نشریه علوم آب و خاک (علوم و فنون کشاورزی و منابع طبیعی)
سال دهم شماره 4 (پیاپی 38، زمستان 1385)

In this paper, the effect of irrigation water salinity levels on seed germination, dry matter weight of seedlings at eight-leave stage, and the salt tolerance of 8 rapeseed cultivars was investigated. Relative yield reduction in saline and non saline conditions, salt sensitivity index and Van Genuchten-Hoffman methods were used to determine the salt tolerance of the cultivars. Results showed that the effect of different salt levels, cultivars and their interactions on germination and dry matter weight of seedlings was significant at 0.01(the higher the salt level, the lower the germination and dry matter). Also, using the Van Genuchten-Hoffman method, the irrigation water salinity corresponding to 10%, 25%, 50% and 90% reducts in germination and dry matter of seedlings were determined. Statistical analysis showed that a single cultivar gives different responses to salinity during growth stages and it may be tolerant in one stage, but sensitive to salinity in another growth stage. In this research, ACSN1, Falcon, and Shirali in germination stage and ACSN1, Falcon, and Cobra in seedling growth stage were salt tolerant. The three cultivars Oyerka, Global, and Ceres and the next three Shirali, Global, and Oyerka were sensitive to salinity in germination and seedling growth stages, respectively. Finally, the ACSN1 and Falcon cultivars were introduced as salt tolerant, and Oyerka and Global were considered as salt sensitive.

Improper management of watershed land utilization has many ill effects on the available resources. Land use optimization is one of the proper strategies to achieve sustainable development and to reduce resource dissipation. Focusing on Brimvand watershed in Kermanshah province which comprises an area of 9572 ha, the present study was conducted to find out the most suitable land allocation to different land uses viz. garden, irrigated farming, dry farming and rangeland to achieve soil erosion minimization and benefit maximization. The soil erosion, net benefit and standard land capability maps were supposed as the inputs of the objective functions and to defined constraints. The multi-objective linear problem was then solved using simplex method with the help of ADBASE software package and ultimately the optimal solution was gained. Additionally, the results of the study revealed that the amount of soil erosion could reduce by 7.78% whereas the benefit increases at the rate of 118.62%, in case of implementation of optimal solution. The above mentioned optimization led to dry farming decrease and garden increase over that area. The results of sensitivity analysis also showed that objective functions were strongly susceptible to the variation of maximum constraint of irrigated farming and garden areas.

Increased chemical compounds in soil are the most important results of irrigation with domestic wastewater and treated effluents which contain some nutrients such as phosphorous (P). This process could increase the soil fertility, leading to the decrease of chemical nutrient consumption and consequently the cost of agricultural production. A research project was carried out in Tehran region for two years in order to investigate the capabilities of soil and plant in absorption and storage of wastewater contaminants, namely, phosphorous, and also the transmission of them to drain depth as a result of irrigation practice. To do the research, a series of lysimeters based on a statistical factorial experiment in the form of randomized complete design (3x3x3) were used. Raw and treated domestic wastewater, obtained from Ekbatan Housing Complex, and well water (control) were used to irrigate raw edible vegetables including parsley, carrot and tomato. The results showed that the amount of phosphorous leaching through soil to drain depth was between 0.90% and 3.56%, and between 1.03% and 4.15% of the phosphorous concentration in raw wastewater and treated one entered into the soil, respectively. Also, mass balance analyses showed the average phosphorous reduction ranged from 97.2% to 99.9% of the phosphorous entered with wastewater. During two years of study, the maximum concentration of PO4 measured in drained water was about 0.21 mg/L obtained from lysimeters irrigated with raw wastewater. This was much lower than the permissible PO4 amount for discharging the effluents to the surface water resources (6 mg/L PO4 is permitted by Iranian Environmental Protection Organization).

Irrigation water Scarcity is the major limiting factor for crop production in irrigated farming. Therefore, optimal use of water is influenced by seasonal rainfall especially where the water price is high. Nitrogen also plays a key role in plant nutrition. In this study, wheat grain yield production as a function of applied water (irrigation plus seasonal rainfall) and nitrogen fertilizer (applied plus soil residual nitrogen) using existing data of a field experiment, were used. This function was obtained based on the data from the Maraghah Agricultural Experiment station. Based on this production function, maximum attainable yield can be 8.12 t/ha obtained by the consumption of 1.56 m of water (irrigation plus rainfall) and 193 kg/ha of nitrogen. An economic analysis based on the Iso-Quant curve was conducted to optimize the application rates of production inputs (water and nitrogen). When land is limited, the optimum water and nitrogen use will be based on maximizing net returns from land unit area. The optimal levels of these inputs were determined on the basis of farmer ability for paying the costs of water and nitrogen. Furthermore, optimum amounts of water and nitrogen were determined for different levels of wheat yield. The results indicated that despite low price of irrigation water and nitrogen fertilizer, at present market value, optimum values of water were more variable than those of nitrogen, for its high effective role in wheat production. The results also indicated that when there is no limitation of the source and use of water and nitrogen, and farmers are also able to pay their costs, application of 1.47 m of water (irrigation plus rainfall) and 190 kg/ha of nitrogen (applied plus soil residual) will produce maximum profit per hectare, reaching Rls 12,207,506. When water is limited, optimum levels of water and nitrogen will be based on the maximizing profit per unit of water. In this analysis, the use of 0.556 m of water (irrigation plus rainfall) and 190 kg/ha of nitrogen (applied plus soil residual) resulted in maximum net income per unit of applied water (irrigation plus rainfall) amounting to Rls/m3 1203. This amount of water use, which is 64.4 % lower than its amount under maximum yield condition, resulted in 181 % increase of cultivated area. Graphic expansion path on the isolines of yield showed more dependence of wheat production on water than nitrogen. Therefore, the optimum amounts of nitrogen in the three mentioned conditions are close to each other due to its subsidized price and lower effect on wheat production relative to water.

