Journal of Agricultural Sciences and Natural Resources
Year:2005 | Volume:12 | Issue:1|Papers Count:17

In an airshed without stationary and mobile recording of index pollutants density and emission, air pollution potential hazard assessing with quantiative experimental models provide a valuable basic data for determination of industry allocation regulations and emission standards of air pollution in Golestan province, a widespread weighted numerical model was prepared with 44 bio-physico-chemical  effective parameters and implemented in the framework of 198 equi-poteial environmental units (a 44*198 matrix). This model according to the effect of each parameter upon air pollution, contains three groups of parameters including I-decreasing (8, indicator of environment refinery capacity), 2- increasing (31, indicator of environment pollution susceptibility), and 3-decreasing-increasing parameters (8,related to critical limits or specific standards). Weight of each parameter was determined according to its relative importance in air pollution potential and exceeding from ambient air standard in a-3 to +3 graded scale, and also rate of parameter class (2 to 5 class) was determined on the range and allowable limit of ambient air standard in a 1to 5 value scale. Total number or hazard index of air pollution in each environmental unit was calculated by multiplying of weight to rate of every parameter and sum of positive and negative values of all parameters, and finally divided to 5 classes. With implementation of model with different data sources, the potential hazard of air pollution in Golestan province evaluated and mapped as choropleth on a semi-detailed level at 1:250000 scale. Results show that the province contains all of the 5 hazard classes of the model, and there are significant differences (at P<0.01 level) between number (and area of the polygons of hazard classes). This numerical model has actually a necessary spatial and thematic resolution for planning of air quality management and control. So that, there are close spatial fitness between high hazard classes with densely populated and urban-industry concentrated area of foot hill belt, and low hazard classes with less populated and rural-agricultural areas of province. Therefore, it is possible to calibrate the regional model via systematic watching and monitoring of index pollutants in different part of the J province especially in the critical areas.    

In order to determine relationship between sperm density and fertilization rate in Persian sturgeon, different density of sperm have used. Results of first method showed that: with different densities of sperm 0.2, 0.5, 1 and 2 ml, rate of monospermic fertilization were 57.7, 58.4, 59 and 61.4% respectively, that there were no significance difference(P> 0.05), rate of polyspermic fertilization were 4.7, 10.3, 15.6 and 17.6%respectively. Results of second method showed that: with different densities of sperm 0.2, 0.5, 1 and 2 ml, rate of monospermic fertilization were 55.7, 52.9, 41.7 and 32.7% respectively, that there were significance difference between two first densities and others (P>0.05), rate of polyspermic fertilization were 2.8, 11, 29.5 and 30.9% respectively, that there were significance difference between two first densities and others (P>0.05). As mentioned above with increasing of sperm densities, rate of monospermic fertilization decreased and rate of polyspermic fertilization increased that it is related to presence of many micropi1eson the oocytes of sturgeons.  

The species richness and floristic composition in three vegetation types of Yakeh-Chanar winter rangeland at Golestan province were studied by surveying and collecting the flora and using the Whittaker' plots. The objectives of this study were to determine the effects of aspect, slope, and elevation on the species richness and floristic composition in three vegetation types. For analysis of species richness, group regression model was used. From stand point of biological types the following relations were obtained: Trophies> Chamaephytes> Hemi cryptophytes> Geophytes> Phanerophytes. From stand point of life forms the relations were Forbs>Grasses> Woody plants. The plant richness inequality of three vegetation types were Woodland> Grassland> Scrubland. The plant richness was usually higher in the north to compare to the south aspects. There were delays in phonological stages as the elevation increased, so when the plants were in vegetative stage at woodlands, the species of grassland were in the flowering stages and most species of the scrubland passed the stages of seed ripening and dissemination. In general, annuals and ephemerals dominated that is the characteristics of the areas with highly variable rainfall. When there is enough rain especially in spring, the seeds of many annuals germinate and species richness highly increases.  

In this research work the effects of pre storage treatments were studied on the quality, physical and chemical characteristics of Tompson orange at the end of a period of 3 months storage. The temperature for cold storge was 7ºC and for normal storge was 130º C. In this work eight treatments were applied on the fruits as follow; A; control (without any treatment), B; cold storge method C; washing orange with Moyan detergent, D; Washing with Moyan and then Tiabendazol as a fungicide, E; washing the oranges with Moyan and then dipped in 50 ppm Gibbereline, F, Using polyethylene bags with holes as a cover for oranges, G; Using polyethylene bags without holes, H; using a mixture of Tiabendazol and wax. The objective was to determine the best treatment to preserve the quality and reduce percentage of fruit. The variables were included; total solube solid (TSS), citric acid, vitamin C, percentage of decade, fruit quality and fruit firmness. All data were applied in a Mstat C software program. A split plot design was used to analyze data. Comparison of means was achieved based on Duncan test at 5 percent probability. Results showed that treatments of D and E were quite effective in reducing percent of orange decade. Treatments E and B were quite advantageous to preserve firmness, vitamin C and citric acid.  

