Year:2008 | Volume:13 | Issue:1 (SUPPLEMENT)|Papers Count:26

Dairy husbandry projects are important activities in the field of agriculture and information on profitability of these projects can help decision makers in both private and public sectors. In this study financial and economic indicators of the profitability of these projects are examined.Some of the projects in Tehran province as sample units were selected and the estimated financial and economic indicators show that the projects are justifiable.Sensitivity analysis indicates that the policies related to stability of incomes are more important compared with stability of inputs prices. The results also showed that the difference between the financial profitability and economic profitability indicates that government assistance to the producers is very important policy and continuation of this policy is recommended.

The superiority of free trade is one of the profession's most cherished beliefs, yet international trade is rarely free. Perhaps no other area of economics displays such a gap between what policy makers practice and what economists preach as does international trade. In this investigation, Tariff protection procedure of agricultural sector is analyzed by statistical analysis approach during the period of 1363-84 in Iran.agricultural sector's tariff regime is characterized by i) a high average tariff ii) an extremely dispersion of tariff levels across tariff lines, iii) significant amount of tariff escalation and ix) a deep gap between average nominal tariffs and import-weighted average tariffs. High tariffs appear consistent with the political economy equilibrium in Iran. To assess tariff structure of agricultural sector, one first needs to understand what determines that structure in Iran .consequently, Several analytical propositions are derived that are broadly consistent with the stylized and observed patterns of tariff protection in developing countries: i) nominal protection rates that escalate with the degree of processing ii) higher average tariff protection in agricultural sector compared to all developed countries agricultural sector (and even many developing countries agricultural sector) and finally often iii) higher agricultural sector's tariff protection compared to non-agricultural sector's tariff protection. This investigation urges designing a long-run optimum tariff structure in which trade reforms and rational tariffs reduction are aimed. It could lead to trade liberalization and pave the way for joining to World Trade Organization.

The purpose of this study was to investigate the effective factors regarding wheat farmers' technical knowledge toward farm's water management. The research design used in this study was a descriptive-correlational. The population of this study included all wheat farmers in Nahavand Township who had used irrigation method to cultivate their farms (N=15364).Stratified proportional sampling technique was applied to select the subjects (n=375). Content validity was achieved by a panel of experts. A pilot test was conducted to determine the reliability of the questionnaire and Cronbach Alpha coefficient of 0.81 was achieved. The result of this study showed that the relationship between the variables of age, experiences cultivating agricultural crops and experiences cultivating wheat were significantly correlative and negatively linked with their technical knowledge about farm's water management, while relationship between the variables of educational level, yield per hectare, size of farm land, size of irrigated wheat farming cultivated, level of economical status, extension contacts, social participation and use of communication channels were significantly correlative and positively linked with their technical knowledge about farm's water management.It is worthy to note, significant differences were found in the mean score of wheat farmer's technical knowledge regarding farm's water management in relation with the use of extension services, type of farm land ownership, type of water source and the method used for irrigation. Also, variables of yield per hectare, use of communication channels, and level of extension contacts, social status and wheat farmers' economical status predict a variation of 60.6 percent of the wheat farmers' technical knowledge toward farm's water management.

This study was to assessment factors effecting on application of internet and website in academic activities of graduate students at the college of agriculture in Azad University- Science and Research Branch. This was a descriptive and correlation method research. Population for this study were all graduate students in college of agriculture at Azad University Science and Research Branch studying at 2005- 2006 academic year (n=671). From this population 244 of them selected through random sampling. After collecting questionnaires, data was analyzed by using SPSS win software. The finding shows that there are a significant correlation in using internet for education-research with recognizing of internet, using internet in school and during undergraduate levels, skill in English language, familiar with internet programs, be able to use search engineer, computer skill, age, grade point average, student encouragement by instructor, having personal computer at home, educational level, field of study, and job status. Multiple-regression analysis shows that about 42 percent of the differences in the amount of using the internet are predicted by independent variables.

This study, was attempted to achive the goals including: 1) posibility of nonchemical method application (Cultural practice-pruning) in order to control of Anarsia lineatella, 2) Assessment of pruning intensity and its effect on pest control and quantitative and qualitative traits of peach, 3) Recommendation for suitable pruning intensity on peach trees in Qazvin region. This experiment was carried out during 2001 -2002 in Feiz abad research station in complete block design with 3 replications.Treatments included, pruning at 1/4, 1/2, 3/4 shoot length that was carried out before blossoming. The factors involved in assessing, consisted of the fruit weight, fruit volume, number of damaged shoots and number of damaged fruits. Results showed that, pruning affected peach twig borer control and fruit quality and quantity increase.Increasing of pruning intensity was related to reducing of pest damage and better fruit characteristics. The lowest pest damage was correlated with the highest fruit weight and volume in 3/4 and 1/2 pruning intensity.

