RESULTS ON THE FLOWERING STAGE IN THE ROMANIAN-GROWN SUNFLOWER HYBRIDS

The present paper presents the results of the research carried out on forty sunflowerhybrids in southern Romania (15 km far from northeastern Bucharest), under the2004 and 2006 climatic conditions, regarding the flowering stage, the period andthe duration of flowering process within the crop, respectively. The studied hybridswere the following: Favorit, Festiv, Florina, Jupiter, Alcazar, Top 75, Venus, Alex,Saturn, Minunea, HS 2442, HS 2606, Milenium, Romina, Performer, Select, Justin,Splendor, Hercule, Felix, and twenty foreign hybrids cultivated in Romania:Huracan, Kasol, Lindor, Masai, Mateol, Podium, Saxo, Sunko, Fly, Rigasol, RigasolOR, Fleuret OR, Arena, Melody, NK Armoni, Alexandra, NK Dolbi, NK Ferti,Opera PR, Sanay. At the studied sunflower hybrids were performed the following determinations: • sum of growing degree days (GDD) from plant emergency (i.e. when 75% ofthe plants emerged) to the beginning of the flowering process within the crop(i.e. when 10% of the sunflower heads are flowered); • date for the first sunflower heads flowering; • date for the beginning of the flowering process, i.e. when 10% of the sunflowerheads have flowered in the whole crop; • date for the plain flowering phase, i.e. when 50% of the total sunflower headshave flowered; • date for the full-flower phase, i.e. when all the sunflower head in the crop haveflowered; • date for the time when only 10% of the sunflower heads were still in flower; • date for the end of flowering, i.e. when no sunflower heads are in flower in thewhole crop; • number of days between different flowering stages.