Year:2004 | Volume:10 | Issue:2|Papers Count:12

Because of well adaptation to cool climate, the cultivation of rapeseeds (Brassica napus) in cold region of Iran has grown rapidly. In order to investigates rosette physiological cold acclimatization in 24 winter type cultivars of rapeseeds, a series of experiments were carried out at the agricultural experimental stations of four cold regions of Iran (Zanjan, Hamedan, Shahr-Kord & Karaj) in cropping season of year 2000-2001. Field experiments were conducted in a randomized complete block design for 24 winter type cultivars of rapeseeds in 3 replications for each region. Crop growth rate (CGR), crown cell membrane stability (CCMS) and crown relative water content (CRWC) were studied during 1st growing stage. In addition, seed yield (SY) was determined at final stage during summer time. The results of combined analysis of variance showed that the difference between locations and cultivars and also interaction effects of these variables with CGR, CCMS and SY are significant. The mean CRWC of all cultivars at Shahr-Kord experiments was 47.14% that is lower than other locations in general. Furthermore, the Alice Cv. showed well adaptation to the cold climate as judged by its highest CCMS (469.5 Sµcm-1) at all 4 locations. Although only one of 24 cultivares, Brassica napes Cv. Consul, indicated the cold-acclimated rosette with high growth rate (4.64gm-2d-1) which also produced the greatest seed yield (4.33 t/h or 123.4% higher than means) in this field test. In conclusion, CCMS of rosette tissues, CRWC and CGR of this experiment was correlated with seed yield (p<1 %).

In order to study the effect of sowing dates on agronomic traits, seed yield and yield components in seven sunflower varieties were conducted in the field experiment of College of Agriculture, Azad university, Astara branch in 2000 cropping season. This experiment was a split plot design based on RCB with four replications. Two Sowingdates (27th of May & 9th of June) were main plots, and seven varieties (Record, Chernienka 66, Vinmik 3931, Louch, Zaria, Armavirski and Peredovic) wereSub-plots. Results indicated that varieties had different plant heights, flowering dates, head diameters, harvest indices, 1000 seed weights, leaf areas and yields in sowing dates. All traits estimated in first sowing date were more suitable than the second sowing date. Also Vinmik 33931 variety had the most harvest index, 1000 seed weight and yield in the first sowing date.

Landraces comprising of many genotypes that have been screened naturally during long time of crop history and are adapted to their natural areas of planting. They are very important materials to breeders. Sardari bread wheat has a long breeding background. At present it is planted about 0.5 million hectares in the west and the northwest cold drylands of Iran and it has shown good adaptability to this conditions. In order to evaluate of genetic diversity in Sardari landrace, morphphysiological traits of 106 pure lines that were selected by spike selection method, studied during 1995-96 and 1996-97. Studied traits were: spike and grain color, spike length, number of seeds in spike, number of spike lets in spike, grain protein percentage, plant height, number of tillers per plant, 1000 kernel weight, days to maturity and reaction to winter cold, lodging and yellow rust. The results of the study showed that: there was high variation in agronomic and morphophysiological traits among pure lines. In spite of susceptibility of Sardari to yellow rust, lodging and low seed protein, there were many desirable lines among studied lines that were resistant to yellow rust and lodging along side having high seed protein. Variability existing in studied traits of Sardari demonstrate its stability and adaptability in dryland conditions. Regarding the obtained results, Sardari wheat landrace is one of the important genetic source to wheat breeding in dry condition of Iran and should be protected and kept against genetic erosion.

In order ro study of using biodiesel a Cl engine RME was made by transesterification of rape oil with methyl alchol in presence of KOH as catulyst. Different blends of fuel were used and performance characteristics of engine were compared. Tests were 5 * 7 factorial experiments in completely ransomized design with three replications. Factors were fuel n five levels (conventional diesel fuel of Iran in term of reference and blends with 25, 50, 75 and %100 of RME in volume basis) and speed of engine in seven levels (550-1150 r.p.m. with 100 r.p.m. increment). Fuel tests indicated that viscosity of net RME was 1.15 times and it's cetane number was %15.9 more than diesel fuel. Heating value of net RME was % 7.8 less ans it's slfur content was trace in comparison aith diesel fuel. The short term engine performance tests indicated that break power, torque, fuel consumption and thermal power of net RME are 18.1, 20.3, 7.8 and 17.6 by percent lower diesel fuel respectively. In generally biodiesel blend's specific fuel consumption were less than net biodiesel fuel do that maximum level refer to net diesel and minimum belon to feul with % 25 biodiesel which redacted by %16.6. The performance of fuel with %25 biodiesel was similar to references fuel. It's break power and torque were lower by %1.83 and %2.4 respectively.

