JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2009 | Volume:18 | Issue:4|Papers Count:27

Every year due to river floods a great number of river structures such as bridge piers are collapsed. The most important reason for failure of bridge piers is the occurrence of scour phenomenon at the bottom of these structures. One method of scour countermeasure is to set a protective device (i.e. collar) around bridge pier. Collars protect efficiently the riverbed against vortices system around pier and reduce scouring. In this research, the performance of series of rectangular collars with different size ratio (i.e. W/D =1.5, 2, 2.5) which seated horizontally in different elevations (Yc/D=- 0.2, 0, 0.2) in respect to bed level were investigated. Experiments carried out under clear-water condition and the results were compared with pier without collar and pier with circular collar. The results showed that the collar resting on and below the bed level have better efficiency compared with the collar resting above the bed level. As the width of collar increased, the performance of collar as a scour countermeasure also increased. Collars with size ratio (W/D) of 1.5,2 and 2.5 reduced scouring 14,29 and 49 percent respectively. The results also indicated that performance of rectangular collar in reducing scour depth and increasing equilibrium time is better than circular one.

The aim of this study was investigate the effects of tariff reduction on vegetable oils such as soybean, sunflower and castor oils. The data was collected from foreign trade statistics year book of Islamic Republic of Iran, Central Bank of Islamic Republic of Iran, PDS statistical collection and export and import regulations and its appendix tables during different years for the period of 1360-83. The results show that castor oil is the most sensitive oil to tariff rate changes. Because castor oil is mainly imported by private sector or government intervention on its market is lower. In addition castor oils tariff rate is rather high and is six times more than soybean and sunflower oils tariff rate. So the reduction of tariff rates in order to trade liberalization, will affect castor oils import more than others.

Water is one of the most important and limited inputs in agricultural sector in Iran. The scarcity of water in our country requires farmers to use water more efficiently. For this purpose, one of the possible approaches is to use water saving systems like sprinkler systems irrigation. The various climatic and structural conditions in different areas of our country have led to the execution, investment and development of water saving systems which depend on different economic and managerial factors. Therefore, the aim of present study was to investigate some important economic and management factors which have influence on willing to investment on sprinkler irrigation systems by farmers in Bukan Iran. To study the impact of economic and management variables (such as farm size, farmer's income, number of land plots, water source type, crop type, farmer's age, education, participation in extension courses and number of farmer's household members that do agriculture operations) in willing to investment on sprinkler irrigation systems, the, logit model was used. After model estimation, the marginal effect of independent variables was calculated. A portion of required data for calculation and model estimation were collected from some documents and reports of related organizations while the other information gathered by filling questionnaires by farmers. Overall results showed that type of water source, ownership of land type and participation in extension courses had the highest marginal effect on independent variables by 9.9, 7.9, 6.3 percent change in the probability of willing to investment, respectively.

Higher education progress has an important role in development. Agricultural education has very significant role in agricultural growth and also, achievement to holistic and sustainable development depends on existence of enough educated manpower. In spite of reaching achievements and with paying attention to country's situation, it should confess that agricultural higher education system has been facing many challenges and dilemmas in Iran's present situation including: graduate's unemployment, lack enough awareness of students about agricultural academic major's importance and function, lack of effective interaction between educational departments and farmers and low quality of instructional methods, lack of students tendency especially the elite's, toward agricultural majors and so on. The main purpose of this study was the investigation of agricultural higher education system's situation and identification of its main problems and challenges from view point of students. The study used a descriptive survey method. The statistical population was 550 students who were at bachelor level in different agriculture majors at Ramin Agriculture and Natural Resources University. This study was carried out through random sampling method and at first sample size was determined as 70 respondents using Cochran's formula and then it was increased to 100 due to specialist's advice in this regard. Totally, 92 questionnaires filled by students and for analyzing data, SPSSwin software was used. Data analysis revealed that 55.3 percent of students had inadequate information about their majors when they had chosen them and only 10.6 percent of students had enough information in this regard. Also, only 10.1 percent of them believed that the agricultural student's selection system is appropriate. According to the findings, 86.8 percent of students believed that their contact with farmers was low. On the bais of analysis of variance, there was significant difference between students who had high awareness of their majors and students who had the low awareness in terms of their motivation when they had chosen their majors.

