Search

To evaluate the effects of potassium and nitrogen fertilizers on yield and lodging characteristics of Gilaneh rice cultivar under two irrigation regimes (permanent flooding and irrigation with to 10 days interval) a field split split plot experiment based on complete randomized block design with 3 replications in Rasht. Nitrogen and potassium fertilizers used were at the 0, 60 and 120 kg.ha-1 and 0, 80 and 160 kg.ha-1 as sub and sub sub factor, respectively. The results showed that the highest seed yield obtained about 3713 kg.ha-1 from permanent flooding with the application of 120 kg.ha-1 of nitrogen fertilizer and 80 kg.ha-1 of potassium fertilizer and the lowest yield 634 kg.ha-1 from 10 days irrigation interval, without using of potassium and nitrogen fertilizers. The 10-day irrigation interval reduced the bending moment of the internode 4 by 40%. With increasing the rate of potassium fertilizer, the lodging index of intermediate 4 decreased, which was due to the increase of cellulose content by 60% in this intermediate. Increasing nitrogen and potassium fertilizers decreased the lodging index at internodes 3 and 4. Irrigation at 10 days intervals decreased plant height, internode bending moment, cellulose and hemicellulose and seed yield It increased lodging index of intermediate, butincreasing fertilizer levels in both irrigation regimes had adverse effect on the traits under study.

To evaluate the effects of potassium and nitrogen fertilizers on yield and lodging characteristics of Gilaneh rice cultivar under two irrigation regimes (permanent flooding and irrigation with to 10 days interval) a field split split plot experiment based on complete randomized block design with 3 replications in Rasht. Nitrogen and potassium fertilizers used were at the 0, 60 and 120 kg.ha-1 and 0, 80 and 160 kg.ha-1 as sub and sub sub factor, respectively. The results showed that the highest seed yield obtained about 3713 kg.ha-1 from permanent flooding with the application of 120 kg.ha-1 of nitrogen fertilizer and 80 kg.ha-1 of potassium fertilizer and the lowest yield 634 kg.ha-1 from 10 days irrigation interval, without using of potassium and nitrogen fertilizers. The 10-day irrigation interval reduced the bending moment of the internode 4 by 40%. With increasing the rate of potassium fertilizer, the lodging index of intermediate 4 decreased, which was due to the increase of cellulose content by 60% in this intermediate. Increasing nitrogen and potassium fertilizers decreased the lodging index at internodes 3 and 4. Irrigation at 10 days intervals decreased plant height, internode bending moment, cellulose and hemicellulose and seed yield It increased lodging index of intermediate, butincreasing fertilizer levels in both irrigation regimes had adverse effect on the traits under study.

The purpose of this study is zoning and analyzing the precipitation cycles in central areas of Irna. For this purpose, 29 climatic variables for 72 synoptic and climatology stations during the statistical period of (1980-2011) have been uses. To this end, by using geostatic methods, a data base of dimension 29×3673 km was formed. Then for climatic zoning, cluster analysis method and discriminant analysis have been used. For detecting hidden or visible precipitation cycles at each area, spectrum analysis have been used. Data obtained from selected climatic variables have been reviewed and analyzed by Ward incorporation cluster analysis method that after drawing Dan Degram, four climatic areas(1- the area with high precipitation, 2-very low temperature and high humidity, 3- very low precipitation, very high temperature and very low humidity 4- low precipitation, high temperature and low humidity) have been recognized. To evaluate the results of the cluster analysis, discriminant analysis method was used to test the mean difference. The results of discriminant analysis showed that 98.87 of the stations are located correctly in their respective groups.The results obtained from using analysis of precipitation cycles of each of these areas showed that short cycles of 2-4years have been mostly dominant in the both four groups. However, the most variable cycles are located in area No.1 due to different factors including vicinity with Persian Gulf waters and locating in the shadow of Zagros mountains.

The purpose of this research survey and descriptive study was to identify strengths, weaknesses, opportunities and threats of dry-bed rice seeding development in Khuzestan province, and provide strategies to develop dry-bed rice seeding cultivation. The statistical populations were all farmers of Ahwaz and Mahshahr township, which were engaged in dry-bed rice cultivation. From them 180 farmers were selected as sample using Cochran’s formula and stratified random sampling method. Data were collected using questionnaire. Data were analyzed using SPSS software and to provide strategies to develop dry-bed rice the SWOT (Strengths, Weaknesses, Opportunities and Threats) matrix was used. Based on the results, reducing in time in dry-bed rice seeding cultivation, reducing in need for labor and low water consumption were important strengths; increasing in weeds growing was the important weakness; The development of culture in favorable soil was the important opportunity and roughness of the farming land and There are environmental threats were important threat of dry-bed rice seeding cultivation.By analyzing the strategic factors, based on common rules in the analysis of SWOT If the average of the weaknesses and threats is less than average strengths, opportunities (WT < SO), Strategy that can be proposed offensive and If the total average of the Weaknesses, opportunities is less than average Strengths and threats (WO