to study the effect of seed sowing rate, different levels of nitrogen and different sowing dates on canola cultivar hyola401, a field experiment was conducted during 2005-2006 at safiabad agricultural research center. the design was a split split plot in a completely randomized block basis of 3 replications. main plots consisted of 3 levels of sowing dates (6, 26 nov and 16 dec), sub plots of 3...

Surface sediments contamination to heavy metals was evaluated in eight creeks of Mahshahr coastal waters (north-west of the Persian Gulf) from October. 2005 to November 2006. Sediments were collected seasonally by Peterson grab and the concentrations of heavy metals were measured using voltammetry and polarography methods. The range and the mean concentrations obtained in mg/kg were 15.03-35.16...

in order to investigate some silvicultural and soil physico-chemical characteristics of christ's thorn (ziziphus spina christi l. desf.) natural stands, ten natural stands of the tree species which have similar climate and aspects were selected and altitude from sea level (asl), the thickest sprout collar diameter (tscd) and total tree height (th) of the tree species were measured in 1000 ...

introduction integrated weed management is based on combination of several management methods, while reducing the rate of the use of herbicides, will result in efficient management and sustainable weed control. ability of crop tolerance and prevent weed growth are two important traits in weed competition. an appropriate and suitable cultivar, has high yield potential in the presence of weed and...

introduction today, attention to safety and environmental issues in all sectors in agriculture, industry and services is very important. chemical poisons play an important role in rapid progress of agricultural products. every year about 25 to 35 percent of the world's crops are affected by insects, weeds and plant pathogens disappear and this figure would be raised to 80% if no control was app...

introduction: oxidative degradation of lipids is a major factor limiting the shelf life of foods. the free radical reaction of lipid peroxidation is generally responsible for the deterioration of fatty foods. in general, use of synthetic antioxidants during the manufacturing process are applied to prevent fat oxidative and rancidity while their carcinogenic effects have been approved. since the...

introduction sulfur dioxide has been widely studied among the human- made pollutants. air pollution is a major environmental risk to health. the less air pollution, the better the cardiovascular and respiratory health of the population will be, both long- and short-term. several studies have demonstrated relation between on short and long term effects exposure to air pollutants with human healt...

Purpose: The purpose of the present study is to investigate the characteristics of external environment of companies in the second industrial area of Ahvaz and its effect on managers' environmental scanning behavior in using information resources. Method: An analytic survey method is used to analyze the relationship between variables. Findings: The findings showed that managers' perception of v...