Fruits and vegetables are important commodities in global agriculture. However, in sub-Saharan Africa, production is sub-optimal in terms of yield, quality and environmental health practices due to several constraints such as insect pests which reduce yields through direct damage, or indirectly as disease vectors often promoting microbial diseases. Pest control still relies mainly on chemicals with their associated risks of resistance selection and toxicity to humans and environment. Several alternatives including biopesticides, semiochemical and nets are being explored in pest management. Insect nets applied on tomatoes, cabbages, beans and leafy vegetables protect them from flies, butterflies, moths, albeit to a lesser extent, whiteflies, aphids and thrips reducing their outbreaks as compared to open cultivation. As a result, pest control is limited and yield quantity and quality are improved. Insect nets are safe and cost effective for a period of 3-5 years if well maintained, and they may be re-used and recycled. Insect nets applied on cabbages in Benin yielded 3-fold more profit than current practice. However, insect nets are not effective against all pests inclusion of insect attractants or repellents may enhance efficacy of netting technology. The use of insect nets offers a cost-effective insect pest management option to among smallholder vegetable growers. The full benefit will be achieved with intensified extension efforts to make this technology better known.

If agro-ecological systems are to realize their potential as sustainable alternatives to conventional agricultural systems, innovation diffusion needs to be enhanced. We conducted surveys among 214 small-scale vegetable farmers in Benin, a food-deficit country in West Africa, on how they perceived the different attributes of eco-friendly nets (EFNs). The nets act as physical barriers against insects in vegetable production and so reduce pesticide use. Understanding farmer perceptions about new technologies helps reveal farmers’ propensity to adopt them. Intensity of attitude was measured on a Likert scale, and an ordered probit model was used to determine which characteristics of nets were most influential. Eighteen percent of farmers thought that EFNs would benefit them, but almost half preferred not to adopt this technology at all. The main reason for rejecting the nets was the perceived high labor requirement, particularly on larger plots of land. This largely negative perception was strongest among farmers with large areas cultivated with vegetables, farmers who had little or no experience in a trial, and those living far from extension services. We recommend expanded trials that engage a higher proportion of farmers, strengthening of external support for those wanting to use the nets and further technological development to reduce labor costs, improved access to finance and increased education about the negative impacts of insecticides abuse.

