Effect of Soaking Treatment on Germination of Hard Coated Tropical Forest Tree Seeds

Abstract

Abstract. Seed germination and seedling growth performance of Maesopsis eminii and Terminalia
catappa under different water soaking treatments were evaluated for 120 days under nursery
conditions. A total of 1400 seeds were pre-treated with hot (95oC) and cold water (ambient
temperature) by soaking for 12, 24 and 48 hours with a control of no soaking. The seeds were sown
directly into polythene pots filled with uniform growth medium (top forest soil, sand and clay soil
mixed in a ratio of 5:3:2) to avoid disturbance of the root system after germination. The seeds were
sown in a randomized block design with seven treatments and three replicates. Data were analysed
using ANOVA in GenStat v18. Results indicated that soaking enhanced seed germination. Soaking
of seeds in cold water for 12 hours resulted into higher germination (90% for Terminalia catappa and
85% for Maesopsis eminii) than the control (48%). Soaking period and water temperature
significantly influenced seedling vigour (F value = 0.962; p = 0.038). Soaking seeds in cold water for
24 hours enhanced Maesopsis eminii seedling growth by 8.0 cm Terminalia catappa seedlings by 7.4
cm. Seed dormancy, germination percentage and growth performance in hard coated seeds such as
Maesopsis eminii and Terminalia catappa can be broken by soaking in cold water for 12-24 hours.
Pre-germination treatments significantly influences the germination and seedling growth.