Allelopathic potential of South American Bothriochloa species (Poaceae: Andropogoneae)

In laboratory bioassays the aqueous extracts from different plant parts of six Bothriochloa species (B. barbinodis, B. edwardsiana, B. perforata, B. saccharoides,. var. saccharoides and B. springfieldii) inhibited the seed germination and root and shoot growth of lettuce (Lactuca sativa L.), maize (Zea mays L.), wintergreen paspalum (Paspalum guenoarum Arechav.) and lovegrass [Eragrostis curvula (Schrad.) Nees)] test species. Aqueous extracts were more inhibitory to shoot and root elongation than to seed germination. Significant inhibition in shoot length at all concentrations indicated the phytotoxic activity of extracts. The toxicity enhanced with increasing aqueous extract concentrations. Perhaps these extracts may contain allelochemicals, which interferes with seed germination and seedling growth of plants. Consequently, the study of these chemical interactions might be useful to develop new classes of environmentally safe herbicides.