Effects of Seed Size on the Germination and Early Growth of African Baobab (Adansonia digitata L.)

Abstract

The effects of seed size on the germination and early growth of A. digitata were assessed. Seeds were sourced locally within the University of Ilorin Campus. One hundred viable seeds were selected from each of the size classes. The seed weight, length, breadth, and width were measured for all the selected seeds. Mean weight, length, breadth, and thickness were: 0.62 g, 9.16 mm, 7.45 mm, and 5.85 mm, respectively for small seeds. 0.41 g, 9.54 mm, 7.68 mm, and 6.03 mm, respectively for medium seeds; and 0.44 g, 9.92 mm, 7.89 mm, and 6.21 mm, respectively for large seeds. The experiment was laid out in a completely randomized design (CRD). Seed dormancy was broken through the acid scarification method by soaking in H2SO4 at 70% concentration for 20 minutes with constant stirring. Variables of interest include: leaves number, seedlings height, collar diameter and leaf area. Based on the results of this finding, medium and large seeds germinated in 7 days after sowing while small seeds germinated in 10 days after sowing. Large seeds had the highest germination percentage (55%), followed by medium seeds with 27%. The small seeds were the least in terms of germination rate (21%). There was no significant difference in mean seedling heights, collar diameters and number of leaves among the seed size classes (P˃0.05). Mean leaf area significantly differed among the three size classes (P˂0.05). The result showed that large seeds gave best germination at a shorter period than the medium and small seed sizes. Thus, large seeds of A. digitata are recommended in propagation activities involving the species.