Effect of seed priming with gibberellic acid (GA3) on seed germination and seedling growth of some barley varieties (Hordeum vulgare L.)

An experiment was carried out in a laboratory of the Field Crops Department/College of Agriculture/Tikrit University to study the effect of treating the seeds of five barley varieties (Samir, Amil, Aksad, Alkhayr, Shueae) with four concentrations (0, 50, 100, and 150 mg L-1) of gibberellic acid on percentage of seed germination, germination vigor, germination speed, shoot length, root length, and total dry weight. The experiment was carried out using a completely randomized design (C.R.D.) with four replicates (Petri dish) for each treatment. The results showed that there were significant differences among the concentrations of gibberellic acid and among the varieties in affecting all the studied traits. Seeds treated with a concentration of (100 mg L-1) of gibberellic acid was superior in all studied traits. Aksad variety was superior to all cultivars in most of the studied traits, which are germination percentage (98.17%), germination vigor (61.83%), germination speed (50.20), and total dry weight (0.04078 g plant-1), while Samir and Shueae were superior in shoot length (19.42 and 19.38 cm), respectively and Samir was superior in the root length (12.79 cm). There was also a significant interaction between cultivars and gibberellic acid concentrations for all studied traits. The interaction of (Samir x 100) was superior to all combinations for all studied traits except dry weight trait, which the interaction (Aksad x 100) was superior.