Storage potentials and influence of moisture contents on the germination of <i>Vitellaria paradoxa</i> C.F. Gaertn

Abstract

Viability of seeds of many tropical tree crops during storage is influenced by several factors among which are moisture content. However, the maintenance of Vitellaria paradoxa seed viability in storage has always been a concern. This study therefore investigated the potentials and influence of moisture content on germination of seeds of the species. Two hundred (200) seeds were selected and weighed. Ten (10) seeds were thereafter selected and oven dried at 60°C for 17 hours until they attained constant dry weight so as to determine moisture content (MC). Another seed lot of 10 was selected and sown in perforated germination trays containing washed and sterilized river sand as treatment 1 (T₁) replicated 4 times. The remaining 150 seeds were spread on a platform at ambient temperature (25 ± 2°C). At 2^nd week, the moisture content was determined and 10 seed lot replicated 4 times were sown (T₂). The procedure was repeated at 4^th week (T₃) and 6^th week. Germination Percentage (GP), Germination Energy (GE), Mean Daily Germination (MDG), Peak Value (PV) and Germination value (GV) were determined. Data were subjected to analysis of variance (ANOVA) and Duncan Multiple Range Test (DMRT) was used in means separation. The highest germination percentage (95%) was recorded for T₁ (MC = 23.33%), followed by T₂ (MC = 20.93%) with (67.5%) while T₄ ( MC = 10.87%), had the least (40%). The freshly depulped sown seeds (T₁) had the highest MDG (1.85), PV (2.26), GV (3.82) and GE (52.2%) while T₄ had least values of 0.42, 0.71, 0.50 and 25% for MDG, PV, GV and GE respectively. There were significant differences among the treatments at P<0.05 and T₁ had the highest means (9.50± 0.13) while T₄ had the least (5.21± 0.81).The progressive decrease in moisture content with increased storage period intensified the loss of viability of the seeds. It is therefore recommended that seeds of V. paradoxa should be stored at the temperature where their moisture content will be conserved and should not be stored beyond 4 weeks at ambient temperature for average germination percentage.

Keywords: Viability, Vitellaria paradoxa, ambient temperature, moisture content