this research in order to identify and introduction of  cotton  suitable cultivar  or cultivars for the double cropping of after wheat and canola harvesting  was carried out in the northern region of ardebil province. in this study, eight  varieties  of    imported cotton germplasm resources in recent years were chosen   and   with the iran's cultivars included  mehr  and varamin  were eva...

precise application of the n fertilizer rate is critical to achieve maximum yield. in major regions, empirical methods were used for determining n fertilizer requirement. these methods cannot take into account variation in management and environmental conditions on determining fertilizer requirement. crop simulation models can provide an alternative means of determining the optimum crop n requi...

rainfall and flow rate are of the most important climatic and hydrologic parameters whose investigation and determination of their behavior are of great importance in water resources management. one of the most suitable methods available for assessment of hydro-climatological conditions in the watershed is trend analysis which is used to examine the changes of a variable during time. current st...

introduction groundwater resources in arid-semiarid zones universally suffer from problems of over-abstraction and declining water tables. in addition to the issues related to quantity, degradation of groundwater quality now assumes major importance in the arid and semiarid regions. in such areas, natural factors such as the low precipitation, combined with high evapotranspiration, result in hi...

background and purpose     methods:     results:     conclusion:

1- introduction crop development is qualitative changes planned that led the plant to ripening. factors such as water available, nitrogen and photosynthetic materials are affected growth and development. under irrigated conditions expected that all of factors except climate elements be controlled. thus, only climate elements able to change of plant growth and development and under these conditi...

drought is the most common environmental stresses that affects plant growth. to study the combined effects of arbuscular mycorrhizal fungi (glomus intratadices) and jasmonic acid on growth and ecophysiologycal characteristics of pistachio seedlings cv. qazvini under drought stress, a greenhouse experiment was conducted in a completely randomized design with three replications. experimental fact...

this research was aimed to investgate the effect of light quality on micropropagation of pear rootstock oh×f333. first, single nodes explants were cultured in modified ql medium containing ba at four levels (0, 0.5, 1, and 2 mg/l-1) and iaa at three levels (0, 0.1, and 1 mg/l-1) and were evaluated for shoot proliferation. then, plantlets subcultured in modified ql medium containing 1 mg/l-1 ba ...

the evaluation and comparison of somatotype with elite athletes is a method to predict the chances of success in sports particularly in the olympic sport of wrestling. the aim of the present study was to describe the somatotypic profile of 9-13-year-old boys in northern, mountainous and desert areas with a territorial planning approach and an emphasis on the geographical areas potential for wre...

the new device made in this study could calculate the proper position of tillage tools relative to the land surface at each point, and hydraulic operator set its optimum position. the optimum position of tools is calculated by depth control software developed for this device, and its input data were depth for root development. the performance of device was tested on subsoiler for precision till...