Duration of vegetation period and hybrid sunflower yield in the breeding for earliness

Sunflower hybrid combinations were studied in 2004-2006. High correlation between vegetation period duration and yield components was observed among the high yielding hybrid combinations. Seed yield depends mainly on duration of period from emergence to flowering. Oil yield and oil content depend on duration of period from flowering to physiological maturity. Early hybrid combination (Kubanskiy 86 x VK 789, we developed) is recommended to future trials.