is a histological approach to gonadal staging in 74 Huso huso in the 4 – and - 5 - year old classes. The fishes were reared in brackish water concert tanks under controlled conditions. A small section of the gonads of each fish was removed by biopsy. The gonadal tissue was fixed in buoin solution. They were dehydrated in different diluted solutions of alcohol and chloroform until they were clear. Then they were embedded in paraffin and sectioned at 7 µm and stained by hematoxylin and eosin method. Of the four-year old fish, %56 and %44 were males and females, respectively. %6 of males were at stage I %11 stage I-II %61 stage II %13 stage II-III %11 stage III-IV and %8 were at stage IV-V. %3 of the females were at unknown stage %3 stage I %11 stage I-II %60 stage II %14 stage II-III and 9% stage III. Of the 5 year old fish, %12.5 of males were at stage II % 25 stages II-III %50 stages III and %12.5 were at stage IV. %62.5 of females were at stage II and %37.5 were at stage II-III. Results of this study Compared with those obtained from fishes of the same age class studied in natural habitats as well as the results obtained for the farmed sturgeons from freshwater medium indicate that there is no similarly in the stage of gonadal development in different conditions. Longest stage in tow sexes was stage II that is longer in females, and passing of stage II in males is faster. Males showed more sexual maturity than females. Gonadic growth in culture medium is faster than wild condition, and it is faster in brackish water than fresh water. So, we can state that brackish water is a suitable medium for gonadic growth of Great sturgeon.