Allelopathic influences of Lagenaria siceraria (Mol.) Standl. was examined on seed germination and seedling growth of Phaseolus aconitifolius Jacq. var – ‘Abhaya’. Leachates and Decomposition bioassay methods was followed for detection of allelopathic activity. Root shows dominant as compare to other three plants in leachates bioassays. In decomposition bioassay Lagenaria siceraria shows the allelopathic activity on seedling growth and seed germination of P. aconitifolius. It was further observed that radicle growth was more hampered of the test plant by leachates bioassay. Inhibition of seedling growth of test plant by leaf, stem and root leachates and decomposition bioassay of Lagenaria siceraria were significant and concentration correlated. Inhibition of Phaseolus seedling growth was in an order to Root < Stem < Leaf.
