Agro-ecological Zones Of Benin Research Articles

Ecological sustainability and environmental risks of agricultural intensification in inland valleys in Benin

To meet food demand after the failure of irrigation system developments, agricultural intensification is occurring in inland valley agro-ecosystems in sub-Saharan Africa. Agricultural enhancement in inland valleys, which undermines environmental sustainability, was assessed using ‘Driving Force–Pressure–State–Impact–Response’ approach in four agro-ecological zones of Benin. The survey revealed that inland valleys are largely devoid of ligneous species. Crop residues are mainly transferred from inland valley fields to feed cattle, burnt in situ by the farmers themselves or abandoned to wildfires or to pasture—not mulched. Crop diversification is not universal and is limited to rice and vegetables crops. Monocropping of rice, practised by 83.3% of inland valley farmers, requires large chemical fertilizer application despite their impacts on environment including land degradation and water contamination. A major challenge is to determine means of characterizing entire agro-ecosystems of inland valleys in a way that is simple enough to be effectively and efficiently monitored. Inland valley agricultural development projects might include backstopping activities and policies that enable monitoring of chemical inputs and farming practices in inland valleys to reduce negative impacts on the environment and human health.

Pigeonpea [(Cajanus cajan (L.) Millsp.)] production system, farmers\u2019 preferred traits and implications for variety development and introduction in Benin

BackgroundThe success of crop varieties introduction is tightly linked to the uses, biophysical conditions, the cropping systems in which the crop is integrated and farmers’ and consumers’ preferences. In Benin, however, pigeonpea production systems including the cropping systems, marketing, utilizations and preferences have received little attention. This study aimed at analyzing farmers’ practices and constraints related to pigeonpea production as well as identifying farmers’ preferred traits in pigeonpea.MethodsThe study was conducted in three pigeonpea-growing agroecological zones in Benin. Participatory rural appraisal tools including individual interview (n = 302) and group discussion were used to collect information on production system, constraints and preferred traits. Fisher’s exact test was used to assess the relationship between crop associated with pigeonpea and the growing areas. Based on preferred traits, villages were clustered using UPGMA.ResultsPigeonpea is predominantly grown by men. Approximately 98% of the pigeonpea growers associated pigeonpea with other crops, while 2% of them grew the crop in pure stand. Pigeonpea grown in association with maize (48.7%) was the most encountered cropping system. The type of crops associated with pigeonpea depended on the growing area (P < 0.001), and a high diversity in crops combination was observed in the Department of Couffo. Lack of improved varieties, low productivity and lack of quality seed were major factors constraining pigeonpea production. The pigeonpea seed system was essentially informal with self-saved seed (79%), purchase from fellow farmers or from local markets (12%) and gift/exchange (9%) as seeds sources. Farmers’ preferences traits varied across pigeonpea-growing area, but overall, high yielding, early maturing, and resistance to pod borers were the main reported preferred traits.ConclusionOur results confirm the importance of pigeonpea both in the cropping systems and in contributing to ensure food security in the growing areas in Benin. Farmers’ varietal preferences were identified. This information is important for designing appropriate strategies for sustainable pigeonpea production. Insight gained into farmers’ preferred traits in pigeonpea varieties will also help in the choice of varieties or advanced breeding materials to be integrated into participatory varietal selection programs in order to improve productivity of the crop in Benin.

Adaptation of the “Indicateurs de Durabilité des Exploitations Agricoles (IDEA)” method for assessing sustainability of farms in the lower valley of Ouémé River in the Republic of Benin

The Indicateurs de Durabilité des Exploitations Agricoles (IDEA) method was adapted and used to study the sustainability of farms in the Ouémé lower valley in the Republic of Benin. The IDEA survey was tested among a sample of farmers, through discussion groups at village level and via interviews with resource staff. The data collected were then subjected to binomial tests and results from the interviews subject to Student t-test. The study showed that some units of sustainability in the initial version of IDEA are applicable in the study area without modification. Other units, such as permanent or temporary grassland, were rejected as they were not considered relevant by village assemblies. Some elementary units, such as the spatial units of the same crop (indicator A6: size of plots), were reformulated to meet the local context. Finally, the scores for some sustainability indicators, such as C1 (economic viability), were adjusted to meet the local context. With further modification, the adapted version of the IDEA method could be used in other agro-ecological zones in Benin and Africa.

