Evaluation of the Effect of Chemical Acids on Breaking Seed Dormancy of Retama raetam
DOI:
https://doi.org/10.37375/susj.v15i2.3728Keywords:
Retama raetam, seed dormancy, acid scarification, sulphuric acid, germination enhancement, desert restorationAbstract
This study investigated the effectiveness of concentrated mineral acids—sulphuric (H₂SO₄), hydrochloric (HCl), and nitric (HNO₃)—in breaking the physical seed dormancy of Retama raetam (Forssk.) Webb, a key leguminous shrub in arid and semi-arid ecosystems of North Africa. Mature seeds were treated with each acid for 6, 12, 24, and 48 hours under controlled laboratory conditions using a completely randomised design. Germination percentage, mean germination rate, and germination speed index were measured to assess treatment efficiency. Results revealed significant differences among treatments (p ≤ 0.001). Sulphuric acid proved most effective, achieving up to 95% germination when exposure lasted 12–24 hours, owing to its capacity to erode lignified and suberised seed coat layers without harming the embryo. Hydrochloric acid showed moderate efficacy at shorter durations (6–12 h), primarily softening the outer testa. In contrast, nitric acid caused oxidative injury and poor germination (<20%) due to its strong oxidising effect on embryonic tissues. The findings confirm that seed coat impermeability is the primary cause of dormancy in R. raetam and can be overcome effectively by controlled sulphuric acid scarification. The study provides a reproducible and low-cost germination protocol applicable to native desert legumes. Ecologically, enhancing R. raetam propagation supports sand dune stabilisation, rangeland rehabilitation, and desertification control in Libya and similar arid environments. This research contributes to the optimisation of propagation techniques for drought-adapted flora and underscores the ecological value of chemical scarification in restoration programmes.
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