Effect of pre-sowing treatment on the germination and early growth of Kalappia celebica Kosterm.: an endemic and vulnerable tree species of Sulawesi, Indonesia

Abstract

Abstract. Tuheteru FD, Husna, Albasri, Arif A, Basrudin, Nurdin WR, Arman E, Agustin DI, Saribadu J, Rahmat, Dermawansyah A, Daliana, Lody LP, Deri AS, Safitri I, Sudrajat DJ. 2022. Effect of pre-sowing treatment on the germination and early growth of Kalappia celebica Kosterm.: an endemic and vulnerable tree species of Sulawesi, Indonesia. Biodiversitas 23: 4297-4302. Kalapi (Kalappia celebica) is an endemic tree species of Sulawesi and is threatened with extinction, so it requires conservation efforts to preserve the tree species. The research aims to determine the effects of seed pre-sowing methods on the germination of K. celebica. Matured seeds of kalapi were collected from several mother trees at the Lalona Village, Kolaka Regency, Southeast Sulawesi, Indonesia. The seeds were treated with six pre-germinations treatments (control, nicking, nicking and soaking in cool water (20°C) for 12 h, nicking and soaking in cool water for 24 h, soaked in hot water (80°C) for 24 h till the water-cooled and soaked in cool water for 48 h. Three replication and each replication using 25 seed were used in this research, so the total seed were 450 seeds. The randomized completely design was used to test the effect of pre-germination treatments on seed germination parameters at the greenhouse. The germination parameters calculated were the first day of germination, last day of germination, germination period, germination capacity, mean germination time (MGT), and mean daily germination (MDG). The results showed that pre-germination treatment affected all seed germination parameters, which significantly increased the germination capacity. The germination capacity with the nicking was 94,67%, nicking and soaking in cool water (20°C) for 12 h (94,67%) followed by nicking and soaking in cool water (20° C) for 24 h (90,67%). In all treatments, germination started 5 to 10 days after sowing and was completed from 4 to 16 days later. The seed treatment by nicking and soaking in cool water for 12 d exhibited the lowest MGT (5.56 days), the highest MDG (0.95 germinate day^-1), the highest seedling collar diameter (1.64 mm), and the highest leaf number (1.95). Therefore, the study recommends nicking followed by soaking in cool water for 12 h as an ideal pre-germination treatment to promote germination and seedling growth of kalapi tree species for supported conservation activity.