INVESTIGATION ON THE ALLELOPATHIC EFFECT OF TITHONIA DIVERSIFOLIA (HEMSL) (MEXICAN SUNFLOWER) ON TRIDAX PROCUMBENS (L)

Abstract

Studies were carried out in the laboratory of plant Science Department of the Ekiti State University to investigate the allelopathic effect of the fresh shoot aqueous extract (FSE) of Tithonia diversifolia on the germination and early growth of Tridax procumbens. 5g, 10g, 15g and 20g of blended fresh shoots of Tithonia diversifolia per 100ml of water were prepared and the filtrate used to moisten filter paper double laid in Petri dishes before Tridax procumbens seeds were sowed. The speed of germination of Tridax procumbens was delayed by Tithonia diversifolia at higher concentrations. Also higher concentrations of Tithonia diversifolia reduced the total germination percentage more than the control experiment. However, the radicule length and plumule length of Tridax procumbens were higher at 5g concentration than the control experiment but started reducing at 10g concentration FSE. The number of secondary
roots observed in Tridax procumbens was highest in the control experiment but reduced as the concentration of Tithonia diversifolia increased. It is concluded that Tithonia diversifolia could be used as bio-herbicide to suppress Tridax procumbens where they are threats to Agricultural crops.