Effects of Diverse Pretreatments on Seed Germination in Cleome gynandra L. (Capparidaceae) - A Threatened Species, Collected from Different Agro-Ecological Zones in Benin

Effects of Diverse Pretreatments on Seed Germination in Cleome gynandra L. (Capparidaceae) - A Threatened Species, Collected from Different Agro-Ecological Zones in Benin

Ethnobotanical Investigation and Collection of the Local Maize (Zea mays L.) Varieties Produced in Benin

Although maize is an economic crop among agroecological zones in Benin, there is a limited information on its varietal diversity, production constraints and ethnobotanical knowledge. To fill this gap, ethnobotanical survey was conducted among 51 communities from 22 ethnic groups randomly selected from 11 departments in Benin using participatory rural appraisal. A total of 161 accession names of maize were recorded and collected from the study area. Results of the study showed a strong correlation between the age of the producers and the number of varieties produced. Similarly, there was a relationship between total maize yield produced and size of the farm cultivated. In the North, maize varieties are classified based on seed color or maturity period, while in the South plant morphology and origin are mostly used. Across ethnic groups, variety preference criteria depended on specific production constraints and its socio-cultural importance. Based on the perceived agronomic traits of the varieties reported by farmers, collected samples were clustered into four groups of complementary characteristics that are of high importance for maize breeding in Benin.

English

Simple sequence repeat (SSR) molecular markers were used for genetic diversity analysis and population structure of the cultivated Pearl millet in Benin, West Africa. In order to assess the level of genetic diversity, 14 polymorphic SSR markers were used to screen 114 accessions from different agro-ecological zones in Benin. SSR markers were found to reveal a total of 57 alleles with an average of 4.071 allele per locus. Genetic diversity index varied from 0.099 to 0.633 with an average of 0.405. The average observed heterozygosity was found to reach 0.425. The analysis of molecular variance showed no real differentiation between regions. Only 5% of genetic variation was observed between samples collected from north-eastern and north-western region. A high level of variation (95%) was observed among accessions. Moreover, both principal component analysis (PCA) and the dendrogram obtained from the genetic distance among accessions revealed the absence of any specific structuration of accessions from each region under study. Our results confirmed diversity among cultivated Pearl millet in Benin and such diversity is not clustering according to geographical patterns. Key words: Cereal, simple sequence repeat (SSR) markers, genetic variability.

Spatial and Temporal Infestation Rates of Apate terebrans (Coleoptera: Bostrichidae) in Cashew Orchards in Benin, West Africa

Cashew, Anacardium occidentale L. is an important export crop in Benin, but incurs serious damage from the cashew wood borer Apate terebrans Pallas. In spite of its economic importance, the population dynamics of this beetle have never been studied, thus precluding any science-based development and implementation of control strategies. The spatial and temporal abundance pattern of A.terebrans was therefore monitored in 17 mature cashew orchards distributed across three agro-ecological zones in Benin. In each orchard, 30 cashew trees were chosen at random and inspected monthly for two consecutive years. As this insect feeds inside branches and trunks by boring holes, direct observations of adults inside the tree are not possible. Therefore infestations of trees were estimated by the occurrence and number of fresh entry holes. Over the two-year observation period, infestations in the cashew trees by A.terebrans started in September, peaked in January–February and sharply declined thereafter, reaching zero by July–August. Whereas the infestation rates were statistically similar between sampling years or among agro-ecological zones, they differed significantly among sampling months. Aggregation indices calculated using Taylor's power law indicated that A.terebrans has an aggregated spatial distribution. Values of the Spatial Analysis by Distance IndicEs (SADIE) index indicated that the spatial pattern of the infestation in a given year does not depend on the pattern observed in the previous years, suggesting that A.terebrans generally prefers to infest new trees. Implications of our findings for the development, implementation and monitoring of effective control strategies against A.terebrans are discussed.