A field study was conducted at the Zabol Agricultural Research Center during the years (2003-2004) to investigate the effect of irrigation with treated municipal wastewater on the yield and quality of wheat and some soil properties. Irrigation treatments were: T1: Irrigation of wheat with well water during entire period of growing season T2: Irrigation of wheat with well water until the begging of flowering stage, and irrigation with wastewater in every other turns of irrigation T3: Irrigation of wheat with well water until the beginning of booting stage, and irrigation with wastewater in every other turns of irrigation T4: Irrigation of wheat with well water until the begging of tilling stage, and irrigation with wastewater in every other turns of irrigation and T5: Irrigation of wheat with wastewater during entire period of growing season. A complete randomized block design with four replications was adopted for this experiment. The soil was sandy loam with no limitation for internal drainage. Chemical and physical aspects of soil were measured during the experiment. Grain yield, yield components and chemical composition of wheat grain were also measured. The results showed that yield of wheat and total biomass production were statistically significant in T3, T4 and T5 compared with the control treatment. Plant height, width and length of flag leaf, numbers of fertile tillers, length of panicle, numbers of grains per panicle and weight of 1000 grains were also statistically significant with the control treatment. Percentages of protein were statistically different among various irrigation treatments. No significant changes in accumulation of heavy metals in soil and plant grains were observed. The increase of SAR, ECe, O.C% and total nitrogen in the T4 and T5 were statistical significant compared with the control treatment. In summary, for sustainable use of Zabol municipal wastewater, the growth stages of wheat should be irrigated with municipal wastewater and other growth stages should be irrigated with nonsalinty water, so that the maximum yield is obtained and soil salinitisation and sodication is prevented.

Heavy metals including cadmium (Cd) and lead (Pb) are entering agricultural soils from different routes and mainly due to human activities. Accumulated Cd and Pb in the soil would eventually enter the human and animal food chains and pose threat to their health. Therefore, evaluating heavy metal accumulation is necessary to prevent soil and environmental pollutions and should be considered by researchers as well as policy makers. This study was conducted to model the accumulation rates of Cd and Pb in the agro-ecosystems of Isfahan, Mobarakeh, Lenjan, Borkhar, Najafabad, Khomeinishahr and Felavarjan. Cadmium and lead accumulation rates in the agro-ecosystems were computed using a stochastic mass balance model which uses Latin Hypercube sampling in combination with Monte-Carlo simulation procedure. Agricultural information including crop types, crop area and yield, the type and the number of livestock, application rate of mineral fertilizers, compost and sewage sludge and also metal concentration in plant and amendments were used to quantify Cd and Pb accumulation rates. Modeling Cd and Pb accumulation rates indicated that the metals are accumulating in the agricultural lands in the studied townships. The largest Cd (18 g ha-1 yr-1) and Pb (260 g ha-1 yr-1) accumulation rates were found in the township of Isfahan but the minimum accumulation rates were found in township of Lenjan for Cd (3 g ha-1 yr-1) and Mobarakeh for Pb (10 g ha-1 yr-1). The major input route to agricultural soils is phosphate fertilizers for Cd but for Pb is manure on the regional scale. High application rates of sewage sludge and compost in agricultural lands in the township of Isfahan could result in considerable amounts of Cd and Pb entering the soils of this region.

In Iran, the development of cultivated areas becomes gradually impossible due to ever-increasing population growth and urban area development. 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 assessment of land suitability in Talandahst area for rainfed wheat, barley and chickpea. Talandasht plain with a surface area of 4500 ha is located southwest of Kermanshah city. The climate is semi-arid with cold winter and moderate summer. The successive stages of this research included soil survey in the field, soil analysis, qualitative and quantitative and economic evaluations of land suitability. In qualitative evaluation of land, climatic, topographic and soil suitability classes were determined according to the degree of the matching. Limitation and parametric methods were used in qualitative evaluation. Quantitative and economic evaluations made based on the observed yield and gross benefit, respectively. Based on qualitative evaluation, the studied area is marginally suitable for rainfed farming of wheat, barley and chickpea. This is due to water deficiency occurring during some stages of the growing cycle. The solution for this problem is supplementary irrigation. In addition to climate limitation, there are also topographic and soil restriction for the growth of the studied crops. On the basis of observed yield, the land units are moderately to highly suitable for rainfed wheat and barley production. Among the three named crops, the most and least profitable ones are chickpea and barley, respectively, and wheat ranks between them.

