Year:2006 | Volume:12 | Issue:1|Papers Count:25

In addition to high nutritional value of almond, it is one of the most important exportable products in Iran.Thus there is a back ground for policy makers to put more effort to increase almond production. In the second and third Social, Economics and Cultural development programs, special attention has been made towards development of almond cultivation in the country. Chahar Mahal Bakhtiary with appropriate natural situation such as 9(M3) annual water and 81000 (ha) sloping lands, could be one of the important region for development of almond in the country. In this study an attempt was made to investigate the comparative advantage of almond production in the province, using Net Social Profit (NSP), Domestic Resource Cost (DRC) and Social Cost – Benefit Ratio (SCB) indicators. The possibility of increasing yield in order to improve the comparative advantage condition was examined by estimating Technical Efficiency, applying Stochastic Frontier Production Function. The computed value of NSP, DRC and SCB indicators were 17960108 (Rials/ha), 0.26 and 0.29 respectively. This indicates the comparative advantage of almond production in the region. The mean technical efficiency was equal to 0.81 which means there is potential to the yield of almond.

Comparative advantage in production is one of the social profitably criteria. Whereas the importance of potato in Iranian’s food, price fluctuation and high demand by consumer, social profitably of potato and effect of policy analysis on producers with policy analysis matrix method in Iran for 1379-80 farming years was performed. The information of the study was provided from the libraries, and FAO. The results of policy analysis matrix (PAM), indicated that Iran has comparative advantage on potato production (DRC=0.54), nominal protection coefficient on product indicated the indirect tax on potato production (NPC=0.49), nominal protection coefficient on input indicated the indirect subsidy on input (NPI=0.54) and effective protection coefficient indicated that, the indirect tax is more than the subsidy that paid for input, by government. By another word the government policy for paying subsidy on inputs should be changed to effective system.

The policies of trade liberalization have Economy wide effects. Many of researchers believed that trade liberalization should result in a free trade system in a way that all of the trade distortions can be eliminated. Limiting the government intervention with economical activities has been depart for Tow decades. Iran is one of the countries aimed at trade liberalization polices. Thus in this paper the effects of trade liberalization on production, demand, export & import of wheat & pistachio has been studied. To get the purpose of level of International trade (LIT) criteria has been used. The necessary data were obtained from www.fao.org. The econometric methods were used to estimate the models. The results showed that the LIT affects domestic supply of wheat & pistachio and export of pistachio, while has a negative impact on both domestic demand and import of wheat.

Feeding behavior of Exochomus nigromaculatus was studied. Feeding capacity of each larval stages of coccinellid was determined under four constant temperatures, 20, 25, 30, and 35ºC and 65±5% R.H. and L/D: 14/10 photoperiod, fed on Aphis nerii. Feeding capacity of adults was counted. During feeding the larvae and adults of coccinellid pierced the cuticle of the preys and sucked the contents of their bodies. Food consumption in fact, was increased with rising temperature. Total food consumption, in fact was changed only slightly with rising temperature and showed that the increase in developmental rate accompanying a rise in temperature naturally resulted in higher predation rate, digestion and absorption of food. Food consumption study of adult coccinellids under laboratory conditions of 30ºC, 65±5% R.H. and L/D: 14/10 photoperiod, revealed that, mean maximum daily feeding rate was 56.4 nymphal stages of Oleander aphid during four weeks of coccinellid lifetimes.

