Seed Pelleting Across Agricultural, Horticultural and Forestry Systems: A Comparative Review

Seed pelleting has emerged as a multifunctional seed enhancement technology with well-documented applications across agricultural, horticultural, and forestry systems. Despite its widespread use, research on pelleting remains largely fragmented across disciplines, with limited comparative synthesis across sectors. This review examines the principles, material components, and sector-specific applications of seed pelleting, drawing on studies from pulse, oilseed, cereal, vegetable, ornamental, and forest tree species. In agricultural systems, pelleting primarily enhances germination, nutrient delivery, and yield performance, particularly through botanical leaf powders, biofertilizers, and organic amendments. In horticultural systems, it facilitates uniform germination, precision sowing, and improved nursery performance. In forestry, pelleting contributes to seed protection, stress tolerance, and establishment success in degraded and inaccessible landscapes. A critical cross-sector analysis reveals that while the underlying principles of pelleting are consistent, the material requirements, performance outcomes, and dominant challenges differ substantially across sectors. Pungam (Pongamia pinnata) leaf powder is frequently reported to improve germination percentage and seedling vigour across multiple agricultural studies, while vermicompost has demonstrated applicability across agricultural, horticultural, and forestry systems in terms of enhancing germination, nutrient availability, and early seedling growth. Key challenges including delayed germination, storage instability, species-specific variability, and economic constraints are evaluated with reference to specific evidence. Future research directions emphasize adaptive pellet formulations, integration with precision sowing technologies, and species-specific protocol development. This review contributes a structured comparative framework intended to guide researchers, practitioners, and policymakers in selecting and developing appropriate seed pelleting strategies for diverse plant production systems.