Year:2004 | Volume:17 | Issue:3 (64 IN AGRONOMY AND HORTICULTURE) |Papers Count:13

Drought is one of the natural disasters that inflict serious damages on human life and natural ecosystems. It differs from other natural phenomena such as flood, tornado and earthquake. Most of these differences relate to the gradual effect of drought during a relatively long-terin periods, impossibility of determining its exact beginning and end, and the geographic extent of its impact. In the other hand, the lack of an exact and acceptable universal definition of drought has mad this phenomenon complicated. Generally there are three types of drought: meteorological, hydrological and agricultural. Meteorological or climatic drought is basically caused by rainfall deficiency which in case of continuation culminates in hydrological and agricultural drought. Precipitation is the most important parameter that is used for defining drought and its lack or deficit implies the threshold of drought. In this paper, considering 52 year of rainfall data from Ekbatan and Nogeh Metrological, stations (1328-1329 to 1379-1380), drought in Hamadan region has been evaluated on seasonal and yearly basis. At first the homogeneity of data was evaluated using Double Mass and Run-Test methods. Then, drought was explained on the basis of fallowing indexes: 60% threshold index, percent of normal index, rainfall standard index, deviation form mean index, and classification of rainfall range on seasonal and yearly scale index. Considering the decrease of precipitation it was concluded that in Hamadan region drought has occurred as a seasonal or a yearly basis. Considering the decrease of precipitation in Hamedan region, drought has occurred either on seasonal or yearly basis.

Alfalfa weevil (Hypera postica Gyll.) is one of the major pests of alfalfa in Iran. It has been proven that environmental stresses like a decrease in water and irrigation may result in the preference and non-preference of pests towards feeding on plants. Water stresses may even result in the decrease or increase of damage to plants. The response of 77 cultivars of alfalfa to water stress was studied in normal irrigation (every 10 days) and water stress (every 30 days irrigation) conditions during 2 years in the field of Tehran University-Karaj. The experiment was conducted as split plot in time in the pattern of randomized complete block design in 4 replications. The first and second replicates were irrigated every 10 days as experiment 1, whereas the third and forth replicates were irrigated every 30 days as experiment 2. Pest infection occurred naturally. Damage percentage was determined through scoring of shoot injuries, then data were recorded for 4 times, 2 times in the first year and 2 times in the second year. Experiment 1 and 2 were pooled as experiment 3. Cultivars and the time of data recording were considered as main or primary and secondary finally respectively. There was not any difference between resistance of cultivars in experiment 1 and 2, whereas highly significant difference was expressed after pooling of experiments 1 and 2. The results from the paired Hest showed that plant cultivars were relatively immune when farm was under water stress. The intensity of damage was decreasing when plants were growing up with age. With regards to the results, it is exteremely recommended that irrigation of alfalfa farms should be restricted to make water stress. This matter causes reduction in the use of pesticide or no usage at all. Since alfalfa plants have usually a low yield of forage in the fist year of seeding only so, this recomendation is useful for second year and following years.

A field experiment was conducted to evaluate the effect of Zn and Fe fertilizer on yield of two Sunflower cultivars. This study was conducted in a split plot arrangement with 4 replications in 2002 at Arsanjan. Main plot consisted of two Sunflower cultivars (Zaria, High sun 25). Sub plots consisted of two levels of zinc and iron (Z1=0, Z2=40, F1=0, F2=20 Kg/ha) have used in this experiment Agronomic characteristic: Head diameter, 1000 - seed weight, stem diameter, plant height, harvest index, kernel ratio, oil and protein percentage were determined. Results showed that seed yield was not significantly affected by cultivars whereas it was significantly affected by fertilizer (40 Kg / ha zinc alone) had highest seed yield (3851.5 Kg / ha), also plant dry matter production was significantly affected by fertilizer and varieties, at the same treatment (40 Kg / ha zn alone) had highest dry matter (11793 Kg / ha). Maximum leaf area index belonged to the (40 Kg / ha zn alone). Head diameter, 1000 - seed weight, stem diameter, was significantly affected by fertilizer and potein percentage was significantly affected by varieties.