Occurrence of Aspergillus section Flavi and section Nigri and aflatoxins in raw cashew kernels (Anacardium occidentale L.) from Benin

The objective of this study was to evaluate the presence of Aspergillus section Flavi and A. section Nigri in cashew nuts harvested in the Northern Guinea (NG) and Southern Sudanian (SS) agro-ecological zones of Benin. Also, the presence of aflatoxins was investigated. For detection of fungal contamination, a total of 100 kernels/sample (with disinfection) and 40 kernels/sample (without disinfection) were plated. Seventy samples from fourteen villages were used. Aflatoxins occurrence was analysed on 84 samples by ultra–high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The average water content and the cashew nuts count were respectively 8.6% and 172 nuts/kg in NG and 8.7% and 174 nuts/kg in SS. Significant differences between villages in both zones were found for both water content and nuts count. In disinfected samples, strains of Aspergillus section Nigri were predominant, in NG and SS zones (90.2% and 87.2%) respectively. When non disinfected kernels were plated, A. section Nigri was predominant in both NG and SS zones, with percentages of 89.7% and 93.4%, respectively. None of the 84 nuts samples were positive for natural occurrence of aflatoxins with a detection limit of 0.05–0.2 μg/kg.

Dominant bacterial diseases in the extensive and semi-intensive animal breeding and their treatment method by ethnoveterinary medicine in Benin

Chlorophytum laxum, R.Br. (Liliaceae): A threatened medicinal herb of soliga tribe from B.R.Hills, Karnataka, IndiaM. H. Niranjan

Colonization and molecular diversity of arbuscular mycorrhizal fungi associated with the rhizosphere of cowpea (Vigna unguiculata (L.) Walp.) in Benin (West Africa): an exploratory study

Arbuscular mycorrhizal symbiosis is an important plant root–fungal partnership/interaction that affects the growth response of crops. We have investigated the molecular diversity of arbuscular mycorrhizal fungi (AMF) colonizing cowpea roots and the associated rhizosphere soil to test the hypothesis that community diversity in rhizosphere soil is similar to that in cowpea (Vigna unguiculata) roots. Cowpea plants were grown in farmers’ fields located in seven agro-ecological zones of Benin, and soil and root samples were collected. The molecular diversity of the AMF in these samples was assessed after amplification of the large ribosomal subunit of DNA extracted from the soil and the root samples. At fruition, the frequency of mycorrhizal infection was unaffected by the agro-ecological zone, but there were significant differences in the intensity of AMF colonization among the zones. Multiple regression analysis showed that the main factor affecting mycorrhizal frequency at flowering was available phosphorus. Phylogenetic analysis revealed 25 operational taxonomic units belonging to two fungal families (Glomeraceae and Gigasporaceae). The diversity of AMF colonizing roots of cowpea in Benin was high and fairly similar to that in the rhizosphere soil but with a prevalence of the Glomeraceae. Despite the absence of strict host specificity in mycorrhizal symbiosis, there was a preferential association between some AMF species and cowpea cultivar IT96D-610.

Influence of Agro Ecology on Rice Varietal Resistance to &amp;lt;i&amp;gt;Sitophilus oryzae&amp;lt;/i&amp;gt; (Coleoptera: Curculionidae) and &amp;lt;i&amp;gt;Sitotroga cerealella&amp;lt;/i&amp;gt; (Lepidoptera: Gelechiidae) in Benin

The rice weevil, Sitophilus oryzae (L.) and the Angoumois grain moth, Sitotroga cerealella (Oliv.), are serious pests of stored rice in Africa. This study aims to evaluate the influence of growing environments to rice resistance to these pests. Thus, eleven rice varieties including 6 upland NERICA, 2 Oryza glaberrima and 3 O. sativa were grown at four agro ecological zones of Benin. After harvest, samples of 1500 grains of each genotype were infested with 20 adults of S. oryzae (10 males and 10 females) and 1500 additional ones were infested with 50 eggs of S. cerealella. Results showed significant effect of agro ecological zones on pest incidence and on varietal resistance as well. O. glaberrima varieties (TOG 5681 and CG 14) were the most resistant in each location whereas the resistance of NERICA and Sativa varieties varied from tolerant to susceptible according to the growing ecology. This result highlights the impact of growing environment on rice resistance status and will provide the best advice to farmers on how to choose best genetic material according to cropping ecology.