Hamadan province is one of the most important alfalfa (Medicago sativa) producing regions in Iran. However, little is known about P status in this region and no suitable extraction method has yet been introduced. This experiment was carried out to determine the available phosphorus by nine chemical extractants in some soils of the Hamadan region. The treatments consisted of 15 soils and 2 P levels (0 and 200 mg P kg-1 as Ca(H2PO4)2.H2O ) in a factorial experiment in a randomized design with three replications. Alfalfa plant were harvested in three cutting. The results indicated that the amount of extractable phosphorus decreased in the following order: Collwell>Bray 2>0.1 N HCl>Bray 1>Olsen>AB-DTPA>Mehlich 1>Mehlich 2 > 0.01 M CaCl2 The amounts of P extracted by all methods except that by 0.01 M CaCl2 method, showed significant correlation. The results of correlation studies showed that in the first cutting, Collwel method, in the second cutting AB-DTPA, Olsen, Collwel, Bray 1, Bray 2 and Mehlich 2 and in the third cutting, AB-DTPA, Olsen, Collwel, Bray 1, and Mehlich 2 methods seems to be suitable extractants for assessing available P of soils in Hamadan province.

Study of phosphorus reactions over time and the role of organic matter in the calcareous soils are important for the development of P fertilizer and manure management practices. The objective of this study was to determine the effect of applied manure on P availability and its chemical forms in the soil, over time. Eight samples were collected from semi-arid calcareous soils of Mashhad plain. The samples were treated with two levels of inorganic P (0 and 300 mg P kg-1 soil as KH2PO4) and two levels of organic matter (0 and 1% cattle manure). The experiment was conducted in a completely randomized design with factorial arrangement. The treated soil samples were incubated for 2, 5, 10, 30, 60, 90 and 150 days, then analyzed for available P (Olsen-P). The result showed that only 17% of added phosphorus was available in P treatment at the end of experiment. In manure treated soils, this figure reached 34% for the same period of time. Application of manure along with P increased the recovery of applied P and CBD-P (Citrate-Bicarbonate-Dithionite). This may be due to the formation of P-organic complexes with Fe oxides. Application of manure in soil increased NaCl-NaOH-P considerably compared with P and P+OM treatments. It can be concluded that P originating from manure compared with inorganic-P may be more available for plants over the time.

To evaluate the effects of chemical and hand fruit thinning on pistachio flower bud retention, experiments were conducted during 1382 and 1383. In the first year, ethephon treatments at the concentrations of 100 and 200 mg L-1, urea at 2.5% and 5%, naphthaleneacetic acid (NAA) 125 and 250 mg L-1 and naphthaleneacetamide (NAD) 250 and 500 mg L-1 were sprayed on two branches of nine uniform trees with four replications. During the second year, hand fruit thinning treatments were used in addition to the previous treatments. Chemical treatments reduced flower bud abscission among them ethephon treatments were the most effective on flower bud retention. As compared with other treatments, hand thinning treatments had also positive effect on flower bud retention. Fruit thinning also increased kernel weight, reduced the number of nuts per ounce and decreased blank fruits. Fruit thinning had no significant effect on the yield of branches during ‘on’ year.

In order to determine the most important quantitative and qualitative characteristics of pomegranate fruit and its components for categorizing the genotypes, a study was carried out using 24 genotypes. In this study 28 quantitative and qualitative characteristics of pomegranate fruit and seed were evaluated. Analysis of variance showed that all of the characteristics in examined genotypes were significant, showing high variability in characteristics. Results of simple correlation analysis showed the existence of significant, positive and negative correlations among some important characteristics. Also, factor analysis showed that most of fruit juice, aril and seed characteristics constituted the main factors. Effective characteristics categorized in seven factors accounted for 89% of total variance. For each factor, eigen value more than 0.7 was considered significant. Cluster analysis was performed using these seven factors and genotypes, in the distance of 9, were divided into 5 main clusters. These groups were mainly distinct in fruit flavor and soft seededness. Furthermore, by using three main factors, genotypes positions determined in 3-plot analysis, which distinguished sweeter genotypes from sweet-sour and sour genotypes.

Turfgrasses are the most important cover plants in the world. Quality evaluation of the turfgrasses is usually done by experienced evaluators using color texture, density and uniformity. The results obtained by different evaluators may be different, leading to researcher’s concern. Therefore, some quantitative methods have been used for increasing the aquracy and stability in results. In this study, three color evaluating methods including, spectrophotometery (chlorophyll content), chlorophyllmeter SPAD-502, and evaluator person, as well as leaf texture by evaluator person compared with leaf width were used for 75 populations of Cynodon dactylon L. and Tifdwarf cultivar. The results showed that there were significant differences between populations for the color and leaf texture. There were no significant corelations between measuring color by using specterophotometery, chlorophyllmeter-502, and evaluator. Use of SPAD-502 instrument for measuring leaf color of bermudagrass is not recommended due to small leaf width of this species. However, there was significant corelation between visual evaluation and leaf width in measuring leaf texture. Therefore, when no experienced evaluator is present, leaf width maybe used for measuring leaf texture.

