Evaluation of Pre-sowing Seed Treatments on Germination of Selected Indigenous Tree and shrub Species in Borana Zone, Southern Oromia

Background The germination success of indigenous tree and shrub species is crucial for ecosystem restoration and biodiversity conservation. This research focuses on the evaluation of pre-sowing seed treatments to improve germination outcome of selected indigenous tree and shrub species in the lowland of Borana Zone. Methods Fruits of selected species were collected local areas, and their seeds were extracted manually, air-dried and, diseased and injured seeds eliminate and, stored at room temperature. The seeds were subjected to four pre-sowing treatments; mechanical scarification, chemical scarification, hot water, cold water, and control. The experiment was conducted in a nursery management system, with treated seeds sown in pots in a randomized design with three replications. Seed pots were watered twice daily and weeds were controlled by hand to prevent competition. Data were collected on seed emergence and the number of emerged daily after the day of first germination to the end of germination. The percentage of seeds germination were calculated using equations for each treatment and, analyzed using SAS statistical software a GLM procedures, and significantly different treatments were separated using the LSD test Results The seed germination rates of Psydrax schimperiana seeds vary significantly among pre-sowing techniques. Cold water and concentrated H ₂ SO ₄ treatments had the highest germination rates, while hot water exposure and 98% sulfuric acid exposure were less effective. The study found that cold water treatment significantly improved germination rates of M. kummel seeds, increasing mean germination rate and germination indexes, and reducing the days until seed emergence, with the lowest rate recorded under control treatments. In the case of Grewia villosa, the highest germination rate (76.67%) was recorded under hot water treatment and mechanical scarification, concentrated H ₂ SO ₄ for 15 minutes had the lowest germination rate. For Terminalia brownie, the maximum germination percentage was recorded under mechanical scarification (50%), and the lowest germination was under the control treatment (19%). The germination percentage of Pappea capensis was greater under soaking seeds in cold water for 36 hours (61%), followed by seeds soaking in cold water for 12 hours (50%). For the B. microphylla, C. myrrha and C. corrugatais species soaking seeds in cold water for 36 or 12 hours more effective technique to get better seeds germination percentage. In the case of Acacia tortilis, the heist germination percentage was observed with the seed soaking in concentrated H ₂ SO ₄ for 15 minutes (81.33±6.41%), followed by the seed soaked in cold water for 36 hours (74.33±6.41%). Conclusion The research highlights the pre-sowing seed treatments increase the seeds germination and, cold water treatments are being recommended as cheaper and less hazardous pretreatment method.