JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2008 | Volume:18 | Issue:1|Papers Count:22

Fast spreading of using artificial neural networks (ANNs), black box and qualified models, in different sciences such as hydrology shows its studying necessity and values. The most important applications of the model in hydrology are water quality modeling and prediction, optimization, classification, estimation of hydrological phenomena and parameters. The aim of this paper was to provide application of artificial neural networks, empirical equation of ascertaining hidden nodes and discussing their strengths and limitations for presenting rainfall artificial neural network forecasting model of Tabriz plain area. In this modeling six different structures of ANNs were used in which the feed forward network with six input nodes and a hidden layer composed the best model. This model was used for showing the effects of learning sample and hidden nodes numbers on minimizing of the model error.

In the present research the transformation of rainfall into runoff was simulated using two-dimensional Saint-Venant equations in the Kamanaj watershed, a subwatershed of Ajichay, located in East Azarbaijan Province, Iran. Rainfall-runoff was simulated based on diffusive model by consideration of momentary infiltration rate for temporal and spatial analysis. Saint-Venant equations were solved using explicit method of finite difference numerical technique as the initial and boundary conditions were defined. For this purpose, the watershed area was divided into 250×250 meters cell size grid by the tools of GIS, then digital elevation model was prepared. Kostiokov infiltration model, as the best fitted model to measured infiltration data was selected for expression of infiltration in Saint-Venant equations. Three hydrographs were used to verify the model. In the calibration of the model, lower relative average error of discharge was equal to %9.4. Comparing the simulated hydrographs to those observed, verificated the capability of model in simulation of rainfall-runoff. The presented model can be used for determination of runoff from momentary rainfall with consideration of temporal and spatial variation of infiltration over the watersheds. This model can also be used to forecast the peak discharge and time to peak in the watershed outlet.

An experiment was carried out for the investigation of the effects of different concentrations of the modified Hoagland's nutrient solution on vegetative characteristics, essential oil content and yield of costmary based on randomized complete block design with six replications. The treatments consisted of 1X (The complete modified Hoagland's solution) and 0.25X, 0.5X and 2X, in which the concentration of macronutrients were increased or decreased by a constant ratio. Essential oil hydrodistillation of dried leaves (medicinal organ of plant) was carried out by Clevenger type apparatus. Essential oil yield was calculated in milliliter per square meter based on the related essential oil content. Results showed that the highest essential oil content and yield were obtained in the lowest level of nutrient solution concentration (0.25X). Essential oil yield in 0.25X treatment was 3.7 percent higher than that of 1X treatment. Fresh and dry weight of leaves and aerial parts were the highest in 1X treatment. There was a significant difference between treatments for total fresh weight, and the greatest amount was observed in 0.5X treatment. There were significant differences between treatments for leaf area and the lowest leaf area was achieved with 2X treatment. Total net photosynthesis of plants was affected significantly by treatments and higher rate was recorded for 1X treatment. Finally, since the 0.25X treatment showed the highest essential oil content and yield, and considering costmary as an essential oil source, it can be concluded that costmary is a low nutrient demand plant which can produce the highest essential oil yield using low concentrations of the nutrient solutions.

In the present work, various extraction procedures including extraction with water and subsequently with chloroform, continuous extraction with chloroform, methanol and acetone were tested for the extraction of physalins from Physalis alkekengy grown in Eastesn Azarbayjan (Kaleibar). It was found that continuous extraction with acetone gives the best results in terms of amount of crude extract. After the preparative extraction, primary separation was carried out by column chromatography using silica gel as stationary phase and ethyl acetate: benzene (7:3) as solvent. In the second step, after choosing suitable solvent systems, the mixtures of physalins from previous step were separated by column and thin layer chromatography. Finally, physalins F and D together with a new compound were identified by using several spectroscopic techniques such as NMR, FT-IR and UV spectroscopy. An appropriate chemical structure based on the spectroscopic data proposed for the new compound.

