Influence of Pre-sowing Treatments on Seed Germination and Seedling Development of Albizia procera: A Review

Abstract

Agroforestry is a broad and integrated land-use system that involves the deliberate cultivation and management of woody perennials, including trees, shrubs, and bamboos, in association with herbaceous components such as crops, pastures, and/or livestock. These components are arranged either spatially or temporally within the same land management unit to promote complementary ecological and economic interactions between the arboreal and non-arboreal elements. Through such interactions, agroforestry systems contribute to enhanced resource-use efficiency, biodiversity conservation, and the sustainable productivity of agricultural landscapes. Albizia procera is an important multipurpose leguminous tree widely used in forestry, agroforestry, afforestation, and ecological restoration programs due to its rapid growth, nitrogen-fixing ability, timber value, and adaptability to degraded lands. However, large-scale propagation of the species is often constrained by poor and irregular seed germination caused primarily by physical dormancy associated with a hard and impermeable seed coat. This review synthesises recent research on the influence of pre-sowing treatments on seed germination and seedling development of A. procera. Various physical, thermal, chemical, and hydration-based treatments have been evaluated to overcome dormancy and improve germination performance. Among the treatments, gibberellic acid (GA₃) application at 50 ppm for 12 hours was reported as the most effective, achieving up to 90% germination along with superior germination rate and seedling vigour. Hot water treatment (70–100°C for short durations followed by soaking) also produced high germination percentages ranging from 75–86%, making it a practical and economical option for nursery operations. Mechanical scarification and acid treatments effectively reduced mean germination time by improving seed coat permeability, while organic hydration methods such as cow dung slurry enhanced seedling vigour and growth under sustainable nursery conditions. The review further emphasises the methodological approaches employed in recent studies, the comparative effectiveness of different treatments, their practical implications for forestry and agroforestry systems, and the major gaps that persist in current research. Although considerable progress has been achieved, inconsistencies in treatment protocols, limited field-based validation, and inadequate physiological and molecular investigations continue to represent significant constraints. Future research should therefore prioritise the standardisation of treatment methodologies, the implementation of extensive field trials, and the development of environmentally sustainable and scalable technologies aimed at enhancing seed germination and successful seedling establishment in A. procera.