ORIGINAL_ARTICLE Population Density and Spatial Distribution Pattern of Empoasca decipiens (Hemiptera: Cicadellidae) on Different Bean Species The population density and spatial distribution pattern of Empoasca decipiens Paoli were etermined in Tehran area, Iran, during 2004-2005 on four species of common bean Phaseolus vulgaris (L.) var. Talash, lima bean P. lunatus (L.) Savi ex Hassk. var. Sadaf, rice bean P. calcaratus Roxb. var. Goli and cowpea Vigna sinensis (L.) var. Parastoo. The higher and lower mean population densities of E. decipiens per leaf were observed on Parastoo cowpea (18.85 in 2004 and 29.94 in 2005) and Talash common bean (1.08 in 2004 and 0.37 in 2005), respectively. Spatial distribution pattern of E. decipiens was described on these four bean species using variance to mean ratios, Taylor's power aw coefficients and Iwao's patchiness regression methods. The spatial distribution pattern of this pest in most cases as aggregated and in a few cases random. In 2004, collected data were in a better fitting with aylor's model in comparison with Iwao's model on Talash common beans (r2= 0.879) as well as on Goli rice bean (r2= 0.967). Iwao's model explained the distribution data of 2004 and 2005 on Sadaf lima beans (r2= 0.746 and 0.906, respectively) more appropriately than Taylor's model (r2= 0.541 and 0.828, espectively). It is concluded that bean species influence the population density and spatial istribution pattern of E. decipiens. Spatial distribution parameters can be employed to develop a sampling program and to estimate the population density of this pest. http://jast.modares.ac.ir/article-1-4838-en.pdf 2009-07-12 239 248 Bean species Empoasca decipiens Leafhopper Population density Spatial distribution B. Naseri 1 Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran AUTHOR Y. Fathipour 2 Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran AUTHOR A. A. Talebi 3 Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, P. O. Box: 14115-336, Tehran, Islamic Republic of Iran AUTHOR
ORIGINAL_ARTICLE Effect of Electrostatic Induction Parameters on Droplets Charging for Agricultural Application In this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. Liquid atomization was achieved by using an ultrasonic nozzle. The nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 kHz. The induction method was used for charging the output droplets. All experiments were carried out within a closed environment with a fixed ambient humidity and temperature to reduce the effect of environmental factors. The independent parameters in this study included: voltage at four levels of 1.5, 3, 5 and 7 kV; air flow speed at six levels of 14, 14.9, 17, 20.2, 21.6 and 23 m s-1; charging electrode radius in two levels of 10 and 15 millimeters, horizontal distance between the electrode and nozzle tip at four levels of 1.5, 6, 10 and 15 millimeters; and liquid flow rate at three levels of 5, 12 and 25 milliliters per minutes. For evaluation of the system, the charging quantities of droplets were measured in different states. The maximum charging occurred at 5 ml min-1 flow rate, voltage of 7 kV, air flow speed of 23 m s-1 and the resulting current was 0.24 μA. On dividing the electrical current by the liquid flow rate and changing the scale, the mean charge to mass ratio was 1.032 μC g-1. Increasing voltage increased the charging quantity slightly but higher voltages and lower air speeds decreased it. The effect of the faster air speed on droplet charging phenomena is positive and the smaller electrode radius causes less charge induction on the droplets. The quantity of droplets charging first increased with increased distance between ring electrode and nozzle tip, and then it was either reduced and/or fixed. http://jast.modares.ac.ir/article-1-9475-en.pdf 2009-07-13 249 257 Induction electrode Charged liquid droplets Charged spray Electrostatic spraying B. Mostafaie Maynagh 1 Mechanics of Agricultural Machinery Department, Tarbiat Modares University, Tehran, Islamic Republic of Iran. Tel: 021-44196522 AUTHOR B. Ghobadian 2 Mechanics of Agricultural Machinery Department, Tarbiat Modares University, Tehran, Islamic Republic of Iran. AUTHOR T. Tavakkoli Hashjin 3 Mechanics of Agricultural Machinery Department, Tarbiat Modares University, Tehran, Islamic Republic of Iran. Tel: 021-44196522 AUTHOR M. R. Jahannama 4 Engineering Research Institute of Jihad-e-Agriculture Ministry, Tehran, Islamic Republic of Iran. AUTHOR