Today, the production of disease-free and identical rootstock seedling in protected environments is a common practice in citrus industry. The process is time consuming, laborious and expensive. Shortening the period to reach suitable size for budding results in the reduction of the costs. It is possible to shorten the period for budding in citrus seedlings through the application of growth regulators. As lime is used widely as a rootstock in Southern Iran, this research attempted to study the effect of paclobutrozol (PP333), ethephon and pinching following gibberellic acid (GA3) treatment on height, diameter and budtake of lime seedlings. To do the research, seedlings with 4-6 leaves were sprayed with 100 mg/L GA3. After GA3 treatment, uniform seedlings 50 cm height were selected, potted and sprayed with PP333 (500 and 1000 mg/L), ethephon (150 and 300 mg/L) or pinched. All treatments, compared with control, increased height, diameter and fresh weight of shoot significantly. GA3 alone caused internode elongation. The effect of all treatments on the number of node, fresh and dry weights of root was not significant. Ethephon reduced chlorophyll content of leaf. And ethephon (300 mg/L) and PP333 (1000 mg/L) reduced budtake percentage of lime seedlings.

In order to study the effects of salinity of irrigation water on the growth and quality of 10 bermudagrass cultivars under saline soil, a factorial plot experiment using a complete randomized block design with three replications was carried out at College of Agriculture, Isfahan University of Technology in 2002-2003. Ten cultivars under five levels of irrigation water salinity (3.30, 6.93, 10.2, 14.8, 17.8 dsm-1) were studied. During experiment, visual appearance of color (1 to 9, best 9), and leaf area, shoot and root dry weights and length and number of stolones were measured. Results showed that salinity of irrigation water affected color of different cultivars, such that with increase in the level of salinity, color decreased. Cultivars showed better color in August, but lower color in January. Annual mean indexes showed that ISF2 and Tifdwarf had highest and lowest color, respectively. Also, with increase in salinity levels, leaf area, foliage dry weight, length and number of stolones reduced. With increase in salinity of irrigation water from 3.30 to 10.2 dsm-1 root dry weight increased, but reduced in higher salinity levels. Due to significant interaction effects between salinity and cultivars for most traits, the responses of cultivars were different. Large differences observed between cultivars for most of traits indicated high genetic variation among the studied bermudagrass cultivars. Under high level of salinity conditions, JP2 and Tifway for foliage dry weight, 3200W18-4 and ISF2 for root dry weight, and cultivars Midlawn and 3200W18-4 for leaf area, were recognized as more tolerant than others.

To determine the role of endophytes in conferring valuable physiological characteristics on and induction inducing cold tolerance in two species of festuca, an experiment was done at Isfahan University of Technology in 2002. Endophyte-infected and non-infected clones from two genotypes of tall fescue and one meadow fescue were prepared and coded 75,83 and 60 respectively. The clones were exposed to cold treatments at 6, -2 and –10C and compared with control treatment at 20C. After three weeks of cold treatments, relative water content of leaf and crown, cell membrane stability (electrolyte leakage), percentage of membrane damage and finally proline content of leaf were measured. The presence of endophyt caused an slight increase in relative water content of leaf and crown. There was considerably higher proline in endophyte-infected plants compared with non-infected ones in both stress and non-stress conditions. Endophytic fungi had strong effects on maintenance of membrane stability and on the decrease of electrolyte leakage at all temperature levels. Among plant genotypes, 83 preformed better for some characteristics, specially in the presence of endophyte, and showed higher cold tolerance.

Relationship between grain filling rate , grain filling duration, yield components and other physiological traits of rice was investigated in 93 genotypes of rice at Rice Research Institute of Iran (Rasht, Iran) during the growing season of 2001-2002. The experiment was performed without any statistical design. Panicles of main stem were tagged and taken at 3- day intervals during the grain filling period. A cubic polynomial model was used to fit the grain dry weight data (mean of R2= 0.98 for all genotypes) and the grain filling rate and duration estimated for the genotypes. Traits related to sink capacity such as grain weight, grain size and grain number per panicle correlated with grain filling rate but source -capacity- related traits except chlorophyll content of flag leaf and secondary leaf did not correlate with grain filling rate. Stepwise regression showed that final grain weight, grain filling duration and flag leaf angle contributed to grain filling rate, however, path analysis showed that only final grain weight and grain filling duration had the greatest effect on grain filling rate. The results of stepwise regression irrespective of final grain weight showed that chlorophyll content of flag leaf, grain width, grain filling duration and grain length contributed to grain filling rate. Path analysis results showed that the final grain weight had the greatest direct positive effect on grain filling rate, while grain filling duration had negative effect on grain filling rate.