The present study investigates the influence of different methods of canopy management on cut rose yield with respect to marketable quality, and compares it with the traditional system. Experiment was based on a randomized complete block design with three replications and was performed in a greenhouse in the vicinity of Tehran during one year. Treatments included types of pruning or bending of primary stem in combination with several harvesting heights. Measurement of developmental stage and growth variables (time to bud sprout, development time from bud sprout to harvest, length, diameter, fresh and dry weight of harvested flowers) was performed through the growth cycles. Results showed that the plants experiencing higher cut position yield 30% and 18% more flowers than the traditional system and the treatments in which the primary stem was pruned or bent at the base, respectively. Extra stems percentage was higher in the treatments with bending shoots when compared with pruned shoots in the traditional method (40% vs. 15%). There were no significant differences among all the treatments for grade 1, 2, and 3 flowers. Orthogonal comparison of treatment group 3 (bending primary stem above 3 buds) with treatment group 5 (bending primary stem above 5 buds) indicated that the number of days needed to bud sprout was higher in group 3 than in group 5. Number of the leaves and length of the stem left under the bending or pruning height may account for the observed results.

In this study, inheritance pattern of plant height, pods and seeds/plant, seed yield/plant of chickpea and combining abilities were assessed by evaluating the six lines and their crosses (half-diallel) in a randomaized complete block design with three replications at the Agricultural Research Station, Sarabchangaei, Khoramabad during the growing season of 2002-2003. Analysis of variance indicated that there is enough genetic variation for all traits. After achievement of diallel assumptions according to Jinks-Hayman’s (1953) approach for all traits, genetic variation was partitioned in additive and non-additive components using the method 2 of Gardner and Eberhart (1966). The results showed that lines and heterosis effects were significant for all traits, indicating the presence of additive and dominance gene action for these traits. Average heterosis for pods and seeds/plant was significant, showing that the mean of the hybrids was significantly different from the mean of the parents and the line heterosis component was significant for all traits, indicating that there were significant differences among hybrid arrays of the different parental lines. The significance of the specific heterosis component, however, indicated that there were hybrid combinations with a high degree of heterosis. Estimate of Baker index revealed that additive gene action was more important in the inheritance of plant height whereas non-additive gene effects were more important for others traits. Estimate of genetic parameters (D, H1, H2) according to Hayman’s (1954a) approach also indicated that additive variance component for plant height was greater than non-additive variance components while it was less important for others traits. Estimates of narrowsence heritability were medium for plant hight and low for others traits.Wr/Vr graphs reflected partial dominance for plant height and over-dominance for others traits. Estimates of specific combining ability effects showed high degree of heterosis for plant height in the cross Filip92-99c × of Filip92-67c and for other traits in the cross of Filip84-48c × Filip93-60c.

This experiment was conducted to study the effects of water deficit stress on yield and yield components in eight corn hybrids. The experiment was laid out in split plot using randomized complete block design with three replications. Treatments consisted of two irrigation levels (in stress condition and without stress) as main plots, and eight corn hybrids (six late maturing single crosses and two three- way cross with moderate maturity) as sub-plots. Yield was significantly affected by water stress (p£%5). Other measured traits were also negatively affected, but not significantly. Hybrids showed significant differences for plant height, stem diameter, number of rows per ear, cob diameter, ear length, number of grain per row, total leaf number, number of leaves above the main ear and plant height up to position of ear emergence (p£%5). Results of stepwise regression and path analysis revealed that in the non-stress condition, selection for increased yield could be performed by selecting genotypes with high percentage of cob, kernel length, number of grain per row, plant height and ear length. In the stress condition, cob diameter, number of grain per row and ear length could be used as components for selection of high yielding genotypes. Among indices used for screening of genotypes to drought stress, tolerance index could differentiate among tolerant and intolerant genotypes. For the selection of high yielding genotypes in water stress conditions, in addition to tolerance indices, other important agronomical characteristics should be considered. Based on results of this experiment Single Cross 704 and Three Way Cross 600 were recommended for normal and water stress conditions, respectively.

