Assessment of Allelopathic Aggression of Parthenium hysterophorus L. on Seed Germination and Seedling Growth of Some Important Cereals

Parthenium hysterophorus L. (family Asteraceae) is an exotic, annual, herbaceous weed, allelopathic aggressions cause suppression of natural vegetation and severely affect the crop plants posing a strong threat to biodiversity and crop production. This paper embodies results of the allelopathic effects of aqueous extract of leaves of Parthenium hysterophorus on seed germination and seedling growth of five cereal crops of India viz. Triticum aestivum L., Oryza sativa L., Hordeum vulgare L., Avena sativa L. and Zea mays L. It has been found that the leaf extract shows complete failure of seed germination at 8% in Triticum aestivum; at 10% in Oryza sativa; at 12% in Hordeum vulgare and Avena sativa. However, the seed germination of Zea mays was not completely inhibited but it was low at high concentrations of the extract. The extract had strong inhibitory effect on the root and shoot elongation and significant reduction in dry weight of seedling over control.