@article{ author = {MaghsoudiMoud, A. A. and Yamaghishi, T.}, title = {Differences between Water Extraction Patterns of Three Wheat (Triticum aestivum L.) Cultivars at Different Soil Depths under Gradually Downward Soil Drying Conditions}, abstract ={In drought prone environments wheat crop growth and production depends strongly on the water stored in the soil before anthesis and, although some water remains in the soil after harvest, plants experience water deficit. In order to investigate whether water ex-traction patterns, as a plant feature, have a regulating effect on the amount of water used by them at different soil depths, three wheat cultivars (Asakaze, BR9, BR10) differing in origin and drought resistance in terms of grain yield were grown in pots under gradually downward soil drying conditions. The total water used by cultivars was the same up to the post anthesis stage of growth when plants were harvested. However, Asakaze used more water from emergence to the beginning of the stem elongation period of growth and BR9 used more after that period up to the post anthesis stage. Cultivars showed significant dif-ferences in root length at different soil depths. Asakaze was predicted to use more water from topsoil layers compared to BR9 and BR10. On the other hand, BR9 was expected to use more water from deep layers in comparison to Asakaze. These were suggested to be the effect of the higher root density of each cultivar in the top and deep soil layers. It is also suggested that higher root length density in deep soil layers could be targeted as a fa-vorable trait for breeding wheat Cultivars, which are growing under gradually downward soil drying conditions.}, Keywords = {Wheat,Root,Water extraction pattern}, volume = {8}, Number = {4}, pages = {271-279}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-5227-en.html}, eprint = {http://jast.modares.ac.ir/article-23-5227-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {MajnounHosseini, N.}, title = {Effects of Plant Density and Nitrogen Rates on the Competitive Ability of Canola (Brassica napus L.) against Weeds}, abstract ={To study the effects of plant density and nitrogen rates on the ability of canola (Regent  Cobra; an inbred variety) to compete with weeds, an experiment was conducted as a factorial complete block design with four replications. The treatments included four levels of plant density at 150, 190, 230, and 270 plants m-2, and four levels of nitrogen (N) fertil-izer at 0, 46, 92, and 138 kg ha–1. Results indicated that different levels of plant density and N fertilizer had significant effects on the canola’s leaf area index (LAI) and dry mat-ter accumulation, as well as on the weed’s dry matter at three stages of plant growth (ro-sette, stem elongation, and 50% flowering). The addition of N fertilizer resulted in in-creasing plant LAI and decreasing weed dry matter. Densities of 150 and 270 plants m-2, along with 138 kg ha–1 nitrogen showed the highest LAI at the rosette and stem elongation stages. The LAI at different plant growth stages was an important factor in enhancing ca-nola’s competitiveness with weeds. There were significant differences between different plant density and N fertilizer levels for traits such as plant height, pod bearing stem length, biomass and seed yield. An increase in plant density significantly decreased the pod bearing stem length and total pod numbers per plant (i.e. pod numbers in main branches and sub-branches), but increased plant height. The highest seed yield was ob-tained with 190 plants m-2 along with 138 kg N ha–1. This study revealed that optimum plant density as well as N fertilizer may increase the competitive ability of canola against weeds.}, Keywords = {canola,Cultural weed control,LAI,Nitrogen rate,Plant density}, volume = {8}, Number = {4}, pages = {281-291}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-156-en.html}, eprint = {http://jast.modares.ac.ir/article-23-156-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Asadi, R. and Talebi, A. A. and Fathipour, Y. and Moharramipour, S. and Rakhshani, E.}, title = {Identification of Parasitoids and Seasonal Parasitism of the Agromyzid Leafminers Genus Liriomyza (Dip.: Agromyzidae) in Varamin, Iran}, abstract ={The agromyzid leafminers, Liriomyza sativae Blanchard and L. trifolii (Burgess) (Dip-tera: Agromyzidae) are major pests that attack vegetables in Varamin, Tehran Province. The parasitoids (Hymenoptera: Eulophidae) of these pests were investigated during 2003. The leafminer infested leaves were collected from different host plants, in particular cu-cumber (Cucumis sativus L.,) and preserved under laboratory conditions until the parasi-toids emerged. The vegetable leafminer were parasitized by an expected range of parasi-toids. The parasitoid species included Cirrospilus vittatus Walker, Hemiptarsenus zilahise-bessi Erdös, Closterocerus formosus Westwood, Diglyphus isaea (Walker), Diglyphus crassinervis Erdös. and Pnigalio sp. nr. pectinicornis. The most common species was D. isaea, followed by C. formosus and D. crassinervis. Although insecticides were applied con-tinuously for control of leafminers, the mean seasonal percentage of parasitism was 51.12%. The morphological characteristics of each species are given in brief.}, Keywords = {Eulophidae,leafminer,Liriomyza,parasitoid,Varamin(Iran)}, volume = {8}, Number = {4}, pages = {293-303}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-6892-en.html}, eprint = {http://jast.modares.ac.ir/article-23-6892-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Pourmirza, A. A.}, title = {Toxicity of Acetone to Stored-product Insects}, abstract ={In laboratory experiments the toxicity of acetone was investigated against four species of stored-product insects. In empty-space trials, estimates of the lethal concentrations of acetone (LC, 72-h exposure) for 50% mortality against adults of the lesser grain borer, Rhizopertha dominica (F.), red flour beetle, Tribolium castaneum (Herbst), rice weevil, Si-tophilus oryzae (L.) and eggs of the angoumois grain moth, Sitotroga cerealella (L.) were 33.64, 41.05, 43.90 and 46.11 µl/liter, respectively. At the LC95 level, the order of sensitiv-ity was rated to be: R. dominica adults > S. oryzae adults > T. castaneum adults > S. ce-realella eggs. Penetration tests revealed that acetone vapour could penetrate into the wheat mass and kill concealed insects in interkernel spaces. Comparison of LC50 values between empty-space tests and penetration experiments (after 72-h exposure) indicated that the increase in penetration toxicity was 8.52- and 8.09- fold for R. dominica and T. castaneum, respectively. A similar trend was observed at the LC95 level. In the hidden in-festation trial, the acetone vapour destroyed all the developmental stages of S. oryzae con-cealed inside the wheat kernels and resulted in a complete control with a concentration of 320 µl/liter for 8 weeks after the exposure. Based on the data collected in this study, ace-tone should be considered as a potential compound for empty space fumigations. How-ever, due to its sorption characteristics and the application of high doses, acetone may have only limited use as a fumigant under practical conditions.