Impact of salinity on the production of tomato along the coastal areas of Benin Republic

The coast of Benin lies on a wide bay in the Gulf of Guinea called the Bight of Benin, about 125 km  between Togo and Nigeria. The coastal areas of Benin cover part of the cultivable lands of the country. A  total of 15 tomato varieties were recorded in the areas of study. The characteristics of each variety grown  under salinity were also recorded based on the assessment of farmers. Salinity causes unfavorable  conditions that restrain the normal crop production. The factors that contribute significantly to salinity were  soil salinity, wet breeze from high tide especially between June to August and direct watering of crop with  saline water. The wetted foliage of growing tomato absorbed the salts directly. The results obtained also  show that salinity in the coastal areas of Benin affected tomato growth, leaf length, and number of leaves,  which reduced yields and in severe cases, total yield was lost. Two varieties (aclinkon and petomèche)  seemed to be tolerant to salinity because of their average yield. Due to the heavy losses in tomato  production, producers were eager to be supplied with new varieties tolerant to salinity. Henceforth, it was  imperative to have an evaluation of the coastal areas of Benin affected by the salinity.Key words: Coastal areas, tomato production, salinity, wet breeze, high tide

Distribution, pathological and biochemical characterization of Ralstonia solanacearum in Benin

In 2006 and 2007, 75 strains of Ralstonia solanacearum were collected from wilting tomato, pepper and eggplant in Benin. The distribution and the incidence of tomato bacterial wilt in the field were assessed by counting wilted tomato plants on 3 plots of 50 m2 per field. The isolated bacterial strains, including the reference strain, were identified using ELISA, pathogenicity test and carbohydrate oxidation. Bacterial wilt is widely distributed in Benin and was found in five of the eight agro-ecological zones (AEZ) of Benin, which correspond to eight of the 12 districts of Benin. The disease was more severe in ferralitic soil (AEZ V), in valleys and lowlands (AEZ IV) and in highlands (AEZ I). The incidence of tomato bacterial wilt was up to 71%. No R. solanacearum strains were isolated from AEZ II, AEZ VII and AEZ VIII. Strains identified as R. solanacearum were more widely distributed in the south than the center and the north of Benin. Based on biochemical characteristics, Beninese R. solanacearum strains were grouped into biovar I/race1 and biovar III/race 1

Diallel analysis of cowpea (Vigna unguiculata (L.) Walp.) genotypes under water deficit stress

Abstract Combining ability is referred to as the hybridization value of the parental genotypes involved in the crossing to develop hybrids. The best parents are selected through combining ability methods and subsequently used to produce high yielding and resistant hybrids. Thus, the objectives of this study were to (i) understand the nature and action of genes controlling water deficit tolerance, and (ii) identify superior genotypes from the genetic breadth provided by hybridization in cowpea. Twenty-four genotypes were subjected to normal irrigation and water deficit condition to examine combining ability, genotypic and phenotypic correlations for traits directly related to water deficit (proline and chlorophylls), grain yield and yield components. The results showed the presence of the action of additive and non-additive genes under both water regime conditions. However, there was the predominance of the action of additive genes for most of the traits studied under both conditions. The parents KVX61-1, IT06K242-3, IT07K-211–1-8, Kpodjiguèguè, IT99K-573–1-1, Tawa and IT97K-206–1-1 were observed to be good general combiners for proline content, chlorophyll content and traits associated with yield, while KVX61-1 × KVX396-18, IT06K242-3 × KVX396-18, IT07K-211–1-1 × KVX396-18, Kpodjiguèguè x KVX396-18, KVX61 -1 × IT97K-206–1-1, IT06K242-3 × IT97K-206–1-1, IT07K-211–1-1 × IT97K-206–1-1 and Kpodjiguèguè x IT97K-206–1-1 were proven to be the best specific combiners for traits directly related to water deficit tolerance and yield. It should be noted that number of days to pod maturity, pod length, number of pods per plant and weight of hundred seeds were highly heritable traits in this study

