COMPARATIVE ALLELOPATHIC POTENTIAL OF Fumaria indica L. AND Polygonum plebejum L. AGAINST FIELD CROPS

The comparative allelopathic potential of Fumaria indica L. and Polygonum plebejum L. leaf, stem, root, fruit and whole plant aqueous extracts was evaluated on germination and seedling growth of Triticum aestivum L., Cicer arietinum L., Lens culinaris Medic. and Brasica napus L. in laboratory condition. Germination and seedling growth of T. aestivum, C. arietinum, L. culinaris was significantly reduced by the leaf extract of F. indica and P. plebejum. But germination and seedling growth of Brasica napus was completely inhibited by the leaf extract of F. indica. The degree of sensitvity of different crops in respect of germination was canola chickpea lentil wheat. The degree of germination inhibition of different F. indica and P. plebejum plant parts can be classified in order of leaf extract root extract fruit extract stem and whole plant extract in wheat; leaf extract root extract and stem extract fruit extract and whole plant extract in chickpea; leaf extract root extract stem extract fruit and whole plant extract in lentil and leaf extract root extract and stem extract fruit extract and whole plant extract in canola. Inhibitorier effect was observed with F. indica than P. plebejum. It was due to more phenolics in F. indica leaves (13091.12 mg kg^-1) as compared to those of P. plebejum (8131.49 mg kg^-1). Chromatographic analysis reveled presence of six phytotoxins, viz., ferulic acid, m-coumaric, syringic acid, caffeic acid, gallic acid and 4-Hydroxy-3-Methoxybenzoic acid in aqueous leaf (1:10) fraction of F. indica. Ferulic acid, syringic acid, caffeic acid and vanillic acid were recorded in aqueous leaf extract of P. plebejum.