}, Keywords = {Wheat,Acetone,Fumigation,Stored-product insect}, volume = {8}, Number = {4}, pages = {305-312}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-11714-en.html}, eprint = {http://jast.modares.ac.ir/article-23-11714-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Rafiee, G. and Saad, Che}, title = {The Effect of Natural Zeolite (Clinoptiolite) on Aquaponic Production of Red Tilapia (Oreochromis sp.) and Lettuce (Lactuca sativa var. longifolia), and Improvement of Water Quality}, abstract ={The effects of natural zeolite as a bed medium in increasing lettuce and red tilapia growth as well as improvement of water quality parameters in an aquaponic system were investigated. An experiment with a completely randomized design was run with two treatments in triplicates, 1) an aquaponic system without use of zeolite as a control group and 2) use of a small cotton bag, containing 10 g zeolite as a bed medium for planting a lettuce seedling. In each experimental unit, 42 seedlings of lettuce were introduced. The individual weight of fish and lettuce yield in treatment 2 was significantly higher (P< 0.05) than treatment 1 at the end of experiment. The initial mean individual weight of red tila-pia juveniles was 6.23 ± 0.06 g and increased to 32.50 ± 2.00 and 37.50 ± 2.20 in treat-ments 1 and 2, respectively by the end of experiment. The yield of lettuce was higher in treatment 2 (1507 ± 445.00 g/unit) compared to the control (275 ± 83 g/unit). The concen-tration of total ammonia-N in the water was significantly lower (P< 0.05) in treatment 2 compared to treatment 1 at the end of experiment. The concentration of phosphorous and potassium in the fish rearing tanks was significantly lower (P< 0.05) in treatment 2. These results indicated that the use of zeolite, as a bed medium to plant lettuce seedlings in a re-circulating aquaponic system could increase the growth of lettuce seedlings as well as im-proving water quality parameters.}, Keywords = {Aquaponic system,Diet,Lettuce,Red tilapia,Water quality,Zeolite}, volume = {8}, Number = {4}, pages = {313-322}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10118-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10118-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Azizi, M. H. and Sayeddain, S. M. and Payghambardoost, S. H.}, title = {Effect of Flour Extraction Rate on Flour Composition, Dough Rheological Characteristics and Quality of Flat Bread}, abstract ={The effect of flour extraction rate on flour composition, dough rheological characteris-tics and the quality of Iranian flat breads (lavash, taftoon and barbari) and their staling rate was investigated. Flours with different extraction rates (70, 75, 80, 83, 86, 88, 90 and 93) were subjected to different tests. Resultes indicated that, by increasing the extraction rate, the amount of protein, fat, fiber, ash, wet gluten, water absorption and the color of the flours all increased but the moisture content, sedimentation value and falling number decreased. Rheological studies of doughs by farinograph showed a reduction in dough stability, whereas the dough mixing tolerance index increased along with the extraction rate. By using an extensigraph it was shown that dough resistance, extensibility and the area under extensigram curves were decreased by increasing the extraction rate. A study of the effects of flours with different extraction rates on bread quality, showed that the overall quality of breads is generally affected by the flour extraction rate. Sensory analy-sis of breads in respect to overall quality and staling indicated that the desirable rates of extraction for lavash, taftoon and barbari, breads are 88, 90 and 88 respectively.}, Keywords = {Flat bread quality,Flour extraction rate,Rheological properties,Staling}, volume = {8}, Number = {4}, pages = {323-330}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-1222-en.html}, eprint = {http://jast.modares.ac.ir/article-23-1222-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Pourjam, E. and Bert, W.}, title = {Aprutides guidettii Scognamiglio, 1974 (Nematoda: Aphelen-choididae) and Subanguina picridis (Kirjanova, 1944) Brzeski, 1981 (Nematoda:Anguinidae) from Iran}, abstract ={Several soil samples were taken from western parts of Iran. One of the samples col-lected from the rhizosphere of nectarine trees (Prunus persica L.) in Moghan, Ardabil Province, contained Aprutides guidettii. The species Subanguina picridis was recovered from leaf gall of Serratula latifolia Boiss (Asteraceae) in the vicinity of Mashhad, Khorasan Province. Although this species showed remarkable differences from the origi-nal description, it was considered to be S. picrides considering the high level of variability described in the literature. Both species are described in detail and documented with drawings. Additional morphological data are illustrated by means of SEM. Subanguina picridis is described here for the first time from Iran.}, Keywords = {IRAN,Anguinids,Aprutides,Prunus,Serratula,Subanguina}, volume = {8}, Number = {4}, pages = {331-342}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-9999-en.html}, eprint = {http://jast.modares.ac.ir/article-23-9999-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Samadi, A.}, title = {Temporal Changes in Available Phosphorus in Some Calcareous Soils}, abstract ={Application of phosphorus (P) fertilizers as solid or liquid fertilizers to soils leads to re-actions of orthophosphate ions with various soil components which remove P from the so-lution phase and convert it to less soluble phosphates. This study was aimed at determin-ing soil properties that affect the rate of phosphate retention in 28 contrasting calcareous soils from different geographical regions (14 soils from Western Azarbaijan in Iran (WAI) and 14 soils from Western Australia in Australia (WAA). The results showed that the mean apparent recoveries of applied available P (Olsen P-based recovery) after 160 d of incubation at field capacity was found to be 7% for the soils of WAI and 25% for the soils of WAA. A study of correlation coefficients showed that, for the soils of WAA, there was a negative relationship between the recovery of applied P and the clay content (r = -0.59, P≤ 0.05), whereas there was a positive relationship between the recovery of P and the active CaCO3 (ACCE) content (r = 0.64, P ≤ 0.01). For the soils of WAI, there was a negative correlation between the Olsen P-based recovery and the clay content (r = -0.61, P ≤ 0.01). The decline in extractable P with time was best fitted to a second order kinetic equation. The kinetic rate constant (k) ranged from 0.092 to 0.55 mg kg-1d-1 for the soils of WAI and from 0.31 to 0.92 mg kg-1d-1 for the soils of WAA. The kinetic rate constant (k) increased with increasing the ratio of the clay content to ACCE for all soils of WAI. A re-gression analysis study showed that the ratio of clay/ACCE was the major factor govern-ing P retention.}, Keywords = {Calcareous soils,Active CaCO3,Kinetic rate constant,Phosphorus retention}, volume = {8}, Number = {4}, pages = {343-349}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-5202-en.html}, eprint = {http://jast.modares.ac.ir/article-23-5202-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Rahmani, H. and Kamali, K. and Saboori, A. and Nowzari, J.}, title = {Report and Survey of Morphometric Characteristics of Varroa destructor (Acari:Varroidae) Collected from Honey Bees in Tehran Province, Iran}, abstract ={This research explains the morphometric characteristics of Varroa destructor Anderson and Trueman in Tehran Province. 