Studies on Allelopathic Effects of Ageratina adenophora Sprengel (King and Robinson) on Some Weed Plants Growing in Forest Ecosystem

ABSTRACT: Invasion of an eco-system by the alien species has now taken serious dimensions all across the world and ever growing menace of it is posing serious threats even to the conservation and sustainable utilization of biodiversity along-with significant impacts on the services provided by the dynamic forest ecosystem. Present study hence, was conducted to assess and evaluate the allelopathic potential of Ageratina adenophora-one of the fast spreading invasive species- on the seedling growth and dry weight of test weed plants like Biden’s pilosa L. and Cassia occidentalis L. growing in its association in a forest eco-system. Aqueous extracts of leaf, shoot and root of A. adenophora having concentrations 0.5, 1.0, 2.0 and 4.0 per cent were used for determining their cumulative effect on these test plants under laboratory conditions. All the concentrations of these extracts used during the study showed inhibitory effects both on the seedling growth and dry weight of the test species which further increased with the increasing level of concentrations. Aqueous extract of the leaves showed maximum inhibition whereas, the least effect was recorded in case of root extracts