The effects of gibberellic acid on some morpho-physiological characteristics of two varieties of white and yellow flowers (Alba and Apollo) Snapdragon (Antirrhinum majus)

The evaluate the effect of gibberellic acid (zero, 100, 200 and 400 milligrams per liter) on quantitative growth characteristics of two varieties of Snapdragon (Antirrhinum majus) a factorial experiment base on a completely randomized block design with three replications were designed. Seedlings 50 days after sowing seed (6 to 8 true leaf stage) was exposure treated with gibberellic acid levels (as foliar). The results showed increased concentrations of gibberellic acid was enhanced significantly traits. The largest number, length and diameter of the branches of flowering, inflorescence length, floret number, number of leaves, vase life and also shoot fresh weight was obtained of the interaction between 400 and 200 ppm gibberellic acid and the yellow varieties (Apollo) and were then white varieties (Alba). Among different concentrations of gibberellic acid maximum diameter of the floret, leaf area, chlorophylls a, b and total and shoot dry weight was obtained of 400 mg/liter GA and the lowest in the control. The leaf area and shoot dry weight in yellow variety was higher than the white variety.