Year:2002 | Volume:15 | Issue:2 (55 IN AGRONOMY AND HORTICULTURE)|Papers Count:22

After trimming forest trees, the amount of woods remaining are about 7´105m3 in average. By adding the remains of trimmed woods of garden and green spaces of cities, it would amount to a considerable volume. If these remarkable volumes of wood are reused correctly in the wood processing factories, it could provide raw material for 70 wood factories with the capacity of 104m3in a year. For the best utilization of these wood remains, a wood chipper machine could be used for this purpose. The main objective of this study was to design and fabricate a wood chipper machine that can be used for Iranian forests, green spaces and garden conditions. The specification of constructed machine consisted of disk cutting unit, automatic feeding unit; by shooting discharge system. This machine is mounted on tractor and P.T.O power requirement (30 hp). The operational testing of the machine showed that all the parts worked properly. After chopping the Populus alba L and pine tree branch samples, it was found that by increasing the diameter of the branches, the wood chips were smaller. Also size, shape and thickness of the chopped woods were more uniform by increasing the branches' diameter. By comparing the wet and dry branch samples, it was observed that the chopped wood size and dimensions of dry samples were larger and nonuniformed. In general, the moisture, diameter of the branches and tree species directly will affect the size, dimensions, shape and uniformity of chopped woods.

Rangeland improvement through using exotic plant species and compatible with the region needs many research and investigation. Before using this species in the extensive area should be investigated positive or negative effects of exotic plant species on small planting site. The aim of this research was to determine the ecological effects of Atriplex lentiformis as an exotic plant on soil characteristic in Dadine Kazeron and Konare Hajidarab regions of Fars province. The methodology of the research is based on the comparison between selected samples measured through the lab experiment. Measured factors were N, P, K, Organic matter (OM), pH, Ec, lime and texture agents (clay, sand, and loam). Samples were taken from control and plantation sites. Duncan test was done for comparison between different sites. Duncan test was used factors to compare factors between three groups of results derived analysis of different position samples. The results of comparison between samples in control region and plantation sites in study area indicated that Atriplex lentiformis increases soil fertility and its resistance against erosion, however, Atriplex lentiformis caused some increment in soil salinity, but not enough to become a saline soil. In general, in this investigation effects of Atriplex lentiformis were evaluated positive on plantation sites in study area.

Agropyron is one of the most resistant plants to biotic and abiotic stresses. It has important role to produce forage yield in rangelands. In a breeding program of agropyron species, cytogenetic study involving karyotypic analysis of different genotypes was carried out. In karyotypic analysis 17 agropyron genotypes of 11 species collected from different part of Iran were studied. The karyotypic characters including long arm length (L), short arm length(S), satellite present, total chromosome length (TL), L/S and S/L, percentage form (TF), chromatin length and class form of chromosome were determind. In this experiment 2 genotypes (Agropyron libaniticus and Agropyron intermedium) were diploid (2n=2x=14), 9 genotypes were tetraploid (2n-4x=27), 3 genotypes were hexaploid (2n=6x=42) and 3 genotypes were octaploid. Cluster analysis of tetraploid genotypes based on the karyotypic characters classified the genotypes into 4 clusters. According to principal component analysis the chromosomes 7, 6, 9, 5 and 8 had most variation, respectively.

The Christ's thron (Ziziphus spina-christi) belong to the family Rhamanaceae is an evergreen tree natural grown and distributed in tropical regions. Drought and salinity tolerance, having tannin and saponin materials in the leaves and organs, adaptable in warm areas, having desirable and edible fruits are well known characteristics of this species, so that it is propagated annually for afforestation and reforestation plans and also using as a multipurpose tree in southern part of Iran. At the present time, this species is only regenerated from seed which often results highly variable progeny. According to high percentage of cross-pollination in this tree, many segregation is occurred, and maintenance of improved traits is impossible in next regenerations. Therefore, it is worth to seek for asexual propagation. This research demonstrates that complete plantlets of Z. spina-christi could be cloned and micro propagated from single axillary bud using tissue culture techniques. Shoot segments (fourth to eighth axillary buds under apical bud) from mature trees were excised and used as explants during February-March, July-August and October-November. Several experiments carried out to determine the best disinfectant chemicals, media type, shoot multiplication and auxin-cytokinin ratios for root induction. The most proper treatment of sterilization, was the use of 70% ethanol (30 sec). and %7.5 Ca(OCL)2 (20 min) and frequent cleaning with sterile distilled water. There were no significant differences between hormonal and hormone-free media as wellas media type. The best root formation treatment was achieved in liquid White medium supplemented with 25 mgl-1 IBA and subsequently cultured in semi-solid hormone free White medium containing l gl-1 active charcoal. Young rooted plantlets transferred to jiffy pot and kept in plant propagator to pass autotrophic stage.

