Abstract

The study was conducted during 2011-2012 season in Al usufyia district( 30 km
southern Baghdad) of onion seedling on Texsas Eerly Grano ( PRR) Var . treat the
seedling with low Tempertures ( 5 , 10 and 15 Co ) for three periods (24, 48 and 72 h)
.the aim of the study was determing the best temperature that cause the high response
of flowering and high seed yeild . The results can summarized as follows :
Thetreatment 5Co for 24 hr gave the best results in vegetative growth characters
(number of tellers and neck diameter ) ( 1.733 teller / plant and 41.90 mm respecte
flly )( earliar flowering ,flowering percentage , number of flowering bolter and the
length of flowering bolter ) ( 150 day , 87.33 % , 1.700 tiller / plant and 126 cm ,
respect) , the seed yeild characters ( set percentage , Inflorecent weight and seed yeild
in area ) ( 43 % , 15.40 gm / inf and 725.3 kg/ha ) respectefly significantly as control
treatmet .