Characterization of weed flora in rubber trees plantations of Bongo (Côte d’Ivoire)

Abstract

Objectives: the main objective of this study is to characterize the weed floristic diversity of the Bongo rubber trees plantation and to provide a map for sustainable weed managementMethodology and results: a floristic survey of the Para rubber plantations of Bongo (Southeast Côte d’Ivoire) was conducted in 2007 and early 2008. The field tour method was used for weed inventory in 27 plots of 25 ha of different ages. Moreover, the coverage rate of weeds was estimated in samples of 100 square meters each for every plot. Weeds flora is composed of 168 species scattered in the entire rubber trees plantation. These species were distributed in 63 families and 140 genera. The eleven most representative botanical families, constituting more than the half of the flora (50 % of the species), are Rubiaceae, Apocynaceae, Poaceae, Cyperaceae, Euphorbiaceae, Moraceae, Amaranthaceae, Mimosaceae, Fabaceae, Cucurbitaceae and Commelinaceae. Weeds’ mapping was established and illustrated by 4 main weed groups in relation with the stage of rubber trees development. For the plantations of 1 and 2 years old, weeds were dominated by leguminous cover crop Pueraria phaseoloides (Roxb.) Benth. Weed species really begin to establish in the plantation from 8 to 12 years old with appearance of species such as Palisota hirsuta (Thumb.) Engl. and Aneilema beniniense Kunth. Fields of 13 to 23 years old are covered at about 83.5% by Palisota hirsuta (Thumb.) Engl.Conclusion and application of results: The weed mapping will assist in weed managementKey words: weeds, floristic study, planting year, mapping