Splwerolecanium prunastri is a serious pest on almond (Prunus amygdalus) trees in Chahar-Mahal & Bakhtiari province. Coccinellids are the most important natural enemies of the pest in the province. During 1999-2000, specimens of coccinellids were collectcd using shaking method in weekly intervals. Collected specimens were identified based on male genitalia and external morphology characteristics. Identified species belongs to 3 subfamilies, 4 tribes and 7 genera. Exochomus quadripustulatus has the highest density among collected species. Adults of E. quadripustulatus were appeared gradually from early March and their population peaked at early April.Larvae of the coccinellid increased in their activity and population from late April along with decrease in population of adults. Larval population were peacked from late April to early May and afterward decreased gradually. Adults were emerged from early May. Population of this gegneration were increased rapidly and peaked at late May-carly June. Overwintering adults were found from early September on the foliage and their activity peacked at early November.

Tetranychus urticae Koch is one of the most serious greenhouse crops pest that requires an integrated pest management program (plant resistance, biological control and so on) to be controlled. In this study, the antibiosis resistance levels in three cucumber cultivar hybrids (Sina, Sultan and Fadia) to this pest were evaluated.Biological and demographic traits of T. urticae population such as developmental time, survivorship rate, fecundity, adult longevity, the intrinsic rate of increase and generation times were determined on plants in the five-leaves stage in a growth room at 25±0.5oc, RH 65±5% and 16L:8D hours by clip cage and leaf disk methods.According to results, Fadia with the longest developmental time (11.07±2.4 days), the lowest survivorship (90.3±9%) and fecundity (10.33±1.02 females) and rm (0.155+0.01), the shortest adult longevity (6.4±2.6 days) and the shortest generation time (9.93±0.84 days) showed the most signs unsuitability of this cultivar for T.urticae population development; in contrast, Sina was the most suitable plant host for the two-spotted spider mites among the tested cultivars.

Benthic macro invertebrate species are differentially sensitive to many biotic and abiotic factors in their environment. The field biotic index (Hilsenh off, 1988) is based on family level identification of water arthropods, amphipods and isopods. An interest in environmental quality is one of the major reasons for the study of aquatic insects.The idea of using the aquatic insect community to "indicate" the degree of purity or pollution of a body of water is over half a century old. It is based on the concept of indicator organisms and tolerance levels. During 2005-2006 studies were carried out on the field biotic index of Parishan Lake in Kazeroon region (South of Iran), using aquatic insect’s fauna. A total of 38 families were collected and identified sin 30 habitat codes of Parishan Lake. Using Hilsenh off formula for biotic index (BI): where ni is the number of specimens in each taxonomic group (family), ai is the pollution tolerances core for that taxonomic group, and N is the total number of aquatic insects in sample. Aquatic insects are given a numerical pollution tolerance score (ai) ranging from 0 to 10 (Hilsenh off, 1987). The value is based on field and laboratory responses of these organisms toward organic pollution. Zero taxa are extremely intolerant of low dissolved oxygen; taxa with score of 2 through 9 are tolerant to varying degrees; taxa which can survive great amounts of pollution are scored 10. In this survey, biotic index of Parishan Lake was 5.62 and evaluation of the water quality based on the biotic index was calculated. Water quality of Parishan Lake was fair (fairly significant organic pollution) during this survey.

Rice is a plant have high water requirement. Therefore, management, agronomic and genetic studies for reduce of water use was done. In this study consumptive use water of rice in Droodzan-Fars irrigation and drainage network was evaluated. Six points of irrigation network was selected for determination of rice consumptive use.Total of growth period is divided to three stages consist of: nursery, paddling and growth in main field. Consumptive use of rice in three stages was studied. Water use of rice in main field determined with field measuring, then regarding to field properties and common methods in this region, consumptive use of two stages, nursery and paddling was estimated. Total of water use in these stages will be consumptive use of rice plant in this region.Results was shown, consumptive use of water in paddy field is more affected to seepage and deep percolation and growth period, too. Finally, maximum and minimum of consumptive use water of rice plant are 14523 and 10177 m3/ha, respectively.

