Assessment of Seed Germination and Nursery Performance of Selected Dryland Tree Species in Sokoto State

Successful dryland afforestation in the Sahel and Sudan savanna zones of northwestern Nigeria is fundamentally constrained by the poor germination rates and low seedling survival of indigenous tree species under nursery conditions, yet species-specific propagation protocols for the region remain inadequately developed. This study evaluates the germination response and early nursery performance of five indigenous dryland tree species (Acacia senegal, Balanites aegyptiaca, Ziziphus mauritiana, Faidherbia albida, and Adansonia digitata) under different seed pre-treatment methods in Sokoto State. A completely randomised design with four replications was used for germination trials, testing mechanical scarification, hot water treatment, sulphuric acid scarification, and untreated control for each species. Germination percentage, mean germination time, and germination value were computed. Seedling growth under standardised nursery conditions was assessed at eight, sixteen, and twenty-four weeks using height and collar diameter measurements. Results show that Acacia senegal responded best to scarification with 92% germination after sulphuric acid treatment. Faidherbia albida showed adequate germination under hot water treatment alone. Adansonia digitata required mechanical scarification for germination rates exceeding 70%. Collar diameter at twenty-four weeks was the strongest predictor of field transplanting readiness. The study provides species-specific propagation guidelines directly applicable to Sokoto State's community tree nursery programme. Keywords: seed germination, dryland species, nursery propagation, scarification, Sokoto State