Preliminary Evaluation of Different Seed Dormancy Breaking Methods in Wild Tuber Cowpea (Vigna Vexillata)

Abstract

Effectiveness of different seed dormancy breaking methods in Vigna vexillata seeds were evaluated. Two germination tests were done at 1 and 4 weeks after seed collection. A randomized completely block design (RCBD) with 8 seed dormancy breaking methods was used. The methods were; pre-chilling (PRC) in 5oC for 1 week, preheating (PRH) at 35oC for 1 week, sealed polythene envelops (SPE), gibberellic acid (GA3) 0.05%, potassium nitrate (KNO3) 0.2%, sulfuric acid scarification (H2SO4) and mechanical scarification (MS) and a control. The H2SO4 and MS had highest germination percentage. There was a significant difference in germination between seeds sown at 1 and 4 weeks after seed harvesting. Sowing V. vexillata seeds at 4 weeks after harvesting had higher germination percentage than 1 week after harvesting. Therefore H2SO4 and MS were effective in breaking seed dormancy at least 4 weeks after harvesting. It is important to repeat the experiment and perform viability tests prior to sowing as this study assumed that all seeds were viable.