In order to study the effect of temperature on growth and biological nitrogen fixation (BNF) in subclover (Trifolium subterraneum L.) an experiment was conducted in a sand medium using hog land nutrient solution (without nitrogen) completely randomized design with 4 replication was used the experimental treatments comprised four temperatures (10, 15, 20 and 25oc). This experiment was conducted at crop physiology laboratory, Gorgan University and agricultural sciences. Nodule fresh weight, nodule number, root and shoot dry weight and leaf area were measured. Results showed obtained at 10oc. treatment. The highest nodule number and the lowest nodule weight were observed at 15 and 25oc, respectively. The highest root/ shoot ratio and nitrogen percentage in root and shoot were obtained at 15oc, but there was no significant difference between this treatment and 10oc in this respect. It was concluded that the best growth and BNF of subclover were obtained at 10-15oc.

Taxus baccata (belongs to Taxacea family) is one of the in extincting conifer in world. It is decious with different color of view and used for production of wood. Mycorrhiza is a sustainable symbiosis between plants root and fungus. Mycorrhiza is divided to two main groups of ectomycorrhiza and endomycorrhiza. Endomycorrhiza contrary to ectomycorrhiza do not create significant macroscopical changes in roots and therefore roots of Taxus and soil of rhizospher in two succesive year (spring and fall in each year). Roots showed high percentage of infection. Isolated spores were identified as four species of Glomus, one species of Acaulospora, one species of Gigaspora and one species of Sclerocysis.

Terminal velocity of chickpea is one of the important parameters in the pneumatic separation and conveying systems and is used extensively in design of agricultural machinery and process engineering. Based on dimension, eight samples of chickpea were chosen and then at three different moisture level the experiment was done. For each replication, four readings near the location of test at four points along the diameter were measured and then the average air velocity at this plane was calculated. The experiment was repeated eight times. There is some completely randomized design with factorial experiment in this study. Geometric mean diameter (gmd) and specific gravity (spg) of dry and moist chickpea were measured in each replication and then the effect of dimension and moisture content on the terminal velocity, gmd and spg of chickpea were investigated. Finally, the results are shown based on the regression analysis with the related equations and tables.

This experiment was conducted in research station of Arsanjan Azad University in 2000, in a clay texture in order to evaluate the different ratios of corn and soyben intercropping comparing to pure cultures of them by using randomized complete block design with 4 replications. Treatments consisted: P1=pure corn, P2=pure soybean, P3=%50 corn + %50 soybean, P4=%75 corn + %25 soybean, P5 = %75 soybean + %25 corn. This Experiment was conducted by using replacement series method. Evaluated factors were as follows: Corn (kernel yield, number of ears per plant, number of kernels per ear, weight of 100 kernels, stem diameter plant height, ear length; ear diameter, harvest index, crude protein percentage leaf area index). Soybean (kernel yield, number of pod, weight of 100 kernels, plant height, crude protein percentage, leaf area index).The final product in pure culture of corn was, 7424 (kg/h) and pure culture of soybean was 2719 (kg/h). The maximum yield in intercropping treatments respectively related to: Treatment of %50 corn + %50 soybean, 6674.5 (kg/h), %75 corn + %25 soybean, 5974 (kg/h) and %25 corn + %75 soybean, 5076.75 (kg/h). Results showed that: With decreasing the percentage of corn, ear length, number of ears per plant, number of seeds, number of soybean pods, 100 kernal weight of soybean and soybean crude protein percentage increased, because of shading corn on soybean. But different planting ratios had no significant effects on height corn, 100 kernel weight of corn and harvest index of corn. The Maximum LAI for corn was 4.51 and soybean 4.21 in the portion of %75 soybean + %25 corn.

Semi-arid ecosystems provide many direct and indirect services and contribute substantially to the gross national production (GNP) of country. Valuation of these ecosystems is necessary for better conservation and exploitation management. In this investigation, ecological values of 608 ha of Palangdarreh region in South West of Qom province were studied. Seventeen kinds of ecosystem services and functions were identified. Each service or function was valuated using appropriate methodology. Total value for all services and functions was estimated as much as 4,400,000 Rials ($550) per rhectare per annual.

