Allelopathic potential of mexican sunflower [tithonia diversifolia (hemsl) a. gray] on germination and growth of cowpea seedlings (vigna sinensis l.)

Abstract

Invasive plant species when introduced into new environments may result into a number of ecological problems (Howard et al., 2000). They may influence other species through pathways such as allelopathy or phytotoxicity (Samuel et al., 2005; Imeokpara and Okusanya, 1994; Ayeni et al., 1997). Allelopathy is the inhibitory or stimulatory effect of a plant on another by chemicals released from the donor plant to the environment (Taiwo and Makinde, 2005; Bano et al., 2012). Allelopathy is a process by which plants release chemical compounds in their vicinity (Rice, 1984). Studies have shown that different plant parts release toxic metabolites into the soil that affect adversely germination and growth of plants (Kumar et al., 2008).