Year:2003 | Volume:9 | Issue:3|Papers Count:12

The reproductive properties of T. brassicae Bezd. That collected from eggs of natural host (WT), Ostrinia nubilalis Hubner and wasp that reared after five generations in the laboratory (LR) on eggs of Sitotroga cerallela Olivier as a factitious host was studied and compared in laboratory condition, with use of this data, the stable population parameters stimated. Results showed that the most evaluated parameters in WT were superior and better than LR with exceptional; longevity. The longevity of LR female wasp (6.59 days) was significantly higher than WT females (5.23 days). Intrinsic rate of increase (rm) estimated 0.315 and 0.2989 for WT and LR respectively. Average of total life oviposition were 77.65 & 68.38 and sex ratio were 68.5 & 67.9 percent of female for WT and LR wasps respectively and had no significant differences. The most eggs of females were laid in the first day of adult longevity (60.74% and 49.66% of total oviposition for WT and LR respectively).

In this research, first the effects of loading rate, almond dimension, and loading direction were studied on force, absorbed energy power for cracking almond of Tegzas variety of Saveh area by using an Instron testing machine. In the meantime, water uptake of kernel during immersion in water was determined and mathematical models developed. Mathematical models expressing relationship among the three dimentions of almond as well as its kernel were determined. Variation range of force, absorbed energy and required power for cracking almond were between 139-1526 N, 70-2093 mJ and 0.015-5.121 W, respectively. Loading rate had a significant effect on cracking a force and required power but its effect was not significant at 1% level for absorbed energy. The almond size and loading direction had a significant effect on cracking force, absorbed energy and required power for cracking almond. The result showed that 1 hourse after immersion the kernels in kernels in water, the moisture content of the kernels was increased from 6.46% to 20.24%, d.b, and after 18 hours was increased to 58%, d.b, The dimention of almond thickness had the highest kurtosis coefficient with average 1.71, but its skew ness coefficient with average 0.045 was near to zero. For kernel, the width dimention had the highest coefficient of kurtosis with average 4.4, and the least value for skew ness coefficient with average 0.28.

The growing interest in simulation of water movements in soils is in response to the need for development of solutions for various agricultural and environment problems, such as irrigation. In order to be able to adapt models for simulation, it is important that the capabilities of these models and credibility of their results be tested. In this study results from LEACHM simulation model are compared with the measured soil water data. We carried out an experiment in Khorasan Agriculture Research Center, which included three treatments: 1- crop was irrigated when Maximum Allowable Deficiency (MAD) corresponded to 50%, 2- crop was irrigated when MAD corresponded to 70% and 3- crop was irrigated once, then irrigation was stopped until MAD corresponded to 90%, after that crop was irrigated normally. A sensitivity analysis was performed to identify the input parameters of LEACHM, which most influence the water content variations. Sensitivity analysis showed that bulk density has an important effect on soil water content. Simulated soil water contents were in close agreement with measured values with a mean absolute error (MAE) between measured and predicted soil water contents, ranging from 1.87 to 4.54% in treatment one, 1.90 to 3.11% in treatment 2 and 3.98 to 5.58% in treatment 3. Generally, the model overestimated water contents.

Soyabean oil is the most important vegetable oil in terms of word production and consumption. The effects of refining operations on the qualitative properties of soyabean oil have been investigated. Two separate laboratory scale refining procedures have been employed consisting of water degumming of water degumming, neutralization, bleaching; using natural earth and deodorisation. Phosphoric acid pretreatment and use of acid activated earth were included in the second method of refining. Free fatty acids, peroxides, phospholipids, induction periods, colour, metals; copper and iron, nonsaponifiable matters and tocopherols have been reduced. It was concluded that the use of acid activated earth; fulmont AA and phosphoric acid pretreatment were important to reduce, copper, iron, colour and phospholipids. Small variations in the fatty acid composition of both crude and refined soyabean oil have been noticed which might be due to the slight oxidation of linolenic acid during the course of refining.

Due to the importance of Fagus orientalis in Iran which based on available statistics accounts per 17.5 of forest cover and 25 of standing volume of the North Iranian forest and is often utilized in the veneer manufacturing, this study was made to evaluate end checks variation between 30 Fagus orientalis logs after cutting, stocking and steaming which are greatly effective on the quality of the logs and finally on veneering efficiency. In addition the relationship of the end checks with the core diameter remained from the peeling process was carefully studied. The findings of this study reveals that beech trees are very sensitive to the development of the end checks after cutting, stocking and steaming, besides it was concluded that the control of the logs in each of the above mentioned stages could reduce the end checks to a considerable extent and eventually cause the production efficiency to increase. The increase in end checks number and their development after steaming had a significant effect on the increase of core diameter and led to production loss.