180 adult female mites were collected from three different colonies of Apis mellifera L. in three apiaries during September 2003 to May 2004. These colonies were divided according to three altitudes-less than 1000m, 1000-1500m and more than 1500m above the sea level. The morphological characteristics of mite samples were examined using light microscopy. Measurements of mite specimens in-cluding body lengths, widths, mean size of leg segments and chelicerae were obtained from 180 females. Data were analyzed using the SAS package. The results revealed that: with 95% confidence intervals, body lengths were 1152.6-1218.9 (for less than 1000m alti-tude), 1163.2-1220.7 (for 1000-1500m altitude) and 1167.1-1228.3 (for grater than 1500m altitude). Also, body widths for those apiaries with 95% confidence intervals were: 1709.8-1818.2, 1712.1-1819.5 and 1720.4-1820.6, respectively. Mean body lengths were 1197.2, 1199.2 and 1200.1 and mean body widths were 1775.6, 1781.7 and 1789.9, respec-tively. No significant differences were observed between the size of leg segments and che-licerae among specimens studied. Comparison between measurements of body lengths and widths of specimens which were collected from Firozkoh (above 1500m altitude), Karaj(1000-1500m altitude) and apiaries in Varamin (less than 1000m altitude) in Tehran Province revealed that there was no significant difference between the three colonies. These specimens were also differ from V. jacobsoni. The results showed that our speci-mens were V. destructor not V. jacobsoni. Moreover, the Tehran Province specimens are similar to V. destructor in that they are less spherical than V. jacobsoni.}, Keywords = {Honey bee,Morphometric characteristics,Tehran Province,Varroa destructor}, volume = {8}, Number = {4}, pages = {351-355}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-12112-en.html}, eprint = {http://jast.modares.ac.ir/article-23-12112-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {TabatabaeeKoloor, R. and Borgheie, A. M.}, title = {Measuring the Static and Dynamic Cutting Force of Stems for Iranian Rice Varieties}, abstract ={In order to help in the engineering design of rice harvesting machines, there is a need to have exact information concerning the physical and mechanical properties of rice stems. The cutting force for rice stems, therefore, was measured by designing and fabricating a static and dynamic shear test apparatus. The effects of moisture levels and the cross-sectional area of stem as well as the variety, blade bevel angle, blade type and cutting speed on shearing strength have been evaluated. The results indicated that the cutting force increased with an increase in the cross-sectional area and decreased with an increase in moisture content. The static and dynamic shearing strength was different among the varieties. The maximum and minimum shearing strengths were related to the varieties Khazar and Hashemi, with an average of 1629 and 1429 kPa for static test and values of 187.4 and 144 kPa for the dynamic test, respectively. The shearing strength decreased from 234.4 kPa to 137.4 Kpa with an increase in blade cutting speed from 0.6 to 1.5 m/s. Blade bevel angle and blade type had no significant effect on the shearing strength of rice stem.}, Keywords = {Dynamic cutting force,Rice stem,Static cutting force,Stem shearing strength}, volume = {8}, Number = {3}, pages = {193-198}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-5-en.html}, eprint = {http://jast.modares.ac.ir/article-23-5-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Dadkhah, A. R. and Grrifiths, H.}, title = {The Effect of Salinity on Growth, Inorganic Ions and Dry Matter Partitioning in Sugar Beet Cultivars}, abstract ={This study investigated intra-specific variation in the growth parameters and dry mat-ter partitioning of sugar beet cultivars at different levels of salinity (0, 50, 150, 250 and 350 mM NaCl + CaCl2 in 5:1 molar ratio) using four cvs, one British (Madison) and three Iranian cvs (7233-P12, 7233-P21 and 7233-P29). The plants were grown in a controlled greenhouse environment for about 18 weeks. Although growth parameters such as leaf area and dry matter accumulation were stimulated or unaffected at a low level of salinity (50 mM), higher salt concentrations significantly decreased all growth traits. At a high level of salinity, cv P29 showed a significantly higher leaf area and total dry matter than others at 16 weeks of salt treatment. Pre-dawn leaf-water potential (ΨL) and shoot water content (SWC) were decreased by salinity. Cvs Madison and P12 had significantly lower ΨL (more negative) and shoot water content at high levels of salt treatment (250 and 350 mM), while P29 and P21 showed higher ΨL (less negative) and shoot water content at the same salt concentrations. Analysis of ion accumulation revealed that Na+ and Cl- contents were greatly increased in leaves under saline conditions. However, salt tolerant P29 had lower Na+ and Cl- concentrations than other cvs at high levels of salinity. The root dry matter of sugar beet cvs at the lowest and the highest salt concentrations reduced by 23.3% and 89.8%, respectively compared to the non-stressed plants, while shoot dry mat-ter decreased by 1.1% and 77% at the same salt concentrations, respectively, after 16 weeks of salt treatment. The pattern of dry matter partitioning to different parts of the plant was changed by salt stress and the dry matter allocated to the storage roots was re-duced by 6% and 18% at the lowest and the highest salt concentrations, respectively, at 16 weeks after salinisation.}, Keywords = {Salinity,Dry matter partitioning,Growth,Sugar beet}, volume = {8}, Number = {3}, pages = {199-210}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-7482-en.html}, eprint = {http://jast.modares.ac.ir/article-23-7482-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Mamnouie, E. and FotouhiGhazvini, R. and Esfahani, M. and Nakhoda, B.}, title = {The Effects of Water Deficit on Crop Yield and the Physiological Characteristics of Barley (Hordeum vulgare L.) Varieties}, abstract ={The effects of water deficit on grain yield, yield components and the physiological char-acteristics of barley (Hordeum vulgare L.) varieties were studied in a split plot design dur-ing the 1999-2000 growing season in Karaj, Iran. Five irrigation levels [0, 25, 50, 75, and 100% crop water requirements (CWR)] and six barley varieties Karoon Kavir , Rei-hani(drought tolerant), Torkman , C-74-9 (intermediate) , Kavir Badia and Gorgan-4 (2 rowed type, drought sensitive) were arranged in the main plots and sub plots respectively. Results showed that water deficit induced stress and this decreased the grain yield and yield components. Water deficit increased the canopy temperature and those varieties showed a higher canopy temperature under non-stress conditions, performed better un-der drought conditions. Severe stress reduced the chlorophyll content (SPAD values) con-siderably, but the differences were not significant between the 50, 75 and 100% CWR treatments. In addition, no significant differences were observed in the chlorophyll con-tent of barley varieties under drought conditions. The effect of irrigation on the photo-chemical efficiency of photosystemII (Fv/Fm) and the other fluorescence parameters for all varieties were significant. Although the Fv/Fm values were not significant in barley varie-ties at any level of irrigation, in general Karoon Kavir and Reihani varieties showed a better performance under water deficit conditions. Proline content was significantly dif-ferent in various irrigation treatments, but its accumulation at any level of irrigation did not differ significantly in barley varieties. It was concluded that the higher canopy tem-perature (less negative T) under well irrigated conditions and higher grain yield, 1000-grain weight, Fv/Fm values under water stress conditions could possibly be the proper cri-teria for screening the drought tolerant barley genotypes under field or laboratory condi-tions.