Power tillers are used for field operations and transportation of load and human in rural dirt roads in Iran. Inspite of their noise adverse effects on power tiller drivers and passengers, they have not been investigated so far. The present paper is the result of an investigation conducted on a 13 hp power tiller to obtain noise level prediction model in transportation. The test site is prepared according to international standards and the noise signals emitted from system are measured and then analyzed in time and frequency domain for audio frequency range (20 - 20000 Hz). The results show that the noise level in driver's ear reaches to 92 dB (A), which is higher than the standard limit of 85 dB (A). Also the engine speed plays a great role in noise generation for power tiller which could be considered in various applications. This is, because the noise is increased up to 7.5 dB (A) with engine speed variations. Lastly the power tiller prediction model of sound pressure level is determined using the experimental data which are useful in finding the optimum speed range for transportation activities.

Shrimp head waste (SHW) has been studied as a valuable source of protein (64.1%, dwb). In the present research the effect of different factors including pH, chemical agents such as NaCl, NaSO3, Triton x-100 and also application of commercial proteolytic enzyme, Alcalase , on the solubility of SHW proteins and electrophoresis patterns of the extracted proteins was investigated. The results show that pH=8 is the optimum for protein extraction. Three of the factors (i.e. NaS03 Triton x-100 and Alcalase) improve the results successfully, at their optimum concentration (200 mmol/l, 1% and 0.5%) respectively. Enzymatic treatment, using Alcalase, alone or in combination with NaSO3 for Triton x-100 resulted in higher solubilization of proteins. SDS-P AGE patterns revealed appearance of small molecular weight proteins, less than 14-20 KDa, due to chemical or enzymatic treatments, which probably contribute to the higher solubility. These results indicate that it is possible to improve protein solubility by treatment with NaSO3, Alca-lase or in combination of both.

In order to obtain the optimum conditions for preparing semi-chemical pulp form baggasse using ethanol - caustic soda organosolv process, depicted baggasse (wet method) was prepared from pars pulp and paper mill , Khozestan province. Firstly, the anatomical and chemical characteristics of baggasse were evaluated. The averages of fiber length and diameter, cell lumen, and cell wall thickness (120 fibers) were determined 1.53 mm , 21.76 m ,9.58 m , and 6.07 m respectively. Chemical composition of baggasse (the average of 3 experiments) were 55.33% cellulose, 21.20% lignin, 9.58% extractives and 21.17% ash. The variables in pulping of baggase were as flowing a) Ethane (weight percent):30,40,60,70 b) Cooking liquor to baggasse (l/w):8,10,12,15 c) Cooking time (minutes):15,30,45,60 d) Cooking temperature (C°): 145,165 ,175,185,195 e) Caustic soda ( weight percent):0,1,3,5,7 In order to evaluate the effect of each variable, the other parameters were kept unchanged and then, on the basis of the pulp yield and lignin content of the pulp, the suitable conditions for pulping was determined. Then, the yield, lignin content and freeness of the pulp sample were measured using three repeats and the results were statistically analyzed using completely accidental plan. The pulping conditions were tailored in such a way that the yield of the produced pulp is placed in the range of semi-chemical pulps.

In the recent years, development of industry as well as large amounts of investment in this field has called for decrease in the current production costs in order to preserve competition performance in the market. In any factory including Iran Choob Co, some part of current production costs relates to the costs of machinery maintenance and repairman. Wood chemical and mechanical conversion industries in Iran are facing with several difficulties including the condition of machinery maintenance and repairmen. Such activities are mainly done by the technicians without any preplanning at the time a deficiency occurs. In this regard, the only important thing is to remove the deficiency and there is no plan to prevent such problems before they happen. This issue seems to be more crucial in continuous production lines where failure in one part can stop the whole line. In this study, using system analysis approach, an executive model was designed for maintenance and repairmen plan of the particleboard line of Iran Choob Company and was applied in the drier. Moreover, drier maintenance guidelines were developed for the production section and maintenance and repairmen guidelines for the technical section.

