Influence of Different Seed Dormancy-Release Techniques on Viability and Early Seedling Growth of Soursop (Annona muricata) Seeds

Abstract

Soursop (Annona muricata L.) is an economic fruit tree with a long history of traditional use. However, hard seed coat dormancy is a major setback, preventing rapid germination and seedling establishment. This study was conducted to break the hard seed coat dormancy of soursop (Annona muricata) seeds using different treatments. The experiment was conducted at the Department of Horticulture, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana. The experimental design was Randomized Complete Block Design with seven treatments replicated three times. The treatments were: no treatment (control), 500 mg/L Gibberellic Acid for 48 hours, 1000 mg/L GA3 for 48 hours, Hot water at 50°C for 5 minutes, Hot water at 50°C for 10 minutes, and cold water at 15°C for 24 hours. The study revealed that Soursop seeds treated at a concentration of 1000 mg/L of GA₃ for 48 hours broke the seed dormancy and promoted rapid germination at 25 days after planting. Soursop seeds treated with a concentration of 1000 mg/L of GA₃ for 48 hours also enhanced the vegetative growth of soursop. However, Soursop seeds treated with cold water for 48 hours produced plants with the lowest plant height, a low number of leaves and thinner stems. A linear regression showed that germination percentage significantly affected vigor index, such 70% of the variation in the vigor index was attributed to the germination percentage The study concluded that to obtain highest germination with improved vegetative growth of soursop, treatment with a concentration of 1000 mg/L of GA₃ for 48 hours is required.

Keywords: seed dormancy, soursop, seed viability, softening, radicle protrusion