}, Keywords = {Water deficit,Barley (Hordeum vulgare L.),Canopy temperature,Drought tolerance,Photosystem II,SPAD}, volume = {8}, Number = {3}, pages = {211-219}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-5420-en.html}, eprint = {http://jast.modares.ac.ir/article-23-5420-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Hosseini, S. Z.}, title = {The Effect of Altitude on Juvenile Wood Formation and Fiber Length, a Case Study in Iranian Beech wood (Fagus orientalis L.)}, abstract ={The mean fiber length of three beech trees (Fagus orientalis L.) at the lower and higher points (1% and 75% tree height) of the stem at an intermediate altitude (500-1000m) in the Caspian forests in Sari region were 1.36 and 1.22mm respectively, close to the values in three trees at high altitude (1000-1500m), that were found to be 1.39 and 1.36 mm. The mean fiber lengths of the whole stem, using stem formula, were considered as 1.31 and 1.38mm at intermediate and high altitudes and so were very close each other. Juvenile wood portions in the stem comprised 17 annual rings, which took up 7.3% of the stem by volume at intermediate altitude. At high altitude, these values were obtained as 18 annual growth rings, and 8.75% juvenile wood in the stem. The reason for greater juvenile wood at high altitude was somehow a wider ring width at higher elevation. The mean ring width of lower and upper points of the stem at intermediate altitude were found to be 1.82 and 2.95mm respectively; meanwhile, at high altitude, the findings were 2.97, 3.37mm. Despite the data obtained, t- test comparison was conducted between mean fiber lengths of the two heights of the stems at two altitudes, and no significant differences were found at the 1% level. The exploitation age was strongly dependent on how much juvenile wood there was in the stems, that at high altitude was greater than at intermediate. However, statisti-cal comparison showed no significant differences between that and the 1% level. There-fore, altitude in the range of about 500m showed no important impact on beech fiber length, exploitation age or juvenile wood border in Caspian forests.}, Keywords = {Beech,Exploitation age,High altitude,Intermediate altitude,Juvenile wood,Mature wood,Papermaking,Wood fiber}, volume = {8}, Number = {3}, pages = {221-231}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-1120-en.html}, eprint = {http://jast.modares.ac.ir/article-23-1120-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Mirabzadeh, M. and Mohammadi, K.}, title = {A Dynamic Programming Solution to Solute Transport and Dispersion Equations in Groundwater}, abstract ={The partial differential equations for water flow and solute transport in a two-dimensional saturated domain are rendered discrete using the finite difference technique; the resulting system of algebraic equations is solved using a dynamic programming (DP) method. The advantage of the DP algorithm is that the problem is converted from solving an algebraic system of order NC(NL-1) NC(NL-1) into one of solving a difference equa-tion of order NCNC over NL-1 steps and involving NL-1 matrix inversions of order NCNC. The accuracy and precision of the solutions are shown by comparing the results with an analytical solution and calculation of mass the balance. In addition, the perform-ance of the DP model was compared with the results of the MOC model developed by US Geological Survey. In all cases, the DP model showed good results with sufficient accu-racy.}, Keywords = {Numerical model,Dynamic programming,groundwater,Solute transport}, volume = {8}, Number = {3}, pages = {233-241}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-728-en.html}, eprint = {http://jast.modares.ac.ir/article-23-728-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Etebarian, H. R.}, title = {Evaluation of Trichoderma Isolates for Biological Control of Charcoal Stem Rot in Melon Caused by Macrophomina phaseolina}, abstract ={Trichoderma harzianum (T39), T.virens (DAR74290), T.viride (MO), T. harzianum (M) and TrichderminB a commercial formulation of T. harzianum(Bi) were evaluated as potential biological agents for the control of charcoal stem rot in melon caused by Macrophomina phaseolina. Cell-free metabolites of T. harzianum(M), T. harzianum (T39) and T. virens (DAR 74290) inhibited growth of M. phaseolina completely in vitro and appeared to be fungicidal. T. viride (MO) inhibited fungal growth from 34.9% to 71%. T. harzianum (T39), T. harzianum (M), T. virens (DAR 74290), T. viride(MO) and T. harzianum (Bi) were tested for their ability to protect melon plants from disease caused by M. phaseolina in a glasshouse experiment. The percentage of stand plants with the antagonist alone or in combination with the pathogen was significantly (p<0.05) greater than in plants inoculated with the pathogen alone. The percentages for the stand plants in treatments were as follows: T. harzianum (T39), T. harzianum (M), T. virens (DAR 74290), M. phaseolina, M. phaseolina + T. virens (DAR 74290), M. phaseolina + T. harzianum (T39) and M. phaseolina + T. harzianum (M),at 95, 100, 97.5, 15, 64.25, 75.25 and 47.55 percent respectively. The percentage for the stand plant in the commercial Trichodermin B + M. phaseolina treatment (96.7%) was greater than for M. phaseolina alone (46.7%) and demonstrated the best result in the control of charcoal stem rot in melon.}, Keywords = {Biocontrol,Charcoal stem rot,Melon diseases,Soilborne pathogen,Trichoderma}, volume = {8}, Number = {3}, pages = {243-250}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10325-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10325-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Samadi, A.}, title = {Phosphorus Sorption Characteristics in Relation to Soil Properties in Some Calcareous Soils of Western Azarbaijan Province}, abstract ={Phosphorus (P) sorption in soils is a key process governing its availability to crops. There has been scanty information available on the P sorption characteristics of calcare-ous soils of Western Azarbaijan Province, Iran. In this study, P sorption characteristics and their relationship to soil properties were determined in 36 soil samples belonging to 15 agricultural soil series located in the south of Urmia, Western Azarbaijan Province. Total CaCO3 contents ranged from 10 to 48.5%. Active CaCO3 contents ranged from 1.7 to 20% and were significantly related (r = 0.61, P<0.001) to the total CaCO3 of the soils. NaHCO3-extractable P contents ranged from 4 to 38 mg P/kg soil. The amount of P sorbed by the soils differed among various soil series. The results showed that equilibrium solution P concentration (EPC) was lower (<0.2 mg/L) than the requirement for most crops. The amount of P adsorbed by the soils at 0.2 mg/L EPC ranged from 5 to 114 mg/kg soil. The phosphate adsorption was well described by the Freundlich (r2 = 0.96) and Langmuir (r2 = 0.88) isotherms. The Langmuir maximum adsorption (Xm) and Freundlich coefficient (aF) estimated from Langmuir and Freundlich equations ranged from 127 to 238 mg P /kg soil and from 43 to 211 mg P/kg, respectively. Soil clay content was significantly related to the soil P sorption indices, P0.4 (P sorbed at 0.4 mg P/L, r = 0.40, P<0.01), PBC (P buffering capacity, r = 0.54, P<0.001), aF (r = 0.48, P<0.01), and Xm (r = 0.40, P<0.01). Total CaCO3 and active CaCO3 were found to be less important factors affecting P adsorption.