Influence of Gliricidia Extract on Cowpea Seed Germination and Seedling Growth Performance under Greenhouse Conditions

Gliricidia sepium is highly regarded as a good soil improver as green manure. A Greenhouse experiment was conducted in a completely randomized design using sand medium for three weeks with the aim to determine the effect of Gliricidia extract from leaves at different concentrations (0, 5%, 10%, 15% and 20%) for irrigation purposes on Vigna unguiculate (cowpea) seed germination and seedling performance. The study showed significant (P<0.05) different amongst the different concentration of Gliricidia extract for cowpea seed germination percentage and seedling growth performance. The Gliricidia extract had stimulatory effect on the cowpea seeds germination and seedling performances at lower Gliricidia concentrations (< 10%) while inhibitory effect was observed at higher Gliricidia concentrations (> 15%). Similarly, all seedling development indicators, including seedling vigor index (SVI) and percentage phytotoxicity (PP), decreased considerably (P<0.05) with higher extract concentrations (>15) compared to lower concentrations (<10%). It was clear that Gliricidia extract had a negative and inhibiting influence on percentage seed germination and seedling growth parameters at higher concentration whilst it has positive and stimulatory impact on seed germination and growth parameter at lower concentrations.