ORIGINAL_ARTICLE Mass Flow Rate Measurement System Performance on Potato Harvesters A project was established to develop a procedure for the selection, design, installation, test and evaluation of mass-flow rate measurement systems for root crop harvesting and to assess the consistency and precision of the weighing systems incorporated into crop feed arrangements in both laboratory and field studies. Studies were conducted to evaluate conveyor belt weighing systems using an experimental apparatus and a commercial potato harvester. Two weighing systems were evaluated: (a) cantilever transducers fitted to the conveyor belt mechanism and (b) a load cell system supporting the total weight of the conveyor and crop. The results of laboratory studies with sugar beet/potatoes showed that the standard cantilever transducers gave the smallest percentage of standard deviation from the mean experimental error ranging from 1.43 kg (connected to one idler roller) to 2.61 kg(connected to three idler rollers) with an appropriate value equal to 0.54 kg (connected to two idler rollers). The load cell supporting system also gave the smallest percentage of standard deviation from the mean experimental error ranging from 1.56 kg (continuous side feeding) to 2.25 kg (side feeding from right side) with an appropriate value equal to 0.84 kg (steady state side feeding). Experiments were conducted in the laboratory and field to assess the effects of belt inclination and extraneous vibration, transferred from the tractor to the harvester, on the measurements of crop mass. The results of field studies with potatoes using the cantilever transducers showed that the most precise system performance was obtained when using the 125 mm idler wheels with standard deviation of the mean experimental error of the sample yield equal to 0.99 kg. The results of barn studies with potatoes using the load cell supporting system showed that there was a good linear relationship between the measured and weighed mass of the potato samples with standard deviation of the mean experimental error equal to 0.34 kg. http://jast.modares.ac.ir/article-1-11346-en.pdf 2009-07-13 259 274 Continuous measurement system Harvesting Mass flow Potatoes Root crops Sugar beet M. R. Mostofi 1 Agricultural Engineering Research Institute, P. O. Box: 31585-845, Karaj, Islamic Republic of Iran AUTHOR
ORIGINAL_ARTICLE Reduction in Primary Tillage Depth and Secondary Tillage Intensity for Irrigated Canola Production in a Loam Soil in Central Iran The introduction of canola (oilseed rape; Brassica napus L.) as a new source of vegetable oil production in Iran prompts evaluation of the performance of this crop under different tillage systems. A field experiment was conducted to determine the impact of depth and intensity of tillage on soil physical properties, crop establishment and yield of irrigated winter canola in a loam soil (Typic Haplargids) near Isfahan in central Iran. In a split-plot design, three primary tillage treatments consisted of moldboard plowing to 20 cm (MP20), two passes of a cultivator first to 10 and then to 15 cm (2TC15), and one single pass of cultivator to 10 cm (TC10), were combined with two seedbed preparation treatments (four passes with a disk harrow as opposed to a single pass with a rotary tiller). Results showed that the soil bulk density in the 0-5 and 5-10 cm layers were not significantly affected by primary tillage treatments. Soil penetration resistance (PR) in the 0-10 cm layer was significantly higher in 2TC15 compared to moldboard plowed soil; however, no significant effect of primary tillage was detected on PR in the 10-20 cm depth. A single pass by a rotary tiller was as effective in seedbed preparation as four passes of a disk harrow, as assessed by bulk density, penetration resistance and the percentage of emergence. The number of plants per square meter at final emergence and at harvest was statistically similar for both the seedbed preparation methods. Mean canola total dry matter biomass was 10,020, 9,860 and 10,410, kg ha-1 and dry grain yield was 2,340, 2,410 and 2,880 kg ha-1 under MP20, 2TC15 and TC10, respectively. However, the effects on mean crop yield were non-significant (P 0.05). The mean oil content of the 2TC15 (40.1%) was significantly lower than the MP20 and TC10 treatments, 43.7 and 42.3%, respectively. Lack of yield response to tillage treatment may have been the result of achieving a good seedbed (aggregate mean diameter of less than 15 mm) under all tillage methods, which help to obtain sufficient plant establishment. These results indicate that the yield of irrigated winter canola is not sensitive to reduction in the depth of primary tillage or intensity of secondary tillage. With reduced tillage, an optimum plant per unit area can also be achieved. Overall, TC10 combined with a single pass of a rotary tiller was considered to be agronomically desirable, due to the absence of grain yield difference compared with both the MP20 or 2TC15 systems and reduced tilling depth. http://jast.modares.ac.ir/article-1-9648-en.pdf 2009-07-13 275 288 Non-inversion tillage Oilseed rape Rapeseed Rotary tiller Disk harrow Grain yield A Hemmat 1 Department of Farm Machinery, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran. AUTHOR