}, Keywords = {Calcareous soils,Active CaCO3,Olsen P,Phosphorus sorption}, volume = {8}, Number = {3}, pages = {251-264}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-2780-en.html}, eprint = {http://jast.modares.ac.ir/article-23-2780-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Afshari, F.}, title = {Protein Marker Assisted Identification of Yr9, Lr26 and Sr31 Genes in a Group of Iranian Wheat Cultivars}, abstract ={The 1RS chromosome segment derived from Petkus rye carries genes for resistance to three wheat rust diseases, namely Lr26 for resistance to leaf rust (caused by Puccinia triticina), Yr9 for resistance to stripe rust (P.striiformis f. sp. tritici) and Sr31 for resistance to stem rust (P. graminis f. sp. tritici). Since Sec-1 is tightly linked with the three rust resis-tance genes electrophoresis it is a useful method to identify and confirm the presence of three rust resistance genes in current wheat populations. SDS-PAGE was used to examine eight Iranian wheat cultivars for resistance to three rusts. The eight Iranian wheat culti-vars examined were Alvand, Darab 2, Tajan, Nicknejad, Mahdavi, Zarrin, Alamoot and Atrak. The SDS-PAGE results showed that cultivars Mahdavi and Atrak have Sec-1 bands and are therefore likely to carry the 1BL.1RS translocation and the linked genes Yr9, Lr26 and Sr31.}, Keywords = {SDS-PAGE,Rust Resistance,Secalins (Sec-1)}, volume = {8}, Number = {3}, pages = {265-268}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10597-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10597-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Salami, H.}, title = {Agricultural Land Productivity Improvement and Trade Liberalization in Iran: A CGE Analysis}, abstract ={This paper examines the effects of agricultural land productivity improvement on the economy of Iran assuming that the domestic and international trade liberalizations will open up the opportunities to expand market access. A 25-sector computable general equi-librium model was developed to simulate the effects of this policy. The simulation results indicate that enhancing agricultural land productivity while implementing trade policy reform results in an expansion of agricultural sector which, in turn, leads to the expansion of food manufacturing and service sectors and mitigating the problem of unemployment. Furthermore, improving land productivity results in a decrease in the price of food prod-ucts and an increase in real GDP. Consequently, food security enhances and Iranian wel-fare improves. As a result, this is an appropriate domestic policy for Iran. This policy re-sults in an expansion of agricultural sector which in turn leads to expansion of food manu-facturing and service sectors, mitigates the unemployment problem, improves the Iranian welfare as the real GDP increases, and improves the food security in Iran, as the price of food products decreases.}, Keywords = {IRAN,CGE,Land productivity,Trade liberalization}, volume = {8}, Number = {2}, pages = {93-106}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-4061-en.html}, eprint = {http://jast.modares.ac.ir/article-23-4061-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {ShabanaliFami, H.}, title = {Relationship between Different Characteristics of Rural Women with their Participation in Mixed Farming Activities}, abstract ={Since time immemorial, Iranian women have played a pivotal role in agriculture, the largest industry contributing to rural livelihoods. Hence, the present study was conducted in Tafresh area of Iran to examine factors influencing participation of rural women in mixed farming activities in 1999.This was a descriptive- correlation research project in which a total number of 300 rural women were selected through stratified random sam-pling technique and interviewed. A questionnaire was used as measurement tool for which the reliability coefficient was 0.90. According to the findings, sixteen characteristics of ru-ral women had significant relationships with their overall participation in mixed farming. Nine variables, namely, women’s age, husband’s age, crop farming experience, animal husbandry experience, perceived role overload, total energy expenditure, energy expendi-ture in animal husbandry, time spent in animal husbandry and time spent in mixed farm-ing were positively and significantly correlated with overall participation of rural women in mixed farming. Whereas, energy expenditure in mixed farming activities, women’s education, husband’s education, animal ownership, extension contact, energy and time spent in household activities were negatively and significantly correlated with the overall participation of rural women in mixed farming. Stepwise regression analysis revealed that 48 per cent of variation in the overall participation of rural women in mixed farming was explained by three variables: marital status, woman’s education and time spent in animal husbandry.}, Keywords = {Energy expenditure,Mixed farming,Participation,Rural women,Time spent}, volume = {8}, Number = {2}, pages = {107-117}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-7015-en.html}, eprint = {http://jast.modares.ac.ir/article-23-7015-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Javadi, A. and Spoor, G.}, title = {The Effect of Spacing in Dual Wheel Arrangements on Surface Load Support and Soil Compaction}, abstract ={This research explores the possible benefits to be derived from interactions between wheels, for supporting a greater proportion of applied loads in the shallower soil layers. This creates possibilities for reducing the risk of deep soil compaction. Previous research indicated that different interaction modes occurred under simulated wheel arrangements, being mostly dependent upon the spacing between them. Hence, field experiments were arranged to investigate a range of spacings between dual wheels in practical situations. Two field conditions were prepared providing loose and firm surface layers. Dry bulk density, penetration resistance, wheel sinkage and contact area were measured under each arrangement. A clear link was identified between results previously obtained in soil bin tests and those in the field, confirming that spacing has a major effect on the potential benefits. As wheel spacing decreased the interaction increased, inducing a greater resis-tance in the soil surface layers to carry higher loads. The optimum range of appropriate spacings and interaction modes identified in the laboratory tests was found to be applica-ble in the field.}, Keywords = {Compaction,Load support,Wheels,Wheel spacing}, volume = {8}, Number = {2}, pages = {119-131}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-2794-en.html}, eprint = {http://jast.modares.ac.ir/article-23-2794-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {AkbarzadehShoukat, G. and Shayesteh, N.