Fitri, RahmiIsda, Mayta NovalizaFatonah, Siti2014-03-282014-03-282014-03-28Rangga Dwujunanda Putrahttp://repository.unri.ac.id/xmlui/handle/123456789/5980The allelopath is a chemical substance produced by a plant that can disturb other plants, so it can cause stunted plant growth. This research was aimed to determine the effect of Ageratum conyzoides L. leaf extract and also to determine the optimum concentration of this extract to inhibit the germination and growth of weed Chromolaena odorata. The leaf extract concentrations used in this study were 0%, 5%, 10%, 15% and 20%. The experiment showed that the germination and growth of Chromolaena odorata were inhibited due to the treatment of leaf extract of Ageratum conyzoides. The best concentration to inhibit the weed germination, growth and damage level was 20%, with the percentages of germination, growth inhibition and damage were 73,2 %, 64,70% and 46.66 %, respectivelyotherAllelopathAgeratum conyzoides LChromolaena odorata L.Other