Abstract
This experiment was conducted at experiment Farm of Agricultural Research Center Ainkawa Erbil Governorate during 2005- 2006 growing season to study the effects of two planting dates : 1st of August and 1st of September as well as the effects of three application methods of gibberellic acid (GA3) at conc. of 250 mg/L : Soaking application , Foliar application , interaction between soaking + foliar in addition to the control application on flowering and seed production of two onion varieties (Local white and Imported Texas Early Grano variety) . Results indicated to an increase in all of the percentage of bolted plants , the number of seed stalks per plant , mean weight of umbel , circumference and diameter of umbel total seed yield and the seed yield per plant for local variety when compared with imported variety . Also the previous mentioned characters increased in the first planting date comparing by with the second planting date. The positive and significant effect of treatment with gibberellic acid with different methods appeared in number of seed stalk and total seed yield especially in the treatment soaking + foliar .