In order to control of S. sclerotiorum, the causal agent of crown and root rot of sunflower biologically, nine highly effective Trichoderma isolates were selected. Two (J1 & J2) and three isolates (J3, J4 & J5) of T. harzianum were isolated from sunflower field soil of Ormiah and Khoy respectively. T. virens, T. harzianum (J6), T. viride (E1) and T. viride (E2) on the other hand were isolated from edible fungi substrate.The above mentioned isolates were evaluated for parasitism, competitive saprophytic ability, inhibition effects of volatile metabolites and culture filtrates and colonization compact on S. sclerotiorum. Microscopic studies showed that all of the isolates disintegrated hypha of S. sclerotiorum through antibiosis mechanism. In addition, T. harzianum (J1 & J2) and T. viride (E1 & E2) hypha grew towards and coiled around the S. sclerotiorum hypha. Dense coils of hypha and degradation of the Sclerotinia hyphae were observed in other stages of the parasitism. Furthermore, T. harzianum (J1) forming short branches and appressorium-like structures which aided in holding and penetrating the host cell wall. In competitive saprophytic ability test, T. virens and T. harzianum (J6) performed more effective than the others, so that, after 5 and 6 days both covered the whole colony surface, respectively, and prevented from forming sclerotium. In colonization ability test, T. harzianum (J1) and T. harzianum (J6) performed more effective than the other isolates, therefore, after 6 and 8 days both were covered the whole colony surface, respectively and prevented from forming sclerotium. In volatile antibiotics test by means of superposal petri-dishes method, T. harzianum (J1) was the most effective isolates which inhibited the mycelial growth of S. sclerotiorum by 77.77%. In non-volatile antibiotics i.e. Culture filtrates effect test on inhibition of mycelial growth, T. harzianum (J6) was more effective to inhibit the mycelial growth by 78.88%. It delayed the myceliogenic germination of sclerotia of S. sclerotiorum more effectively than the other isolates.

Nabis capsiformis Germ. (Heteroptera: Nabidae) and Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae) are important predators of Creontiades pallidus Ramber (Het., Miridae).The main purpose of this study was to determine preference of N. capsiformis and C. carnea to different nymph instars of C. pallidus. Individual predators were presented to equal combination of prey nymph stages for 24 hours and then the numbers of eaten nymphs of each stage were counted. Experiments were carried out in growth chamber at 26±1°C, 50% RH and a photoperiod of 16:8 (L:D) h. The second instar larvae of C. carnea and also first to fifth instar nymphs and adult females of N. capsiformis were selected and different nymph instars of C. pallidus were exposed to above mentioned predators to determine the rate of preference.Different nymphs of C. pallidus that were used in preference experiments were first, second and third instars for larvae of C. carnea, second and third instars and adult females of N. capsiformis, first and second instars for first instar nymphs and second and third instars for fourth and fifth instar nymphs of N. capsiformis. The results indicated that second instar larvae of C. carnea and second to fifth instar nymphs and adult females of N. capsiformis preferred the second instar nymphs of C. pallidus for feeding. The first instar nymphs of N. capsiformis preferred first instar nymphs of C. pallidus for feeding and it may be due to their (prey and predator) small size.

