Research was conducted to develop and release new improved winter safflower (Carthamus tinctorius L.) cultivar suitable for cold and semi cold areas of Iran. In 1995, 1996 and 1997, line L.R.V.51.51  was selected from Uromeieh landraces based on agronomic traits, resistance to diseases and abiotic stresses under field conditions. It was included in yield trials in main Research Stations Karaj, Isfahan and Darab, together with 9 safflower lines, as well as widely grown improved cheek cultivar Zrgan-279 Results showed that this line produces significantly higher and stable yield. Analysis of the grain and oil yields using Eberhart and Russel method showed significant difference for the main effects of genotype and genotype × environment (linear) interactions and non-significant difference for deviation from regression. According to the classification of genotypes based on the mean of grain and oil yields, coefficient of regression and deviation from regression, the new line L.R.V.51.51 with its high grain and oil yields and stability was selected as a desirable genotype while it has more tolerant to cold than Zargan-279, with mean grain and oil yields 2205 kgha-1 and 600 kgha-1 respectively. The new line was released in 2005, with the name of Paideh. 

In this study, effects of bio-fertilizers on yield potential and agronomic characters of safflower (Carthamus tinctorius L.) cultivars under different irrigation regimes were evaluated. Experimental design was RCBD with split plot factorial arrangement and 3 replication that was done on growing season of 2010-2011 at Kerman, (Iran). Different irrigation intervals included 5 days, 10 days and 15 days was applied in main plot and two levels of bio-fertilizers control and Azotobacter sp. And Azosprillum sp.+ phosphate bio-fertilizer as well as three cultivars (Goldasht, Sina and Mex. 22-191 line) were placed as sub plot with factorial arrangement and different agronomic traits were measured. Results showed that all of the traits significantly affected by irrigation regimes except harvest index. Delay in irrigation from 5 to 15 days reduced 33.11% of the seed yield, also all traits except number of seed per head and harvest index significantly affected by application of bio-fertilizers. There were significant differences in all of the measured traits except harvest index among the cultivars that represented variation among them while Irrigation×cultivar intraction was no significant that represented same responses of cultivars to different irrigation regimes. Irrigation×fertilizer×cultivar interaction effects were significant for number of head per plant and 1000-seed weight and the interaction effect of fertilizer×cultivar was significant for biological and seed yield. Biological and seed yield increased with application of bio-fertilizers compared to the control. According to the obtained results the highest seed yield was obtained from Mex. 22-191 line, in application of bio-fertilizer conditions.

Safflower (Carthamus tinctorius L. ) is an important oilseed crop in Iran and many other countries around the world. Safflower fly, Acanthiophilus helianthi Rossi is one of the main limiting agents to expand the production area of the crop in different countries and the most major pests of safflower in Iran. In this research, the influence of 10 safflower genotypes on biology and population parameters of A. helianthi was evaluated under the laboratory conditions at 25± 1° C, 65± 5% relative humidity, and a photoperiod of 16: 8 (L: D) hours. The shortest and longest total developmental time were recorded in Mexico 37 (16. 85± 0. 31) and Goldasht (21. 76± 0. 59), respectively. The intrinsic rate of natural increase (r) ranged from 0. 129 to 0. 186 (day-1), which was lowest on Goldasht and highest in Mexico 37. The net reproductive rate (R0) ranged from 50. 809 to 125. 846 offspring on different genotypes. The values of finite rate of increase (λ ) and mean generation time (T) on different safflower genotypes ranged from 1. 138 to 1. 205 day-1 and 25. 778 to 30. 421 days, respectively. The results demonstrated that Goldasht, Line 411, and KW2 genotypes were less suitable host plants, suggesting that they are more resistant to A. helianthi than the other genotypes, have high yield, and could have the potential for using in Integrated Pest Management program (IPM) of A. helianthi in safflower fields.

Safflower capsule fly, Acanthiophilus helianthi is a serious pest on safflower, could reduce crop yield up to 25 %. To study the reaction of different safflower cultivars to safflower capsule fly in different planting dates, an experiment was conducted during three consecutive years (2006-2009) in split-split plot design with three replications, in Kaboutar-Abad research station (Isfahan, Iran). The main plot was spraying in two levels (sprayed and unsprayed), subplot was sowing date in 8 levels (from early March to late June) and sub-sub plot was cultivar in three levels (Arak, Soffe and Goldasht). Sampling was carried out in 5 times, according to the growth stages of safflower. In each sampling, percentage of infested heads, percentage of damaged seeds and number of larvae per head were counted. The results showed significant difference among planting dates for above three factors. The highest and lowest percentage of infested heads were recorded on late (late May to late June) and early planting dates (early March to early May), respectively. The highest and lowest number of larvae per head and the highest and lowest percentages of damaged seeds were observed on last planting date (late June) and early planting dates (early March to early April), respectively. Significant differences were found for the three factors among the studied cultivars. Goldasht cultivar had the highest percentage of infested head and percentage of damaged seeds. In order to control safflower capsule fly in the region, cultivation of Arak and Soffe cultivars in early planting dates (early March to early April) is recommended.