In order to evaluate endophyte effect on plant earliness, compatible host-endophyte combinations including four genotypes of tall fescue and two genotypes of meadow fescue were selected and used in this study. One tiller-part of each genotype was treated using a fungicide mixture of Propiconazole and Folicur. New tillers of endophyte-infected and endophyte-free plants were planted in the field according to a complete block design with three replications. The traits including days to head emergence, days to 50% anthesis, days to maturity initiation, number of heads (as a weekly measurement), total seed weight, net seed weight and empty seed weigh were measured. Results showed that endophytes can enhance head emergence, maturity initiation and periodical seed yield. Days to 50% anthesis, and days to maturity initiation were also reduced. Head numbers in some genotypes increased up to 2 times. Increase in net seed yield may show some physiological alterations in plant such as hormonal balance alteration which may provide better seed setting in infected plants. Based on this study, we concluded that endophytic fungi can induce earliness in infected host plants.

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

The present experiment was aimed to evaluate the freezing tolerance of two cold tolerant (MCC426 and MCC252) and a cold susceptible (MCC505) chickpea genotypes. The study was carried out in a split-plot factorial design with three replications. Factorial arrangement of genotype and acclimation (acclimation and non acclimation) were imposed as main plot and temperatures (0, -4, -8, -12, 16, -20ºC) as subplot. The effect of freezing temperature (FT) on plant survival was significantly different among genotypes (p<0.05). According to the average effects of acclimation and FT, the plant survival in MCC426 and MCC252 was 40% and 31% respectively more than in MCC505. Lethal temperature for 50% response (LT50) and temperature resulting in 50% lower dry matter (DMT50) in MCC426 were –10.8ºC and –8.4ºC, respectively and were lower than the other genotypes. Acclimation increased the freezing tolerance such that MCC426 tolerated up to –12ºC without any mortality, however, at this temperature, plant mortality rates in MCC252 and MCC505 were 25.7% and 67.7%, respectively. Plant regrowth was affected by the intensity of FT, such that plant dry weight (PDW) and stem height (SH) in –12ºC decreased about 63% and 50%, respectively, compared with non - frozen control plants. The most freezing damage was observed in MCC505, -12ºC treatment caused 90% decreases in PDW and SH, but at this temperature, PDW and SH in MCC425 decreased 55% and 49% and in MCC252, the reduction was about 60%and 54%, respectively. It seems that the use of controlled experiments would contribute to the evaluation of freezing tolerance and screening programs in chickpea germplasm for the estimation of LT50 and DMT50 .

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

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

Effect of nitrogen (N) fertilizer levels and its split applications on yield and yield components of rice (Oryza sativa L.) Cv. Khazar was investigated in a completely randomized block design with 3 replications in a paddy light soil at Guilan province, Iran, 2003. In this experiment, six treatments including: T1-control (no N fertilizer) T2- 40 kg/ha N (at transplanting time) T3- 80 kg/ha N (at transplanting, and tillering times) T4- 80 kg/ha N (at transplanting, tillering, and panicle initiation times) T5- 120 kg/ha N (at transplanting, and tillering times) and T6- 120 kg/ha N (at transplanting, tillering, and panicle initiation times) were compared. Results showed that the highest fertile tiller number was obtained in the fifth and sixth treatments with double and triple split applications of 120 kg/h N (236 and 248 m-2). The highest fertile filled spikelets percentage (84.8%), 1000-grain weight (26.1 g) and grain yield (4.83 t/ha) belonged to the sixth treatment, but grain yield and 1000-grain weight were not significantly differerent in the fourth and sixth treatments with three fertilizing times. This finding may have resulted from the third topdressing application of nitrogen fertilizer in panicle initiation and higher leaf area (44.8 and 45.5 Cm2), leaf greenness (39.4 and 39.9) and leaf nitrogen concentration (31.2 and 33.6 g/kg) during grain filling in the fourth and sixth treatments. Regression analysis also showed that flag leaf greenness (SPAD values at 5 days after flowering) and flag leaf area accounted for about 75% and 78% changes in yield, respectively. In conclusion, triple split application of 80 kgN/ha could be suggested for rice Cv. Khazar in these regions since the yield would be the same as the application of 120Kg/ha N.

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

In order to evaluate grain yield potential and study dry matter remobilization to seed, 8 commercial bread wheat cultivars were examined in two separate experiments, using randomized complete block design with 4 replications in 2003. There were significant differences for most traits in normal and drought conditions. Sarday variety had the least grain yield in the two environments. There was considerable variation between genotypes for independent parameters of dry matter remobilization to different plant parts in the two environments. Factor analysis showed that seven factors accounted for 100 % of the data total variance in normal and drought conditions. Factor analysis also showed that the effective traits to components grain yield , height and phenological traits were important for the selection of appropriate genotypes. Calculation of drought resistance indices showed that four indices including mean productivity, geometric mean productivity, harmonic index, stress tolerance index were more effective than other indices for the selection of drought tolerant genotypes.