HomePlant DiseaseVol. 99, No. 11First Report of Bacterial Wilt of Gboma (Solanum macrocarpon) Caused by Ralstonia solanacearum in Benin PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Bacterial Wilt of Gboma (Solanum macrocarpon) Caused by Ralstonia solanacearum in BeninR. Sikirou, B. Zocli, M. L. Paret, P. Deberdt, R. Coranson-Beaudu, J. Huat, F. Assogba-Komlan, M. E. E. A. Dossoumou, S. Simon, and E. WickerR. Sikirou, B. Zocli, M. L. Paret, P. Deberdt, R. Coranson-Beaudu, J. Huat, F. Assogba-Komlan, M. E. E. A. Dossoumou, S. Simon, and E. WickerAffiliationsAuthors and Affiliations R. Sikirou B. Zocli , Institut National des Recherches Agricoles du Benin (INRAB/LDC), 01 B.P. 884 Cotonou, Benin M. L. Paret , University of Florida, North Florida Research and Education Center, Quincy, FL 32351-5677 P. Deberdt R. Coranson-Beaudu , CIRAD, UPR HORTSYS, Campus Agro-environnemental Caraïbe, Le Lamentin, F-97285, Martinique, France J. Huat , CIRAD, UPR HORTSYS, Montpellier, France/Africa Rice Center, Cotonou, Benin F. Assogba-Komlan M. E. E. A. Dossoumou , Institut National des Recherches Agricoles du Benin/ (INRAB/LDC), 01 B.P. 884 Cotonou, Benin S. Simon , CIRAD, UPR HORTSYS, Montpellier, France/(INRAB/LDC), 01 B.P. 884 Cotonou, Benin E. Wicker , CIRAD, UMR Peuplements Végétaux et Bioagresseurs en milieu Tropical (PVBMT), 7 Chemin de l’IRAT, F-97410, Saint-Pierre, Réunion island, France. Published Online:15 Sep 2015https://doi.org/10.1094/PDIS-02-15-0213-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Gboma (Solanum macrocarpon) is the major leafy vegetable cultivated in Benin, with many people depending on this crop for their livelihood. In March 2012, wilted Gboma plants without foliar yellowing were observed at three locations (Dogbo, Lokossa, and Athiémé) in the southwestern districts. Longitudinal sections of most stems of Gboma showed brown vascular discoloration. The cut stems released whitish bacterial ooze in water. Bacterial colonies on modified semi-selective medium from South Africa SMSA (Engelbrecht 1994) were mucoid and round with red centers with beige peripheries, thus morphologically similar to Ralstonia solanacearum. To fulfill Koch’s postulates, 19 different isolates were inoculated on susceptible Gboma cv. Kpinman, grown in sterilized field soil. Plants (10 per isolate) were inoculated by drenching the soil with 40 ml of a bacterial suspension containing 108 CFU/ml. Plants treated in a similar manner with sterile water served as a negative control. Inoculated plants were incubated under a protected shed at about 30°C. By 15 days after inoculation, 100% of the inoculated plants were wilted whereas all control plants remained healthy. R. solanacearum was recovered from all symptomatic plants on modified SMSA medium. In 2014, a survey throughout the Abomey-Calavi area (Atlantic District) identified bacterial wilt of Gboma within all cultivated farms, with incidences ranging from 15 to 75.2%. Thirty newly collected bacterial isolates were identified as Ralstonia solanacearum using ImmunoStrip assays (Agdia Inc., Elkhart, IN, USA), and diagnostic PCR with 759/760 primers (Opina et al. 1997). A phylotype-specific multiplex PCR (Fegan and Prior 2005) classified all strains in R. solanacearum Phylotype I. Partial sequences of the egl and mutS genes were deposited in GenBank under Accession Nos. KP730628 to KP730687. Alignment of these to R. solanacearum reference sequences confirmed that all strains from Abomey-Calavi and two from Dogbo belonged to one unique Sequence Type (ST) within Phylotype I (egl ST 43 (sequevar 31), mutS ST 22). This ST has also been reported to be widespread in the Ivory Coast (N’Guessan et al. 2012), and in South Africa, India, and Reunion Island (Wicker, unpublished data, 2015). This is the first report of R. solanacearum causing bacterial wilt on Gboma in Benin. Further surveys will help to assess the precise distribution of bacterial wilt disease on Gboma in Benin, and allow development of integrated management strategies combining currently available resistant cultivars and rotation with suppressive crops.References:Engelbrecht, M. C. 1994. ACIAR Bact. Wilt Newsl. 10:3. Google ScholarFegan, M., and Prior, P. 2005. Page 449 in: Bacterial Wilt Disease and the Ralstonia solanacearum Species Complex. Allen, C., et al. American Phytopathological Society, St. Paul, MN. Google ScholarN’Guessan, C. A., et al. 2012. Phytopathology 102:733. https://doi.org/10.1094/PHYTO-11-11-0300 Link, ISI, Google ScholarOpina, N., et al. 1997. Asia Pac. J. Mol. Biol. Biotechnol. 5:19. ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 99, No. 11 November 2015SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 4 Nov 2015Published: 15 Sep 2015First Look: 18 May 2015Accepted: 10 May 2015 Pages: 1640-1640 Information© 2015 The American Phytopathological SocietyCited byGenetic and pathogenic diversity of Ralstonia solanacearum species complex strains isolated in Burkina Faso25 November 2022 | Journal of Phytopathology, Vol. 171, No. 1Ralstonia solanacearum (bacterial wilt of potato)CABI Compendium, Vol. CABI CompendiumDistribution and Incidence of Tomato Bacterial Wilt Caused by Ralstonia solanacearum in the Central Region of TogoBitang Bamazi, Agnassim Banito, Kwasi Dzola Ayisah, Rachidatou Sikirou, Mathews L. Paret, Sanju Kunwar, Kpatcha Kamde, Pouwéréou Tchalla, and Afole Sister-Love N. A.24 April 2022 | Plant Health Progress, Vol. 23, No. 2Screening of Amaranthus sp. Varieties for Resistance to Bacterial Wilt Caused by Ralstonia solanacearum4 November 2021 | Horticulturae, Vol. 7, No. 11Identification and characterization of Ralstonia spp. causing bacterial wilt disease of vegetables in Mali6 August 2020 | Journal of Plant Pathology, Vol. 102, No. 4Sequevar Diversity and Virulence of Ralstonia solanacearum Phylotype I on Mayotte Island (Indian Ocean)5 January 2018 | Frontiers in Plant Science, Vol. 8Genetic Diversity of the Ralstonia solanacearum Species Complex in the Southwest Indian Ocean Islands19 December 2017 | Frontiers in Plant Science, Vol. 8

