Effect of pawpaw latex, plantain stem juice and sulphuric acid on seed germination of <i>Albizia lebbeck</i> (l.) Benth

Abstract

Albizia lebbeck is an important economic tree known for its medicinal, industrial and environmental benefits but exhibits dormancy problems. The study aimed at determining the effect of pawpaw latex, plantain stem juice and sulphuric acid on seed germination of A. lebbeck to improve seedling regeneration for afforestation programmes. Seeds of A. lebbeck were harvested from mother trees within the University of Ibadan premises and pawpaw latex from the unripe fruits of Carica papaya subjected to various pretreatment methods. The six pretreatment methods used were: T1-50% pawpaw latex (24hours), T2-100% pawpaw latex (24hours), T3-50% plantain stem juice (24hours), T4-100% plantain stem juice (24hours), T5-50% sulphuric acid (10minutes), T6-98% sulphuric acid (10minutes) and control (without pretreatment); with four replicates. Germination variables examined include Germination percentage (GP), Mean Germination Time (MGT), Complete Dormancy Period (CDP), Peak Period of Germination (PPG) and Peak Germination percentage (PGP). Pretreatments with 98% concentration of sulphuric acid recorded the highest GP (76%), early complete dormancy period (CDP) (3days after planting) and PPG (5 days). Seeds pretreated with pawpaw latex at 50% had GP (55%), CDP (7days) and PPG (9 days). Seeds sown without pretreatments (control) recorded 33% GP, CDP (9 days), PPG (13 days) MGT (21.96) and PGP (25%). Breaking of dormancy of A. lebbeck seeds was effective using sulphuric acid at 98% concentration. Results from plant juice were effective and could serve as promising alternatives that can support large scale plantation establishment for plant breeders at all levels.

Keywords: Albizia lebbeck, Pretreatment, Seed dormancy, Pawpaw latex, Plantain stem juice, Seed Germination, Sulphuric acid.