Onion (Allium cepa L.) and Drought: Current Situation and Perspectives

Onions (Allium cepa L.) are the second most commonly produced and consumed vegetable worldwide due to their economic, nutritional, and medicinal benefits. However, drought hinders vegetative growth, lowers yields and bulb quality, reduces photosynthetic activity, and alters the onion plant’s metabolism. This review provides a summary of global research on the impact of drought on onions. It specifically seeks to shed light on aspects that remain unclear and generate research avenues. Relevant scientific articles were sourced from the AGORA database, Web of Science (WoS), and search engines such as Google Scholar, Scopus, MEDLINE/PubMed, and SCImago to achieve this objective. A total of 117 scientific articles and documents related to onion and drought were critically examined. The review revealed agromorphological, physiological, biochemical, and genomic studies depicting factors that contribute to drought tolerance in onion genotypes. However, there was little research on the physiological, biochemical, and genetic characteristics of drought tolerance in onions, which need to be deepened to establish its adaptation mechanisms. Understanding the mechanisms of onion response to water stress will contribute to fast-tracking the development of drought-tolerant genotypes and optimize onion production. Future research should be more focused on investigating onion drought tolerance mechanisms and structural and functional genomics and identifying genes responsible for onion drought tolerance

Assessment of production and marketing constraints and value chain of sweet potato in the municipalities of Dangbo and Bonou

Abstract Background Sweet potato [Ipomoea batatas (L.) Lam.] plays an important role in ensuring food security and incomes for local communities. It is particularly grown in southern region of Benin, and its production over the last few years has declined due to disease and severe pest infestation. Therefore, it was imperative to carry out this study to identify the main constraints related to the recent decline in sweet production and more specifically analyzing the production and marketing constraints of sweet potato in the townships of Dangbo and Bonou. Results The results of the survey revealed that many varieties of sweet potato were grown, mainly “Vobodouaho” (local name in Goun language), the most preferred variety by producers. Weedicides and insecticides were used to control weeds and insect pests, respectively. There was no efficient control methods against black rot, Alternaria blight, cylas spp., and caterpillar among the pathogens and insects that damaged sweet potato production in the study areas. The main constraints reducing sweet potato production in the townships of Dangbo and Bonou are: lack of adequate methods for controlling pest and diseases, lack of financial resources due to no access to credit, absence of modern equipment, scarcity and high cost of labor and absence of best methods for long-term storage. The average yield of sweet production per hectare ranged from 6.5 to 15.1 tons fresh matter/ha. The market value of sweet potato is still low at farmers’ level when compared to that of other stakeholders along the value chain. Conclusion This study calls for the attention of public and private sectors and policy makers for more investment in sweet potato research. Avenues for further research on sweet potato have also been suggested

Influence of the programmed cell death of lymphocytes on the immunity of patients with atopic bronchial asthma

BACKGROUND: Fairly recent data highlight the role of programmed cell death and autoimmunity, as potentially important factors in the pathogenesis of chronic obstructive airway diseases. The purpose of our research was to determine the influence of apoptotic factors on the immunity of patients with atopic bronchial asthma according to the degree of severity. METHOD: The study was performed on the peripheral blood of patients with atopic bronchial asthma with different severity. The Immunological aspects were determined with ELISA, the fluorimetric method and the method of precipitation with polyethylene glycol. And the quantification of the parameters of the programmed cell death was performed by the method of flow cytometry and electron microscopy method. RESULTS: The data obtained from morphological and biochemical parameters show the deregulation of Programmed Death of lymphocytes of patients with atopic bronchial asthma but individual for each group of patients. This dysfunction might induce the secretion of autoantibodies against DNA. This could explain the accumulation of circulating immune complex with average size considered as the most pathogenic in patients with bronchial asthma especially in the patients of serious severity. It should be noted that Patients with bronchial asthma of mild and severe severity had different way and did not have the same degree of deficiency of the immune system. CONCLUSION: These data suggested that apoptotic factor of lymphocytes may play an important role in controlling immunity of patients with atopic bronchial asthma