Evaporation from bare soils plays a significant role in hydrological cycle, particularly in arid and semi-arid regions. In such areas, a large amount of the water that enters into the soil returns to the atmosphere through evaporation. Although, in the vegetated areas, depends on the irrigation method and the growing stage of the plants, over 10 to 61 percent of the total evapotranspiration belongs to evaporation alone. In these regions, there are some areas with shallow groundwater table, evaporating a considerable amount of water into the atmosphere and accumulating salts at the upper parts of the soil profile. Thus, the evaporation phenomenon not only is responsible for water loss but also is a major reason for soil Stalinization. One major difficulty for accurate estimating of evaporation in the field conditions arises from the lack of simple function with less needed input parameters. The main purpose of this study was to develop and verify an analytical solution for one-dimensional non-steady upward flow from shallow ground water table with minimum input data. Consequently, an analytical solution was developed based on the Richards" equation with the initial and boundary conditions governing evaporation process. In this solution, the amount and instant of evaporation from the soil surface can be estimated as function of water table drawdown, impermeable layer depth, and soil hydraulic functions. The solution is based on the Campbell’s parametric equation for water release curve. Nine-soil column experiments consisting of three disturbed sandy Loam, Silty Clay Loam, and Silty Clay soils were conducted to evaluate the analytical solutions. The results indicate a reasonable agreement between the data collected and the theoretical solution. As well the analytical model underestimates the evaporation and water table drawdown in a certain period. Also the solution seems to be applicable for different soil types, requiring only few accessible input parameters.

African violet (Saintpaulia ionatha) is a day - neuter indoor plant that has the ability to flower throughout the year, is traditionally propagated from leaf cutting. The purpose of this study was the optimization of two hormones concentration for better proliferation and micro shoot transplant directly to the rooting media. The MS medium was prepared with IAA (2.0 mg/liter) and BA (0.08 mg/liter) and then used for establishment stage according to the method of Cooke (Cooke, R.C. 1977). In second stage The leaves and petioles formed in the glass jars to 3×3 treatments and then analysed by factorial arrangement design. The treatments were include 1) IAA with 1.0, 2.0 and 3.0 mg/liter, 2) BA with 0.04, 0.08 and 0.12 mg/liter and 3) Thiamine - Hcl with 0.1, 0.5 and 1.0 mg/liter.The results of this study indicate that the best hormones concentration for proliferation is IAA (3.0 mg/l), BA (0.12mg/1). Micro shoot transplant directly in jiffy - 7and perlite media that jiffy -7 compared with perlite was more effective. The plants flowered 4-6 month later in a good condition.

This experiment was conducted in research station of Arsanjan University in 2000, in a Piece of land with a clay texture. In order to evaluate the different ratios of CORN and SOYBEN intercropping, in comparison to pure culture a Randomized complete block design with 4 replications. Was adapted Treatments consist of: p 1=pure corn, P 2=pure soybean, P 3=50% corn + 50% soybean, P 4=%75 corn + %25 soybean, P 5=%75 soybean + %25 corn. This Experiment was conducted by using replacement system. Evaluated factors are as follow: soybean and corn seed yield in pure culture and intercropping, land Equivalent Ratio, Relative corn yield, Relative soybean yield, Aggresivity. Results showed that the treatment with %75 SOYBEAN + %25 CORN whit LER= 1.19 and also the treatment with %50 soybean + %50 corn with LER= 1.11 have preference %9 and %11 respectively higher yield compared to pure culture. Also as for the aggresivity, in treatment with %50 corn + %50 soybean and also with %75corn + %25 soybean, corn was dominant. Finally the best treatment was %75 soybean + %25 corn with %19 efficiency compared to pure culture.

In this survey, physical and mechanical properties of Quercus Castaneaefolia in Golband site of Noshahr were measured in green moisture content. Based on ASTM Standard, results indicated that the most important mechanical properties of the above-mentioned species of oak with specific gravity 0.618 (based on dry weight & green volume) and volumetric shrinkage 13%. include MOR (744 kg/cm 2), MOE (82556 kg/cm 2), work to maximum load in bending (56 kj/m 3), maximum stress in compressive strength parallel to grain (317 kg/cm 2), stress at proportional .limit in compressive stress perpendicular to grain (112 kg/cm 2), maximum stress in shear strength parallel to grain (109 kg/cm 2), maximum stress in tensile strength perpendicular to grain (63 kg/cm 2), toughness strength (3.34 kg.m), cleavage (90 kg/cm). In addition, hardness of tangential, radial and cross-section surfaces were respectively 642. 661, 665kg, and withdrawal load in these surfaces were 54. 62 and 40 kg/cm. Moreover, the impact of the tree height well as geographical direction of the site on the mechanical properties of oak were investigated.

This research is dealing with attitudes of active actors in pasture management towards criteria of integrated sustainable pasture Management Development (ISPMD), along with analysis of introducing the Influential Factors. This is an applied as well as quaisi - Experimental (Ex-post-facto) by hn depth survey method. The research population was consisted of all researchers (110 person), executives (135 person) and extension agents (89 person) active on ISPMD all over the country. (in order 47, 49, 51 persons selected as sample). Results taken from the study shows that the respondents had no statistically significant difference on attitudes towards social and technical integrated pasture management sub - system. Although, their attitudes towards natural and political subsystem were significantly different. This situation was the basic reason for the participants to have no general and unique attitudes to integrated management sustainable development although? actors in all three sub-networks had mutual understanding of ISPMD criteria. None of them rejected general traditional standards for ISPMD and believed some kind of trans-passing criteria from traditional to modern ISPMD.Multiple Regression analysis of variables, age, job experience, ability of executives and pastures, grade point average of attitudes towards executives, belief towards the impact of field actors to achieve pasture Sustainable development Management and... totally expressed 67 percent of the variance of attitudes towards ISPMD.