Since the 1990s the benefits of urban and peri-urban agriculture (UPA) have been widely recognized, and there has been extensive research characterizing UPA. However, most research has neglected the role played by indigenous underutilized species, even though increasingly it is recognized that promoting these species (which include African indigenous vegetables – AIVs), will be a crucial factor in the development of more resilient, sustainable farming systems for sub-Saharan Africa. Furthermore, although fewer varieties of AIVs are being used today, certain species are still very popular and in high demand. Understanding to what extent and how AIVs are currently being produced in UPA is an essential step towards developing a coordinated strategy for research and development efforts to support the production of these species. This paper analyses primary data on the production systems for AIVs in UPA in four West African cities: Cotonou and Lokossa in Benin, and Abidjan and Yamoussoukro in Cote d’Ivoire. The AIVs which contribute most to farmers’ income for both countries include Abelmoschus esculentus, Amaranthus spp., Corchorus olitorius and Solanum macrocarpon/S. aethiopicum. Certain locations appear to be specializing in particular AIVs, e.g., C. olitorius in Lokossa. In Cote d’Ivoire, urban locations had higher AIV diversity than peri-urban locations. Intercropping of the most commercially important AIVs was widespread in urban locations in Cotonou, Abidjan and Yamoussoukro. Pesticide use was common in all locations except in peri-urban Yamoussoukro. Inorganic fertilizer was used by 85-100% of farmers in UPA in Cotonou and Abidjan, and in urban Yamoussoukro. Organic inputs were used by over 90% of farmers in urban Cotonou, Abidjan and Yamoussoukro, mainly in the form of chicken manure. Comparison of production practices and farmer motivation suggest that production of AIVs in Benin is more market-oriented than in Cote d’Ivoire. The paper concludes with recommendations for future work.

7 Claude Ahouangninou , Thibaud Martin , Françoise Assogba-Komlan 8 , Serge Simon , Luc Djogbénou , Ibrahim Siddick , Cédric Pennetier , 9 Vincent Corbel 5 and Benjamin Fayomi 1 10 11 (* Corresponding author : Claude Ahouangninou, 02 BP 433 Cotonou, Bénin, Tel : 00229 97575366, 12 cahoun83@yahoo.fr) 13 1 Institut des Sciences Biomédicales Appliquées, Université d’Abomey-Calavi 14 2 Cirad UR-Hortsys 15 3 Institut National de Recherche Agronomique du Bénin 16 4 Laboratoire d’Entomologie Médicale, Institut Régional de Santé Publique, UAC, Bénin 17 5 Institut de Recherche pour le Développement-Unité Mivegec, Centre de Recherche Entomologique de Cotonou 18 19 20 21 . 22 ABSTRACT 23 24

Onion is the third most important vegetable after tomato and pepper for income generation by farmers in Benin, West Africa (Agossou et al ., 2001; MAEP, 2006). Since 1995, a serious disease of onion has been reported by farmers…

