Year:2000 | Volume:6 | Issue:3|Papers Count:9

Nitrogen fertilization at early stages of plant development do not always result maximum yield and protein. The objectives of this study was to determine the effect of pre and post an thesis foliar spray of urea on car development, leaf area duration, grain protein percentage and yield of two winter wheat cultivars. Foliar N (20 kg/ha) as an aqueous solution of urea (50 g/lit) was applied at four stages of development in 1373. Maximum effect of supplementary N was achieved at the jointing and flag leaf emergence stage. At these developmental stags, supplementary N increased the number of florets per spiklet and grains per car. In spite of significant increasing at seed yield, hut harvest index do not vary. Foliar spray increase "Anthesis spike weight to stem weight ratio" a little. Nitrogen added at anthesis and milk stage mainly increased the kernel weight and grain protein percentage hut did not increase grain yield significantly. Although foliar fertilization around a thesis decrease rate of N-depletion ofleaf during grain filling, hut it did not increase leaf area duration. Its reasons can his positive effect of foliar spray on N percentages of high leaves on stem only at two last weeks of seed filling period. Total N uptak at a thesis and at maturity in low protein cultivar (Navid) was greater than high protein cultivar (Bezostaya).

This study deals with efficiency assessment of probability function by using different time series. Eight hydrometric stations in Karun drainage basin selected and their maximum instantaneous discharge completed for an 85 years period. Tow sets of 10-10 and 5-5 established in each station by splitting stations' long record into series with different lengths of five and 10 years intervals that finally led to obtaining 192 time series. Frequency analysis of maximum annual instantaneous discharge studied in time series of two sets. Analysis consisted seven methods, Normal, 2PL Normal, 3PL Normal, 2P Gamma, Pearson type III, L Pearson type Ill, Gumbel type I distributions. Goodness of fit studied by calculating sum squares of relative deviations and chi-square. Compression of the Frequency Analysis' results indicates that estimated floods, up to 50 years return periods, are very close to each other and the differences increase in high return periods. Estimated floods with selected functions are close to calculated floods by empirical probability methods up to 100 years return periods. In spite of variation in period's covering time series with equal length, Tree parameter functions are most selected as best distributions. Results show that L Pearson type III has a good flexibility and selected as best fitted distribution in 192 time series of two sets. Results show a considerable Convergence from application of tree parameter distributions. To test the major obtained results, 72 hydrometric stations over the Zagross zone, covering 10 provinces, selected and flood frequency analysis carried out with different time series. Log person type III selected as best distribution in 53 stations. The tree parameter distributions in general, with 79 percent t-elative frequency, are the hest probably function in flood frequency analysis in region under consideration.

Some of the typical shortcomings of conventional extension services common in many developing countries, are highly bureaucratic, ineffective organizational structure, and personnel lack of motivation. Excessive rigidity, impersonality and other inherent dysfunction of the bureaucratic organization brought about interest in participative management approach. The extension organizational structure of Jahad Sazandegi Organization (JSO) is characterized as a traditional and an industrial-age structure which is derived from 19th century practices. In an industrial-age organization, managers are seen as the boss and everyone else as subordinates. By contrast, the work of extension profession is considered knowledge work and in this context extension scientists believe that the workers should be seen as boss and extension managers and administrators as facilitators.The primary purpose of this study was to measure the perceptions of the Qom Jahad Sazandegi Extension Organization (QJSEO) professional staff toward the organization's management systems (existing and desired). Another purpose was to measure the professional staff members' self-perceived level of motivation and determine its relationship to the management system. A total of 148 professionals made up the population (N=148) for this study.A sampling size of 98 (n=98) was computed and a complete randomized sample was drawm from the population. The Profile of Organizational Characteristic (POC) which is based on Likert's system -4 theories was used to gather data on management systems and motivation.Findings indicated that the QJSEO epitomizes a typical bureaucratic organization where rewards and motivation are dealt with in a traditional manner. The QJSEO is characterized as a benevolent authoritative (a system -2 by Likert classification of management system) organization where most of the decision making and goal setting are done at the top of the organization. The QJSEO organization has a great potential to become a participative management system because the professional staffs favor a management system based on a participatory style. There is a very strong association between the participant's motivation level and their perception of management system (r=0.72; R2 = 0.52). The findings of this research support the likert's theory and other research findings in this regard. The professional staff members' level of motivation could be greatly enhanced by improving the existing management system of the QJSEO. Less than 8% of the variation in motivation score could be explained by the respondents' individual characteristics. Therefore, a great amount of variation in staffs' level of motivation (about 60%) could be explained by organization's management structure, level of education, age, marriage status, years worked for the organization, and income. This means that there are other unknown variables that affect staffs' level of motivation.