The main purposes of this study were to: Investigate agricultural budget as a portion of Gross National Production (GNP) in Iran and world, determine of Benefit- Cost Ratio and internal rate of return in improved varieties of irrigated wheat crop (Mahdavi, Niknejad, Atrak, Tajan, Alamoot, Zarrin, Alvand, Darab2, Marvdasht, Kavir, Chamran and Shiroodi), that, carried out at cereal research department in 2000. In this study for assessment of investment economic efficiency in varieties production used Benefit- cost Ratio and Internal rate of return, of course, the total costs and benefit change to present value and economic rate of return with discount rate 18.5% are estimated. Results showed that: With official and floating exchange rate, benefit-cost ratio for improved varieties of bread wheat was estimated 25.8 and 22 units. The cost of research and net present value of substitution in studied varieties were estimated 39300 and 2401700 million rials, respectively. Investment rate of return in new varieties of irrigated wheat crop were estimated 77.8 and 75.2 percent, respectively. Varieties production activity of bread wheat was economical, because, rate of return estimated more than discount rate (18.5%). With official exchange rate, investment rate of return for Mahdavi, Niknejad, Atrak, Tajan, Alamoot, Zarrin, Alvand, Darab2, Marvdasht, Kavir, Chamran and Shiroodi varieties of wheat were estimated 61.7, 55.3, 91.5, 137.3, 68.4, 53.1, 70.2, 35.6, 69.2, 55.5, 192.3 and 159 percent, respectively. With floating exchange rate, investment rate of return for Mahdavi, Niknejad, Atrak, Tajan, Alamoot, Zarrin, Alvand, Darab2, Marvdasht, Kavir, Chamran and Shiroodi varieties were estimated 55.2, 50, 83.9, 129.2, 61.4, 48.6, 62.4 , 28.5, 68.1, 49.5, 185.9 and 152.7 percent, respectively. Varieties production activity of bread wheat was economic. Because, Rate of return estimated more than opportunity cost of capital (18.5%).

Soil salinity and its development in the sarrounding lands are the main problem which should be prevented by good management. The first step is recognition and then preparing soil salinity map. In this paper an attempt made is to use the correlation method with ancillary data such as satellite and laboratory analysis of 236 soil samples data in the Qazvin plain. In the first blush, an EC point map was prepared. Then this point map was crossed with every ETM images. Finally the digital numbers of every sample points was extracted. In this connection a high correlation between band 7 ETM and EC sample points was detected, so in mapping the soil salinity, band 7 was used. Final accuracy of produced map by field control showed that the correlation method in mapping soil salinity can be recommended.

To study the intercropping system of maize and sunflower an experiment was Conducted at Jiroft Agricultural Research Center In 1376 cropping. Experimental design was R, C. B. D. with five treatment and three replication. The Treatment were as fallows: M1: sole cropping of maize M2: 75 % maize + 25 % sunflower M3; 50 % maize + 50 % sunflower N4:25 % maize + 75 % sunflower M5: sole cropping of sunflower. The plants were planted as replacement method. calculation LER indicate that Ms treatment of intercropping system of 75% maize + 25 % sunflower had highest fresh matter, dry matter grain yield and total protein in the region. Also this treatment had higher efficiency in term of using of moisture as well. In general the Ms treatment could be recommended for high Yielding cropping system in this region.

Soybean [Glycine max (L.) Merr] Protein, which is deficient in the amino acids, methionine and cysteine, is consumed worldwide as protein sources by both humans and other animals. About 70% of total proteins of soybean are glycinin and b-conglycinin. Methionine plus cysteine account for 3 to 4.5% of the amino acid residues of glycinin. High concentration of glycinin proteins and variation of glycinin: b conglycinin ratio affects on nutritional value of soybean. The nutritional value of soybean enhanced by increasing its concentration of s-containing amino acids. Protein quality in soybean is strongly influenced by the nutritional conditions, especially the nitrogen, potassium and phosphorus sources. An attempt was made to study the effects of different concentrations of P and K on glycinine and b conglycinine of soybean calli and leaves. Quantitative and qualitative changes in total proteins was determined by lowey test and SDS-PAGE, respectively. Lowry test and SDS-PAGE showed that highest protein content and also subunit of glycinin with MW of 38KDa was observed in plants leaves grown in the soils containing 0/02gP/ 100kg and 30g K/100Kg soil and calli grown in the media containing 30mM K with 1mM P. Glycinin subunits contained more methionine and cysteine than other subunits of glycinin and b conglycinin.

Growth and development of three annual Medicago species under different air and root zone temperatures annual medics is the most commonly grown forage legume in ley-farming systems. However, its lack of persistence under severs winter and early spring conditions reduced its utilization in cold zones of the world. Cold tolerance (between 0-5oC) has been shown to be the most important factor in winter and early spring survival. Selection for cold tolerance is difficult due to the complexity of field evaluation. A method of selection performed under environmentally-controlled conditions has been used for the identification of genotypes having superior cold tolerance. Three annual medic species (Medicago polymorpha cv. Santiago, Medicago radiata cv. Radiata, and species Medicago rigidula cv. Rigidula), were evaluated for traits under three levels of day/night air temperatures (DNAT, 15/10, 20/15, and 25/20 ±0.2oC) and four root-zone temperatures (RZT, 5, 10, I5, and 20±0.2oC).The experimental design was a split split-plot with treatments organized following a randomized complete block design with three replications. The result showed that M rigidula and M polymorpha were the best cultivars for leaf, stem and root dry matter, plant height, leaf and stem to root ratio, leaf to stem ratio, leaf number and leaf area at low and moderate RZT respectively. At low RZTs (5 and 10oC) and high DNAT (25oC) M. rigidula produced the most stem node number, leaf number, leaf area, leaf dry matter, stem dry matter and leaf to stem ratio. Thus M rigidula performed well at low RZT and high DNAT and probably the most promising for the production of herbage at low temperature.