Electrokinetic soil remediation is an innovative method for decontamination of heavy metals from polluted soils. In this research a clayey soil spiked with Zn at the concentration of 350 mg/kg used to investigate electrokinetic remediation at pilot-scale with different treatments. Nitric acid (0.1 M), acetic acid (0.1 M), EDTA (0.01 M) and deionized water (at the two different applied initial electrical current densities. 30 and 150 mA) were used as the experimented treatments. All treatments were imposed with a constant voltage gradient of 1 V/cm for 120 hours. Among these treatments. EDTA showed the highest Zn removal efficiency (more than 55%); maximum percent of local In removal along the column reached to 74%. Nitric acid and acetic acid produced similar results; mean Zn removal percentage became about 15%. Efficiency of electrokinetic remediation increased about 12% and reached to 20% by increasing current density from 30 to 150 mA. Further. the changes in pH along the soil columns after the experiment run (120 hours). showed an increasing trend from anode to cathode.

In order to determine the Fe critical value in soils of West Azarbaijan, East Azarbaijan, Kurdestan and Kermanshah dry land areas, this study was conducted in randomized complete block design with four treatments (0, 5, 10 and 15 kg.ha-1 from iron chelate (NaFeEDDHA)) with three replications for four years (1998-2002). Then, the crop and soil data uniformity test were completed for experimental sites. The results of the experiments were interpretated by different soil testing interpretation methods as Cate- Nelson graphical, Cate- Nelson two and three classes ANOVA models, Mitcherlich equation, plant response column order procedure and interaction chi-square methods. The results showed that Fe critical value by the above mentioned methods were 5.2, 8.5, 9.5, 8.7 5.5 and 4.7 mg.kg-1 respectively. Regarding nutrients absorbtion limitation in dryland condition, and significant plant response for Fe fertilizer application of 6.5 mg Fe.kg-1 in soiL final critical value by averaging of Cate-Nelson two and three classes ANOV A models and Mitshcherlich equation defined 8.9 mg.kg-1 for dryland wheat in North West of Iran. It can be concluded that soil testing interpratation methods could affect the Fe critical value. Therefore, from different soil testing interpratation mehtods, Cate-Nelson two and three classes ANOV A models, and Mitshcherlich equation can be recommended for determination of Fe critical value for dryland wheat in North West of Iran.

An experiment was carried out in the Experimental Field of Faculty of Agriculture, University of Urmia during 2003 and 2004 growing season. The type of design was randomized complete block design in factorial arrangement and three replications. The main goal was to assess the effects of irrigation and plant density on yield of German chamomile. Irrigation had four levels (irrigation at 25, 50, 75 and 100 mm evaporation from evaporation pan class A) and plant density of German chamomile cv. Bodegold was 30 em inter-row spacing with five levels of intra-row spacing (5, 10, 15, 20 and 25 cm corresponding to 66.67, 33.33, 22.22, 16.67 and 13.33 plants per meter square, respectively). The highest number of flowers per plant was obtained from irrigation on 50 mm evaporation and 20 cm intra-row spacing. The highest number of flowers per hectare was obserred from irrigation on 50 mm evaporation and 10 cm intra-row spacing. The highest flower weight resulted from irrigation at 100 mm evaporation and 10 cm intra-row spacing. However, the highest yield of dried flower and the highest rate of water use efficiency belonged to irrigation on 50 mm evaporation and 10 cm intra-row spacing.