To determine the optimum sowing and sowing pattern of sunflower (Azargol cultivar), an experiment was conducted at Agriculture Research Station of Uremia, Iran during 2005-2006. A split-plot design based on randomized complete blocks with four replications was used. The main factor involved three row distances (45, 60 and 75 cm) and the subplot factor involved four plant distances on the row (15, 20, 25 and 30 cm). The results indicated that the space between the rows had significant effect on grain yield, head diameter, weight of 1000 seeds, number of seeds per head, percentage of hollow grains and number of rings per head. Furthermore, seeds per head, 1000 seed weight, head diameter, percentage of hollow grains and rings per head were significantly affected by the within-row distances. There was also a significant interaction of row space×plant distance on row for grain yield. Based on these results, regarding grain yield, sowing pattern of 75×25 was recommended for sunflower cultivation in Uremia and similar regions.

In order to investigate the relationship between plant density and grain yield of three pinto bean cultivars at three different sowing dates, a split plot factorial experiment based on randomized complete block design (RCBD) and three replications was conducted in Zanjan Agricultural Research Center in 2003. Three pinto bean cultivars (Talash, Khomein 5 and COS16 ) at three different sowing dates (9 May, 21 May and 2 June) with four densities (15, 20, 25 and 30 plants/m2) were sown in a loamy soil. Days to flowering, pods per plant, seeds per plant, 100 seeds weight, days to maturity and grain yield were significantly affected by sowing date, cultivar and plant density. The interaction effects of sowing date and cultivar were olso significant for days to flowering, days to maturity and grain yield but interaction effects of sowing date and plant density were only significant for days to flowering and grain yield. All these traits were decreased with delaying in sowing date. Grain yield of COS16 was higher than that of Talash and Khomein 5. Days to flowering, pods per plant, seeds per plant, 100 seeds weight and days to maturity decreased, but empty pods per plant and grain yield per unit area increased, with increasing plant density. The relationship between plant density and grain yield of the three pinto bean cultivars were analysed, using equations 1/w=a+bp and y=p/a+bp, where: 1/w=reciprocal of yield per plant , y=grain yield per unit area, p=plant density, a and b=constants. The results indicated that delayed sowings reduce grain yield of low densities more than that of high densities. Consequently, estimated optimum economic densities for delayed sowings were more than those for early sowings. Therefore, it is necessary to increase seeding rate at delayed sowings, in order to prevent or to reduce the yield loss.

Grain yield is one of the most important creteria in screening wheat genotypes for salinity conditions. In order to study the effects of NaCl induced stress on yield and yield components and to determine threshold salinity, an experiment with ten wheat genotypes (Alvand, and 9 advanced lines) was conducted in the glasshouse of Agricultural Biotechnology Research Institute of Iran. Five levels of salinity (control, 50, 100, 150 and 200 mM NaCl) were imposed through irrigation. Reasults showed that 200 mM NaCl treatment decreased time to physiological maturity, plant height, number of tillers, number of kernel per main spike, 1000 kernel weight, biomass, total grain yield, tiller grain yield and main stem grain yield, 20%, 31%, 85%, 52%, 52%, 86%, 89%, 97% and 66%, respectivley as compared to control. The reduction in the number of tiller and tiller grain yield were the main cause of yield reduction. Genotype 3 had the lowest biomass and grain yield per plant in all salinity levels. Relative yield reduction and relative biomass yield of genotype 12 consistently was lower than the others in all salt levels. Salt tolerance threshold of genotype 12 for biomass (10.8 ms/cm) and grain yield (8.25 ms/cm) was higher than the others. Alvand variety that was recommended for salinity areas of cold regions, had salt tolerance threshold of 5 and 6 ms/cm, for biomass and grain yield, respectively. Genotype 12 had higher stress tolerance index (0.27) and less stress susceptibility index (0.87) than the other genotypes.

