Enhancing Seed Germination in Ceratonia Siliqua L.: Comparative Effects of Scarification, Chemical, and Hormonal Pre-Treatment

This study investigated effective methods to overcome seed dormancy in Yemeni carob through comparative analysis of 14 pre-sowing treatments, including chemical scarification with sulfuric acid, hot water soaking, and GA3 priming in addition to mechanical scarification. The experiment followed a completely randomized design and was analysed using ANOVA and LSD tests (p ≤ 0.05). The 20-minute sulfuric acid treatment (T5) was optimal, achieving 100% germination, the shortest germination time (4.0 days), the highest vigor index (13.3), and the longest seedling length (13.4 cm). The 10-minute acid treatment (T4) also performed well, resulting in 83.3% germination and a high vigor index (10.3). Furthermore, hot water treatments (T2 and T3) showed notable effectiveness, achieving 66.7% germination and a reduced germination time (5.0 days). Acid treatments followed a clear optimization pattern (T4: 83.3%, T5: 100%, T6: 76.7%), with efficiency declining under prolonged exposure. Absorption traits were the most treatment-sensitive (F = 45.67), while Seedling Moisture Content showed no significant variation. Correlation analysis revealed strong associations among key traits, including germination percentage and rate (r = 0.96) and vigor index and stem length (r = 0.99). A notable Correlation was observed between root length and absorption (r = –0.58). Overall, 20-minute sulfuric acid scarification is identified as the most effective protocol for nursery propagation, while hydro-priming emerges as a sustainable alternative for field establishment in arid regions.