39 MAG C-" NN08201 40951 2006-10-04 Participatory developmento f weed management technologies inBeni n Pierre Vinasseho Vissoh 8201,4053 Participatory development ofwee d management technologies inBeni n PierreVinasseh oVisso h Supervisors: Prof.Dr . Ir.N.G .Rolin g Hoogleraar Landbouwkennissystemeni nOntwikkelingslande n Wageningen Universiteit Prof.Dr .Th .W .Kuype r Persoonlijk hoogleraar, sectie Bodemkwaliteit Wageningen Universiteit Prof.Dr .A .Ahanched d Maitred e Conferences Facultede sScience sAgronomique s Universite d'Abomey-Calavi, Benin Prof.Dr .V . Agbo Maitre de Conferences Faculte desScience s Agronomiques Universite d'Abomey-Calavi, Benin Promotiecommissie: Prof. Dr.A . Niehof Wageningen Universiteit Prof.Dr . Ir.PC . Struik Wageningen Universiteit Dr. O.N . Coulibaly IITABeni n Prof.Dr .A . Sanni Universite d'Abomey-Calavi Dit onderzoek isuitgevoer d binnen deonderzoekschool : CERES,Researc h School for Resource Studies for Development Participatory development ofwee d management technologies in Benin Pierre VinassehoVisso h Proefschrift terverkrijgin g vand egraa d vandocto r opgeza gva nd erecto r magniflcus vanWageninge n Universiteit, Prof.Dr .M.J.Kropf f inhe topenbaa rt everdedige n opvrijda g 20oktobe r200 6 desmorgen st e9:0 0uu ri nd e ILACISall ed eConference , Universite d'Abomey-Calavi,Beni n Pierre V. Vissoh (2006) Participatory development ofwee d management technologies in Benin. PhDThesi s Wageningen University,Wageningen , The Netherlands. With ref. - With summaries in English, Dutch and French. ISBN 90-8504-434-0 Propositions 1. Weed scienceprovide snecessar ybu tno t sufficient knowledge for effectively dealingwit h speargrass andStriga sp.(Thi sthesis) . 2. The emergence of novel herbaceous weeds is both a cause for and a consequence of the impoverishmento frura lpeopl e inWes tAfric a (Thisthesis) . 3. In the Republic of Benin,mos t intellectuals have lived, at least during their childhood, in thatched houses, made of shoots of speargrass {Imperata cylindricd).Thi s awareness shouldhel pthe mt orealis etha tweed sar esociall y constructed. 4. Local dynamics may under very unfortunate biophysical and socio-economic conditions (as in Some central) be insufficient for development. The creation of artificial conditions may be aprerequisit e to open the windows ofopportunity ,withou t which the local cradle cannot behear d (thisthesis ,i nreactio n toHounkonnou ,2002) . 5. It is more important for scientists and extensionists to deconstruct their own assumptions and the theories that inform their work while engaging in experiential learning with farmers, than tocarr you t interdisciplinary research. 6. The (increasingly) erratic nature of rainfall in southern Benin will make the test of even the most effective and acceptable technology a gambling game (G. Vigan, late chief of Somevillage) . P.V .Visso h Participatory development ofwee dmanagemen t technologies inBeni n Abomey-Calavi,2 0Octobe r200 6 Abstract Vissoh, P.V. 2006. Participatory development of weed management technologies in Benin. Ph.D thesis, Wageningen University, Wageningen, The Netherlands, 187 pp.with English, French and Dutch summaries. Weeds constitute a major constraint to agricultural production in the Republic of Benin. Agricultural intensification and the evolution towards permanent cropping systems have led to the emergence of novel weed problems. A diagnostic study identified speargrass (Imperata cylindrica) and the parasitic weed Striga spp. as major novel weeds. Both weeds are difficult to eradicate, cause substantial food crop losses and exacerbate rural poverty through crop failure, higher labour inputs, rising costs of production and reduced availability of suitable land. Different actors reacted differently to the weed problem, in terms of the construction of knowledge, labour practices and technology development. Farmers have actively engaged in technology development and new labour practices have emerged. Researchers have not translated the new weed problem into a research priority until recently. As a consequence, inappropriate weed management technologies were proposed, and these showed low adoption. As part of the Convergence of Sciences (CoS) programme, this study attempted through a multiple stakeholder approach, using discovery learning and joint experimentation, to enable farmers to co-develop and use low-cost technologies that are effective and acceptable. The joint learning enabled farmers to better understand the biology of these weeds as a basis for choosing appropriate measures. An integrated strategy, which included deep ridging, deep hoe-weeding and shading by legumes, was more effective in suppressing speargrass than farmers' practices. While this new strategy also improved soil