Forest which is one of the most valuable natural resources, has got a considerable protective role in biological and ecological evolution and its economic and environmental aspects is getting progressively more important. Forest ecosystems, having spent a long time to reach their present situation, play an effective role to keep balance in nature. Unfortunately in spite of these advantages, in theoretical and practical forest management which has figured in forestry plans in the north of Iran, just economic aspects of forest productions has been considered and outdoor recreation uses, environmental affairs, forest site capability and its mutual relationship to economic and social matters are not completely inspected. These parameters are so important and must be recognized in the basin area. On the other hand, industrial development and high rate of population growth has caused many social and environ mental problems such as farming and natural resources reduction so considering sustainability and survival of forest ecosystems in a way which would lead to both suitable economic production and effective environmental roles is an important and vital issues. In the first step of the following research, ecological parameters, consisting of physical parameters (physiography, topography, soil, geology, climate, hydrology and …), biological parameters (vegetation cover and wild life) and socioeconomic parameters were studies and recognized. Then produced data (several maps and reports) were digitized and integrated by geographic information system (GIS). The final information coverage which was obtained from data analysis and integration consists of environmental units and all characteristics of each unit is available in the from of database in the mentioned information coverage. The environmental units were evaluated by designing a specific environmental evaluation model (site capability evaluation) and giving privilege to ecological parameters so forest was divided to four main land uses: commercial forests, rehabilitated forests, protected forests and conserved forest. There is also a tourism land use (extensive and intensive out door recreation) which is compatible with forest land uses. Specific evaluation model is based on following models: Makhdoum ecological model, Bibby forest land capability classification model and FAO land evaluation model for forestry. It is necessary to mention hat Makhdoum model (with little changes and omitting the ineffective parameters) is used for tourism use determination. Effective ecological parameters on forest site capability were recognized and used as evaluation criteria in specific evaluation model this process was performed by using Lorey average height of trees which was applied as an index to show the difference between sites. Minor sample models were recognized to investigate the method for applying evaluation results in forest activities management. The research consequences is Kazemrood region shows: firstly altitude, slope, soil (type, depth, texture and drainage), climate are the effective ecological (physical) parameters on site capability. Secondly site capability evaluation by using specific evaluation model has presented better results while evaluation methods based on giving privilege (either applying weight of parameters or not) is not rejected and it com be provided to determine location of fields which are appropriate for a special kind management. Thirdly applying socioeconomic characters of environmental units is incompatible with one of the hypothesis of research which is related to sustainability and survival of forest ecosystems. Socioeconomic studies should be only used in the programming, used to solve the problem of livestock and human being in the north forests of Iran.

Needleleaves have been planted in the country for almost half a century. One of the exotic species is the elder pine which has been planted on a large scale in different regions. The site covers an area around 3400 hectares in the west of Mazandaran. In this study 120 round-shaped samples were randomly chosen, each being 500 m2, and the quantitative characteristics of trees were measured. The effects of some environmental factors, the correlation of the variables using the F test, and multifactorial analysis of variance and stepwise linear regression were examined. The results of this study show the optimal quantitative status of the tree in different site conditions.

To design a furrow irrigation system, various methods have been presented. These methods are based on mathematical or emperical relationships. In this study, three methods of designing furrow irrigation including: the Food and Agricultural Organization (FAO) method, the Soil Conseravation Service (SCS) method, and the Walker and Skogerboe (W & S) method were evaluted in order to determine the most suitable method for recommendation to executive organizations. To compare these methods in Fars Area an irrigated farm with respect to land slope, topography, soil depth, and so on were selected. After plowing, land leveling, and preparing the furrows, gated pipes were installed at the upper end of each irrigation set. Then, field experiments were carried out to determine the maximum non-erosive inflow rate, constants of Kostiakov infiltration equation, Kostiakov-Lewis infiltration equation, intake family, and advance equation within selected sets of furrows. Afterwards, inflow time and the amount of run off were computed for each treatment. This procedure was repeated for two consecutive years. And the results were compared with each other. The differences in average design infiltration depths and the applied ones calculated by F.A.O., W & S, and S.C.S. varied from (-2 to 3.9), (-7.6 to8.6), and (-19.5 to -35.7), respectively. The results of the analyses indicated that F.A.O. and W & S methods showed closer agreements with field data. Hence, the results of this study can be used in design of furrow irrigation system at an acceptable level of confidence.