An experiment was conducted to investigate the genetic diversity in the cultivars and F1 hybrids of durum wheat, using agronomic and morphological traits. Evaluation of consistency between choosing parents of crosses based on morphological and agronomic observations and genetic distance obtained from cluster analysis were objectives of this study. Fourty- two genotypes were evaluated using a randomized complete block design with three replications in 2003. Agronomic characteristics comprised days to 50% flowering, days to 50% pollination, days to maturity, plant height (cm), spike length (cm), grain weight per spike (gr), number of grain per spike, number of spike per m2, grain yield (t/ha), biological yield (t/ha), 1000 grain weight, test weight (gr/L) and harvest index were measured in the studied genotypes. The results of analysis of variance showed significant differences among genotypes for all the studied traits. The results also revealed that grain yield had the highest coefficient of variation (CV= 21.6%), followed by spikes per m2 (CV= 20%) and number of grains per spike (CV= 18.9%). Lowest coefficient of variation was observed in days to maturity, days to 50% pollination and days to 50% flowering. Moreover, correlation analysis indicated that grain yield correlated with harvest index, biological yield, grain per spike and grain weight per spike. Cluster analysis of genotypes based on agronomic traits defined desirable clusters. These clusters have desirable characteristics and are beneficial for breeding objectives. Results of evaluation of consistency between choosing parents based on observation and those of cluster analysis showed varing degrees of consistency in 12 conducted crosses, ranging from highly similar parents in Eupoda6×Chahba88 to relatively distinct parents in PI40100×PI40099 cross.

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

Seven species of aphids belonging to the family Aphididae in six genera were collected and identified in wheat and barely fields in Sistan region (Miankangi, Shahraki-Narooi, Shibab and Markazi) during1999-2000. Among them, Schizaphis graminum (Wheat green aphid) was the dominant species with an abundance of about 85.4% in the area. The seasonal population changes of Schizaphis graminum were studied simultaneously in the fields of Sistan region (Zahak research station and its surrounding fields). The research was conducted in half a hectar of each farm. Thirty leaves from each field at weekly interval were randomly picked up and the aphids were collected and identified at the species level. The Schizaphis graminum had a peak of activity in the second half of March to April at the temperature and R.H. ranges of between 22-28ºC and %45-65R.H. respectively. The control conditions study (Incubator with 25±2ºC and %75±5R.H.) indicated that the Schizaphis graminum had a life cycle of 5-7 days and adult female longevity was 20-31 days. Rearing study also revealed that this species had ability to reproduce up to 18-98 nymphs in the laboratory condition (Cultural room with 20-25 ºC and 55±5R.H.) and an apterous female gave birth to 22-93 nymphs in her life. Samplings for recognition of predators and parasitoids were also done at 3-day intervals. Natural enemies in the fields during the two years were identified as consisting of six coccinellid (Col:Coccinellidae), ten syrphid (Dip:Syrphidae) and two chrysopid species (Neu: Chrysopidae). Also in Hymenoptera, five parasitoids (Hym:Aphidiidae) were determined.

Ascochyta blight caused by Ascochyta rabiei is one of the major diseases of chickpea (Cicer arientinum) in Iran. Many phytopathogenic microorganisms, incuding A .rabiei, attack their host plant by secreting pectic enzymes including polygalacturonase (PG) which causes modification of cell-wall structure, increasing accessibility of cell-wall components for degradation by other enzymes. Polygalacturonase is the major factor in the initiation of Ascochyta blight disease, therefore in this study, the enzyme was purified from a virulent isolate of A .rabiei (IK06). Fungi were cultured in PZ medium culture media were harvested and after dialysis used for purification. Purification was achieved by Carboxy Methyl Sepharose Fast Flow ion exchange column equilibrated to pH= 5.5. Zero to one molar NaCl gradient was used for elution of the proteins from the column. Determination of protein content and enzyme activity of each fraction showed that PG was eluted from the column in 0.3 to 0.4 M salt. The purity of the protein and the MW of the enzyme were determined using SDS-PAGE technique. The MW was found to be around 27 KDa. The activity of the purified protein was also evaluated using polyacrylamide gel containing pectin as substrate (zymogram gel). Optimum pH for the purified enzyme was 7.5.

The cottony Cushion Scale, Icerya purchasi Mask., is a polyphagous, cosmopolitan and destructive pest that infests more than 200 plant species apart from citrus. Laboratory studies were carried out on the orange at three temperatures, 17±1, 27±1 and 40±1°C 65±5% RH and 14:10 (L:D). The duration of nymphal stages, female longevity and the life cycle at 17±1°C were 85.8±3.83, 74.9±3.53 and 173.6±7.63 days and at 27±1°C were 62.6±4.40, 72.6±4.59 and 144.1±9.26 days, respectively. The duration of pupal stage and the life cycle of male at 27±1°C were 16.1±0.78 and 59.4±1.30 days, respectively. Field studies on the pest were conducted from July 2003 to September 2004 at Sharafabad region of Dezful. At 10-days intervals, five randomly selected orange trees in a citrus orchards (3ha) were sampled by taking 75 twigs, 15cm in length, at random. Number of eggs, nymphal stages and adults were recorded. From these observations I. purchasi had three generations in a year that were recorded as spring, summer and autumn-winter generation for I. purchasi. The autumn-winter generation developed in 6 months. I. purchasi overwinters as different developmental stages on different host plants with the 2nd nymphal stage was more abundant. Apart from different citrus cultivars, altogether 41 species of 22 different families of plants were recorded as the host plants of this scale in Khuzestan province.

