S.s. Pourdad, K. Alizadeh, R. Azizinegad, A. Shariati, M. Eskandari, M. Khiavi, E. Nabatee,
Volume 12, Issue 45 (fall 2008)
Abstract
Safflower (Carthamus tinctoius L.) is an Iranian native crop that is adapted to different environmental conditions of this country. Sixteen safflower varieties/lines were spring-planted in 6 research stations including Sararood (Kermanshah), Maragheh, Ghamlo (Kordestan), Khodabandeh (Zanjan), Shirvan (North Khorasan)and Khohdasht (Lorestan) with and without drought stress conditions each in a RCBD with 3 replications. Some drought resistante indices including Mean of Productivity (MP), Geometric Mean of Productivity (GMP), Tolerance (TOL), Stress Tolerance Index (STI), Stress Susceptibility Index (SSI) for seed yield and genotypes Cell Membrane Stability (CMS) were calculated. Results showed that STI was the most appropriate index to identify drough resistant genotypes. Estimation of STI from mean of all stations revealed that Gila, CW-4440 and PI-537598 with high STI showed high seed yield in both stress and non-stress conditions. Caculation of STI standard deviation for these genotypes showed that Gila had less STI stability over the locations than other two genotypes so, CW-4440 and PI-537598 are more stable in drought stress resistance. Analysis of variance for cell membrane stability (CMS) of genotypes showed the significant differences in 1% level of probability between genotypes. S-541 had the highest and Kino-76 had the lowest CMS. There were significant and strong correlations between STI, MP and GMP with CMS namely, genotypes with more stable membrane having more drought resistance in field condition. So, cell membrance stability can be a useful and fast method to screen germplasm and identify drought resistant genotypes. Cluster analysis based on STI,MP,GMP, CMS and seed yield in both stress and non-stress conditions divided genotypes into 3 groupes. Results of clustering also identified S-541, Gila, CW-4440 and PI-537598 as 4 superior genotypes and confirmed the results of other methods.
Engineer H. Talebikhiavi, Engineer M. Zabihi, Dr. R. Mostafazadeh,
Volume 21, Issue 2 (Summer 2017)
Abstract
Effective soil conservation requires a framework modelling that can evaluate erosion for different land-use scenarios. The USLE model was used to predict the reaction of appropriate land-cover/land-use scenarios in reducing sediment yield at the upland watershed of Yamchi Dam (474 km2), West Ardabil Province, Iran. Beside existing scenario, seven other land-use management scenarios were determined considering pattern of land-use through study area within a GIS-framework. Then, data inputs were prepared using terrain data, land-use map and direct observations. According to the model results, the generated erosion amount was 3.92 t/ha/yr for the current land-use (baseline scenario). For this purpose, conservation practices in dry farming slopes and implementing the scenario 5 (contour farming and remaining crop residuals) can reduce the sediment to 2.02 t/ha/yr. The lowest and highest decreases in sediment yield are projected to be through implementation of scenario 6 (irrigated farming protection with plant residuals) and 7 (biological soil conservation in dry and irrigated farming). The results indicated that, implementing scenario frameworks and evaluating appropriate land-use management scenarios can lead to the reduction of sediment entering the reservoir, and prioritizing soil conservations in the studied area.