Date is an important product in Iran that is produced about 980,000 metric tones per year. Different varieties of dates are different in appearance, chemical and organoleptic properties. The differentiations are mainly due to chemical composition of dates. In this study, chemical composition and energy content of three varieties of Mazafati, Shahani, and Halavi have been evaluated. The results obtained show that total solid, brix, energy and mineral content are different in these varieties(p<0.05). Mazafati Variety has the highest amount of total solid, brix and minerals. The sugar content is also different (P<0.01). It is highest in Mazafati variety as well. Highest rates of sucrose (S), lowest rates of reduced sugar (RS) and lowest ratio of RS/S are monitored in Halavi variety. In Mazafati variety, calcium, phosphorous, and iron have the highest values (P<0.05).    

In shis study, HPLC was used to determine the amount of glucose, fructose and sucrose content of sarieties of row potatoes, stored at zero (fresh), 1,2 and 3 months of periods at 4CºC. During the storage periods, the amount of these sugars, particular, glucose and fructose content of sarieties of Cosima, Draga and Folva were increased. At zero storage period, Cosima contained lowest amount of glucose and fructose but sucrose content of this same variety showed no significant (p>0.01) difference. Considering the results obtained in this experiment, no significant difference (p>0.01) in glucose and fructose were noticed between Folva and and Draga accordingly. But when Cosima variety compared to other two varieties, a significant diffrennce in the amount of glucose and fructose were noticed among them (p<0.01). The results of this experiment showed that Cosima is a desirable Variety for producible partially fried potato with attention to factoriale statistical test.  

Whenever good quality water is scarce, water of margiual quality, such as treated municipal wastewater, will be considered for using in agriculture. In this study, secondary treated municipal wastewater effluent of Isfahan Wastewater Treatment Plant is used to irrigate two varieties of potato (Morfona and Navita) in 2000-2001 cropping season. Five irrigation treatments including: furrow irrigation with well water (TI), drip irrigation with treated wastewater (T2), subsurface drip irrigation (at a depth of 15 cm) with treated wastewater (T3), subsurface drip irrigation (at a depth of 30 cm) with treated wastewater (T4) and furrow irrigation with treated wastewater (T5) were considered. Crop water requirement was determined by ET-HS model and some contamination indices were measured in irrigation water and potato tubers. The results showed that surface and subsurface drip irrigation has decreased soil pollution as compared to furrow irrigation. T3 had highest yield (46 tons per hectare for Marfona and 22.56 tons per hectare for Navita). Part of this increase in the yield over other treatments was attributed to better soil moisture and more available nitrogen. T3 had the highest water use efficiency, too. T1 and T4 treatments had the least microbiologic contamination.  

Since the world's population is increasing very fast, the need for agricultural products exceeds this rate. So cultivation of more land should be considered. On the other hand, the limitation of water resources is another problem which makes the optimum use of water and soil resources necessary. Therefore, the development of new irrigation networks makes the evaluation of performance factors so necessary. In this study, conveyance and distribution efficiencies in Gilan and Foumanat irrigation network (Fouman, Rasht and Lahidjan Regions) with various types and qualities of canals were determined. The first step was to choose a reach with about 1000 m length in each canal. Then the water flow rate was measured in the upstream and downstream of each reach with a current meter in different times of day during irrigation season. The results showed that average conveyance efficiency in lined canals with high and medium construction quality, unlined canals and the Noroud River with 1100m reach length was 90.9, 82.5, 77.2 and 69.9%, respectively. The average distribution efficiency in first order lined canals, first order unlined canals, second order unlined canals and second order flumes with a reach length equal to 700 m was 85.1, 67.9, 63.9 and 91.5%, respectively.  

Large hydraulic structures such as dams are designed on extreme situations basis. Probable maximum precipitation (PMP) is one of the most important criteria in this regard. Synoptic methods are considered to be the more desirable ones to calculate PMP. In spite of its accuracy, relying on huge and not readily data is the main obstacle in extensively applying the method. To overcome this problem, a number of statistical methods that use only maximum precipitation have been developed, though the precision is reduced. An effort to compare these methods and assess the accuracy of the statistical methods in the eastern part of Hormozgan province has been introduced in this paper. The convergence synoptic method and Hirschfield statistical methods (methods one and two) have been used for the evaluations. The results show that the Hirschfield's second method estimates PMP close to the synoptic estimations, after omitting the outliers.  