}, title = {Thrips Species Found in West Azarbaijan (Orumieh) Vineyards, and Seasonal Abundance of the Predominant Species (Rubiothrips vitis)}, abstract ={Thrips species injurious to grapes are known as pests in vineyards all over the world and belong to the main pests of grapes in West Azarbaijan, Iran. In this study, thrips species occurring in West Azarbaijan vineyards were identified and the predominant species documented according to their relative abundance at different growth stages. The seasonal abundance of predominant species was investigated by means of yellow sticky trap catches and weekly sampling from vegetative and reproductive organs of vines. Five species including: Rubiothrips vitis (Priesner), Thrips tabaci Lindeman, Tenothrips discolor (Karny), Tenothrips reichardti (Priesner), and Limothrips angulicornis Jablonowski, were collected and identified. R. vitis, constituting 92 and 66 percent of the thrips population on vegetative and reproductive organs, respectively, was found to be predominant. T. tabaci was not found on vegetative organs, but it was found to constitute 32 percent of the thrips found on reproductive organs (flowers). The two species R.vitis and T. reichardti are new records for the Iranian fauna. The number of adult thrips caught by sticky traps was positively correlated with the density of the adults on vegetative (buds and leaves) and reproductive (flower) organs in the first and second generations, respectively.}, Keywords = {Grapevine,Limothrips angulicornis,Rubiothrips vitis,Tenothrips discolor,Tenothrips reichardti}, volume = {8}, Number = {2}, pages = {133-139}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-1923-en.html}, eprint = {http://jast.modares.ac.ir/article-23-1923-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {OmidiTabrizi, A. H.}, title = {Stability and Adaptability Estimates of Some Safflower Cultivars and Lines in Different Environmental Conditions}, abstract ={The stability of ten winter safflower cultivars and lines was evaluated in three different environmental conditions in Karaj, Isfahan and Darab in Iran, a randomized complete block design with 4 replications over three years (1995, 1996 and 1997). Simple analysis of variances of grain and oil yields from each experiment showed significant differences among the genotypes. After conducting a homogeneity test for error variances, combined analysis of variance was performed. An F. test of different sources of variation revealed that the effect of genotype  year  location interactions was significant (P<1%). Analysis of the grain and oil yields using the Eberhart and Russel method showed significant dif-ference for the main effects of genotype and genotype  environment (linear) interactions and non-significant difference for deviation from regression. According to the classifica-tion of genotypes based on the mean of grain and oil yields, coefficient of regression and deviation from regression, the new line L.R.V.51.51 with its high grain and oil yields and stability was selected as a desirable genotype.}, Keywords = {Stability,Safflower,Adaptability,Grain and oil yields}, volume = {8}, Number = {2}, pages = {141-151}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-4404-en.html}, eprint = {http://jast.modares.ac.ir/article-23-4404-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Azizi, F. and Rezaie, A. M. and Saeidi, G.}, title = {Generation Mean Analysis to Estimate Genetic Parameters for Different Traits in Two Crosses of Corn Inbred Lines at Three Planting Densities}, abstract ={The choice of an efficient breeding procedure depends to a large extent on knowledge of the genetic system controlling the character to be selected. The objective of this study was to determine genetic parameters for yield and other traits including some of the yield components under three planting densities, using analysis of generation means (P1, P2, F1, F2, BC1 and BC2) derived from crosses of B73 with Mo17 and K74/1 inbred lines of corn. Analysis of variance reinforced the hypothesis that interaction of plant density on genera-tion means depends on evaluating genotypes and the kind of trait. Generation mean analysis suggested that both additive and dominance effects were important for most of the traits evaluated in this study, but dominance had a more pronounced effect. Epistasis affected the expression of nine traits in both crosses at three planting densities. Expres-sion of epistasis and genetic parameters differed in the two crosses and were influenced by plant density. Plant densities interacted more strongly with epistasis gene action than with additive or dominance gene action in both crosses.}, Keywords = {heritability,Additive,Dominance,Epistasis,Gene action,maize,Variance components}, volume = {8}, Number = {2}, pages = {153-169}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-6196-en.html}, eprint = {http://jast.modares.ac.ir/article-23-6196-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Yousuf, D. D.}, title = {Effect of Variation in Tillage Systems on Maize (Zea mays L.) Establishment and Grain Yield in a Semi-Arid Tropical Climate}, abstract ={On-farm experiments were designed to investigate the response of maize establishment and grain yield to variation in tillage systems. The tillage treatments included arara ploughing followed by zig-zag harrowing and arara ridging (T1); emcot ploughing fol-lowed by zig-zag harrowing and emcot ridging (T2); mouldboard ploughing followed by disc harrowing and mouldboard ridging (T3); disc ploughing followed by disc harrowing and disc ridging (T4); manual ridging (T5). Generally, shallow (0-15.0 cm) tilled plots of T1 showed lower root lengths and root length densities than deep (0.28.0 cm) tilled plots of T4. However, there was higher soil penetration resistance (PR) in T1 than in T4. In-creased PR in the range of 4.0 – 4.5 MPa decreased plant height (Hp), leaf area index (LAI), and maize grain yield (Yg). Reductions in Yg in the range of 35 – 50% can be ex-pected for a reduction in soil moisture contents from 24.2 – 15.7%, w/w. Tillage treat-ment significantly (P<0.01) affected Yg. However, there were no significant differences at P<0.05 in the emergence rate index (ERI), LAI and Yg for the interactions of nitrogen levels  planting methods  tillage treatments.}, Keywords = {Leaf area index,Soil penetration resistance,Tillage systems}, volume = {8}, Number = {2}, pages = {171-179}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-4507-en.html}, eprint = {http://jast.modares.ac.ir/article-23-4507-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Keshavarz, P. and Malakouti, M. J. and Karimian, N. and Fotovat, A.}, title = {The Effects of Salinity on Extractability and Chemical Fractions of Zinc in Selected Calcareous Soils of Iran}, abstract ={Use of saline water for irrigation has shown considerable promise. However, its effect on the solubility and bioavailability of native soil nutrients is not well understood. This study was conducted to evaluate the effects of salinity on the behavior of zinc(Zn) in calcareous soils. The soil samples with different physiochemical properties were collected from four locations in Khorasan province (Iran). The factorial experiment was carried out as a completely randomized design on soils with four levels of water salinity (0, 37.5, 75 and 150 mole m-3 prepared with the same equivalents of NaCl and CaCl2) and four reaction times (0, 10, 20, and 30 days) with three replications. DTPA-extractable Zn was measured in the incubated soil samples after the given reaction times. Different chemical forms of Zn were characterized after 30 days using the sequential extraction procedure. DTPA-extractable Zn increased by 1 to 6.3% with the increasing levels of salinity, and decreased from 8.7 to 3.9% by increasing the reaction time significantly (P<0.05). The determination of Zn compounds by the sequential extraction procedure revealed significantly different forms of Zn with the average amounts in the following order: (KNO3+H2O)-Zn(soluble+exchangeable forms) < NaOH-Zn(organic form) < EDTA-Zn (carbonate form) << HNO3 -Zn (residual). Salinity affected various forms of Zn i.e. soluble + exchangeable, organic and residual. Increasing soil salinity level increased the KNO3+H2O extractable Zn by 20 to 80% and the NaOH extractable form by 8.6 to 43%. DTPA-Zn was significantly correlated with the NaOH extractable form (r=0.98 P<0.05) and with the (KNO3+H2O)-Zn, (r=0.94 P<0.05). It was concluded that increasing salinity redistributed HNO3-extracted Zn (residual) to the KNO3+H2O extractable (soluble + exchangeable) and NaOH extractable (organic) forms of Zn.