This study was designed in Karaj in 1998 to determine of economy amount in inputs consumption, to determine of profitability and mean comparison for yield in different groups, to investigate satisfaction of farmers from agricultural job and breakeven analysis of activity in different groups. The required data were obtained from 102 farmers from 11 villages who were selected by simple random sampling method and to fill questionnaire. This study carried out on insured and none-insured groups. Methodology was break even analysis equations and different tests (t-test and chi-square). The results showed that: 1-ln insured group, farmers who used modern varieties, increasing yield was 24.8%. In this group to other group, declining of inputs consumption including seed, water, labor, urea and phosphate fertilizer were 12.9, 6.3, 24,9 and 25.1 (percent/ha), respectively. 2-for insured group, gross income was 6% higher than none-insured group. 3- There were no significant difference between yield in insured and none-insured groups on the basis (t-test).4 about 20.6, 13.7 and 65.7 percent of farmers had (low, average and none) satisfaction from agricultural job respectively. 5 - breakeven points for output price in insured and none - insured groups estimated 396.7. Breakeven points for output yield in insured and none - insured groups estimated 3694.8 and 3340.8 (kg/ha) respectively. In this points, profitability of activity was zero.

In this research, the first maternal plants selected from Elizabeth cultivar were kept in the greenhouse for environmental treatment and control of the diseases and pests for 1-2 months. Nodal segments were selected at the 2cm size and were sterlized in 2.8% sodium hypocholoride. They were cultured in a modified MS medium containing different levels IAA, BAP and severals subcultures. Then isolated shoots were placed in different rooting culture medium. The implemented observations showed significant differences between IAA levels, BAP levels and several subcultures and reciprocal effects between them. In this experiment, MS medium (supplemented with 0.1 mg/1 IAA and 1 mg/I BAP and 3 stages of subculture) induced medium (supplemented with 0.1 mg/I IAA and 1 mg/I BAP and 3 stages of subculture) induced the highest number of new shoots. In the rooting stage camparsion between few culture medium on the rooting of the plantlets showed significant difference, and MS medium including 0.5 mg IAA produced the best roots (75% rooting). Produced plants then were transported to mixed medium sand and peat in the ratio of 1:1 and kept in greenhouse.

Base on appearing numerous problems in spreading flood stations, caused by fine grains sediments after flood sedimentary, like decreasing the permeability and hardening of the soil and also, producing 15000 ton sedimentary clay and silt during two floods in spreading flood station of Kabudar Ahang and decreasing the permeability rate about 0.35 cm/h this survey aims to determine the provenance of these sediments, in order to control them. For this reason, after producing the map of drainage net and watershed, there obtained about 60 samples from fine sediments main drainage, spreading flood area, sedimentation basin and soils. Also, 18 lithic samples were obtained from different lithologies, of which 8 samples analyzed by the method of x-ray differactometery (X.R.D). Another 18 samples analyzed by the method of neutron activation analysis to calculate R.E.E. rate, "Th" and "Sc" elements. There is also 9 samples analyzed by the method of producing thin section. At first, geological map was drawn, by the help of results, second RE.E. rates were normalized based on cl-chondrites and Post Archaen Australian Average shale (P.A.A.S), as the base values. Then scatter and pattern diagrams and their abundance were drawn after calculating different factors like La/Sm,… , Eu/Eu* in addition abundance diagrams of "Th", "Se" and "La/Th", "Th/Sc" rates were also drawn and studied. results were: Pattern diagram of Naser Abad drainage and samples of PS formation, were simillar and parallel with samples of sedimentation basin. Also, they show good genetic relationship in scatter diagrams. This shows that sources of fine grain sediments of spreading flood station are from soils of PS formation at the end of Naser Abad drainage, Gand tapeh and Gavzian villages. Base on the result of this study and other surveys, first, studing R.E.E will be useful for provenance of sediments, and second, different subwatersheds which are producing similar minerals, studying their by X.R.D. is not helpful and no produce reliable results.

