Spodoptera frugiperda has caused significant losses of farmer income in sub-Saharan countries since 2016. This study assessed farmers’ knowledge of S. frugiperda, their perceptions and management practices in Benin. Data were collected through a national survey of 1237 maize farmers. Ninety-one point eight percent of farmers recognized S. frugiperda damage, 78.9% of them were able to identify its larvae, and 93.9% of the maize fields were infested. According to farmers, the perceived yield losses amounted to 797.2 kg/ha of maize, representing 49% of the average maize yield commonly obtained by farmers. Chi-square tests revealed that the severity of the pest attacks was significantly associated with cropping practices and types of grown maize varieties. About 16% of farmers identified francolin (Francolinus bicalcaratus), village weaver (Ploceus cucullatus), and common wasp (Vespula vulgaris) as natural enemies and 5% of them identified yellow nutsedge, chan, shea tree, neem, tamarind, and soybean as repellent plants of S. frugiperda. Most farmers (91.4%) used synthetic pesticides and 1.9% of them used botanical pesticides, which they found more effective than synthetic pesticides. Significant relationships exist between farmers’ management practices, their knowledge, organization membership, and contact with research and extension services. More research is required to further understand the effectiveness of botanical pesticides made by farmers against S. frugiperda and to refine them for scaling-up.

Spodoptera frugiperda was first reported in Africa in 2016 and has since become a serious threat to maize/cereal production on the continent. Current control of the pest relies on synthetic chemical insecticides, which can negatively impact the environment and promote the development of resistance when used indiscriminately. Therefore, great attention is being paid to the development of safer alternatives. In this study, several biorational products and a semi-synthetic insecticide were evaluated. Two household soaps (“Palmida” and “Koto”) and a detergent (“So Klin”) were first tested for their efficacy against the larvae under laboratory conditions. Then, the efficacy of the most effective soap was evaluated in field conditions, along with PlantNeem (neem oil), Dezone (diatomaceous earth), and Emacot 19 EC (emamectin benzoate), in two districts, N’Dali and Adjohoun, located, respectively, in northern and southern Benin. The soaps and the detergent were highly toxic t second-instar larvae with 24 h lethal concentrations (LC₅₀) of 0.46%, 0.44%, and 0.37% for So Klin, Koto, and Palmida, respectively. In field conditions, the biorational insecticides produced similar or better control than Emacot 19 EC. However, the highest maize grain yields of 7387 and 5308 kg/ha were recorded, respectively, with Dezone (N’Dali) and Emacot 19 EC (Adjohoun). A cost-benefit analysis showed that, compared to an untreated control, profits increased by up to 90% with the biorational insecticides and 166% with Emacot 19 EC. Therefore, the use of Palmida soap at 0.5% concentration, neem oil at 4.5 L/ha, and Dezone at 7.5 kg/ha could provide an effective, environmentally friendly, and sustainable management of S. frugiperda in maize.

Bacterial wilt (BW) is caused by Ralstonia solanacearum species complex (RSSC) and can lead to severe losses in a wide range of crops, including many traditional African vegetables (TAV). Given the critical role of TAV in African food security, investigations of BW incidence, distribution, and effective breeding strategies are needed to support public and private TAV breeding programs. In this review, we address key questions related to the diversity of BW pathogens, susceptible TAV hosts, distribution, incidence, breeding strategies, sources of resistance, and gaps in the development of resistant TAV varieties in Africa. We also discuss the potential of multiomics integration to enhance our understanding of the host plant defense system against BW in Solanaceae crops. We curated BW strain databases obtained from several online platforms, representing a total of 948 BW strains. Using a refined database, we highlighted the diversity of RSSC and TAV crops affected by RSSC in different regions of Africa. Out of 29 species documented to be affected by BW in Africa, ten are TAV, including widely consumed TAV such as Amaranths and nightshades. In addition, phylotypes I and III are reported to affect TAV, and the incidence can reach up to 72.4% in farmers’ fields. An overview of the first reports revealed that the disease has become a serious threat to TAV in the past decade. Finally, this review proposes a schematic map of possible avenues for successful breeding of BW-resistant TAV using Gboma eggplant as a case study.

Bacterial wilt, caused by Ralstonia solanacearum, is an emerging constraint in amaranth production in Benin. Host resistance is the most sustainable disease control measure. Ten amaranth varieties including A2002, Bresil (B) -Sel, Madiira 2, AC-NL, GARE ES13-7, Madiira 1, UG-AMES13-2, AM-NKGN, IP-5-Sel and a local variety from Benin were screened for resistance to bacterial wilt. The study was conducted in a screen house and in the naturally contaminated open field during a consecutive rainy and dry season using a randomized complete block design with four and three replications, respectively. In the screen house, plants were inoculated by drenching a 40 mL of bacterial suspension containing 10⁸ CFU/mL of R. solanacearum strain NCBI 5 GenBank N° MH397250 at the collar region. The bacterial wilt incidence (BWI) and the area under the disease progress curve (AUDPC) suggested differential reactions of amaranth varieties to the pathogen. BWI and AUDPC were low for UG-AMES13-2, moderate for Madiira 2, AM-NKGN and the local variety and very high for A2002, Bresil (B) -Sel, AC-NL, GARE ES13-7, Madiira 1 and IP-5-Sel. The World Vegetable Center’s UG-AMES13-2 can be considered as first choice, which is resistant to R. solanacearum, and should be scaled up for seed production towards supporting farmers.

Tomato (Solanum lycopersicum L.) is one of the most important vegetables in Togo. Unfortunately, tomato is susceptible to many diseases, among which bacterial wilt caused by Ralstonia solanacearum causes major yield losses. In this study, incidence of bacterial wilt and its distribution was evaluated in the central region of Togo, the major tomato-producing area in the country. Overall, 16 localities were surveyed in four prefectures. In each locality, three fields were visited, the incidence of the disease was recorded, and diseased samples were collected for laboratory investigation. The results showed that bacterial wilt occurred in all of the fields visited, indicating a field incidence of 100%, whereas the plant incidence ranged from 10.00 ± 00 to 43.33 ± 3.33%, with an average of 20.94 ± 1.77%. The antibody-based ImmunoStrip test was positive for R. solanacearum in 100% of the visited fields. From 144 samples collected from fields, 45 R. solanacearum isolates were isolated on modified selective medium from South Africa. These survey results show that tomato bacterial wilt is a real threat to tomato production in the central region of Togo.