National agricultural statistics show that, level of farm mechanization is not at a desirable status. This shows that farmers in the country are facing difficulties and challenges in adopting farm mechanization. The main objective of this study was to assess corn grower's level of mechanization practiced on farm and determine the effects of professional characteristics and extension factors on the level of mechanization. The population of this study consisted of all corn growers in Fars province. The result indicated that almost half (48.7%) of the respondents' level of mechanization practiced were characterized in "good" and "excellent" ranges. Similarly, 51.3% of the respondent's level of mechanization practiced was characterized as "week" and "average" levels. Statistically significant relationship found between farmers' technical knowledge related to mechanization; area of land under corn cultivation; level of access to technical information on mechanization; and the level of farm mechanization practiced.

Whenever good quality water is scarce, water of "marginal quality" will have to be considered for using in agriculture. Municipal wastewater is marginal quality water and using of this for irrigation can be an important considration when its disposal is being planned in arid and semi-arid regions. In this study, secondary municipal emuent was used for irrigation of potato and tomato. This emuent is using activated sludge process to treat the municipal wastewater. For these crops, five different irrigation tratments were desingned with three repetitions and these treatments were as follows: T1: Furrow irrigation with drinking water network, T2: surface drip irrigation (DI) with emuent, T3: Sub surface drip irrigation (SDI) in 15 cm depth with emuent, T5: Furrow irrigation with emuent. Crop water requirement was determined by ET-HS model. Also in this study, mircobiological characteristics crops have been analyzed. Results Show that the drip irrigation filter caused 51% BOD3, 44% TSS, 52% N-N03, 84% N-NH4, 81% TN, 94% Faecal coliforms and 57% Nematodes removal efficiency in this condition. Also, the results of this study indicated that application of DI and SDI could be control environmental contamination and to compare the surface irrigation had decreased the pollution problems in the soil. Additionally, with regard to health, in SDI, minimum contact was generated between the emuent and the workers or the plant parts above the soil. But the microbiological test indicated that between T2 to T5, in potato T2 and in tomato T3 and T4 had better mircobiological yield's quality.

In agricultural research, the Cone Index is used for soil penetration resistance of implement, and compaction of soil. Tractor pass, soil moisture content, soil texture, and environment affect this Index. The effect of different passes of tractor on the Cone Index of clay-loam soil (Zarghan area of Fars province) with different moisture content levels were investigated. The parameter's effect on Cone Index (three levels of pass and moisture content) with three replications were studied. Also the mathematical model for Cone Index was developed through multiple regression analysis. The results were in agreement of previous studies, which showed the Cone Index was affected directly by tractor passes. It means the soil Cone Index increased with additional tractor passes. Studies on the moisture content levels showed a reverse result (increase in moisture content caused a decrease in Cone Index). Two mathematical models were obtained in this study by multiple regression analysis. The R2 of 0.86 and 0.88 were obtained for linear and non-linear models respectively. The linear model is suggested for further study for the area since there is not a big difference between the R2 of the two models and also the other model is non-linear with the degree of four.

Effects of sowing date and plant density on seed production and seed essence of "Cuminum cyminum" under Tabriz climatical conditions was studied in 2001-2002 using a factorial based on a randomized complete block design with four replications at Tabriz. Seeds were planted at four sowing date (26 Mar., 5, 15 and 25 Apr.) and four plant density (625000, 417000, 313000 and 250000 plants/ha). Variance analysis indicated that traits of time to emergence, seed production, 1000 seeds weight and seed essence percentage in 99% probability, and emergence percentage, stem height at flowering stage and time from sowing to maturity in 95% probability were influenced by sowing date. All the studied traits were influenced by different plant densities in 99% probability. Effects of sowing date and plant density was significant for the traits of time to emergence, time from sowing to maturity and seed production in 99% probability. There were positive and significant correlation between 1000 seed weight with time form sowing to maturity (0.93), stem height at flowering stage (0.70) and seed essence percentage (0.91) and seed production with seed essence percentage (0.50). Sowing date of 26 Mar. and density of 625000 plants/ha is the best treatment in Tabriz similar environmental conditions.