Evaluation Of Garlic Extract As A Biotic Elicitor For Induction Of Secondary Metabolites Production In Cocoyam:- Ukpong, Joseph U

ABSTRACT x Cocoyam is affected by the fungus phythophtera colocasiae which significantly decrease both yield and quality. Plants can be sensitized for a greater mobilization of defensive secondary metabolites leading to enhanced resistance to stress. Induction of host defence is achievable through elicitation by biotic stress. The phytochemical profile of cocoyam was improved by foliar spraying of potted cocoyam leaves in green house with 1% and 5% of methanol extract of garlic for three days at the rate of 10ml per day. Two drops of tween 20 was added to every 10ml of solution. The result showed significant (P<0.05) raise in phytochemical levels compared to the control. 1% extract concentration gave a raise in alkaloids (6%), flavonoids (3%), phenols (0.003%) and anthocyanins (0.004%/). 5% extract concentration gave a raise in content of alkaloids (10%), flavonoids (11%), tannins (0.008%), phenols (0.005%), and anthocyanins (0.001%). This increase is significantly (p<0.05) higher than the tween 20 control result showed raise in alkaloids (3%), flavonoids (9%), tannins (0.005%), and anthocyanin (0.002%). However, there was no significant difference (p>0.05) in the level of flavonoids and tannins caused by the 1% extract concentration; tween 20 did not show significant difference on phenols level before and after treatment. Preliminary phytochemical analysis of garlic gave; phenol (0.13% ±0.01), tannin (0.30% ±0.03), flavonoid (1.03% ±0.30) and alkaloid (2.32% ±0.02). This study on induction of host defence through an elicitor promises to be an effective and sustainable approach in disease management.