The imagination an economy without any intervention and policy of Policy makers is very difficult. Therefore the decrease of government intervention costs and the augmentation of the policy et1iciency are very important. The current Agricultural policies of Iran are Unsuccessful. This situation in our believes has happened because of two following reasons: 1- The policy maker's do not believe the current firm acts that governs the economies.2- The Lack of relevant literature about decision making process of Iranian agricultural economies. In this article, after the estimation of supply and demand functions of rice of Iran with "dead weight loss per doller transferred" The efficiency of the Iranian rice policies and their alternatives are calculated. The result of this study show that by substituting "The Target price policy" for "The current qauntitive ristriction of imports" some amounts of 271 Billion Iranian Rials will be saved annually.

In recent years the population density of cereal sawfly has in creased in Karaj area and central provinces of Iran. Researches were carried out to stimate the effect of fenitrothion normally used against sunn pest during 1991-1992. For this purpose an experimental field of about 6000 m2 area was planted. Experiment arranged in randomized complete block design with 4 treatments and 5 replications each. The treatments were:1- Spraying against (over-wintered adult of sunn pest2- Spraying against nymphs of sunn pest3- Spraying against over wintered adults and nymphs4- Check (without spraying)Percentage of infestation was determined for each replication. The data obtained at the end of two years were analyzed. The F figured out from the variation table revealed that, there was significant difference among the treatments.Treatment No.1 having 4.44 contaminations was less contaminated of cereal sawfly in Comparison with the other treatments

Anise (pimpinella anisum L.) is an important annual herbaceous plant of umbelliferous family and its active substance is widely used in pharmaceutical, food, cosmetic and hygiene industries.To study the effect of sowing datas and N-fertilizer on the growth, development, seed yield and essential oil of, anise, experiments were carried in a randomized split plot in four replications in khoramabad, Iran in 1998. Sowing datas of March 6, April 4 and May 5 were used as the main plots and nitrogen fertilizers of 0, 100 and 200 Kg/Hectare were used as the subplots.Only plots sawn in March 6 were used for the measurements and the data were statistically analyzed and Dunken tests showed that by increase of N-fertilized the seed and essential oil yield were increased. Nitrogen fertilized of 0, 100 and 200 Kg/Hectare increased the seed yield by 546, 794 and 897 Kg/Hectare and essential oil by 13.46, 21.16 and 24.88 Lit/Hectare respectively. The hest time of sowing seed was noted to bee March 6 and the hest rate of nitrogen fertilizer was 100 Kg/Hectare.

This work aims to study on of the important species of conifers in Iran (cupressus sempervirens Var horizontals) in the north of the country. Evergreen cypress trees, which are unique and distinct in their own right, are highly prone to destruction in this region.The cypress site with an area of 4781.25 hectares has six deferent plant types of these, 57.9% covering (2768.75 hectares) are the natural cypress type, and 42.1% comprise the planting types (C.S Var horizontals, pinus eldarica, pinus brutia, Fraxinus excelsior and Robinia pseudacacia) and large hardwood, conservation area, areas with no vegetation and farmlans.The most important factors leading to distraction are divided into two parts: a biotic (parent rock, sleep sloop, low percipitation, lock of vegetation and erosion) and biotic (humans, cattle, pest and disease). In order to work out a program of preservation, reproduction and manipulation with regards to this issue it is necessary to gain know ledge of existing types in this area and the effects of destructive factor.