To carry out this study, total DNA was extracted from eggs and from second stage juveniles of several populations of Meloidogyne javanica and Meloidogyne incognita, using phenol / chloroform method. Following extraction, DNA was electrophoresed on 1% agarose gel to determine its quality and quantity. A specific primer pair (C2F3 / 1108 23 and 20 nucleotides, respectively) was used to discriminate M. javanica from M. incognita populations using polymerase chain reaction (PCR). Primer annealing sites were located in the 3′ portion of mitochondrial gene encoding cytochrome oxidase subunit II (COII) and in the 16S rRNA gene. Following PCR amplification, electrophoresis of amplified DNA showed 1.7 kb fragment in populations of both species. Digestion of 1.7 kb amplified product with HinfI restriction endonuclease resulted in the generation of two DNA fragments of 0.7 and 1.0 kb in M. javanica and three DNA fragments of 0.3, 0.4 and 1.0 kb in M. incognita. There were no differences in the digestion patterns among various populations of each species examined.

Canola (Brassica napus) is one of the important oil seed crops cultivated in many parts of Iran. One of the main problems of seed production of canola is pollination and fertilization of flowers. Insects are the major pollinators. In order to study the fauna of insect pollinators of 3 cultivars of canola including Talaye, Okapi and S.L.M. and the difference between the attractiveness of these cultivars to insects during the flowering period, insects were collected by sweeping net and identified. Their abundance was determined at different periods of time during a day. Results showed that insect pollinators belonged to five orders and 18 families. The most abundant pollinators were Hymenopterous insects specialy honey bees (Apis mellifera) which were about 50%. Irrespective of Apis mellifera, the most abundant insects captured belonged to Diptera. Three Dipterous insects, Bibio hortulanus, Metasyrphus corollae and Platypalpus sp. were collected and identified. During the flowering period (March to mid April) in Isfahan, honey bees were more abundant in the warmer hours of the day, mostly noon and afternoon, but were less active in the early hours of the day, morning, because of cold weather and low nectar production. Honey bees were more active than other pollinators on Talaye at 9 a.m. and on Okapi at mid-day, noon, and during afternoon. Results also showed that insect pollinators could increase seed yield by 53%.

A dairy chocolate-flavored beverage was prepared using 55 % whey permeate and 45% whole milk. The beverage was sweetened by 3% date extract and 3% sugar. The blend was mixed with 0.7% cacao powder, 0.2 % caraginan, 0.15% vanilla , 3% skim milk powder, and 3% pasteurized cream(30%fat). Control sample was prepared by 100% whole milk without skim milk powder and cream. Both samples were heated up to 50 0C , blended by a mixer for 2 minutes, then pasteurized at 850C for 30 seconds and immediately cooled down to room temperature. Stability, pH, protein, total solids, fat and acceptability of the beverage and control samples were then evaluated. The new beverage had high acceptability.

Qualitative indices including moisture content (M), total lipid (TL), peroxide value (PV), free fatty acid (FFA), heme iron (HI), TBA, neutral lipid (NL) and phospholipid (PL) content were investigated on anchovy fish immediately after harvesting and during frozen storage at -18 and -30°C up to 8 months (2, 4, 6, 8). Profile of their fatty acid and any possible changes were also determined. Statistical analysis of the results showed significant increase of PV, FFA, NL and significant decrease of TL, HT, PL, poly unsaturated fatty acid (PUFA) and omega-3 at each temperature rate in relation to time of storage. Based on the statistical analysis, storing of the sample at -30°C had higher lipids quality. The principal component analysis (PCA) showed that HI can be grouped with important quality indices such as PUFA and omega-3.

An experiment was carried out to investigate the effects of different levels of energy (2700, 2900 and 3100 kcal/kg) and protein (13, 14.5 and 16 %) on laying performance of Fars native hens during the first phase of production. Two hundred and sixteen 25-week-old native pullets were put into fifty four groups of similar live weight (994 ± 169 gr) of four chickens, which were randomly allocated to nine experimental diets. Each treatment was replicated six times in factorial CRD design (3×3). At each level of energy, three diets were formulated to contain three levels of protein (16, 14.5 and 13%). The diets were fed ad libitum for a period of 20 weeks (week 25-45). The treatments 1 with 3100 kcal/kg ME and 16% protein and 3 with3100 kcal/kg ME and 13% protein had less daily feed consumption than treatment 7 with 2700 kcal/kg ME and 16% protein (90.50 and 87.30 vs 101.20 gr respectively, P<0.05). The effect of energy levels on daily feed and energy consumption and feed conversion ratio was significant (P< 0.05). Feed conversion ratio for energy level of 3100 kcal/kg was significantly different from 2700 kcal/kg (2.85 vs 3.08 respectively). The effect of protein levels on uric acid content of excreta and daily protein consumption was significant (P< 0.05) and protein level of 16% was significantly differed from protein level of 13% (11.40 vs 10.50 gr respectively). The results of this experiment showed that it is preferable to use the energy level of 2700 kcal/kg and protein level of 13% during the first phase of production of Fars native hens.