ORIGINAL_ARTICLE Determination of Proper Conditions for the Production of Crude Beta-galactosidase Using Lactobacillus delbrueckii ssp. bulgaricus Proper conditions for producing crude beta-galactosidase from waste materials were de-termined. This enzyme is to be used in the production of lactose-hydrolyzed milk. Whey permeate was used as a basic medium. Twenty seven treatments were developed by 3 vary-ing factors of: yeast extract (1, 2, and 3 %), wheat steep liquor (1, 2, and 3 %), and whey powder (0.5, 1, and 1.5 %). Crude enzyme extract was obtained by sonication of the cells collected from cultivation of Lactobacillus delbrueckii ssp. bulgaricus in various media at 43oC. The beta-galactosidase activity was assessed using Ortho-Nitro-Phenyl-beta-D-galactopyranoside (ONPG). Yeast extract and whey powder had both significant effects (P< 0.01), while wheat steep liquor proved to be ineffective. Yeast extract had the most pro-nounced effect on the production of beta-galactosidase. The effect of the interactions of yeast extract-whey powder and wheat steep liquor-whey powder were significant at 5 % level (P< 0.05), while the effect of the interaction of yeast extract-wheat steep liquor was sig-nificant at 1% level (P< 0.01). Interaction effect of the 3 factors on the production of beta-galactosidae was significant (P< 0.01). The best combination for production of beta-galactosidase (4.924 U ml-1) was 3% yeast extract, 1.5% whey powder and 2% wheat steep liquor. http://jast.modares.ac.ir/article-1-11175-en.pdf 2009-07-13 301 308 Beta-galactosidase Crude enzymatic extract Lactobacillus bulgaricus Lactose hydrolysis Wheat steep liquor Whey permeate A. Jokar 1 Department of Food Science, College of Agriculture, Shiraz University, Shiraz, Islamic Republic of Iran AUTHOR A. Karbassi 2 Shiraz university AUTHOR
ORIGINAL_ARTICLE Thin Layer Drying Properties of Soybean (Viliamz Cultivar) This paper peresents a mathematical model for the thin layer drying of the Viliamz cultivar of soybean. The thin layer drying behaviour of soybean was experimentally investigated and the mathematical modelling performed by using thin layer drying models provided in the literature. Experiments were conducted at inlet drying air temperatures of 30, 40, 50, 60 and 70ºC and at a fixed drying air velocity of 1 m s-1. Thirteen different thin layer mathematical drying models were compared according to their r values, RMSE, 2 and EF by non-linear regression analysis. The effect of drying air temperature on the model constants and coefficients was predicted using multiple regression analysis. According to the results, the Midilli et al. model was found to be the best mathematical equation for modelling thin layer drying of soybean. http://jast.modares.ac.ir/article-1-1698-en.pdf 2009-07-13 301 308 Drying kinetics Effective diffusivity Modeling soybean Thin Layer sh Rafiee 1 Faculty of Biosystem Engineering, University of Tehran, Islamic Republic of Iran AUTHOR
ORIGINAL_ARTICLE Moisture Dependent Physical Properties of Canola Seeds Physical properties of four common Iranian varieties of canola seeds (Hyola, Okapi, Orient and SLM) were evaluated as a function of their moisture contents. The average seed length and thousand seed mass varied linearly from 1.925 to 2.262 mm and from 3.06 to 4.84 g, respectively. The average diameter, geometric mean diameter, and sphericity varied non-linearly from 1.475 to 1.911 mm, 1.625 to 2.02 mm and from 0.82 to 0.93, re-spectively in a moisture content range of 5.27 to 23.69% wet basis (w.b.). Among the va-rieties, Hyola had the highest values for length, diameter, geometric mean diameter, sphericity and thousand seed mass at all moisture levels. Maximum and minimum values of bulk density were obtained for SLM (738.8 kg m-3) and Hyola (666.06 kg m-3). The fill-ing and emptying angles of repose ranges were determined as 25.37-28.54o and 25.48-28.68o, respectively. At all moisture content levels, the static coefficient of friction was the greatest against rubber (0.372-0.460), followed by plywood (0.358–0.449), galvanized iron sheet (0.301–0.419) while fiberglass sheet (0.260-0.414) while the least for glass sheet (0.253–0.392). Among the four canola varieties, Orient and SLM showed respectively the least and the greatest static coefficients of friction at all moisture levels studied. http://jast.modares.ac.ir/article-1-3411-en.pdf 2009-07-13 309 322 Canola seed Geometrical properties Gravimetrical properties Frictional properties S.A.M Razavi 1 Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, P. O. Box: 91775-1163, Islamic Republic of Iran AUTHOR S. Yeganehzad 2 Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, P. O. Box: 91775-1163, Islamic Republic of Iran. AUTHOR A. Sadeghi 3 Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, P. O. Box: 91775-1163, Islamic Republic of Iran AUTHOR