organic matter and nitrogen to a subsequent maize crop, farmers' need to bridge the hungry gap forced them to trade off legume grain production against speargrass suppression and subsequent maize yield. Farmers are also constrained by labour shortage and the lack of credit. Given their small windows of opportunity, farmers can only gradually reclaim land that is infested by speargrass. Early planting, sorghum transplanting, crop rotation and intercropping, and trap cropping were partly effective in increasing cereal and cowpea yield and in reducing Striga hermonthica and S. gesnerioides. However, these improved practices made also clear that the Striga problem can only be addressed within an integrated crop and soil fertility management strategy. Improved weed management can be best achieved through a Farmer Field School to empower small-scale farmers to be self-reliant in finding their own solutions. Farmer self-assessment indicated that the CoS approach contributed to their increased human and social capital assets, which are a prerequisite for raising their livelihoods. The CoS approach, as applied in this study, is critically reflected upon and recommendations are made for the next phase. Keywords; permanent land use, weeds, indigenous knowledge, integrated crop and soil management, participatory learning, co-research Preface My dream to build on farmers' knowledge dated back from when as a fresh Ingénieur Agronome, I joined a R&D team at the headquarters of the CARDER Atlantique in 1989. I realised that most research recommendations were only partially or not at all used by the small-scale farmers. The members of the research team thought that in order to increase the rate of adoption of the recommended technologies, it would be necessary to build on farmers' own practices. I had become strongly convinced of this idea by the time that I completed my Masters programme, after carrying out my fieldwork in 1993 in the three former southern departments (Atlantique, Mono and Ouémé) of Benin. Subsequently, from my experiences of working with the Sasakawa Global 2000 project, I drew the conclusion that technologies developed by scientists should take into consideration both biological and socio-economic aspects in order to increase their chance of acceptability at farm level. At this time I submitted a PhD research proposal to the University of Reading (UK), which was accepted, but because of a lack of funding, I could not benefit from this opportunity. My dream none the less has become a reality through the Convergence of Sciences (CoS) programme, funded through the International Research and Education Fund (INREF), Wageningen University, The Netherlands, and by the Directorate General of International Cooperation (DGIS), Ministry of Foreign Affairs, the Netherlands, for which I would like to express my deepest gratitude. My sincere thanks go to the brains trust who conceived this programme, especially to the general coordinator Prof. Dr. Ir. Arnold van Huis for this initiative and his intellectual rigour. I am appreciative also of the scientific coordination committee, composed of Prof. Dr. Ir. Niels Röling, Dr. Dominique Hounkonnou and Prof. Dr. Ir. Arnold van Huis, for their commitment throughout the completion of the first phase of this programme. I here acknowledge in addition the contributions of the national coordinators in Benin and Ghana, respectively Prof. Dr. Ir. Dansou K. Kossou and Dr. O. Sakyi-Dawson. Interdisciplinary work is never the sole effort of the author and this study is no exception. I wish to thank especially the promotors, the CoS working group, farmer colleagues, friends, and my nuclear family, all of whom have contributed in one way or the other to the completion of this thesis. 1 acknowledge above all the invaluable support and contribution of my supervisors, without whom this study would not have been completed. I am indebted to Prof. Dr. Ir. Niels Röling, who at first doubted if working on weeds was opportune and worthwhile but who became convinced by my early results and thereafter showed enthusiasm, faith, trust, support, and scientific rigour, and who contributed substantially to the development of this thesis. I also owe Prof. Dr. Thorn W. Kuyper for his close supervision, his scientific criticism, his perfectionism and his constructive input, without which this work would not have been approved. I am heartily sensible of his extensive comments, recommendations, contribution and the considerable time he has devoted to shaping this thesis. Special thanks go to Prof. Dr. Paul Richards who in fact was the one who triggered the idea of addressing the current pressing weed problems when I presented to him my initial proposal in Wageningen. My thanks go also to Prof. Dr. Janice Jiggins,