According to the official report, total sandy soil and sand dune in Khuzestan province are more than 350000 hectares, and the large scale of these are located in around of Karkheh river. The implementation of desertification control and sand dune fixation started from 1969 from which to now more than 85000 hectares were implemented by biological operating and physico-chemical activities and people's participation schemes. The main objective of this investigation was to estimate suitable emitter in sand dune and to suggest some recommendation in terms of cultivating potato (Solanum tubberosum L.) plant in such condition. Potato tuber planted in plot, the size of each plot was 20´10m. and the distance of two plants were 0.5´0.9m, in form of Split Latin Squar Design on two artificial hard pan in 40 and 60 centimeters depth. Potato plants were irrigated by drip, spray jet emitters and furrow systems. The depth of irrigation was estimated based on 40% of total available water and 80% of evaporated water from the installed pan evaporation class A. Results show that the trickle irrigation increase water use efficiency, leaf tickness and yield (17.31ton/ha). The average yield in all treatments was 16.25 ton per hectar. It is concluded that the trickle irrigation could provide water requirements in zoon root with less waste water percolation. Comparison of the results shows that the application and distribution efficiencies are higher for the trickle irrigation, but according to the Leaf Area Index (LAI) measurements, conventional planted distance must be improved for increasing yield per hectar.

Nitrogen is one of the most important elements in plants. But gas is not usable by most higher plants. For many years nitrogen fixation by micro-organisms has been proved. Many researchers pointed that Agrobacterium tumefaciens has ability to fix nitrogen. To investigate the role of this bacterium in nitrogen fixation; three cultivars of Medicago sativa (Bami; Australian and American cultivars) which were either inoculated with nif-nod+ sinorhizobium or with sinorhizobium contained plasmid (pSRK9) were used and compared with wild type and control. The results showed that those plants which had higher growth; had the lower amount of reduced sugars in their roots. The lowest amount of sugar was recorded in plants which were inoculated with nifK-(pSRK9). The results indicated that; there is a correlation between decrease in roots sugars and increase in dissolved protein. Measurement of the total protein of the stem and leaves showed that those plants were inoculated with sinorhizobium contained plasmid (pSRK9) had the most amount of protein in comparison to the other plants. Those plants which were inoculated with sinorhizobium contained plasmid nifK-(pSRK9) converted higher amount of acetyl en to ethylen and the rate of ethylene produced were higher significantly. In Conclusion, in our study the system which include nif gene effectively increased growth of the three Medicago sativa cultivars.

Concerning the newness of economical valuation of methods of the country parks and forests, In this research it is attempted to validate Sisangan forest park using one of the classical methods. On this basis, some semicircle was drawn with the park as center and with equal radiuses. The result was the division of the whole country in to six different zones. Then, through calculating the surface of each region and its resident population and also the money required by people to visit the parks from questionnaires, estimation of regressional equation between the parameters was attempted. Through data analysis, we were able to draw the forest park demand curve, which was indicator of high recreational value of the Sisangan park (52.932 million Rials). Therefore by using right & proper management conservation of the natural environment and environmental value, as well as part of the recreational requirements of the people was provided.

Forage quality information is important for determination of grazing. Forage quality affected by location and phenological stages. Different factors influence on forage quality phenological stages specially flowering and seeding times are one of the most important factors affecting forage quality. In present study, forage quality of two important legume species of Mazanderan lowland were considered namely Trifoliom repens and Vicia tetrasperma. In this experiment crude protein (CP), total energy (TE), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF) and dry matter digestibility (DMD) were measured using invitro procedures. Data were analysed using one way and Duncan tests. the results showed that in both species forage quality in flowering stage was higher than seeding stage. In spite of no different between CP and TE of species but NDF and CF were higher in V. tetrasperma. So it will cause higher quality of Tr. repens forage compare with forage quality of V. tetrasperma. The reason in higher amount of leaves in forage of Tr. repens.

Biotypic variation among Russian wheat aphid, Diuraphis noxia (Mordvilko) isolates, collected from six different areas of Iran including, Eqlid, Abhar, Brujerd, Dehaqan, Razan and Shabestar were evaluated on resistant and susceptible wheat entries. Dependent variables were damage rating (based on leaf chlorosis. leaf rolling, wilting and death of host plant), host plant dry weight and root length. Multivariate analysis of variance of the data indicated that the damage rating was the best criterion for detecting biotypic variation in D. noxia. The Eqlid, Abhar, Brujerd and Dehaqan isolates were most virulent. The Shabestar isolate was moderately virulent, while the Razan isolate was the least virulent on all plant entries. Also, canonical discriminate anaylsis in most cases correctly classified the virulent and non-virulent isolates in respective groups.