}, Keywords = {Salinity,Chemical forms,DTPA,Sequential extraction,Zn}, volume = {8}, Number = {2}, pages = {181-190}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-2592-en.html}, eprint = {http://jast.modares.ac.ir/article-23-2592-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Loghavi, M. and Khadem, M. R.}, title = {Development of a Soil Bin Compaction Profile Sensor}, abstract ={Development of sensors to detect the location and depth of hard pans in real time is a major restriction on the application of Site Specific Crop Management (SSCM). In this study, a soil compaction profile sensor equipped with four horizontal operating penetro-meters for on-the-go sensing and mapping of the location and intensity of hard pans arti-ficially formed in a soil bin was developed and tested. The leading edge of a 600 mm long vertical soil cutting blade held four 8 mm diameter, 80 mm long, and 30 degree conic tip stainless steel soil penetrating rods equally spaced at 100 mm vertical intervals. With this arrangement, when the cutting blade was driven into the soil up to a 500 mm depth, the conic tips sensed soil penetration resistances at 100, 200, 300 and 400 mm depths. The penetration resistance force was transmitted by the rod end to the elastic diaphragm of a hydrostatic oil chamber beneath each rod. Each oil chamber was connected to a force magnifying piston and cylinder located off the soil engaging tools. The penetration force was magnified five times before being sensed by a strain gage load cell. Software pro-grams with the capability of discriminating 16 levels of soil compaction intensity were de-veloped for monitoring soil impedances sensed by the soil probes and for converting them to soil compaction maps. For conducting the tests in the soil bin, the sensor mounted on the tool carrier frame was moved along the bin, where artificially formed compacted soil blocks with various densities (1.45, 1.65 and 1.85 Mg/m³) were placed at different loca-tions and depths (up to 500 mm deep at 100 mm increments). While the probe was cutting and advancing through the soil, the corresponding compaction map was simultaneously displayed on a PC monitor, and the soil penetration resistance data of all four sensing tips was displayed and stored in program files.}, Keywords = {Compaction map,Hardpan,Sensor,Soil compaction profile}, volume = {8}, Number = {1}, pages = {1-13}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-8847-en.html}, eprint = {http://jast.modares.ac.ir/article-23-8847-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Masoumi, A. A.}, title = {Physical Attributes of Garlic (Allium sativum L.)}, abstract ={Some physical attributes of two common types of Iranian garlic cloves (white and pink) were identified and compared. A machine vision system was used to determine three di-mensions and both major and minor projected areas of garlic cloves at a moisture content of 42.4% w. b. The geometric mean diameter and sphericity were calculated, as well as the unit mass and volume of cloves were measured. In the moisture range from 34.9 to 56.7% w.b., the unit density, bulk density and porosity for both types were measured. Re-sults showed that the unit density, bulk density and porosity of cloves were affected sig-nificantly by moisture content (p<0.01). The type of garlic had a highly significant effect on the unit density and porosity (P<0.01), and a significant effect on the bulk density (P<0.05). The relationship between volume and dimensions of cloves was established using regression analysis. The effect of moisture content on physical properties of cloves was also expressed by appropriate equations.}, Keywords = {Garlic,Machine Vision,Physical attributes}, volume = {8}, Number = {1}, pages = {15-23}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-11521-en.html}, eprint = {http://jast.modares.ac.ir/article-23-11521-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Bakhshandeh, A.}, title = {Determination of Optimum Row-Spacing and Plant Density for Uni-branched Sesame in Khuzestan Province}, abstract ={There are varying patterns for growing different varieties of branched or non-branched sesame. This experiment was conducted during a two-year period (2000-2001) to identify the optimal practice for cultivation of the uni-branched sesame in the Safi-Abad Agricultural Research Center, Khuzestan Province. The statistical design was set up as strip-plot in a randomized complete block with four replications. Rows were adopted at varying spaces of 37.5, 50 and 60 cm while the plants were arranged horizontally at 5,10,15 and 20 cm. In this way, the density of the plot was surveyed over an area ranging from 83000 to 530,000 plant/ha. Combined analysis of two years, results showed a significant effect on the yield component due to an increase in row-spacing from 37.5 to 60 cm. This increase in row-spacing from 37.5 to 60 cm. could also increase the stem diameter from 16.3 to 19.4 mm, the pod number from 59 to 84 per plant, as well as the weight per thousand seeds from 3 to 3.3 grams. Moreover, an increase in plant spacing from 5 to 20 cm caused a decrease in stem height from 180.2 to 169.7 cm, an increase in stem diameter form 15.8 to 19.8 mm, a rise in pod number from 44.6 to 96.5 and in the seed content from 59.3 to 74.4 per pod. The relevance of the seed yield and row spacing obeyed a falling linear regession curve, while the seed yield and plant intervals showed a non-linear behaviour and estimated a maximum yield at 10 cm distance. Finally, the planting density reflected a non-linear fourth power equation. The maxinum seed and oil yield was then estimated at a density of 200,000–250,000 plant per hectare. In view of higher yield at the 37.5 cm row treatment and the 10 cm plant treatment, together with regressive equations, the above pattern (37.510cm) shall be recommended for uni-branched sesame growing in Khuzestan.}, Keywords = {Plant density,Row spacing,Sesame,Yield component}, volume = {8}, Number = {1}, pages = {25-33}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-3091-en.html}, eprint = {http://jast.modares.ac.ir/article-23-3091-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Pezeshki-Raad, Gh. and Karamidehkordi, E.