Field evaluation of the synergistic effects of neem oil with Beauveria bassiana (Hypocreales: Clavicipitaceae) and Bacillus thuringiensis var. kurstaki (Bacillales: Bacillaceae)

In the present study, the synergistic effects of Beauveria bassiana (Bals.-Criv. Vuill.) (isolate Bb11) and Bacillus thuringiensis var. kurstaki (Berliner) with neem oil were evaluated in three agroecological zones in Benin. Four bioinsecticide treatments (neem oil, neem oil and B. bassiana used separately for different target pests, neem oil mixed with B. bassiana and neem oil mixed with B. thuringiensis) were compared with a calendar-based treatment using synthetic insecticides and a control without insecticides. The bioinsecticide treatments were less effective than the calendar-based treatment at controlling cotton pests. There was no difference in yields and the number of damaged bolls in plots under treatments with the four bioinsecticide formulations, suggesting an absence of synergy between neem oil and B. bassiana and neem oil and B. thuringiensis. The numbers of natural enemies in all the bioinsecticide treatment plots and the control plots were similar and higher than those in the calendar-based treatment plots. The highest yield and profitability were obtained with the calendar-based treatment. Screening the compatibility of plant-based products and biopesticides through bioassays is essential for a successful application of their combinations in any integrated pest management strategy.

Ethnobotanical investigation and diversity of Gbolo (Crassocephalum rubens (Juss. ex Jacq.) S. Moore and Crassocephalum crepidioides (Benth.) S. Moore), a traditional leafy vegetable under domestication in Benin

Thirty five villages randomly selected across ethnic and agro-ecological zones of Benin were surveyed to document the indigenous knowledge associated with the domestication (bringing into cultivation), production and utilization of vegetable Gbolo (Crassocephalum spp.). The study revealed the existence of different morphotypes (1–4 per village) corresponding to two botanical species (Crassocephalum rubens (Juss. ex Jacq.) S. Moore) and (Crassocephalum crepidioides (Benth.) S. Moore) found unequally distributed throughout the country. The domestication (bringing into cultivation from the wild) of Gbolo was started in many villages and with some tribes in southern Benin, the vegetable is already being produced in sole cropping for commercial purposes. Regular consumption (49.90 % of responses) and scarcity (20.30 % of responses) were the two main reasons attributed by the interviewees for domestication of the vegetable. The cultural practices recorded were of five categories. The commonest cropping system found was mixed or inter-row cropping (92.31 % of producers) with either vegetable crops (53.85 % of producers) or non-vegetable crops (38.46 % of users). Sauce prepared with either fresh or dried leaves was the main type of preparation of Gbolo and the vegetable was reported to possess special nutritional and medicinal values. For further promotion, important researches directions are suggested.

Farmers’ perceptions on characteristics of cassava (&lt;i&gt;Manihot esculenta&lt;/i&gt; Crantz) varieties used for chips production in rural areas in Benin, West Africa

A survey aimed at collecting information about cassava varieties/cultivars and farmers&rsquo; perceptions concerning cassava and chemical food safety was conducted in 10 villages located in two agroecological zones in Benin. A structured questionnaire to interview farmers was employed. Out of 100 farmers sampled, most of them relaying on chips as food and source of income were women. Overall, 40% of all farmers marketed chips locally. Tasting was the main technique use by farmers to discriminate cassava varieties including Kpaki Kpika, Kpaki Soan, Logo Guesse Kotorou and BEN 86052. The latter being introduced by research centres. Both bitter and sweet cassava were produced and the sweet varieties being used for chips production by farmers who do perceive bitter cassava as toxic crop. Our results call for more investigations in promoting gender oriented safety and hygiene/sanitation techniques.

Analysis of pre- and post-harvest practices of cowpea (&lt;i&gt;Vigna unguiculata&lt;/i&gt; (L.) Walp.) in Benin

Cowpea is an important leguminous crop in Benin. Practices such as farming and storage conditions may influence the production yield and the grain quality. In this study, pre- and post-harvest practices ofcowpea were analysed in relation to the quality of the grains. A survey on cowpea farming activities was conducted in the four agro-ecological zones of Benin. Three localities producing cowpea were selected in eachagro-ecological zone. Information was obtained through individual interview and focus group discussions. Cowpea was mainly cultivated either as a monocrop or intercropped with maize and groundnuts in the fouragro-ecological zones. Cowpea infestation by insects on farm and in storage was a major problem mentioned by farmers. To prevent insects’ infestation in storage, cowpeas were thoroughly sundried at harvest andadequately sorted prior to storage. Such post-harvest practices could limit cowpea grains quality deterioration. Cowpeas were mainly stored in bags for about 3 months. About 23 cowpea based foods were identified. Majorcowpea foods were ata (akara), moin-moin and adowe. Common processing operations included sorting, washing, dehulling of cowpeas, boiling and frying. These processing operations as practiced by processors are generally recognized as a good practice in food preparation.