Wheat is one of the most important food crops in Iran and making efforts for yield increasing is very essential .Since tillage methods have major effects on agricultural productivity thus in this study, effect of different tillage methods on wheat yield were evaluated in silt clay loam (Typic Calcixeroll) during 3 successive years begun in 2000. A Randomized Complete Block Design with six tillage methods were used to evaluate wheat yield in irrigated and non-irrigated practices.Treatments were included T1) subsoiling + moldboard plowing + disking T2) subsoiling + disking T3) moldboard plowing + disking T4) chisel plowing + disking T5) disking T6) no tillage. Results showed that tillage methods had no significant difference in increasing or decreasing bulk density during plant growth stages and %21 soil moisture content has been caused to pulverize almost %60 soil clods with less than 25 mm diameter .Median weighted diameters of the clods (MWD) for T1, T2, T3, T4, T5 were obtained 29, 34, 31, 34, 28 mm respectively. Tillage methods had significant difference on the wheat yield and average of wheat yield for treatments T1 until T6 were 3041, 2581, 2750, 2123, 1940, 1745 kg/ha in irrigated and 2238, 2234, 2258, 2338, 2547, 1509 kg/ha in non-irrigated practices respectively. Also results indicated that deep tillage with subsoiling before plowing (T1) and irrigation during plant growth stages increased wheat yield about 300 kg/ha rather than conventional methods (T3) and minimum tillage with disking (T5) had the highest yield in non-irrigated wheat condition.

A first order Markov chain for forecasting precipitation occurrence, and two different distributions (exponential and gamma) were used for estimating the rainfall amounts on rainy days, by using 33 years historical daily rainfall data, in Bajgah area in Fars province. To determine Markov chain transitional probabilities, rainfall events equal or greater than 5 mm, were considered. The results showed that gamma distribution is more appropriate than exponential distribution, and the mean number of rainy days and mean annual rainfall forecasted by this distribution, were estimated 19 days and 371.2 mm, respectively.Also, the actual mean number of rainy days and mean annual rainfall are 21 days and 394.3 mm, respectively.

In order to investigate the effects drought stress on 48 cultivars of rapeseeds (Brassica napus)a research was conducted in a R.C.B dicign with four replications .In this research some charactristics of it during growing were determined. And also the number 4.5 (according to coding method for rapeseed in growing period. On the basis of silvester- Bradley and micpes, 1984). 4 the same bushes one size and shape per replication were used after taking them to the pots. Some charactristics as Irrigating stage, Temperory and permanent wilting with the other features like potential water of leaves, relative water content (RWC) and water saturation on Deficit (WSD). The number of day s for folding relaxation of leaves. Loosing leaves looping and finally becoming yellow and dry determined. You could use spss software and draw dendrogram figure of 12 factors of resistance and sensitive cultivars to drought stress had be determined.According to the results of experiments, in drought stress. The cultivars Hyola – 42 , syn-1 and PF– 7045.01 had the highest yield with average 2685, 2224 and 1812 kg/ha respectively and two cultivars such as Symbol and Mohican were the lowest rate of Yield with 693 and 692 kg / ha respectively. In dendrogram curve we could see 12 charactristics. The cultivars of Hyola- 42 ,syn-1 Were the top of the table. Mohican and Symbol were in the below of the table. And now by checking of relations between potential water of leaves and resistance to water stress, you can see a correlation of 99 percent between them. In which the other researchers have the same a theories.

To study the effects of the sowing date and the plant density on the yield and the quality of the broad beans (Vicia faba L.) c.v. “Barkat”, an experiment was done in 2001-2002 in“Astaneh”(Gilan province). This experiment was done as a factorial experiment based on randomized complete blocks with three replications. The treatments of the sowing date include two levels (i.e., the first November and the 16th November), and the treatments of the plant density contain four levels (i.e, 17, 22, 25 and 29.7 plants/m2). In this experiment, any characteristics such as yield, number of branches per plant, fresh weight of plant, percent of plant dry matter, percentage of seed nitrogen, weight of 100 seed, number of pods per plant, number of seeds per pod, plant length and number of nodes per plant were measured. Results showed that the delay in sowing date causes the decrease of the node numbers, yield, fresh weight of the plant, the numbers of branches per plant and the number of pods per plant. But it doesn’t have a significant effect on the weight of 100 seeds, the number of seeds per pod and the percent of the of seed nitrogen. In the abovementioned characteristics, a1 treatment (sowing date: November I) had an obvious superiority over the a2 treatment (sowing date 16th of November). Reduction in plant density has increased the number of nodes per plant, the weight of 100 seeds, the fresh weight of the plant, number of plant branches and pods per plant; but it did not have any significant effect on the plant length, percent of the dry seed, percent of seed nitrogen, yield and the number of seed per pod. Although the plant density has no significant effect on the yield, but the treatment of 17 plants/m2 with the average of 11.34 ton/ha had the highest yield among other treatments. The mutual effect of the sowing date and the plant density didn’t have a significant effect on the percent of seed nitrogen and the effect of these treatments on the other measured characteristics is positive.