In this research, Gardner method was used for measurement of unsaturated soil hydraulic conductivity by measuring the volume of outflowing water with respect to time in pressure plates apparatus for five pressures of 03, 1, 5, 10 and 15 bar. The predictive methods of van Genuchten, Saxton et al., and Zand-Parsa were used for estimating the unsaturated soil hydraulic conductivity for 20 soil samples. The soils were collected from Marvdasht and Fasa regions in Fars province, and had different textures groups. The results showed that Saxton et al.'s method was the least accurate of three above named methods in predicting unsaturated hydraulic conductivity in most soils. On the other hand, van Genuchten method had the least differences with measured data. Therefore, on the basis of limited data gathered in this experiment we can conclude that van Genuchten method is the superior method due to its simplicity and wide testing across the world. However, since the Zand-Parsa method in many soils tested by- us gave closer results to experimental values than van Genuchten method, therefore, Zand-Parsa method, which is based on specific liquid-vapour interfacial area around the soil particles, can be used as a new approach for estimation unsaturated soil hydraulic conductivity. Zand-Parsa method uses the van Genuchten equation for estimation soil moisture characteristics curve, and the thickness of water layer and the specific liquid-vapour interfacial area around soil particles could be determined at each water content.One advantage of Zand-Parsa method is estimating unsaturated soil hydraulic conductivity function without needing a value for soil saturated hydraulic conductivity, which is in contrast to the van Genuchten and all other empincal methods of estimating soil unsaturated hydraulic conductivity.

Water for paddy fields irrigation is getting scarcer in Guilan. water input can be reduce by reducing ponded water depths to another water managements. The research was conducted a RCB design with 4 treatments and 3 replications at rice research Institute of Iran, Rasht in one rice variety consisted of Hashemi. The results over this and another research of Hashemi variety showed, water saving was on average 40% with yields reductions of only 10%. Water Productivity and Water Use Efficiency were 0.28-0.75 and 0.29-0.92 Kg grain per water. Total rice production can be increased by using water saved in one location to irrigation new paddy field in another. If this is not done, a strategy of saving water at the field level potentially threatens total rice production at large.

This experiment was performed in 2004 to evaluate the effects of different rates and methods of nitrogen fertilizer application on morphological characteristics and yield of Melissa officinal is L under field conditions. The treatments were consisted of two levels of pure nitrogen fertilizer (4.5 and 6% from urea) applied as solution on foliage, and two levels (60 and 90 kg/ha) applied through the soil and the control (applied in three stages at the end of vegetation growth and prior to reproduction stage.The experiment was carried out under Randomized Complete Block Design with 4 replications. Some characteristics such as plant height, tiller number, leaf length and width, stem diameter, canopy number or lateral stems, internodes length, root length and weight, shoot/root ratio and dry matter were measured. The results showed significant effect of fertilizer treatment on plant height, tiller number, stem diameter, canopy, root length, root weigh, shoot/root ratio and dry matter yield at 1% and leaf width at 5% levels. The highest plant height, tiller number, canopy, root length and weight was absorbed in the 90 kg/ha treatment (solid nitrogen application in the soil). Whereas, the highest biological yield observed in the 60 kg/ha treatment (solid nitrogen in the soil). Spraying 6% of pure nitrogen on foliage had the highest effect on shoot/root ratio.

Agricultural section is regarded as the economic development basis in economic, social and cultural development programs of Iran. The statistics and reliable data portray more advantages in the sector compared with other economic sections. Based on this notion, more labor productivity and added values, in every branch of investment, are mainly devoted to agriculture. Sub branch of agronomy and horticulture in Central Province with having 371 thousand hectares under cultivation of permanent and annual products which are regarded prominent from social and economic point of view.Despite this, some challenges and problems have prevented the full utilization capabilities. The present survey based on survey method is apt to the recognition of the challenges and problems to eradicate them. The statistical society include: managers, experts and extension agents in sub branches of agronomy and horticulture in Jihad Agriculture Central Province Organization. The experts and extension agents' sample quantity was determined by the use of Cocran formula and for managers, it was through census that was about 199 people. The research findings showed that the external problems and challenges were more the issues of development prevention than those of internal in the mentioned province. The most distinguished external problems in agronomy and horticultural sectors were the lack of law and rules to support from the economic collapse of the sectors and the obligatory regulations about generative units' economic and standard status of the districts, and the lack or weakness of packaging, processing, transport, marketing and distribution of agricultural products were of the main concerns. The main determining factor of challenges and problems in the traditional and life based agriculture was 49.3 percent. In order to reduce or eradicate the mentioned problems, the following steps should be taken: developing farmers' extension and educational programs and also using experts' skills and abilities as counseling for the farm.