Crops that control weeds by allelochemicals are receiving increased attention. Allelochemical concentration and allelopathic interactions are affected by invironmental stress conditions. It has been demonstrated that phenolic compounds are involved in wheat allelopathic potential. The present study was conducted to investigated the effect of salt stress (0, 50, 150 and 200mM NaCl) on phenolic compounds of three cultivars of Triticum aestivum (Pastor, Tagan and Zagros) and T durum (cv Aria). The results indicated that phenolic compounds rate in both of roots and leaves decreased as the concentration of salt increased to 100 mM with the exception of Arya cv. and there was increased phenolic compounds level up to 200 mM NaCl except of Tagan cv. Leaf and root alcoholic extracts analyzed by TLC. TLC chromatogram showed the number of phenolic compounds increased with Increasing phenolic compounds. In general salt stress change phenolic quality and quantity and may be increase allelopathic potential of wheat.

In order to determine the genotype × enviromnent (GE) interaction and yield stability, eight treatments including seven promising rice lines and one check (Khazar) were evaluated during 2000-2003. A randomized complete block design was used with four replications in three locations (Rasht. Hashtpar and Rudsar) of Guilan province. Separate analysis of variance for grain yield showed highly significant differences among the genotypes. Combined analysis of variance showed significant differences among genotypes and locations. The interactions of cultivar × location and cultivar × year were not significant. The interactions of year × location and year × location × cultivar were significant, that proved the existence of GE interaction. The stability was evaluated through nine different methods including: Wricke's equivalence (Wi2), stability variance (si2), coefficient of regression of mean yield on environmental index (bi), variance of deviation from regression line (S2di),variance (S2i) and coefficient of variability (CVi), of environments within location variance (msy/p), within location coefficient of variance (CVy/p) and Ranking (R-, S.D.R). The results showed that Lines No.829, 830, 831 and 833 were stable. Line No.831 was most stable with less S2di, Wi2, si2, R-, S.D.R and abi near to unity. line No. 830 also was the most stable one with less S2i, CVi, msy/p and CVy/p. In addition Lines No. 830 and 831 yielded 5 - 5.5 t ha-1, significantly more than Khazar (improved check).The above genotypes were aromatic rice having high resistance to blast. Consequently, these two lines were selected to release as new stable varieties for Guilan province because of having other desired morphological and grain quality traits.

In order to accelerate of harvesting time of rapeseed crop, to free the farm for rice transplanting and to prevent yield reduction due to grain shattering after physiological maturity, the effect of pre-harvest chemical desiccants application on grain moisture reduction, grain yield and oil content of rapeseed were evaluated in a completely randomized block design experiment with 3 replications in a paddy field at Rice Research Institute of Iran, during cropping season of 2004-2005. The effects of Three desiccants each in three rates including: a) glyphosate (1.64, 2.46 and 3.28 L. ai/ha), b), paraquat (004, 0.8 and 1.2 L. ai/ha), c) sodium chlorate (4, 5 and 6 kg/ha) and un sprayed check plot were evaluated on Hayola 308 rapeseed. Results sowed that the effect of desiccants on grain moisture reduction rate, yield and oil content were significant. The upper rates of paraquat and sodium chlorate promoted harvesting time 11 days earlier than control. The other rates of paraquat and sodium chlorate by 10 days of acceleration on harvesting time located in next score. The glyphosate rates promoted the harvest time 9, 9, and 5 days earlier than the control, respectively. In contrast, paraquate with 0.8 and 1.2 L. ai/ha had the lowest yield (1735.3, 1784 kg/ha, respectively) but did not show significant differences with control. The highest rate of oil content (40.48%) obtained by the maximum rate of glyphosate and the highest rate of sodium chlorate produced the lowest oil content (35.3%) and the other treatments did not have significant differences with control (36.9%). In regard to no any adverse effects on grain yield and oil content of rapeseed, it seems that all pre-harvest desiccants promoted harvesting time by 9-11 days, with the exception of 1.64 L. ai/ha of glyphosate (with desiccation effect in 5 days), could be considered as beneficial desiccants. The application of 1.2 L. ai/ha of paraquat and 6 kg/ha sodium chlorate could be reliably been applied as rapeseed crop desiccants in the north climatic conditions of Iran.

