List of Articles Economic Threshold

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  1 - The role of urban network in urban sustainable development of mazandaran province
  ali sheikhazami Assadollah Divsalar
  Today, development is a concern for many countries, and the development is more satisfying of people's lives situation. Study of urban networks gives people an awareness of how in certain geographical areas to overcome on barriers of communication and exchange and Econo More

  Today, development is a concern for many countries, and the development is more satisfying of people's lives situation. Study of urban networks gives people an awareness of how in certain geographical areas to overcome on barriers of communication and exchange and Economic machine its regions how and to use of which data applied. And due to the role of existing cities in the network, the complex relationships between them in the area how interact and to order, this causes the system to be satisfied with their life. The research method in this study “descriptive - analytic “is. Thus, of break- point model are used to determine the province's urban network based on economic thresholds or boundaries of the principal cities in the area, and then using the composite index of development, sustainable urban development in areas of the province (or city's) network has been set under the main cities. In this study, a library and cartographic methods used to collect data. Statistical community of the research is 51 city of Mazandaran provinces and especially 21 city of the district center of the province. Some results obtained in this study are as follows: Mazandaran province have not single urban network (cross-sector network in the East and a linear network in the West), Disparities in rates of sustainable urban development in the province prevails, Almost "towns urban network of linear in the level of development high and cities urban network of sectoral in the level of development down is located,Regions of deprived and under development of the province have high percentage of urbanization .Due to the break-point of the centers of districts of The City of Surrey, urban network of province  through Timely and equitable transfer of the flow (in the linear network) Led development and the suction flow untimely and colonial (in the sector network) is caused underdevelopment and exclusion in cities and etc.   Manuscript profile
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  2 - Determination of the economic threshold of damage of red root pigweed (Amaranthus retroflexuxs L.) in green bean (Phaseolus vulgaris L.) field
  Bahram Mirshekari Adel Dabbagh Mohammadi Nasab Mahmood Pouryousef
       In order to determine the economic threshold of damage of red root pigweed (RP) in green bean, a two years experiment was conducted in agricultural research station of Islamic Azad University of Tabriz, Iran, based on a randomized complete block More

       In order to determine the economic threshold of damage of red root pigweed (RP) in green bean, a two years experiment was conducted in agricultural research station of Islamic Azad University of Tabriz, Iran, based on a randomized complete block design with three replications. The treatments were RP interference times at 2, 4, 6, 8, 10 weeks after green bean emergence until late growth season (GBE); full season interference (FSI) and control weed free plot. Data were analyzed with Mstatc software and Duncan's test was used for mean comparison. Results showed that the above ground biomass and yield of green bean in control plot was similar to treatment of weed interference at 10 weeks after GBE. Yield loss in FSI was 67.36% in comporison to control. RP emergence at density of 8 plants-m-1 of row at early 6 and 8 weeks of green bean growth stage to later, was caused 21.5% and 6.2% yield loss, respectively, in comparison to control. With attention to 10% maximum permissible yield loss in green bean, RP must be controlled, if it was emerged within a period of 6 weeks of early green bean growth stage and economic threshold of damage of RP at studied density level was determined until 6 weeks of early green bean growth stage. Manuscript profile