A new technique to control phytophagous mites was tested in West Africa on the African eggplant Solanum macrocarpon. This technique consisted of covering plants with a net impregnated with the acaricide dicofol. The net was applied during the night to protect the net fabric and the active ingredient from UV degradation and to avoid interference of the net with overhead watering. The technique was evaluated in three trials at the INRAB research station and in a grower's field in 2006 and 2007. Results showed that the broad mite Polyphagotarsonemus latus (Banks), the major pest of S. macrocarpon which causes severe damage to leaves, and spider mites (Tetranychus spp.), were completely controlled by the dicofol-treated net. Very few mites and practically no mite injury were observed on plants covered with the dicofol-treated net compared to 12–94% damaged leaves in the unprotected control plots. The acaricide-treated net was as efficient when used temporarily (once every three nights) as when used every night. No difference in the percentages of leaves damaged by mites was apparent at harvest between plots covered with a non-acaricide deltamethrin-treated net (40%) and unprotected control (32%). This new concept of mite control using an acaricide-treated net temporarily covering vegetable crop appears to be an efficient tool which is easy to use. It can be used repeatedly reducing costs and poses a very low risk of environmental pollution when used in the dry season or in greenhouses.

Protecting vegetables with a screen in peri-urban areas of tropical countries could reduce or even prevent often indiscriminate insecticide applications by small-scale farmers. The advantages of such an approach are protection of human health by reducing insecticide sprays, reducing environmental pollution from insecticide residues and increasing effectiveness of crop protection. Tunnel screens are well adapted to farmers cultivating intensively on small plots. Two trials were conducted to test the ability of screened tunnels to protect Brassica oleracea crops. The first was carried out on-station and the second in partnership with three farmers in Cotonou, Benin, West Africa. Tunnel screens impregnated with deltamethrin were found to be particularly well adapted to protect young plants in seedling nurseries against infestations by the aphid Lipaphis erysimi (Kaltenbach). The number of diamondback moth Plutella xylostella (Linnaeus) and borer Hellula undalis (Fabricius) on cabbages protected with the tunnel screen was significantly lower than that of plots conventionally treated with insecticides. The tunnel screen was not efficient against the armyworm Spodoptera littoralis (Boisduval) which laid eggs on the screen. After planting out, the use of a temporary screen from 1700 to 0900h gave better control against pests than the use of a permanent screen possibly due to the impact of natural enemies during the day. The field trials showed that the protection of cabbage with a tunnel screen could be an economically viable method. The costs of pesticides are on average US$ 45 per 100 m2 for one crop cycle compared with US$ 24 per100 m2 for tunnel screen material (assuming that this material can be used for 10 consecutive crop cycles). In addition, there are environmental benefits from a reduction of pesticide use. Farmers will have to cope with the initial investment for the screen material, which is, however, very cost-effective and locally available. Tunnel screens for vegetable protection can be easily combined with other integrated pest-management techniques.

The efficacy of a mosquito netting to protect cabbages, Brassica oleracea L., against pests was investigated in field trials in Benin, West Africa. A polyester net covered the plants at night by using a wood armature. The net was removed during the day to prevent overheating and excessive shade, both problems of insect-proof screens used under tropical conditions. The number of all lepidopteran larvae with netting protection and foliar insecticide sprays was significantly lower than the unprotected control. The number of diamondback moth, Plutella xylostella (L.), was significantly lower with netting protection compared with foliar insecticide sprays and control. Netting treated with deltamethrin gave total protection of young plants against the aphid Lipaphis erysimi (Kaltenbach). At harvest, the number of marketable cabbages protected with untreated netting was significantly higher compared with the production with foliar insecticide sprays. The protection of cabbages with netting can be an economically viable method. Considering the price of cabbages on local markets (US dollars 1/unit), the net returns per 100 m2 were US dollars 247 by using netting, US dollars 149 by using insecticides, and US dollars 117 for controls. The net returns for using netting are based on replacing the netting each crop cycle. But netting can be reused several times, depending upon conditions, increasing the profit margin. The netting protection may be an alternative to the growing unsustainable practices of vegetable cropping in peri-urban areas of tropical countries.