This study was conducted to evaluate the effects of different irrigation conditions on 12 genotypes of vetch (Vicia dasycarpa) at the Agriculture and Natural Recourses Center of East Azarbaijan province, Iran, during 2003. Field trial was conducted as a split plot design based on randomized complete blocks with three replications. Three irrigation regimes were considered as regular (irrigation at 5-day intervals), water deficit (irrigation at 10-day intervals) and rainfed (no irrigation). Several characters including biomass and grain yield were measured. Path analysis of biomass and grain yield under the above mentioned conditions, using stepwise ridge regression, indicated that some yield components had significant direct effect on these characters. Under regular condition the direct effect of number of grains per pod and number of lateral branchs were positive and significant and that of stem length was negative and significant in relation to the biomass. Also the direct effect of number of grains per pod was positive and significant and that of grain density was negative and significant in relation to grain yield. Under water deficit condition the direct effects of number of grains per pod and grain density on biomass and 1000 grain weight and stem length on grain yield were positive and significant. In the rainfed condition because of severe stress, grains were not matured and path analysis was carried out only on biomass. Results showed that in this condition, only number of grains per plant had important effect on the biomass.

Application of DNA marker technology in poultry as a tool for species and strain identification has progressed rapidly during the last decade. Random amplified polymorphic DNA (RAPD) markers can be generated using short arbitrary primers to amplify genomic DNA, giving a genotype-specific pattern of bands. RAPD analysis should lead to the saturation of the genome without the requirement of previous genetic information. The purpose of this study was to evaluate genetic similarities and distances among four-colored phenotype of turkey population that kept in Turkey Research Station of Iran using RAPD technique. Blood samples were taken from 20 Black, 16 Golden, 24 Pied and 18 White local turkeys. Genomic DNA was extracted from 25 ml blood samples. RAPD technique, using 15 primers, was applied to amplification of different fragments of genome. The genetic similarity between the groups varied from 0.94 to 0.98 between phenotypic groups. The highest genetic distance (0.06) was determined between the White and Golden phenotypic groups and the lowest genetic distance (0.02) was obtained between White and Black groups. The results of this research showed that RAPD-PCR is an appropriate tool for evaluation of genetic variation in poultry and color is not an useful character to differentiate turkey genetic groups.

This experiment was carried out to evaluate the nutritional value of hull-less barley varieties and also, to investigate the relationship between its non-starch polysaccharides and metabolizable energy for poultry. Eight improved varieties of hull-less barley were examined for chemical composition. Metabolizable energy of hull-less barley varieties were determined using cockerels. The differences between metabolizable energy content of barley varieties were analyzed using completely randomized design. There was no significant difference between varieties based on AMEn content. The average metabolizable energy of barley sample was 3.112 (kcal/kg DM) and crude protein, fat, ash, starch, soluble sugar, soluble NSPs and insoluble NSPs were 11.51, 1.03, 2.27, 3.19, 60.91, 5.57, 5.14 and 12.79 (%), respectively. There was high negative correlation between non-starch polysaccharides and AMEn (r=0.92, p<0.01) in hull-less barleys. Therefore, the equation for estimating AMEn by soluble NSPs was AMEn= 3.324-0.061 S-NSP, R2=0.91. The correlation between crude fiber and NSPs was significant (r=0.87, p<0.01) and their regression equation was: S-NSP=2.253 + 0.91CF, R2=0.77. The results of this experiment suggested that the metabolizable energy of the hull-less barley grain is highly affected by its soluble non-starch polysaccharides content. Thus, soluble non-starch polysaccharides content of hull-less barley could be use for predicting of its metabolizable energy.

Eighteen female Holstein calves were divided to three groups and received similar basal diet and different levels of yeast (Saccharomyces cerevisiea) daily (0, 0.5 and 1% DM basal diet). Rumen samples derived at 30, 60 and 90 days old. Results showed that PCR could detect Fibrobacter succinogenes up to two copy of pure DNA. Also it was shown that Fibrobacter succinogenes and Ruminococcus flavefaciens could be detected at rumen samples and introduced bands were similar to other studies. In addition multiple-PCR could be used for detection of them. Results showed that quantitative PCR could be used for enumeration of Fibrobacter succinogenes and showed that different levels of yeast had no significant effect on population of Fibrobacter succinogenes. Sampling time had a significant effect on population of Fibrobacter succinogenes (P<0.0001) and population of this bacteri in different sampling times (30, 60 and 90 days old) in each treatment increased by time. Generally, it seems that quantitative PCR technique could be used for enumeration of Fibrobacter succinogenes in rumen samples.