The safflower fly, Acanthiophilus helianthi Rossi, is an important pest of safflower in Isfahan region. In this study, population density and damage of the safflower fly on ten safflower genotypes namely Mexico 37, Mexico 38, Mexico 39, Mexico 50, Mexico 51, KW2, Line5, Line 411, Padideh and Goldasht were studied in an experimental field (not using of insecticide) during 2012 and 2013. Furthermore, yield indices of ten tested genotypes were studied in a control field (using of Chlorpyrifos). The densities of larvae and pupa on Goldasht (7.6 and 8 larvae and pupa/plant) and Line 411 (8.8 and 10.4 larvae and pupa/ plant) were lower compare to the other tested genotypes of safflower. In addition, the percentage of infested heads/plant, the percentage of reduced weight of infested head, the percentage of infested seeds/ head, and the percentage of seed loss/ infested head on Goldasht and Line 411 were lower than on the other tested genotypes. Yield indices including the number of heads/plant, the number of seeds/ head and the weight of 1000 seeds on Goldasht and Line411 were higher compare to the other tested genotypes. These results indicated that Goldasht and Line 411 were the least suitable genotypes to the safflower fly, and these genotypes with high yield have the potential for using in integrated management program of A. helianthi in safflower fields.

Growth analysis is a valuable method in the quantitative analysis of crop growth, development and crop production. In order to evaluate effects of nitrogen rates and plant density on physiological growth indices of safflower, an experiment was conducted at Khorramabad, Lorestan province in 2008. The experiment was carried out as split plot in basis of randomized complete block design with four replications. Three nitrogen application rates were as main plots (N1=control, N2=75 and N3=150 kg/ha net nitrogen) and plant density was as sub plots in 3 levels (D1=40, D2=50 and D3=60 plant/m2). The growth degree day index was used to examine more closely fitting growth curves using non-linear regression models. Appropriate model was selected for each growth index. The results showed that application of nitrogen led to increasing of growth indexes including leaf area, total dry matter and crop growth rate. But, net assimilation rate was reduced. Growth indexes such as, leaf area, total dry matter, did not change with increasing plant density, due to branching of safflower. However, crop growth and net assimilation rate were reduced in plants. Overall, the results show that applied nitrogen has a more positive effect on safflower growth index compared to density changes.

To assess resistance of different genotypes of safflower to safflower shootfly, 10 genotypes of this plant were evaluated in autumn sowing. The experiments were conducted in a complete blocks design with three replications in Agricultural Research Station Gryzeh-Sanandadj and two growing seasons (2011-2012 and 2012-2013). In this trial some parameters such as rates of infestation and damage, yield, weight of 1000 seeds and percent of oil were measured and compared in different plots. Analysis of variance of percent of infested capitula, number of larvae and pupae, number of damaged seeds, weight of 1000 seeds, percent of oil of seeds, and yield revealed significant difference between genotypes at the 1% probability level. Based on the comparison of mean values, the local varieties named Isfahan and Lesaf had highest and Syrian had lowest percent of infested capitula. Accordingly, local variety of Isfahan had maximum and local genotype of Marand had minimum number of larvae and pupae per capitula. The Lesaf genotype was more susceptible and had highest percent of damaged seed and genotypes of local Isfahan, Marand and Syrian had the lowest number of damaged seeds. Evaluated genotypes were divided into two main groups based on the results. The first group including Syrian, local Marand, Sina, 411 and IL111, with lowest percentage of infested capitula, lowest number of larvae and pupae in the capitula and lowest percent and number of damaged seeds, could be considered as relatively tolerant to the safflower fly. Syrian and local genotype of Marand, were more tolerant among the rest. The second group including Isfahan, Lesaf, S-541, Dinser and coarse-grained Almaneh, with the highest percentage of infested capitula, the highest number of larvae and pupae in the capitula and highest percent of damaged seeds, could be considered as susceptible to the safflower fly. Local cultivar of Isfahan and Lesaf were more sensitive than others.

To determine the effects of potassium foliar application (with two levels, use and nonuse) from potassium sulphate source and top-dressing application of potassium fertilizer (with two levels, use and non-use) from potassium chloride source on number of seeds per capitulum, number of side branch per plant, seed yield, seed oil content, oil yield, seed to coat ratio, plant height and shoot dry weight in three safflower, genotypes including KW.2, Padideh and Goldasht a factorial experiment based on the randomized complete block design (RCBD) with three replications, was conducted during 2013 growing season at the Agricultural Research Center of Semnan province (Shahroud). Results showed that the highest average of number of seeds per capitulum (28.70), number of side branch per plant (17.83) and seed to coat ratio (1.47) were found in KW.2 genotype. The highest seed yield (2627.7 kg/ha) and oil yield (1350.5 kg/ha) were found from potassium sulphate foliar application in Padideh and KW.2 genotypes respectively. The interaction effect of genotype × potassium foliar application was significant for seed and oil yields. In conclusion, it was determined that potassium sulphate foliar application has better impacts on seed and oil yield of safflower genotypes than potassium top-dressing application.