Abstract

Parkia biglobosa is an economically important multipurpose tree species having poor performance of early seedlings, and seed dormancy hinders domestication and high-scale multiplication of the plant in sub-Saharan Africa. This experiment determined the impact of pre-treatment of seeds and the media of planting on germination and early growth of P. biglobosa in nursery conditions within Kano State, Nigeria. The study employed a completely randomized design with two factors: seed pre-treatment (mechanical scarification, cold-water soaking, warm-water soaking and uncovered control) and planting substrate (river sand and sawdust). The percent germination and initial growth parameters (seedling height, collar diameter, leaves, length of leaves, and breadth of the leaf) were measured, and data were compared using ANOVA at p= 0.05 levels of significance. The germination of the seeds differed greatly between the treatments, with the highest germination being in untreated seeds (53.3%), and the cold-water soaked in river sand (40.0%). Seeds that were sown in sawdust and scarified had the lowest germination (6.7%). The growth of the seedlings was, in most cases, better in river sand than in sawdust. The mean seedling height varied between 9.2 and 9.7 cm in river sand in most treatments, whereas it was 3.6 to 6.2 cm in sawdust. River sand also enhanced leaf growth and scarified seeds germinated to grow up to 9.6 ± 4.2 leaves, but sawdust always gave low growth performance. Interaction effects showed high differences in height and the number of leaves of seedlings between media among some pre-treatments (p < 0.01), but collar diameter and leaf width were not largely affected. The results indicate that P. biglobosa seeds could germinate successfully without pre-treatment, but river sand will offer a more appropriate medium through which young seedlings of the plants will grow.

Keywords

Agroforestry species; Seed dormancy, Substrate suitability; Silvicultural practices; Seedling vigor