This experiment was conducted to evaluate productivity of Iranian native Marandi (MA), White Plymouth Rock (PR), Cornish (CR) as meat types and Rhode Island Red (RIR) as dual purpose breeds and their crosses in 12 breeding combination. No crosses were considered between pure breeds. In meat type crossing, thirty chicks produced (in total 1680 chickens) in three successive hatches and were reared separately up to 56 days of age. Chickens were weighed at third, sixth and eighth week, and feed consumption was also measured. At the end of experiment, one cock and one hen were randomly chosen and slaughtered. In dual purpose type crossing, chicks from crosses were kept at 28 boxes in litter system up to four months of age separately. During this period eight pullets from each box were randomly selected and transferred to individual cages. Traits such as egg numbers and weights, Hugh unit, index and feed intake were measured for six months. The results showed that hybrids from MA with PR or CR had significantly higher body weight, carcass weight, most parts of carcass and feed intake, and lower FCR at the end of 21, 42 and 56 days of age in comparison to pure MA (P<0.05). Significant sex effect was observed for body weight and carcass weight and whole pieces except abdominal fat. The highest and lowest egg production (EP) was for RIR and pure MA, respectively, and EP in hybrids were about 29.84% higher than pure MA. Feed intake, Hugh unit, egg index differed significantly among the different crosses. Heterosis in MA and PR crossing was negative for all traits except for feed intake in 42 days, percentage of carcass, breast, wing, back and neck and giblet. However, it was positive in MA and CR crossing for all traits except for percentage of breast, giblet and FCR. A negative heterosis was observed in crossing between MA and RIR for all traits except for mean egg weight and feed intake. Crosses MA♂ PR♀ , CR♂*MA♀ and MA♂ *RIR♀  had superiority to their reciprocals MA♀ *PR♂, CR♀ *MA♂  and MA♀ *RIR♂, respectively.

This study was conducted to compare the effects of b-glucanase of two preparations on the male and female broiler performance. 540 day-old chicks from either sex were randomly assigned to 9 dietary treatments for 49 days (6 replicates of 10 chicks were used for each treatment). The experimental design was a completely randomized with factorial arrangement of treatments: 3×3 (kinds of enzyme × levels of hull-less barley). Numbered plates dangled to day-old chicks shank and individuals weighted for determining of sex effects. The experimental design for weight gain and carcass performance was a completely randomized design with factorial arrangement of treatments: 3×3×2 (kinds of enzyme×levels of hull-less barley×sex). In the end of experiment, two chicks were selected from each replicate and considered for carcass analysis. Results showed that weight gain from day 1-21 and 21-42 were significantly (p<0.05) influenced by hull-less barley and enzyme levels; i.e., either enzyme significantly (p<0.05) increased weight gain. Inclusion of enzyme and hull-less barley (HB) to diets had significant (p<0.05) effect on feed intake (FI) and feed conversion (Fc). Locally produced (GP82b-Glucanase) and commercial (ZYb-Glucanase) enzyme from day 1 to 49 increased FI significantly (p<0.05) at 7.3, 4.3 and FC at 13.3, 9.4, respectively. No significant difference was observed between two kinds of enzymes. Enzyme inclusion from both preparations to HB diets appeared with significant increase (p<0.05) on edible carcass and abdominal fat, but significantly (p<0.05) decreased the visceral of both sexes. No significant differences were observed between two kinds of enzymes. Breast percentage (BP) again was influenced by enzyme, HB and sex. Locally produced enzyme led to significant (p<0.05) increase in BP at 9.6, 8.7% and commercial enzyme at 8.7, 6.3% in male and female chicks, respectively. In conclusion, GP82 b-glucanase enzyme is of a great potential and comparable to commercial enzyme (b-glucanase hydrolysis).

