Abstract:
Invader species are a great threat to local flora. Eight invader species of Pakistan were screened for their allelopathic activity through sandwich method. Toxic (inhibitory) and non-toxic (stimulatory) effects were assessed by recording their effect on germination and growth of lettuce. Radicle and plumule growth of lettuce were recorded at 5, 10 and 50 mg leaves concentrations of each species. Among all species the growth activity was found to be concentration dependent. Except Eutcalyptus glabra all species resulted in inhibitory effects at 5, 10 and 50 mg leaves concentrations. Xanthium strumarium and Cannabis sativa showed strong inhibitory effects on radicle and plumule growth of lettuce. Maximum inhibition was recorded at highest concentration; even growth of lettuce was stopped with 50 mg leaves concentration of C. sativa.