In order to determine the most important traits that affecting grain yield of com, a field Study was conducted similary in 1999 and 2000, in Khoramabad, as a split-factorial in RCBD in four replicates. Drought treatments were the plant irrigation after soil water reached 70% (without stress), 60% (medium stress), and 50% (high stress) of FC as a main factor and Zn (0, 10 and 20 kg/ha Zn S04, 7 H20) and P (0 and 150 kg/ha P205) as factorial were the factors of this design. Grain yield was positively correlated with yield components (ear No. per m2, row No. per ear, grain No. per row, 100-grainweight), relative water content, leaf area index, biological yield and harvest index; but negatively correlated with straw yield. According to the stepwise regration analysis grain and straw yield were the most effects on harvest index, and on grain yield were yield components in different levels of drought stresses. Other traits affected on straw yield differently. Path analysis showed that grain yield was most direct effect on harvest index in different levels of phosphorus. Ear No. per m2 was the most effect on grain yield in without and medium stresses, but row No.per ear in high stress. With increasing in phosphorus application above critical limit, the direct effect biological yield on straw yield was increased, showed that the effect of grain yield on harvest index decreased.

In order to direct-seeding of rice for wet-land A hand operated (drum seeder) was manufactured at Iranian agricultural Engineering Research Institute. This machine was made of light weight tubing and sheet metal and there was not any measuring device.This machine had 4 hoppers and 2 rows of drilled holes on drums (hoppers). Drums was driven by cage wheel and seeds was dropping to puddle soil through holes. The machine handled to Mazandaran province. Transplanted method (T1), direct seeding in wet land by broadcasting (T2) and direct seeding by using drum-seeder (T3) were compared in A Compele rondomized Design whit 3 replications. Pulling force, Field efficiency, Effective Field Capacity, uniformity factor, yield and yield components were measured. Results showed that grain yield was significantly (p<05) affected by treatments and the maximum yield was obtained from T1.However the yield of grain in T3 (using drum seeder) was higher than T2. Althogh statistical differences between them were not significant. Due to lake of grain tube and covering device The sowing uniformity factor was high. The required man-h per hectare and time of sowing per one hectare was redused to 1/7 and 1/20 respectively.

Inoculant of Brady rhizobium japonicum bacteria is one of the important factors affecting soybean yield. To study the effects of farmyard manure, mineral nitrogen and different bacterial strains on seed yield of William’s cultivar, an experiment was carried out during two years (1991-1992) at research field of Karaj. A strip-split plot design was used with four replications.The treatments were consisted of horizontal strip (0, 30 and 60 kg h-l mineral nitrogen); vertical strip (0, 5 10 ton h-l farmyard manure) and four bacterial strains (Helibioagri) (first strain), Grip (second strain), A sofix (third strain) and control (seeds without inoculants). The complex analysis showed that, in presence of Bacterial strains, application of farmyard manure and mineral nitrogen could be avoided. Bacterial strains had positive significant effect on seed yield and increased them 68, 95 and 93/7 percentages for first, second and third bacteria strain, respectively. Generally, different rates of farmyard manure and mineral nitrogen caused different responses of bacteria, but second strain (Grip) produced the highest seed yield among strains under both conditions (control and using bacteria). These results mentioned that determination of manure use threshold is necessary. In fact, the results of this study emphasized on complex analysis for separating year and other traits effect.

In this study, the decay resistance of acetylated Iranian beech was investigated against the white rot fungus Tramets versicolor. Iranian beech (Fagus orientalis), which is a nondurable wood was modified with acetic anhydride at different temperatures, concentrations and times without using any catalyst. Aceylattion of beech was determined by calculating volume change (Ve) and weight percentage gain (WPG) after solvent extraction using acetone. Different WPGs were obtained at ditTcrent conditions. VC increased linearly with increasing WPG. The decay resistance of the acetylated wood was studied according to ASTM D1413 standard against Tramel. versicolor.Weight loss (WL) due to decay was reduced significantly when WPG increased. A WPG of 17% was found to be the threshold level of the acetylated wood.

In this study some physical characteristics of poplar (populus nigra var pyramidalis) wood, heat treated whut linseed oil was investigated. For comparison of time and temperature effects on those characteristics, three temperature stages and two time levels was selected.Preparations of samples were according to ISO standards regulations. The results of this study shows significant differences in effects of treatment temperature, also insignificant differences in time effects and shows that in general to use heat treatment whit linseed oil in 200 Co temperature in 4.5 hours, give the best results between six different treatments that were employed. Interaction effects between temperature and time, only was seen in water absorption of samples.Moisture contents of wood decreased from 6.02% in control samples to 3.91 in wood samples that treated in 220 Co for 4.5 hours. The least radial, tangential and volumetric shrinkage in treated samples was seen in 200 Co temperature. Amount of wood's water absorption which was 117% in untreated samples was decreased to 24.94% in samples that were treated in 200 Cin this conditions improvement of ASE were, hours' \for' that showed poplar, Color changes was noticed as a qualitative parameter. reached. wood samples after all treatments become darker

