Lichen (Usnea barbata L.) Extract on the Growth of the Broadleaf Weed Bandotan (Ageratum conyzoides L.)

Abstract

Bandotan (Ageratum conyzoides L.) grows on agricultural land and is considered a weed because it can cause disruption to cultivated plants. Therefore, its growth needs to be controlled, one of which is using herbicides. However, long-term use can have negative impacts. An environmentally friendly alternative for weed control is the use of botanical herbicides such as Lichen (Usnea barbata L.). This study aims to determine the effect of the lichen extract of U. barbata L. in inhibiting the growth of broadleaf weed bandotan A. conyzoides L., and to determine the effective concentration of lichen in inhibiting the growth of bandotan weed A. conyzoides L. The research method used a Completely Randomized Design (CRD) with 5 treatments and 4 replications. The treatment consisted of a negative control using distilled water, lichen extract concentrations of 50%, 62.5%, 75%, and a positive control using Gramoxone. The parameters observed included the number of leaves, dry weight, and phytotoxicity of A. conyzoides L. The results showed that the administration of U. barbata L. extract at a 75% extract concentration treatment had an effective inhibition of bandotan weed growth in observing the number of leaves and dry weight, while for phytotoxicity, the efficient extract dose used was a concentration of 62.5% because it had seen a stop in the number of leaves and the intensity of severe damage to bandotan (A. conyzoides).