This experiment was conducted to determine the most suitable condition for increasing the storage life of seed potato. In this experiment, 10 tons from four potato cultivars (Kozima, Dezira, Pervento and Marfona) harvested in Sep. 2003 were placed in 28×33×52 cm woody boxes. After curing, they were stored in a cold room (4oC and 85-90% RH) and also in a semi-technical room (4oC and 85-90% RH) for six months. All experiments for measuring weight loss, total sduble solids (TSS), solanin absorption and starch percent were carried out three times everyone month. Solanin absorption and starch percent were less in cold room than semi-technical room. The loss of weight in semi-technical room was higher than the cold room. The percentage of starch in Pervento and Marfona was higher than other potato cultivars. In the cold room, the lowest solanin absorption belonged to Kozioma cultivar. Solanin absorption increased during storage more in cold room than the semi-technical room. The highest TSS was observed mainly in samples after five of six monthes of storage.

An experiment was conducted usmg randomized complete block design (RCBD) with three replications to evaluate the effect of post-pollination water deficit and nitrogen fertilizer on yield, yield components and grain protein of barley (var. Valfajr) at the Agricultural Research Station of University of Tabriz in 2005. The treatments were a factorial combination of four levels of irrigation (1-weekly irrigation after pollination, as a control (I1), 2- one irrigation 10 days after pollination (I2), 3- one irrigation 20 days after pollination (I3), and 4- no irrigation after pollination (I4), and four levels of nitrogen using urea (N1=0, N2=40, N3=80, and N4=120 kgN.ha-1). Nitrogen was applied before pollination equally at the tillering, stem elongation, and heading stages. The results indicated that with increasing nitrogen applications, the grain yield, grain protein percentage and protein yield were increased. With increasing post-pollination irrigation intervals the grain yield was decreased however protein percentage was increased and the protein yield remained unchanged. N fertilizer treatments significantly affected the grain number per spike in main stern, spike number per plant spike number per m2 and main stern spike length. The effect of water shortage on grain number per spike of main stern, 1000-kernal weight, the grain yield, and grain protein percentage was also significant. There was no significant interaction between nitrogen and Irrigation levels for any of the studied characteristics. Since there was no significant difference between the application of 80 and 120 kgN.ha-1 for most studied characteristics, except grain protein percentage and grain protein yield, therefore use of 80 kgN.ha-1 seems be suitable to produce an optimum yield at the conditions of this experiment. In addition, because there was no significant difference between the first and second levels of irrigation, only one irrigation at the beginning of pollination stage will be sufficient.

A study was carried out to determine the genetic diversity of Raeini Cashmere goat, using eight micro satellite markers. A number of whole blood samples were randomly collected from 120 individual goats (male and female). Genomic DNA was isolated using a salting-out method with some modifications. All of the loci concerned and they showed polymorphism between 6-12 alleles. Five studied loci (LSCV11 OraFCB20, ILSTS059, IL2RA, ILSTS034) were at Hardy- Weinberg disequilibriwn (P<0.05). Heterozygosity varied from 0.7607 for IL2RA to 0.8766 for OraFCB20 locus. Within eight polymorphic loci, these two loci had the lowest and the highest diversity, respectively. The study of Shannon index and PIC (Polymorphic Information Content) also indicated the lowest and the highest diversity for IL2RA and OraFCB20 loci, respectively. Average heterozygosity was estimated as 0.80 for this population. It could be concluded that Raeini Cashmere goat has high genetic diversity.

