Weeds as agricultural constraint to farmers in Benin: results of a diagnostic study P.V. Vissoh 1,4,', G. Gbehounou2 , A. Ahanchede 1, T.W. Kuyper 3 and N.G. Roling4 , Faculte des Sciences Agronomiques, Universite d'Abomey-Calavi, 01 BP 526, Cotonou, Benin , Laboratoire de Defense des Cultures, Institut National de Recherche Agricole du Benin, Cotonou, Benin ] Soil Quality Group, Wageningen University, Wageningen, The Netherlands 4 Communication and Innovation Studies Group, Wageningen University, Wageningen, The Netherlands * Corresponding author (e-mail:
[email protected]) Received 31 May 20°4: accepted 7 December 2004 Abstract Weeds are an emerging constraint on crop production, as a result ofpopulation pressure and more intensive use of cultivated land, A diagnostic study was carried out from June through August 2002 in the five agro-ecological zones of Benin (I) to identifY the relative importance ofweeds among major production constraints, (2) to better understand farmers' perceptions ofweed problems, and (3) to take cognizance oftheir reactions and the different actors involved in weed management technology develop• ment, The study also aimed at suggesting the development ofweed management strategies that work and are acceptable under small-scale farmers' conditions, Data were collected through semi-structured and unstructured group and/or individual interviews, and through participant observation, transect studies and weed identification during field visits, The results show considerable diversity in biophysical constraints and socio-economic conditions, Population density has led to high pressure on arable land, resulting in land degradation and weed problems, In all situations, pernicious (Imperata cylindrica, Cype• rus spp" Commelina spp,) and parasitic (Striga spp,) weeds are difficult to eradicate, causing substantial food crop yield losses and threatening the livelihood ofpeople, Land and labour shortage, low commodi• ty prices and lack ofcredit were the main constraints hindering weed management.