Rice production in most of Asian countries has been increased more rapidly than population and this has been led to increase in supply and proportionately decrease in the real price of rice in world and domestic markets. Furthermore, together with growth in production and national gross income of the country per-capita income has been increased and also demand for rice at national and internati...

in the present study, effects of iron excess treatments (0, 250, 500 mg l-1) were evaluated in four rice varieties including shafagh, khazar, hashemi and sadri in pot condition. afterward, effects of iron excess (10 and 250 mg l-1) were further investigated in the most resistant variety (shafagh) in sand culture with yoshida nutrient solution. this experiment was arranged as factorial in rcbd w...

in this research, the frequency of the jet streams associated with extreme and pervasive precipitation has been analyzed using environmental to circulation approach. based on the 99th percentile index, 109 days of the extreme and pervasive precipitation was selected from the irimo data base ( including 33 synoptic, climatic and rain gage stations during 15992 days from farvardin, 1st, 1340 to d...

this study was conducted to evaluate the water-use efficiency of rice (khazar cultivar) at rasht research institute of rice. the treatments were four different irrigation intervals (two, five, eight and 11 days) in a randomized complete block design (rcbd) with three replications. the plot size was 15 square meters in area and 50 cm in depth. the spacing between plants was 25 x 25 cm and the so...

estimating and determining of rice water requirement, being the main cultivate of rasht region, is crucial for devoting water to this region. equations which are used to calculate the reference evapotranspiration (et0) are not match to all climatic conditions, due to their empirical bases. so, it is necessary to clarify proper methods for each region. crop coefficient (kc) is also the main para...

spiders are the powerful and efficient predators in almost all ecosystems which have effective role in different pest control. the fauna of these arthropods was surveyed during 2005-2009, and their population fluctuations and activities were studied in mazandaran paddy fields in 2005-2006. a total of 53 spider species of 44 genera were collected and identified from paddy fields of mazandaran pr...