Polymorphism of CAST gene was investigated with 200 purebred Ghezel sheep which were randomly collected from Ghezel breeding station of Myandoab. After extracting of genomic DNA, exon 1 of calpastatin gene with 622 bp was amplified with specific primers. The SSCP technique was used for detecting the PCR products using polyacrilamid gel and silver staining method. In this research three alleles were observed having the frequencies of 0.62, 0.35 and 0.03, respectively. Comparison of allele frequencies indicated that Ghezel population was not in Hardy-Weinberg equilibrium. Average heterozygosity for Ghezel sheep was 37%. The result 'also indicated that genotype had a significant effect on daily gain from birth to six month's weight (P£0.05). Therefore, the results confirmed that polymorphism at this gene can be a useful tool for selection programs based on marker-assisted selection.

Microcerotermes diversus (Silvestri) is the most economically destructive termite in structures in Ahwaz, because the species consume on anything with cellulose. One tactic for the control of subterranean termites is the use of a slow-acting toxicant in a bait. In the laboratory assays described here, the delayed toxicity of borax (disodium tetraborate decahydrate) to M diversus was evaluated under two-choice and no-choice conditions. A probit analysis of the data using time instead of dosage indicated that the level of mortality and the speed of death were dependent on concentration. An inverse relationship between time mortality (LT50 and LT90) and concentration was observed. Althogh total filter paper consumption after exposure to a range of concentrations of borax (0.2%-2%) was significantly less than that associated with water-only exposure, but feeding inhibitory effect was not observed. These assays suggest that the concentration of 1.8% could be applicable in bait formulation. A new bait matrix synthesized with nitrogenous compounds and food additives increased the consumption rate of borax and as a consequence LT90 decreased to suitable time period (14-day span). Borax-treated bait exhibited a much lower LT50 than borax-only treatment which is necessary for increasing efficacy of baiting procedure in field conditions. Collectively, these results indicated that borax bait is effective for controlling M. diversus and baiting tactic presents a solution for protecting structures from termite attack in Ahwaz.

Nine species of the family Belonolaimidae were isolated and identified from collected soil samples of lucerne farms in East-Azarbaijan province during 2004-2006. The species were including Amplimerlinius macrurus (Goodey, 1932) Siddiqi, 1976, Geocenamus brevidense (Allen, 1955) Brzeski, 1991, G. nanus (Allen, 1955) Brzeski, 1991, G. pseudobavaricus (Saltukoglu, Geraert & Coomans, 1976) Brzeski, 1991, G. rugosus (Siddiqi, 1963) Brzeski, 1991, Tylenchorhynchus brevilineatus Williams, 1960, T hordei Khan 1972, T. maximus Allen, 1955 and T. usmanensis Khruma & Mahajan, 1987. The species of G. pseudobavaricus, Tylenchorhynchus brevilineatus, T. hordei and T. usmanensis are new records for nematode fauna of Iran. Herein the latter species are described.

Previous study had been shown that 75o ethanol inhibited the salivary a-amylase activity of the stripped bug Graphosoma lineatum. For better understanding of the effects of ethanol on the enzyme activity, probable effects of absolute, 96o, 85o, 75o, 50o and 25o alcoholic solutions were tested during 90 minutes incubation. Distilled water was considered as the control. Effects of incubation period on enzyme activity was significant (P<0.01), except for 25o ethanol and distilled water. After 10 minutes of incubation, enzyme activities increased in absolute, 96o and 85o ethanol (102.04, 96.33 and 100.51 U/mg protein, respectively) as compared to the control (77 U/mg protein) so that absolute alcohol showed an increase (up to 117.34 U/mg protein) until 30 minutes after incubation. Enzymes activities in absolute, 96o and 85o ethanol after 40, 30 and 20 minutes incubation, respectively, became less than the control. After 90 minutes of incubation, enzyme activities in absolute and 96o ethanol decreased down to 20% and 10% of their primary values. The highest inhibition of enzyme was caused by 75o ethanol, so that at the beginning of the experiment its activity was about half of the control (50% inhibition). Finally, at the end of 90 minutes of incubation it got the lowest observed values (2.04 U/mg protein) in the experiment (nearly 97% inhibition). In 50o ethanol, enzyme activity at the beginning of the experiment (65.82 U/mg protein) was significantly less than the control, but its activity at the end of the experiment (36.22 U/mg protein) was considerably greater than that in absolute, 96o, 85" and 75o ethanol (18.37, 17.35, 8.67 and 2.04 U/mg protein, respectively) and showed significant differences. Enzyme activity in 25o ethanol (73 U/mg protein) was less than that the control, but remained constant during the 90 minutes of incubation and showed no significant difference with the control. Enzyme activity in the control was also constant during the incubation period.