ORIGINAL_ARTICLE Decreasing the Intensity of Date Bunch Wilt and Dry Disorder (DBWD) by Using Balanced Proportions of Nutrient Elements There are more than 37,000 hectares of land cultivated with date palm in Hormozgan Province producing around 145,000 tons of date annually. Therefore, increasing date yield and quality can ender positive effects, especially on farmers, income in the region. One of the most important agricultural practices is mineral nutrition nd soil fertility management that can improve yield and fruit quality of date palm. This research was conducted for a duration of three years to study the effect of essential nutrients application on Date Bunch Wilt and ry disordr (DBWD) which has caused large production reductions in recent years. Two palm groves of “Mordasang” cultivar were chosen as experimental sites. One was afflicted with DBWD and he other one healthy. Fertilizer treatments were applied on the basis of soil and leaf nalysis as follows: 1- Control (with no use of fertilizers) 2- Addition of balanced amounts of macro-nutrients and 3-Addition of balanced amounts of macro as well as micro-utrients. Theexperiment was arranged with a complete randomized block design of five replications. Maintenance operations consisted of pollination, weeding, disease and pest control. Such plant esponses as fruit yield, bunch number and percentage of bunches fflicted by DBWD were determined and compared among treatments. There was no significant difference observed between bunch numbers per tree in the fertilizer treatments. Application of ssential nutrient elements (treatments 2 and 3) resulted in a onsiderable increase in date yield and a decrease in dried bunches percentage. http://jast.modares.ac.ir/article-1-708-en.pdf 2009-07-14 323 329 DBWD IRAN Macro nutrient micro nutrient b mostafaei 1 tehran AUTHOR j saleh 2 tehran-t.m.u AUTHOR
ORIGINAL_ARTICLE Object Oriented Simulation; Its Application in Water Reservoir Management and Operation Reservoir dams are among the main storage systems employed in agriculture for the several past decades. Proper operation of these reservoirs is important for irrigation espe-cially in such arid and semi-arid areas like Iran, and particularly during dry years. A computational framework for reservoir simulation and flood routing is hereby presented. A key aspect of the reservoir simulation is the ease of use by managers and model users. In this paper, an object-oriented toolkit for building computer models for simulation of reservoir operation and flood routing in Boukan reservoir dam is used. The modeling ap-proach taken in this paper is significantly different from that typically employed in the development of water resources planning and management models. The medium in this kind of model provides a graphical object-oriented interface that allows the user(s) to model complex systems without even requiring a profound proficiency in computer pro-gramming. The Object Oriented Programming (OOP) environment chosen to develop the model of Boukan dam reservoir was STELLA Software. The probability of flood occur-enceis also taken into account for a prediction of more accurate results. http://jast.modares.ac.ir/article-1-3017-en.pdf 2009-07-26 331 340 Modeling Flood routing Object oriented Reservoir operation simulation S. Javadi 1 Department of Irrigation and Drainage Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran. AUTHOR M. S. Kiapasha 2 TMU AUTHOR K. Mohammadi 3 Department of Irrigation and Drainage Engineering, Tarbiat Modares University, Tehran, Islamic Republic of Iran. AUTHOR
ORIGINAL_ARTICLE Monthly Runoff Estimation Using Artificial Neural Networks Runoff estimation is one of the main challenges encountered in water and watershed management. Spatial and temporal changes of factors which influence runoff due to het-erogeneity of the basins explain the complicacy of relations. Artificial Neural Network (ANN) is one of the intelligence techniques which is flexible and doesn’t call for any much physically complex processes. These networks can recognize the relation between input and output. In this study ANN model was employed for runoff estimation in Plaszjan Riv-er basin in the central part of Iran. The models used are Multiple Perceptron (MLP) and Recurrent Neural Network (RNN). Inputs include data obtained from 5 rain gauges as well as from 2 temperature recording gauges, the output of the model being the monthly flow in Eskandari Hydrometric Station. Preprocessing of the data as well as the sensitivity analysis of the model were carried