Evaluation for Allelopathic Activity of Selected Tree Species Grown in BRIS Soil

This study was carried out to evaluate the allelopathic activity of selected tree species grown in BRIS soil. The mature leaves from ten different tree species were collected as the material of donor plants. They were evaluated for the allelopathic activity of the leaf litter leachate and leaf volatilization by using Sandwich and Dish pack methods respectively, while Lactuca sativa (lettuce) was used as the receiver plant. Different amounts of leaf litter leachate were tested on the lettuce seedling growth for Sandwich method whilst, for Dish pack method the allelopathic activity was tested on different distances of the receiver plant from the donor plants. The results for Sandwich method showed that the tree species that gave the highest radical inhibition was Mangifera indica (mango) (60.05%) while the highest hypocotyl inhibition was Peltophorum pterocarpum (Yellow flame tree) (12.58%). Meanwhile, Manihot esculenta (cassava) showed the highest inhibition of radicle and hypocotyl by 86.50% and 76.63%, respectively, compared to control using Dish pack method. Based on this study, the evaluation for allelopathic activity of selected tree species grown in BRIS soil showed that there is significant presence of the allelochemicals in the tested tree species. The development of natural herbicides can be achieved with further studies to determine the effectiveness of allelochemicals in the tree species