}, title = {Linking Agricultural Research with Extension: Iranian Agricultural Researchers’ Attitude Toward Collaboration with Extension Workers}, abstract ={This study examines Iranian agricultural researchers’ attitudes regarding collaboration with extension workers and the variables associated with the researchers’ attitudes. Data were obtained using a questionnaire developed by Agricultural Research Centers of Charmahal and Bakhtiari, Isfahan, Safiabad and Khuzestan in 1998. The findings re-vealed that the researchers’ attitudes towards collaboration with the extension workers were generally positive although actual collaboration between researchers and the exten-sion workers was at a low level. Therefore, it seems that lack of an overall strong relation-ship of attitudes with current behavior as well as weak collaboration is related to other factors that need to be studied more, for example management of participation or internal factors in each sub-system of extension or research etc. identified that The following fac-tors/characteristics of agricultural researchers were identified as having a positive corre-lation/association with their attitude towards collaborating with extension workers: higher research experience, greater interaction with extension workers, a lower scientific position or possessing a higher management position, greater participation in seminars and colloquiums related to extension, and the influence/thinking of colleagues and man-agers.}, Keywords = {Attitude,Agricultural Research,Extension}, volume = {8}, Number = {1}, pages = {35-46}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-923-en.html}, eprint = {http://jast.modares.ac.ir/article-23-923-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Jalali, B.}, title = {Fish Parasites in Zarivar Lake}, abstract ={Twenty four ecto- and endo- parasite species were found in different organs of eight na-tive and exotic fish species in Zarivar Lake situated in the far west of Iran. Overall, 1000 fish specimens belonging to the Dactylogyridae, Gyrodactylidae families the Cyprinidae, Poeciliidae and Mastacembelidae families were examined during 2001 and 2002. Of them, five Protozoans, including Trichodina pediculus, Trichodina sp and Myxobolus molnari, a pansporogenic stage of the Myxosporean plasmodia and Ichthyophthirius multifiliis were recorded. Of the Metazoan parasites, 12 monogenean species, mostly belonging to the Dactylogyridae, Gyrodactylidae families and the Ancyrocephalinae subfamily, were found and identified at species and genus level. The number of helminthes reached 15 by adding one Digenea metacercaria (Diplostomum spathaceum) and 2 coelozoic Cestoda species. Crustacean species found on both of native and exotic fishes, belonging to Copepoda and Branchiora orders comprised of Argulus foliaceus and Lernaea cyprinacea, in addition an unknown Argulus was also found on skin and gills of spiny eel which identified to genus level. The only nematode found in the intestine of common carp was identified as Pseudo-capillaria tomentosa. Besides the first record of parasites of spiny eel, the seasonal preva-lence of ligulosis is presented. Additionally, zoogeographical analysis and species compo-sition of parasitic fauna of Zarivar Lake are discussed.}, Keywords = {IRAN,Fish parasites,Kurdistan,Zarivar Lake}, volume = {8}, Number = {1}, pages = {47-58}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-3801-en.html}, eprint = {http://jast.modares.ac.ir/article-23-3801-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Amiri-Tokaldani, E.}, title = {A Model for Stability Analysis of a Multi-Layered River Bank (SAMLR)}, abstract ={River bank erosion can result in considerable riparian land loss and the delivery of large volumes of sediment to reaches downstream. Consequently, the ability to predict the stability and failure geometry of eroding river banks is an important prerequisite for es-timating the rate of bank erosion and sediment yield associated with bank erosion. In this paper a new model capable of analyzing the stability of layered river banks is introduced. The new model takes into consideration the effects of positive pore water pressure in the saturated portion, and negative pore water pressure in the unsaturated portion, of the bank. Also, the role of hydrostatic confining pressure due to the water level in the river and the effects of the water in tension crack on stability analysis is accounted for. Unlike many previous analyses, the failure plane is not constrained to pass through the toe of the bank. However, it considers only planar-type failure mechanism. Finally the bank profile geometry is not restricted to a special case. The new model has been tested using field data sets from a site on the Sieve River in Italy and a site on Goodwin Creek in Mississippi. The results show some agreement between the predicted and observed values of bank sta-bility.}, Keywords = {Bank erosion,Bank stability,Failure plane angle,Layered banks,Negative pore pressure,Planar failure,Tension crack}, volume = {8}, Number = {1}, pages = {61-76}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-10694-en.html}, eprint = {http://jast.modares.ac.ir/article-23-10694-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} } @article{ author = {Samadi, A.}, title = {Contribution of Inorganic Phosphorus Fractions to Plant Nutrition in Alkaline-Calcareous Soils}, abstract ={To evaluate the relationships between soil inorganic phosphorus P (Pi) fractions, the soil P test and plant parameters such as plant P uptake, dry matter yield, tissue P concentra-tion and relative yield, glasshouse experiments and chemical analyses were conducted on 13 calcareous soils from six agricultural and seven adjacent bushland (virgin soil) sites. Four rates of P (0, 15, 30, 60 mg/kg soil) were applied as reagent-grade KH2PO4 to the soils in a randomised complete block design with three replications. Perennial ryegrass (Lolium perenne cv. Roper) was grown and forage was harvested five times over a period of 210 days. Successive harvesting resulted in the depletion of plant available P as meas-ured by NaHCO3-extractable P, which coincided with the decrease in the plant dry matter yield and P uptake. After five harvests, the order of reduction in Pi fractions induced by cropping without added P was Ca10-P>Al-P>Ca2-P>Ca8-P>occluded-P>Fe-P for the vir-gin soils and Ca2-P>Al-P>Ca10-P>Ca8-P>Fe-P>occluded-P for the agricultural soils. The order of abundance of Pi fractions for P treated-soils was non-occluded Al and Fe phos-phate (Al-P+Fe-P)>secondary Ca-bound P (Ca2-P+Ca8-P)>acid-extractable P (Ca10-P)>occluded-P for both virgin and agricultural soils. Although a marked proportion of added P was transformed into less soluble Al and Fe phosphates, successive harvesting had depleted considerable percentages of these fractions. Highly significant (p<0.001) re-lationships were found for P uptake vs. Olsen-P, P uptake vs. Pi fractions (Ca2-P, Ca10-P, Al-P, Ca8-P, Fe-P) and Olsen-P vs. Pi fractions. NaHCO3-extractable P seems to be ade-quate for evaluating plant available P in calcareous soils. However, the closer relationship for the Fe-P fraction vs plant P uptake than for Olsen-P versus plant P uptake indicates that NaHCO3 may not provide the best estimate of plant available P for calcareous soils. Using stepwise regression analysis, it was found that the Ca2-P fraction was most predic-tive of P uptake (60%), total dry matter (68%), relative yield (74%) and Olsen-P (69%), followed by the Fe-P fraction.}, Keywords = {Calcareous soils,Availability,Inorganic P fractions,NaHCO3-extractable P,Plant P uptake}, volume = {8}, Number = {1}, pages = {77-89}, publisher = {Tarbiat Modares University}, url = {http://jast.modares.ac.ir/article-23-1325-en.html}, eprint = {http://jast.modares.ac.ir/article-23-1325-en.pdf}, journal = {Journal of Agricultural Science and Technology}, issn = {1680-7073}, eissn = {2345-3737}, year = {2006} }