In order to study relationship between morphological traits in cowpea (Vigna unguiculata), 234 accessions were planted in an augmented design at experimental station of Agriculture College at the University of Tehran, in 2002. Every 30 entries were planted in each block and 5 check cultivars were considered in each block, randomly. The studied characters were total seed yield, 100 seeds weight, plant shape, plant vigor, days to first flowering and days to maturity. Simple correlation was the most between days to first flowering and days to maturity. The result of stepwise regression and path analysis showed that traits like plant shape, plant vigor, days to first flowering and days to maturity have significant effect on total seed yield.

Rice is moderately sensetive to salinity. Salinity affects virtually all aspects of rice growth in varying degree at all stages starting from germination through maturation. It is now recognized that tolerance to salinity is genetically and physiologically complex and also inherited quantitatively. Molecular-marker aided selection technique for salinity tolerance would accelerate breeding progress by increasing selection efficiency. In order to map the Genes/ QTLs for salinity tolerance in rice, 62 advanced backcross lines (BC2F5) derived from a cross between Tiqing as recurrent parent and Tarom molaei as donor parent, investigated in International Rice Research Institute (IRRI). The map length was 1747.3 cM with an average interval size of 15.3 cM. The phenotypic traits under study included: Sodium (Na) and Potassium (K) concentration in root and shoot, Dry and Wet weight of root and shoot, Salinity tolerance at 15 and 22 days after salt treatment in phytotron, Na-K ratio in root and shoot. We analyzed 235 SSR markers with uniform coverage on all 12 linkage group for parental survey by agarose and polyacrylamide gels, through that 114 markers showed polymorphism and assigned for genotyping. Transgressive segregation observed in all traits. The maximum correlation observed between dry and wet weight of Shoot (r =.94**). At least one QTL with additive effects mapped for all traits except for Na in shoot and salinity tolerance after 21 days (FLS) .For K in root and Na-K ratio in root one QTL obtained with additive effect on each of chromosomes 1, 4, 8.

In order to decrease the application rate and chemical in Varamin province, have been payed excessive cost for spraying of cotton field each year. It take place because of the absence of a suitable farm machinery calendar. The aim of this study is: 1-Collecting required informations about limiting factors for spraying 2. Determining permissive limits of limiting factors for spraying. 3-Recognizing and determining time limits for controlling of pests diseases and weeds of cotton field. There are limiting factors for air and ground spraying. The most important of which, as mentioned in this study are rainfall, wind, temperature and relative humidity. The authorized limits of any of these factors have been determined. Since in this study, description and analysis of the data collected from the studied community were intended, first a measure was taken to gather a ten year period data (94 -2008) from local weather station. To analysis these data, a policy was made to divide each month into six sections with five day. (Months with 31 days have one 6 day section each on their last columns). Then, taking the authorized limits of limiting factors into consideration, the numbers of suitable working days were determined for each month. Given the typical theory and the materials used in variables, t- test was used to measure the possible limits of means.After the analysis of data, it was made known that the most limiting factor in the region was the temperature that influenced in determining the number of working days. The total suitable working days were set to be 18.2 days based on this limiting factor.

