ABSTRACT
Red Sanders (Pterocarpus santalinus), or Rakta Chandana, is an endangered tree native to the Southern Indian peninsula, valued for its medicinal and dye properties. However, its seed germination is hindered by a hard seed coat, phenolic compounds and hormonal imbalances. This study aimed to determine the most effective seed priming treatment to improve germination rates in Red Sanders. The research was conducted with three replications and evaluated seven pre-sowing treatments: T1 (AgNPs at 1000 ppm for 24 hours), T2 (ZnNPs at 2000 ppm for 24 hours), T3 (Conc. H2SO4 for 12 minutes), T4 (NaDC 500 ppm), T5 (Dewinging), T6 (Soaking in hot water at 100°C for 5 minutes) and T7 (Control) in Completely Randomized Design (CRD). The experiment was conducted in Department of Seed Science and Technology and Green Nano-Technology Laboratory, Uniervsity of Agricultural Sciences, Dharwad, during 2023-24. Results indicated that seeds treated with ZnNPs at 2000 ppm (T2) exhibited highest germination rate (56%), germination speed (1.04) along with root length (17.05cm), shoot length (16.33 cm) and highest dry weight (6.22 g) and highest Seedling Vigour Index-I (1869). In comparison, H2SO4 treatment (T3) achieved 51.67 per cent germination and a speed of 0.95, with root length (15.28 cm), shoot length (16.22 cm), dry weight (5.24 g) and Seedling Vigour Index (1628) slightly lower but still significant. The control (T7) had the lowest performance with 31 per cent germination, a speed of 0.36, root length (15.28 cm), shoot length (16.22 cm), lower dry weight (1.63 g) and the lowest Seedling Vigour Index (649). Overall, ZnNPs at 2000 ppm for 24 hrs (T2) were the most effective in enhancing germination, seedling growth and overall vigour in Red Sanders.