Allelopathic inhibition of germination, seedling growth and cell division of selected plant species by Calotropis procera (Ait.) Ait.

Calotropis procera (Ait.) Ait. is perennial medicinal obnoxious shrub growing in Pakistan up to 1500 m altitude. Hot and water aqueous extracts from leaves and young stems of C. procera were used against Pennisetum glaucum (Linn.) R. Br., Setaria italica (Linn.) P. Beauv., Brassica campestris Linn. and Lactuca sativa L. under laboratory condition. It was seen that germination, seedling growth, fresh and dry biomass reduced in concentration dependent manner. It was observed that the allelopathic effects depended upon the tested species, growth parameter measured, soaking duration and concentration of the donor plant material. The C. procera litter incorporated into the growth medium inhibited the test species used. The C. procera extracts from leaves were more inhibitory than stem extracts. The tendency of inhibition was radical growth > germination > plumule growth suggesting radicle growth to be a better measure of allelopathy. Leaf extracts significantly reduced division and size of cells. It is suggested that aqueous extract from C. procera can be further assessed against microbes and weed under laboratory and field condition