CORRELATION AND PATH COEFFICIENT ANALYSIS ON SEED YIELD IN SUNFLOWER

The research was conducted to investigate the correlations among agronomic and yield-related characters of sunflower and to verify their direct and indirect effects which will be used for the selection for seed yield. Twelve candidate synthetic varieties and 4 check synthetic varieties were evaluated at Suranaree University of Technology experimental farm, Nakhon Ratchasima, Thailand, in November, 2006 using a randomized complete block design with 4 replications. Eight characters were collected and analyzed for correlations and path coefficients. The results showed that the seed yield was strongly correlated with head diameter and plant height. Furthermore, seed yield was also positively correlated with percent seed set and 100-seed weight. A highly negative correlation coefficient was found between days to flower and oil content. Significantly positive correlations were found between percent seed set and number of seeds per head, head diameter and 100-seed weight and between number of seeds per head and oil content. The head diameter showed the highest positive direct effect on seed yield followed by plant height. In addition, the indirect effects of most characters were high through head diameter. Therefore, head diameter and plant height should be used in the selection for yield in sunflower. The results obtained from correlation and path analyses showed that the efficiency in the selection for seed yield in sunflower should increased through the selection of head diameter and plant height.