Temprature is a determining factor in species dispersion in geographical areas. Therefore the study of temperature effect from zero to 40oC with 5 interval was conducted on standard germination, normal seedling percentage and germination rate. Using Ellis and Roberts relation and drawing regression curve, the germination rate and Tb of Melilotus alba collected from three areas of Gorgan, Tehran and Tabriz were studied. It was determined that the germination rate was highest at 25 to 30oC. Optimal temperature range of germination rate in Gorgan, Tehran and Tabriz seeds populatoin changed between 25 to 30, 24 to 28 and 29 to 31oC, respectively. Optimal temprature of germination rate was 27, 26 and 31oC, respectively.Optimal temprature of normal seedling percentage was 22, 23 and 23oC and changed in 19 to 26, 21 to 25 and 20 to 26oC, respectively. Base temperature (Tb) as a genotypic index in Gorgan, Tehran and Tabriz seeds in the range between zero to-1oC changed and there has been a change however, having no significant meaning. Therefore this study showed that there is not any difference in genotypes (Tb) of seeds population in Gorgan, Tehran and Tabriz.

The effect of different concentration of vitamin A and vitamin E on humoral immunoresponse of layer and Khorasan native chicks for optimal immunity was evaluated. Experimental design was full factorial with vitamin A in 4 levels 6000, 12000, 18000 and 24000 IU per kilogram of feed and vitamin E in 4 levels 20, 50, 80 and 110 IU per kilogram of feed with 4 replicates each with 5 day old commercial and native layer chicks for 8 weeks. Antibody titers against Sheep Red Blood Cells, Avian Influenza virus and Newcastle Desease virus, evaluated. SRBC, AI and ND titers, were significantly affected by different levels of vitamin A and vitamin E and their interaction. Increasing vitamins A and E levels in diet, causes better responses from humoral immune system of chicks. With 18000 IU per kilogram feed level of vitamin A the best responses was observed but increasing this vitamin to 24000 IU per kilogram of feed lead to lower responses. The best level of vitamin E was 80 IU per kilogram of feed. The results of this experiment show that humoral immunity response is directly affected by vitamin A and vitamin E in diet. Vitamin A and vitamin E have antagonistic interaction over immunity response. NRC recommended doses of vitamin A and vitamin E is not suitable for humoral immune system needs. No differences observed between native and commercial chicks in response to different doses of vitamin A or Vitamin E.

Without calculation of the technical factors, operation of an equipped furniture factory would result in irrecoverable losses for the whole system. The required technical factors can be calculated using the data acquired from technical information of the machinery, catalogues, and the engineering consultants. This research had been carried out with the aim of introducing the electrical and utility devices required for the technical design of a wood industry producing unit, investigating the effects of each factor in the production line, and presenting the related calculation method. The systems referred to in this research are divided into three categories: electrical systems of a factory (the electricity used in the production line), positive air pressure systems, and negative air pressure systems. To calculate the above-mentioned parameters, we should firstly know what types of machinery are used in the production line. Then, considering the technical information of the machinery we would be able to calculate the systems. The results of the design and calculations of the development plan of Honar Choob Arjan Furniture Factory showed that with regards to the all installations of the factory, the consumed electricity was 357 Amperes. In addition, the appropriate capacity for the bag filter was 40,000 m3/h, and the air capacity of the air compressor would be adjusted to 40,000 m3/h. The obtained results were affected by the factors calculation of which has been considered in this research.

Decision making about replacement of a used farm equipment with a new similar one is one of the important items in farm machinery management. Proper performance in this case can lead to timely, high quality farm operations which in turns results in considerable decrease in product expenditures and also more income. In this way, a study was conducted to determine economic life of 36 active tractors in three models including Massey Fergusen 285, John Deere 3140 and John Deere 4955 in Mazandaran Dasht-e-Naz Farm Company. Considering Initial Purchase price of the tractors, annual depreciation and interest along with repair and maintenance costs were calculated separately. Economic life (Optimum Replacement Age) was evaluated for each tractor model finally. Results revealed that estimated economic lives were highest and lowest for John Deere 4955 and Massey Fergusen 285, respectively.