EFFECTS OF PLANTING MEDIA, SEED PRIMING AND PHYTOHORMONES ON GERMINATION AND SEEDLINGS’ GROWTH OFAnogeissus leiocarpus (DC.) Guill. and Perr. (AFRICAN BIRCH)

Abstract

ABSTRACT Anogeissus leiocarpus (African birch) is a multipurpose agroforestry tree species found in most savanna and woody grassland areas. The germination requirements and silvicultural information necessary for successful seedling establishment of the species are not widely explored. This study was conducted to assess effects of planting media, seed priming and phytohormones on seed germination and growth of A. leiocarpus. Seeds of different weights (10, 20 and 50 g) were soaked in hot water at 20, 40 and 60°C for 5, 10 and 15 minutes respectively and percentage germinated were calculated.The effect of phytohormones on the germination of A. leiocarpus seeds was carried out using Gibberellic Acid (GA3), Indole Acetic Acid (IAA) and Indole Butyric Acid (IBA) applied at 10, 20 and 30 ppm with a separate control and arranged in 3x3 factorial experiment with four replicates. The planting media wereRiver sand-50% + Top soil-50% (R50T50), River sand-75% + Top soil-25% (R75T25), River sand-100% + Top soil-0% (R100T0), River sand-0% + Top soil-100% (R0T100) and River sand-25% + Top soil-75% (R25T75) which were laid out in a completely randomized design. The study had five replicates and were observed for a duration of eight weeks. The datacollected on percentage germination and growth parameters including plant height (PH), collar diameter (CD), number of leaves (NL) and leaf area (LA)were subjected to descriptive and inferential statistics using Statistical Analysis System (SAS vs 13.0). The means were separated using the Least Significant Difference at p≤0.05. Results obtained revealed that a combination of soil potting media significantly increased all measured parameters. A. leiocarpus seeds (10 g) soaked in 20°C of hot water for 15 minutes had the highest germination percentage (46.60%) at eight Weeks After Sowing (WAS) which was significantly different (p≤0.05) from other treatments while 50 g of seeds soaked in 60°C of hot water for 10 minutes recorded the least germination percentage (1.00%) at eight WAS. Seeds of A. leiocarpus soaked in GA3 at 10 ppm recorded the highest germination percentage (36.60%) while seeds soaked in IBA at 30 ppm recorded the least germination percentage (7.80%) at eight WAS. Seedlings grown in R75T25 treatment recorded the highest PHof 23.42±1.27 cm, CD: 0.38±0.08 mm, NL: 21.20±2.28 andLA: 26.25±2.30 cm2at eight WAS while seedlings grown in R50T50 treatment had the lowest PH (19.82±1.25 cm), CD (0.26±0.05 mm), NL (19.20±2.28) and LA (19.11±0.05 cm2). The study concluded that the use of GA3 at 10 ppm, 10 g of seeds soaked in 20°C of hot water for 15 minutes and R75T25 planting mediaaided the germination and growth of A. leiocarpus.Further investigations should be carried out to determine other priming methods for improved germination of A. leiocarpus seeds.