First Report of Bacterial Wilt of Tomato (Solanum lycopersicum) Caused by Ralstonia solanacearum in Benin.

In June 2004, wilted tomatoes with no foliar yellowing were observed in Ouègbo, Atlantique District, Benin. The cut tomato stems released whitish bacterial ooze. Longitudinal sections of most stems showed brown vascular discoloration. Twenty symptomatic tomato plants were collected from 10 fields and exported to the Institute of Plant Disease and Plant Protection, Leibniz Universität Hannover, Germany. Bacteria were isolated on triphenyl tetrazolium chloride (TTC) medium (2) and three of the nine bacterial isolates that resembled Ralstonia solanacearum (colonies with red center and whitish periphery) and reference strain ToUdk (race 1 biovar 3; N. Thaveechai, Kasetsart University, Bangkok, Thailand) were used for pathogenicity tests. Five 4-week-old tomato plants cv. Tohounvi, grown in individual plastic pots (14 × 16 cm) containing sterilized field soil, were inoculated with each of the four isolates individually by soil drenching with 30 ml of the test cultures at 108 CFU/ml. Control plants were treated with 30 ml of sterile water. All plants were incubated in a glasshouse at 30°C. All plants inoculated with the isolates from Benin wilted 4 days after inoculation with symptoms similar to those observed in the field. Plants inoculated with the reference strain wilted 7 to 11 days after inoculation. Control plants treated with water remained healthy. R. solanacearum was recovered from the 20 symptomatic plants on TTC medium. The identity of the strains in comparison with the reference strain was confirmed by PCR with species-specific primers 759/760, which produced a single 281-bp fragment (3). Because similar symptoms were being increasingly reported by farmers across Benin and linked with reduced tomato yields, a disease survey was undertaken by IITA in 2006 and 2007. Wilted tomato plants were found across all agro-ecological zones of Benin (3 to 72% of plants per field). Isolates were recovered from the southeastern districts of Adja-Ouèrè, Sakété, Adjohoun, and Dangbo, the southwestern districts of Klouékanmè and Athiémé, the southern districts of Toffo and Bohicon, the central districts of Dassa and Savè, and the northern districts of Malanville and Karimama. Identification of R. solanacearum was confirmed following inoculation of tomato, production of characteristic wilting symptoms, recovery of the pathogen on TTC medium, and positive identification with ELISA kits (Pathoscreen Rs; Agdia Inc., Elkhart, IN). To our knowledge, this is the first report of R. solanacearum infecting tomato in Benin. Tomato is the most cultivated vegetable crop in Benin and important to the livelihood of many people in peri-urban and rural areas. Understanding that the cause of the observed crop losses is R. solanacearum may lead to implementation of management strategies such as deployment of disease-resistant cultivars or grafting tomatoes onto bacterial wilt-resistant rootstocks (1).

Infestation and Population Dynamics of Insects on Stored Cassava and Yams Chips in Benin, West Africa

Natural insect infestation in cassava (Manihot esculenta Crantz subspecies esculenta) and yam (Dioscorea spp.) chips was evaluated during two consecutive storage seasons (2003-2004 and 2004-2005) in two agroecological zones of Benin (Northern Guinea Savanna [NGS] and Sudan Savanna [SS]). The insects infesting chips were collected, identified, and counted, they included Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), Cathartus quadricollis (Guerin) (Coleoptera: Silvanidae), Carpophilus dimidiatus (F.) (Coleoptera: Nitidulidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), and Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). P. truncatus and C. quadricollis were observed with a higher prevalence on cassava than on yam chips. During both seasons after 3 mo of storage, all (100%) cassava chip samples were infested with P. truncatus and C. quadricollis in both agroecological zones, whereas yam chips only showed lower infestation rates of 59.5 and 19.1% for P. truncatus and C. quadricollis, respectively, at the end of storage in 2003-2004. During the 2004-2005 season after 3 mo of storage infestation rate in yam chips was 66 and 24% in NGS and 100 and 0% in SS for P. truncatus and C. quadricollis, respectively, showing that insect infestation levels vary significantly with commodity, year, and fluctuate during the storage season.