out. Different topologies of Neural Networks were cre-ated with change in input layers, nodes as well as in the hidden layer. The best architec-ture was found as 7.4.1. Recurrent Neural Network led to better results than Multilayer Perceptron Network. Also results indicated that ANN is an appropriate technique for monthly runoff estimation in the selected basin with these networks being also of the ca-pability to show basin response to rainfall events. http://jast.modares.ac.ir/article-1-1879-en.pdf 2009-07-26 335 362 Artificial Neural Networks Monthly rainfall–runoff models Runoff estimation M.R. Yazdani 1 Department of Climatology, College of Literature, University of Isfahan, Isfahan, Islamic Republic of Iran. AUTHOR B. Saghafian 2 Soil Conservation and Watershed Management Research Center, Tehran, Islamic Republic of Iran. AUTHOR M. H. Mahdian2 3 Soil Conservation and Watershed Management Research Center, Tehran, Islamic Republic of Iran. AUTHOR S. Soltani 4 Department of Watershed Management, College of Natural Resources, Isfahan University of Technology, Isfahan, Islamic Republic of Iran. AUTHOR
ORIGINAL_ARTICLE Correlation and Sequential Path Model for Some Yield-related Traits in Melon (Cucumis melo L.) Investigation of the interrelationships between yield and its components will improve the efficiency of a breeding program with appropriate selection criteria. In this study, the relationship among yield components and their direct and indirect influences on the total yield of melon were investigated. The study was based on evaluation of 49 entries gener-ated from a 7×7 diallel involving Iranian melon landraces under two conditions of cultiva-tion, pruning and non-pruning. A sequential path model was used for ordering the vari-ous variables in first and second-order paths based on their maximum direct effect and minimal colinearity. Two first-order variables, namely the number of fruits per plant and average weight of fruits per plant accounted for 91% and 83% of total variation in total weight per plant under the pruning and non-pruning conditions, respectively. The direct effects of these two variables on total weight per plant under non-pruning conditions were nearly equal, but the direct effect of average weight of fruits per plant in the pruning data set was much higher than the number of fruits per plant (1.14 vs. 0.73). All direct effects were found to be significant as indicated by bootstrap analysis. The results indicated the utility of the sequential path model for determining the interrelationships between yield and related traits in melon. http://jast.modares.ac.ir/article-1-551-en.pdf 2009-07-26 341 353 Colinearity Correlation Sequential path analysis Cucumis melo L H. Dehghani 1 Department of Plant Breeding, College of Agriculture, Tarbiat Modares University, Tehran, Islamic Re-public of Iran. AUTHOR E. Feyzian 2 Department of Plant Breeding, College of Agriculture, Tarbiat Modares University, Tehran, Islamic Re-public of Iran. AUTHOR A. M. Rezai 3 Department of Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan, Islamic Republic of Iran. AUTHOR M. Jalali 4 Department of Plant Breeding, College of Agriculture, Tarbiat Modares University, Tehran, Islamic Re-public of Iran. AUTHOR
ORIGINAL_ARTICLE Degradation of Mollisols in Western Iran as Affected by Land Use Change The present study was carried out in Kharkeh Research Station, Kurdestan Province, western Iran to investigate the effects of the change in land use on the degradation of Mol-lisols, their organic carbon content, clay mineralogy and K+ status. The study area was partly under cultivation (for over 40 years) and partly preserved as rangelands. The re-sults revealed that Mollisols are the dominant soils in non-cultivated natural rangelands. The adjacent cultivated soils, however, lack enough organic carbon to meet the require-ments of Mollisols. Cultivation practices had exerted adverse effects on some such major soil properties as organic carbon, cation exchange capacity, as well as macro- and micro-structure. Clay minerals and different forms of potassium did not show significant differ-ences in the two land uses. Parent material rich in such potassium bearing minerals as feldspars and mica, as well as the dominance of illite in soils, were probably the main fac-tors responsible for adjustment of the soil K+, rendering the changes relatively non-significant. http://jast.modares.ac.ir/article-1-7454-en.pdf 2009-07-26 363 374 Clay mineralogy Land use change Mollisols Potassium F. Khormali 1 Department of Soil Science, College of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Islamic Republic of Iran. AUTHOR K. Nabiollahi 2 Department of Soil Science, College of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Islamic Republic of Iran. AUTHOR