Comparative Effect of Wet and Dry Heat Methods on Afiziella africana Seed Emergence and Germination of different Temperature and Durations

Abstract

This study investigated the effects of wet and dry heat treatments on the germination and early growth of Afiziella africana, a tropical African plant species with hard seeds. The experiment tested five temperature levels (10°C, 20°C, 30°C, 40°C, and 50°C) and three exposure durations (10, 20, and 30 minutes) to assess seed emergence and seedling development after five days of planting.  Results showed that temperature and heat treatment methods significantly (P< 0.05) influenced germination. The highest seed emergence (13 seeds) occurred at 20°C with a 10-minute treatment, while the lowest (7 seeds) was recorded at 40°C for 30 minutes. At 10°C and 50°C, emergence remained consistent across all time intervals. Wet heat treatment reduced seedling height over time (from 20.45 ± 3.56 cm to 14.78 ± 3.17 cm) but enhanced leaf development at lower temperatures—producing a higher mean leaf count (16.00 ± 2.74) compared to dry heat (12.20 ± 2.17) at 10°C. Additionally, wet treatment at 10°C resulted in greater seedling width (1.40 ± 0.07 cm) than dry heat (1.20 ± 0.17 cm).  The findings highlight that both wet and dry heat, along with temperature variations, critically affect Afiziella africana germination and early growth. Optimal conditions (moderate temperatures and shorter heat exposure) improved emergence, while extreme temperatures or prolonged heat reduced success. These insights are valuable for improving seed pretreatment methods in agriculture and ecological restoration, particularly for hard-seeded tropical species. Further research could explore long-term growth responses to refine cultivation practices.