In order to assess and determine amino acids profile and their availability in different sorghum grain (SG) varieties, three SG varieties including low tannin (0.09% , LTS), medium tannin (0.19%, MTS) and high tannin (0.37%, HTS) were grown at the same location. The grains were analysed for their proximate analyses, tannin and amino acids. True amino acid availability (TAAA) was obtained by Sibbald’s method using ceacectomized single comb leghorn cockerels. The results showed that methionine and cystine were the first and the second limiting amino acids, respectively in LTS and MTS. But in HTS, lysine (0.166%) was the first and methionine (0.176%) was the second limiting amino acid. Methionine content was 0.114% , 0.182% and 0.176% for LTS, MTS and HTS, respectively. Although, crude protein was lower in HTS (10%) than the other SG, but histidine, methionine and isoleucine were higher for HTS in comparison to LTS and MTS. TAAA decreased when tannin content increased and all amino acids had a lower availability in HTS than LTS and MTS (P<0.05). Methionine in HTS and LTS and glutamic acid in MTS had the highest availability. The availability of proline was most affected by tannin, and its availability was 91.55% for LTS, 84.82% for MTS and 22.82% for HTS (P<0.05).

To study the effects of terbutaline (a beta adrenergic agonist) on performance of broiler chickens, 21 d-old male and female Cobb broiler chicks (n=300) were randomly assigned to one of five dietary treatments containing 0 (control), 5, 10, 15 and 20 mg terbutaline per kg diet. The feed conversion ratio (FCR), feed intake and body weight gain were measuered after 3 weeks. At 42-d age, six males and six females were randomly selected from each treatment and their live weight and weights of carcass, breast, breast muscle, drumsticks, drumstick muscle and abdominal fat were determined. Terbutaline didn’t affect daily weight gain, but FCR of male chicks was reduced for 5 and 10 mg/kg terbutaline treatments comapared with the control group (p<0.05). Carcass weight and weight of drumsticks, drumstick muscle, breast, breast muscle and ratio of breast to live weight of female chicks reciving 5 mg/kg terbutaline were higher than for other treatments (p<0.05). In male chicks, the live weight and weight of carcass, ratio of carcass to live weight, drumsticks and drumstick muscle at 5 mg/kg terbutaline treatment were higher than for other treatments (p<0.05). This experiment also showed that the addition of 5 mg terbotaline per kg diet during growing period improved FCR and ratio of carcass to live weight of male chicks, increased the ratio of breast to live weight of female chicks, and increased the carcass weight of male and female Cobb chicks.

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

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

Phenology is the study of time and sequence of recurring stages in the life history of an organism. The occurrence fashions of the phenophases form different phenological behavior patterns. Despite the importance of phenology and wide applications of knowing phenophases, few studies have been done on the wooden species in Iran. The goals of this study are identification and designation of the phenophases occuring time and their successions, phenological behavior patterns and finally phenological patterns assay of 35 fruitful and fruitless woody species in the northeast of Esfahan during 2003-2005. Leaves, flowers, fruits, buds, bark and color changes were observed weekly or every other week. Analysis of the obtained charts and tables shows that with respect to the environmental and climatic condition of the area, observed phenological behavior patterns are two- leaf, two-flower and two-fruit emergent patterns two-flower peak patterns three-fruit perpetuity patterns and three leaf shed patterns. Finally, there are three comparative successions, six-flower and three-leaf phenological patterns. Based on the findings, blooming and leaf shed calendars were also achieved.

Stress tests are commonly applied in shrimp hatcheries to estimate the quality of postlarvae to be used during growout. The highest larval survival rate during culture and in shrimp stress tests has been reported when specimens are offered a diet containing high levels of highly unsaturated fatty acids ( HUFA ) . Also vitamin C has positive effect to resistance and survival of larvae . In this study in postlarvae stage 1 in the salinity stress tests (10 and 20 ppt ) the highest survival rate was observed in treatment 3 ( 56.667 % and 90.00 % ) which was enriched with highly unsaturated fatty acids and vitamin C . As for the second, treatment 2 ( 43.333 % and 76.667 % ) which was solely enriched with highly unsaturated fatty acids showed significant differences at a level of ( P < 0.05 ) with treatment 3 . The difference between these two treatments and treatment 1( larvae fed rotifers cultured on Chlorella sp. ) and control ( larvae fed newly hatched Artemia nauplii ) was also significant . No significant difference was observed in formalin stress test ( 100 ppm ) in this stage between treatments 3 ( 86.667 % ) and 2 ( 80.00 % ) which shows the highest survival rate . But difference between them with treatment 1( 60.00 % ) which was unenriched and control ( 53.333 % ) was significant . Also, in postlarvae stage 5 in the salinity stress tests (10and20 ppt) the highest survival rate was observed in treatment 3 ( 56.667 % and 83.333 % ) and later treatment 2 ( 40.00 % and 70.00 % ) which showed significant difference . In this stage , the survival rate the treatment control ( 60.00 % and 86.667 % ) and treatment 3 showed no significant difference but they showed significant differences with treatment 1 and 2 .The lowest survival rate was observed in treatment 1( 26.667 % and 56.667 % ) . And the highest survival rate was observed in formalin stress test ( 100 ppm ) in this stage in treatments control , 3 and 2 ( 76.667 % , 73.333 % and 70.00 % ) among which there were no significant differences . However, the difference between these three treatments with treatment 1 ( 53.333 % ) was significant .