The interference of weeds in agro-forestry systems production factors varies according to species and infestation density. This assay was conducted at the Federal University of Amazonas Experimental Farm, using separate cupuaçu and peach palm plantations and an agro-forestry system (AFS) of both species. Six monocotyledonous and fifteen dicotyledonous species were identified. The major five families with the most number of species were Poaceae, Euphorbiaceae, Fabaceae, Cyperaceae and Verbenaceae, in decreasing order. Desmodium incanun, Cyperus rotundus, Clidemia sp. and Spermacoce verticillata were found in the tree cropping systems. The highest weed similarity coefficient was found between the cupuaçu and peach palm plantations (54.50%) and the lowest between the AFS and peach palm plantation (32.00%). Starchytapheta cayennensis frequency was 33% in the AFS area; 44% for Eclipta alba in the cupuaçu plantation; and 44% in the peach palm area for D. incanun, C. rotundus and Clidemia sp.
frequency; abundance; similarity; agroforestry; weeds
