Combining ability analysis of some yield characters of sunflower, Helianthus annuus L

The experiments comprising 25 sunflower hybrids were conducted in three locations in 2000 and 2001. These hybrids were evaluated for combining ability of 6 important yield components. Based on observations in this research, the average flowering duration of the hybrids ranged from 69.6 to 71.8 days, physiological maturity from 98.7 to 104.2 days, hectoliter weight from 355.2 to 408.5 g, 1000-seed weight from 32.5 to 43.5 g, plant height from 98.3 to 134.3 cm and head diameter from 12.6 to 14.0 cm. Based on all combining ability analyses performed in this research, the cross 2453-A x R-1001 was determined as the best hybrid in the experiment. Among the parental lines, HA89-A and 2644-R were chosen as first female and male testers, respectively; BAH8-A and 2280-R were chosen as second testers for testing combining ability of lines for use in future breeding programs in sunflower.