Propolis is a sticky and resinous substance that honey bees collect from different plant sources. The chemical composition of propolis is very complex and contains more than 200 different chemical components. The biological activity of propolis depends on its polyphenolic contents. The flavonoids are the most important group of polyphenols which are devided to sub groups such as, flavones, flavanones, flavonols, dihydro flavonol and chalcones. This survey was conducted to determine propolis contents from citrus (S1), forest trees (S2) and pines (S3) in Chaboksar, Seahkal and Talesh, respectively in 2002-2003. In Guilan Province twenty honey bee colonies were prepared and placed in these areas. The samples were collected every two weeks in warm and end of the cold seasons. After extraction and separation of waxes and lipids, the samples were analysed by GC-MS and obtained mass spectra were compared with standards. The results showed the presence of Chrysin, Tectochrysin, Pinobanksin-3-aceatate and Pinostrobin in three areas, Aceacetin, Pinocembrin chalcone in S1, Galangin-3-methyl ether in S1 and S3 and Pinocembrin in S2 and S3. Pinobanksin-3-propanoate was obtained only in S2. The amount of total flavonoids in S1, S2 and S3 were 12.3, 11.4 and 10.6, respectively. The results showed that propolis from three plant origins has good amount of flavonoids but different in quantity and type of these compounds.

Vegetative compatibility groups of Magnaporthe grisea was determined using nit mutants of 147 monoconidial isolates collected from different areas of Mazandaran province. Nit mutants were selected from fast growing sectors on MMC medium. Two hundred twenty- two nit mutants were selected and kept for experiment related to genetic complementation. Phenotype of nit mutants was identified using sodium nitrate, sodium nitrite, hypoxantine, ammonium tartarat and uric acid. Most of the nit mutans (50%) belonged to nit1 phenotype. Each mutant was crossed with tester isolates. As a result three vegetative compatibility groups were identified among rice blast isolates in Mazandaran region. VCG2 was the most abundant group and VCG3 had the lowest number of isolates.

One of the most important thermal properties of unhulled pistachio nuts, namely bulk thermal coductivity, was evaluated as the function of moisture content and temperature. The moisture content of nuts ranged from 20.9% on the wet basis to 51.8% (moisture content at harvest time) and the temperature ranged from +20oC to +40oC. In order to measure the thermal conductivity of agricultural materials, a specific probe was developed. Thermal conductivity was measured in transient state by calculating the maximum instant slope, using the line heat source which was assembled in the probe. Bulk thermal conductivity varied significantly with moisture content and temperature. It ranged from 0.1145 to 0.1904 W/mK and increased with moisture content in the range of 20.9-51.8% on the wet basis. Furthermore, increasing the temperature from 20 to 40oC raised the average thermal conductivity from 0.1448 to 0.1585 W/mK. The conducted tests on two varieties of nuts (Akbari and Kallehghoochi) demonstrated that the thermal conductivity of Kallehghoochi cultivar is lower than that of the Akbari cultivar at a=0.05. Quadratic regression equations were developed depicting the effect of moisture content and temperature on thermal conductivity.

Electrostatic spraying is the method that is noted for improving the spraying efficiency and droplet deposition on plant. The merit of this method is related to the generation of dynamic attraction between the charged pesticide droplets and plant which obtains plant peripheral coating ability against usual spraying methods. In this research design and evaluation of an electrostatic sprayer was described. In this sprayer, electric charging of droplets is performed through the induction method. Atomization of nozzle flow is accomplished by ultrasonic method and the generated droplets buoyancy and guiding them is achieved by airflow of a fan. To evaluate voltage effect, air speed and liquid flow rate on quantity of droplet charging, the tests were conducted in a closed environment. The results showed the positive effect of inductive voltage on charged droplets creation. Increasing of fan speed improves the droplet charging by increasing of passed air flow rate. However, because of wetting phenomenon, increasing of spray flow rate has a negative role during charging process. The maximum charging is occurred at 25 ml/min flow rate, voltage of 7 kV and air flow speed of 23 m/s and the resulting current is about 0.42 mA.