The proposed Irrigation Performance Assessment Module has been developed using Irrigation performance indicators of Irrigation system, for different irrigation system conditions and objectives, and conducted for different levels of assessment with limited parameters. An internal-comparative standard has been developed for interaction-influence of indicators. Defined linguistic-expression indicators has been developed the combined qualitative-quantitative model to use "subjective" and "objective" judgment of water users and experts on system "productivity" and "convenience", respectively. The model was tested by Standard method in Ghazvin Irrigation system. The F-TEST for comparison between Mamdani fuzzy Product and Minimum inference is 98%, and correlation coefficient is 0.99. These results indicated that, the selection of fuzzy Product or Minimum inference is not important in this model. Results of comparison to Standard method indicated that product combination gives the better result. The separation of initial condition, process, effect and result of performance is indicated that, 12% of performance deficit is subjected to initial condition of the system. Management Delivery Performance measures from water users and irrigation water supply agency's judgments in this pilot were 39% and 58%, respectively. The results demonstrated that, unfavorite physical and natural conditions are not the main problems of the system. But difference between actual water users needs and insufficient plan of water delivery, is the main problem of the system. Assessment of Irrigation system with this model is more applicable with limited requirement data, and it can be easily adapted and programmed on different Agricultural and Natural Resource management systems.  

A detailed description of the behavior of cohesive fine-grained sediments is a very complicated task. Simulation of cohesive sediment movement has been successfully treated in the past using the macroscopic properties of the water-sediment system. In this study, a 1-Dimensional equation of cohesive sediment has been proposed for deposition term of mass transfer equation. This equation has been solved by Control Volume method and calibrated with laboratory data. The tests have been done in a flume with 0.3m diameter, the slope 0.00008, dischange between 6~12 liter per second and the concentration of 4~7 gram per liter. The model shows that the deposition is a function of flow concentration, flow depth and rate of bottom shear stress to threshold shear stress of deposition.  

In order to identify the nematodes (order: Tylenchida) in wheat fields, 54 soil, root and ear samples were collected from different localities of Isfahan province. The nematodes were extracted by centrifugal flotation technique. Then they were fixed according to the De grisse method. Investigation of specimens revealed 17 species belonging to 12genera of order Tylenchida. Thegenera Geocenamus, Helicotylenchus and Pratylenchus have been most frequently observed nematodes, respectively.Two species Seinura demani and Tylenchorhynchus teeni are first species records for Iran. Because of importance and lack description, morphological and morphometrical information and drawing for each species with description of Heterodera filipjevi are discussed.  

In this study the effects of pH and temperature on antagonistic activity of the fungus Trichoderma koningii (KR7) from Gorgan area (Agh-ghaleh) were compared with two species of Fusarium causal agents of wheat head-blight disease. This T.koningii had significantly the most growth rate at 25°C and pH 4.5. The growth rate was more in all tested temperatures (20, 25 and 30°C) with pH 4.5, than two others pH 5.5 and 6.5. Reduction of pH resulted in an increase in the sporulation of T.koningii, but, Fusarium graminearum and F. culmorum were associated with growth reduction more at 30°C. Optimum growth for two species of Fusarium was 25°C. After 48h F.culmorum produced high level of macroconidia on PDA whereas, none with F.graminearum. Growth rate of T.koningii was significantly more than two Fusarium species in dual cultures. Phenomena of mycoparasitism and colonisation of T.koningii on Fusarium hyphae was associated with coiling around hyphae in various experimental conditions, observed by light microscope. T.koningii fungus produced green conidia and chlamydospore after 48h, in dual and single culture.  

Ginkgo biloba one of the primary gymnosperms is important in term of ornamental and medicinal usage because of its Ginkgolide and Flavonoid contents. Earlier research embryo has tended to emphasize specific use of embryo to obtain explants. Three experiments was conducted to determine the kinde of hormones and their proper concentrations on growth potential of mature Ginkgo biloba explants (single node). In first experiment, a combination of two hormones of BA (0.0, 0.05, 5.4, 16.1 µM) and NAA (0.0, 0.05, 5.4 16.1, 26.1, 37.6 µM), were cultured on Murashige and Skoog medium. The result showed that the 0.05 µM concentration could increase the explants growth in both hormones. In second experiment, different hormones (IAA, IBA, NAA, 2, 4-D, BA, 2ip, BPA, Zeatin) separately or as combination with obtained proper concentration in first experiment (0.05 µM) was used. The results showed that two hormones of Zeatin and IBA had best results on growth of explants. Third experiment was conducted to find the best concentration of Zeatin (0.01, 0.05, 0.25, 1.25. 2.5 µM) and IBA (0.002,0.01,0.05,0.25 µM)obtained hormones in second experiment. It was concluded that Zeatin and IBA with 0.25 and 0.01 µM had proper growth of shoots and leaves respectively.  

This paper estimated annual changes of soil components and value of it with using of survey data from soil. Results of this study showed that with increasing of slope and soil depth, annual amount of decreasing of soil components have increased and decreased, respectively. Value of soil components under vertical plow management is less than of parallel plow. Average value of soil components is equal to 174511 rials per hectar. With considering of chemical fertilizer for compensation of loss fertility, value of soil components is equal to 204411 rials per hectare. With regards to this results, determination of fertilizer regime based on plow management, slope, depth and texture of soil, attention to economic effects of erosion on poverty of soil especially on drainage land, payment subsidy to soil conservation practices, transition from annual cultivation system and extension of soil conservation programs as suggestion has introduced.