In order to control greenhouse environment, a computer-based control and monitoring system was designed and implemented. Performance of the system was evaluated by installing it in a constructed model greenhouse. The greenhouse has a floor area of 8m2, covered with 200 ?m polyethylene film. The set of experiments were carried out during December 2003 in the city of Karaj. The simulation results achieved for the air temperature and relative humidity are shown. The results indicate that the outside temperature is always less than the inside one, because the solar radiation entered the greenhouse through transparent plastic. This is a further confirmation of greenhouse effect. The fluctuations in temperature inside the model greenhouse during observation time were recorded. These fluctuations were affected by natural conditions such as surface evaporation within the greenhouse, solar radiation and ambient temperature and weather changes. Also, it was found that the rate of change of temperature in the upper part, i.e. near the plastic cover, is higher than that of the height of plants. This rise of vertical temperature is due to receiving solar incident radiation.

Hamedan province with more than 2000 hectares of garlic growing areas ranks first in Iran. About 62% of garlic of Iran is produced in this province. The main purpose of this study was to measure the level of technical efficiency of garlic producers. A sample of 148 producers in the main garlic growing areas of Bahar and Hamedan was selected by two stage cluster sampling method. Data were then collected through interviews for farming year of 2000-2001.Technical efficiency of garlic producers were estimated using transcendental stochastic frontier production functions, Also, effects of various social and economical factors were then studied on the level of producer's technical efficiencies. Based on the results of this study, it was found that average technical efficiency for garlic growers was 74%. There are many discrepancies between technical efficiency of the best garlic producers with that of the others. Therefore, it is possible to increase production without any major change in technology and used resources, thus decreasing the discrepancy between the best and the other producers. Production increase potential has been 26 percent. The main social-economic factors affecting the technical inefficiency of garlic producers have been educational levels, garlic growing area, owner ship of land, number of land units under garlic cultivation. Age of farmer, farmer's job and experience.

Extension specialists and experts in examining the performance of Extension organization in developing countries have noted several factors regarding the failure of the system and among these factors is the organizational structure. The main goal of this research is to find the reconstruction components of the structure in relation to the new implications. The research is an applied research and It is analytical aimed at solving the problem. The population for this study included directors of Extension service in Tehran and all provinces, Extension specialists within the office of vice minister in Extension affairs, and faculty members of Extension department within the universities. The main instrument for collecting the data was questionnaire. The dependent variable for the study was the perception of respondents regarding needs of restructuring the organization of extension service. The independent variable was age, degree, work experience, major study position, and location of employment. In order to analyze the results of the study, statistical methods such as Mann-Whitney (u), Kruskalwallis, and spearman was used .On the basis of the results, research model have introduced. In the model, 17 factors have been recognized, which the total variation percent for these 17 is 74/10percent.The main factors were supportive obligations with 16 percent variation, flexibility with 11.7 percent, participation with 5.8 percent, and Human resource with 4.7 percent and target technology with 4.2 percent variation.

The manipulation of bacterial EPSPS gene in order to reduce its affinity to glyphosate, is one of the most effective methods for production of glyphosate tolerant plants. In this research, we study on glycine 96 of E. coli EPSPS enzyme. This amino acid is an important residue for EPSPS-Glyphosate binding. We used site directed mutagenesis method to inducing a point mutation in E. coli EPSPS gene to convert glycine 96 to alanine. The manipulated EPSPS gene was cloned in pUC18 as an universal cloning and pBI121 as a plant expression vectors. The results of molecular analysis and sequencing showed that the manipulated genes has been changed and cloned in correct orientation in both plasmids. Recombinant pBI121 containing altered EPSPS gene were transferred to rapeseed (B. napus), PF-7045-91 cv, via Agrobacterium tumefaciens mediated transfonnation method. The target tissue for transformation was the cut end of cotyledonary petiols. At the first step the transformed explants were screened in kanamycin containing media. Result showed that plant regeneration and transformation frequency was 73 and 30% respectively. Glyphosate tolerance will be assayed in next generation.