Effects of Seed Source, Moisture Content and Duration of Storage on the Viability of Vitellaria paradoxa C.F. Gaertn

Viability of tropical seeds is crucial in plantation establishment. Temperature – moisture duration relationship of the seed is of great significance in seed viability. 3000 ripe fruits of V. paradoxa C. F. Gaertn were collected from each of three sources where it is endemic: Eruwa, Sakiand New-Bussa. The fruits were depulped; a sample of 100 seeds was drawn from each of the three sources and sown in washed and sterilized river sand to monitor the germination percentage of the seeds. The seeds were dried under dehumidifier to attain two moisture contents (43% and 32%). Thereafter, each seed lot from the three sources was divided into two batches (A and B) of 1200 seeds each, divided into four and stored at four different temperature regimes: -20°C, 5°C, 22°C and 28± 2°C. Samples were taken monthly for germination test for six months. Data were subjected to percentages and analysis of variance (ANOVA). Results showed that freshly collected seeds of V. paradoxa had 98% germination when sown within 48 hours of fallen and collection which eventually dropped to 4.4% after the six months storage. Storage temperature had significant effect (P > 0.05) on germination of the seeds. Seeds stored at 28±2°C had the highest mean germination (72.2%), those stored at 22°C had 70.2% while seeds stored at -20°C and 5°C failed to germinate. The seeds of V. paradoxa readily lost viability with time, hence fallen fruits should be collected during fruiting season processed and sown immediately or within 7 days of collection.