As the yield is a complex character in improvement endeavor, determining the relationship of the component characters as well as the cause and effect relationships are essential for indirect selection in enhancing the yield potential of safflower (Singh, 1991; Consentino et al., 1997; Patil, 1998; Omidi, 2002; Mahasi et al., 2006; Mozaffari and Asadi, 2006; Ahmadzadeh et al., 2012). Studies showed that number of head per plant had significant positive correlation with seed yield in safflower (Nezhad and Talebi, 2015; Shinwari et al., 2014). Ahmadzadeh (2013)reported significant positive relationship among number of seed per head and seed yield. Same author also indicated that number of seed per head had positive direct effect on seed yield of safflower.  This study was undertaken to determine the associations of the characters, and identify the direct and indirect effect of these characters on the yield of safflower.

Path analysis showed that days to flowering, plant height, number of branches, number of seed per plant and hundred seed weight had positive direct effect while number of capitula and number of seed per capitula showed negative direct effect on the seed yield of safflower (Table 2). The highest positive direct effect on seed yield was recorded by number of seed per plant and hundred seed weight. Therefore, considering these traits as selection criteria in improving seed yield of safflower would be worthy. Similar result was also obtained by (Eslam et al., 2010; Ahmadzadeh et al., 2012). A high positive direct effect of 100 seed weight was also reported by (Mahasi et al., 2006; Patil et al, 1994; Ashri et al., 1976; Uslu et al., 1997; Lahane et al., 1999) reported that capitula per plant was the most important yield component. In this study, the positive correlation of number of capitula with seed yield was a result of the indirect effect of this character via number of seed per plant, which was the most important yield component as depicted in path analysis.