Allelopathic effect of aqueous extracts of different part of Eclipta alba (L.) Hassk. on some crop and weed plants

The present study was conducted to investigate the allelopathic effects of Eclipta alba weed on seed germination and seedling growth weed plants (Cassia tora L., Cassia sophera L.) and crop plants (Phaseolus aureus L., Oryza sativa L.). Root, stem and leaf aqueous extracts of Eclipta at 0.5, 1.0, 2.0, and 4.0% concentrations were applied to determine their effect on seed germination and seedling growth of test plants under laboratory conditions. The aqueous extracts from root, stem and leaf had no effect on seed germination of test plants. Aqueous extracts from leaf, root and stem inhibited root length, shoot length and dry weight. Root length, shoot length, and dry biomass of weed and crop species decreased progressively when plants were exposed to increasing concentration (0.5, 1, 2, and 4%). However, the more pronounced negative effect on seedling growth and dry biomass was on weeds than on crops. Aqueous extract of leaves shows the maximum inhibition followed by root and stem. The pH of aqueous extracts of different parts of E. alba does not show any major change when the concentration increased.