Mechanized planting is the first step in mechanization of different stages of agricultural crops planting and processing. In order to evaluation different planter parameters for mechanized Canola planting, this project was conducted. Experimental treatments consisted of: Planting method with grass seeder, planting method with seed drill without cover, planting with ordinary seed drill, pneumatic planter with special press wheel, pneumatic planter with oblique press wheel. The workshop tests were conducted upon the metering system of the pneumatic planter as well as seed drill at four different forward speeds. The results indicated that metering systems of the two machines were dependent on forward speed. Field tests were conducted using randomized complete block design. The number of plants per unit area for five treatments and planting depth for seed drill treatments and pneumatic planter treatments, were significantly affected by planting methods. Field test observation indicated the equidistant distribution of seeds with the pneumatic planter treatments and optimized planting depth with the seed drill without covering mechanism.

The existing mowers are not suitable for drylands, steep and small scale irrigated farmlands. The numbers of existing combines in the Iranian market are not enough to fulfill the demands. However, they could work satisfactory in the flat areas. Therefore, for supplying the need for harvesting machine, especially mower for dry lands, one must think of its improving and developing as well. As the result, front mounted mower-swather was improved and modified. Two important factors forward velocity and feed rate in the front mounted mower-swather and BCS mower binder were evaluated in a factorial experiment based on a randomized complete block design with three replications. working-place showed the appropriateness of driving system, rotating parts, control system of flotation and height adjustment of the front mounted mower-swather performance. Field-test, front mounted mower-swather and BCS mower binder in Khozestan and Lorestan provinces. Field capacity in front mounted mower-swather was 1.7 the times more than BCS mower binder. The front mounted mower-swather performed well in slope, stony and drylands and small fields. This device was more economical than combine and can be recommended for small size dryland fields.

Apple pomace is a by product that is annually produced in fruit juice production units in large quantity. If it is dried, it can be used for different products such as pectin. A prototype rotary dryer with a capacity of 10 Kg per hour was constructed and evaluated, Based on heat transfer models, the dimensions of dryer, ie. the diameter of 0,325 m and the length of 4.5m, were calculated. Laboratory tests indicated that a reduction of 12% moisture content (from initial moisture content of 78%) can be achieved at air velocity of 1.5m/s with the drum slope of 0o (completely level) at 3 r.p.m. Three types of flights, with angles of 0o, 45o and 90o were compared by image processing. In conclusion, the flight with an angle of 45° had the best result.

High quality image acquision is the first and the most important step in machine vision applications. The. image of an object, as captured by a machine vision system, is not only a function of the spectral properties of the object surface, but also is a function of the illumination spectral distribution and the camera's spectral response. On the other hand, poor illumination may creat shallows that cuase mistakes in image processing. Uniform illumination is important for contrasting between background and object. The objective of this study was to evaluate four types of light sources, namely halogen, fluorescent, LED and incandescent lamps in the following variables such as sensitivity to lamp voltage variations and uniformity over the field of view of the camera. Based on LSR test, the best voltage in which RGB values have the least differences was selected for each type of light sources. The best voltage for LED and Flourescent were 10V and 130V respectively. Then based on t-test, LED and Flourescent sources were compared for the uniformity of FOV. Since the variance of LED was lower than Flourescent source, so according to statistical analyses, the LED light source was selected to have the best results.