Traditional leafy vegetables and their use in the Benin Republic

Seventy-three villages randomly selected in 29 ethnic areas and three regions or agro-ecological zones of Benin were investigated by a participatory rural appraisal survey to assess the diversity of the species used as traditional leafy vegetables (TLVs). In total, 187 plant species belonging to 141 genera and 52 families were recorded. Among these, 47 (25.13%) were cultivated and 140 (74.87%) were gathered from the wild. Herbs (64.78%) were the most numerous followed by shrubs (19.78%) and trees (15.50%). The Shannon-Weaver diversity index calculated was 3.232. The total number of TLVs used highly varies, across ethnic groups, from 15 (Toli tribe) to 58 (people Mahi) with, on average, 36 species per ethnic group. The relative proportions of the wild and cultivated species used also vary with the tribes but on average appeared almost the same. Of the species inventoried, 18 of national importance were found among which Solanum macrocarpon, Corchorus olitorius, Amaranthus cruentus and Gymnanthemum amygdalinum ranked first. The matrix scoring technique yielded 12 criteria of different natures used to define preference. Among these, four (taste, ease of preparation, availability and quantity of required condiments) were the most important and represent, all together, more than 72% of responses. Despite the diversity of species used as leafy vegetables, they were all basically consumed in the same way. Sauces were the main type of preparation and involved all the species. The perceived nutritional and medicinal (curative, regulative and stimulative) properties of the species as well as their cultural significance were documented. Some TLVs are known and consumed by all or many ethnic groups while many others were simply ethnospecific or used by only a few peoples. However, no correlation was found between the distribution of the utilisation of the species and their degree of consumption which all depend on the eating habits of the peoples. Cluster analysis revealed that peoples sharing a common geographical space and/or cultural identity or origin seem to consume almost the same types of TLVs and cluster together. Given the large quantity of evidence of the importance of the TLVs, there should be a systematic effort to improve their understanding and their uses to reduce if not alleviate rural poverty and malnutrition in Benin.

Mycoflora and natural occurrence of aflatoxins and fumonisin B 1 in cassava and yam chips from Benin, West Africa

The presence of fungi, aflatoxins and fumonisin B 1 in cassava and yam chips (during 28 processing and storage) were evaluated during two consecutive seasons in two agroecological zones of Benin (Northern Guinea Savannah, NGS and Sudan Savannah, SS). The Benin samples were assessed for moisture content, fungal infestation and total aflatoxin and fumonisin B 1 contamination. During the two seasons, samples collected from the NGS, had moisture contents ranging from 10.0 to 14.7% in cassava chips and from 11.4 to 15.3% in yam chips. In samples from the SS, moisture content ranged from 10.1 to 14.5% and 11.1 to 14.5% in cassava and yam chips, respectively. A. flavus was the predominant fungal species. The maximum cfu/g in cassava and yam chips was 8950 and 6030, respectively. Other fungal species isolated included P. chrysogenum, M. piriformis, Phoma sorghina, F. verticillioides, R. oryzae and Nigrospora oryzae. High performance liquid chromatography analysis of both cassava and yam chips showed no contamination by either aflatoxins or fumonisin B 1.

Weeds as agricultural constraint to farmers in Benin: results of a diagnostic study

Weeds are an emerging constraint on crop production, as a result of population 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 (1) to identify the relative importance of weeds among major production constraints, (2) to better understand farmers' perceptions of weed problems, and (3) to take cognizance of their reactions and the different actors involved in weed management technology development. The study also aimed at suggesting the development of weed 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, Cyperus spp., Commelina spp.) and parasitic ( Striga spp.) weeds are difficult to eradicate, causing substantial food crop yield losses and threatening the livelihood of people. Land and labour shortage, low commodity prices and lack of credit were the main constraints hindering weed management. Causes, effects and consequences were analysed, taking into account the socio-economic context. The study's findings with respect to weed management measures, and their adaptation and constraints in using them, suggest that effective and acceptable weed management strategies should be developed, taking into account both biological and social science perspectives with a focus on adding value to indigenous knowledge. Promising strategies for discovery learning about weed management were identified, in order to foster sustainable crop production in Benin.