To study of Beech Wood Flour as high -density polyethylene reinforced, composites product were used, The reinforced percent in four levels 10, 20, 30 and 40 percent and the dimension of reinforced particles reinforced in four levels with mesh size 40, 60, 80 and 100 with high -density polyethylene were mixed. Also of anhydride maleic polyethylene as coupling agent was used. Composites were product using two method Extrusion and Resin injection molding, and finally their Physical strength was measured. The results showed that in reinforced 1° percent and mesh size 60, water Absorption after of 24 hours immigration in Beech wood flour with high - density polyethylene composites water Absorption percent minimum were. Also of reinforced percent 1o and mesh size 40 Thickness swelling minimum after of 2 hours immigration in Beech wood flour with high -density polyethylene composites view that.

This research down with aim. of study of substitution possibility of bagasse neutral Sulfite semi chemical (NSSC) instead of division of wood pulp for production of newsprint paper in Mazandaran wood and paper complex. Cooking of pulp with use of chemicals of Mazandram wood and paper factory equal to 20 percent (in dry material basis) in 40 minutes time and 170oc heat. After that bagasse pulp refined with (PFI Mill) refiner to 400±25 CSF Freeness and mixture with CMP pulp of Mazandaran and paper factory. Bagasse pulp in ratio 20%, 30%, 40% and 100% of (pure bagasse).Mixture with CMP pulp of Mazandaran wood and paper factory with 350±15 CSF Freeness. Bleached long fiber pulp (import) with 550±15 Freeness in 20% level mixture with CMP pulp of factory as blank. One hand sheet with 60 gr/m2 basic weight make from each pulp. Finally: strength properties of hand sheet were determined with used of TAPPI standard. Studies show that, with increasing bagasse pulp, the strength index like Tensile Strength, Burst Strength and Breaking length increased, The only exception was tear Strength, probably the reason of this subject can related to the 20% long fiber pulp in blank sample because long fiber is one of the major factor that influence tear strength and increase it.

To study the influence of water absorption on Flexural properties of Wood-plastic composites (WPCs), The WPCs made of virgin and recycled high density polyethylene (as resin) and 4 types lignocellolusic fillers (wood flour, MDF waste, particleboard waste and rice hull) at 60% by weight fiber loadings, were manufactured using a dry blend/hot press method. The prepared specimens were immersed in water for 1 and 4 weeks. Flexural specimens based on ASTM D7031-04 were tested. The results showed that the flexural modulus and strength were affected by polyethylene (virgin or recycled), type of used fillers and immersion time in water.

This research is commissioned in order determine the Yellowness variation of chemimechanical papers produced in the wood and paper factories of Mazandaran when sample treating with metal ions of medium elements and methods of them reading. Two types of chemimechanical paper samples were prepared: bleached and unbleached papers.Samples included two types of smears:1. First, The samples were smeared with EDTA in different densities. This process ended in neutralization of existent ions in CMP paper samples.2. in the second stage treatment, after dehydrating each of the above- mentioned samples that were combined with EDTA, The CMP samples were smeared with solvents including metal ions of medium elements and then put them under the radiance of UV Black Light lamps.One of the objectives of this research was to determine what kind of effect could have different metals on the Aging and Yellowing process. In the final stage, the light specification of samples such as Yellowness was measured. The highest spoiling effect on the yellowing process was determined to be F e2+ ion and the lowest effect was issued by Al3+ ion. For decreasing the effect of each metal ion, increasing the density of EDTA, decreasing the pH of pulps and methods such as methylation methods were suggested.

Because of apparent similarity, wood identification is very complicated. In this research cross section of 10 species of diffuse- porous wood of Iranian northern forests (Hyrcanian) with loupe have been studied precisely. The species which were similar have been situated in same group.All 10 species, expect of Juglans spp were Diffuse - porous wood and divided to 4 groups (1. Fagus orientalis and Platanus orientalis 2.Carpinus betulus and Alnus glutinosa 3. Pterocarya fraxinifolia, Diospyros lotus, Juglans regia and Ficus carica 4. Betula alba and Populus nigra). Apart from color and texture of species, distinction or indistinction of tree ring, kind of rays and its visibility and presence and lack of axial parenchyma are 4 important characteristics which have important role in identification of 10 above Iranian Diffuse - porous wood.