Secondary metabolite effects of different cocoa genotypes on feeding preference of the mirid Sahlbergella singularis Hagl

Sahlbergella singularis is a major insect pest of cocoa in Cameroon. Conventional insecticides remain the most widely used option for mirid control, which unfortunately have adverse effects on the environment and human health. Improved methods of controlling this species, both environmentally friendly and inexpensive to farmers, are requirements. Varietal control based on the selection of resistant and/or tolerant genotypes can be an interesting approach. Nonetheless, the role of secondary metabolites (SMs) in cocoa defense against mirids is poorly documented; yet, these compounds are reported to be key elements in plant defense against herbivores. For this purpose, SMs of twelve cocoa genotypes were identified and quantified, as well as their impact on food preference by mirids. Food preference was assessed through microtests measuring cocoa attractiveness and antixenosis toward mirids. The results showed that cocoa genotypes were differently accepted as food by mirids, with a significant preference for hybrid IMC60 x SNK605 and a non-preference for T60/887. The ten other cocoa genotypes showed intermediate results. Five SMs classes: alkaloids, flavonoids, polyphenols, saponins, and tannins were identified. Their rates varied between cocoa genotypes: polyphenols > alkaloids > flavonoids > tannins, and saponins. Cocoa genotypes with high total phenolic contents were significantly preferred by S. singularis (rα = 0.86, R2 = 74.0%, P < 0.001), while those with low saponins contents were lowly accepted (rα = − 0.83, R2 = 68.9%, P < 0.015), independently of the levels of other SMs. Given SMs high potential to affect mirid feeding behavior, analyzing cocoa SMs composition may help in early selection of resistant cocoa varieties against S. singularis

Modulation of carotenoid/flavonoid profiles and sugar content of a potential functional citrus-based food through crossflow microfiltration

Crossflow microfiltration was implemented to enrich a clementine/pink grapefruit juice in carotenoids, flavonoids and pectins modulating its sugar content thanks to an added diafiltration step. Using tubular ceramic membrane with pore diameter of 0.2 μm at 30–40 °C, a crossflow velocity of 5 m‧s−1 and a transmembrane pressure of 2.6 bar, the impact of the process was assessed focusing on bioactive compounds and physical characteristics of the concentrates. With permeate flux above 30 kg‧h−1‧m−2, the process resulted in an increase of 8–10 times in the content of provitamin A carotenoids (33 mg‧kg−1 in the final products), lycopene (43 mg‧kg−1), hesperidin (3.2 g‧kg−1) and pectin (5.5 g‧kg−1) giving a unique and interesting composition profile. Moreover, diafiltration divided the sugar content by 3. This can be relevant for the product to be recommended as part of a reduced sugar diet for diabetic people. By modelling the retention of bioactive compounds, we showed that it was possible to modulate sugar, flavonoids, carotenoids and pectin contents in the concentrate that could be a key issue for the biological activity of this potential functional citrus-based food

Morphophysical and biochemical traits involved in maize grain varietal susceptibility to the maize weevil, Sitophilus zeamais (Coleoptera, Curculionidae)

Description of the subject. Maize (Zea mays L.) is a major staple food providing nutrients for humans and animals worldwide. In Sub-Saharan Africa, maize is stored to ensure food resource availability throughout the year. However, stored-product pests such as the maize weevil, Sitophilus zeamais (Motsch.) (Coleoptera; Curculionidae) can cause huge grain losses. Objectives. This study aimed to assess the oviposition preference of Sitophilus zeamais over maize varieties commonly cultivated in Senegal and the effect of grain morphophysical and biochemical characteristics on their susceptibility to the maize weevil. Method. Twenty-five S. zeamais pairs (M/F) were placed in the center of an arena at equal distance of small heaps of maize grains (30 g) from nine maize varieties. Adult abundance, damaged grains, grain weight loss, and progeny were confronted to grain characteristics (phenolics and ferulic acid content, hardness, brightness, color and size of grains). Results. Susceptibility to the maize weevil varied significantly among maize varieties. Synth-9243 was the most susceptible variety with greatest damaged grains (10.5 ± 2.3%), grain weight loss (2.3 ± 0.6%), and progeny (17.3 ± 3.8 adults). The least susceptible varieties were Across-Pool, SWAN, Obatampa, and Tzee-Yellow. Grain characteristics such as phenolics and ferulic acid content were negatively related to susceptibility, but other constituents may have antixenosis or antibiosis effects. In addition, grain brightness may also have a visual effect deterring oviposition. Conclusions. The most repellent and less favorable varieties for S. zeamais were Tzee-Yellow, Across-Pool, Obatampa and SWAN, that presented high content of phenolics and ferulic acid, hardness and brightness of grains

Shifting from sectoral to integrated surveillance by changing collaborative practices: Application to west nile virus surveillance in a small Island State of the Caribbean

After spreading in the Americas, West Nile virus was detected in Guadeloupe (French West Indies) for the first time in 2002. Ever since, several organizations have conducted research, serological surveys, and surveillance activities to detect the virus in horses, birds, mosquitoes, and humans. Organizations often carried them out independently, leading to knowledge gaps within the current virus' situation. Nearly 20 years after the first evidence of West Nile virus in the archipelago, it has not yet been isolated, its impact on human and animal populations is unknown, and its local epidemiological cycle is still poorly understood. Within the framework of a pilot project started in Guadeloupe in 2019, West Nile virus was chosen as a federative model to apply the “One Health” approach for zoonotic epidemiological surveillance and shift from a sectorial to an integrated surveillance system. Human, animal, and environmental health actors involved in both research and surveillance were considered. Semi-directed interviews and a Social Network Analysis were carried out to learn about the surveillance network structure and actors, analyze information flows, and identify communication challenges. An information system was developed to fill major gaps: users' needs and main functionalities were defined through a participatory process where actors also tested and validated the tool. Additionally, all actors shared their data, which were digitized, cataloged, and centralized, to be analyzed later. An R Shiny server was integrated into the information system, allowing an accessible and dynamic display of data showcasing all of the partners' information. Finally, a series of virtual workshops were organized among actors to discuss preliminary results and plan the next steps to improve West Nile Virus and vector-borne or emerging zoonosis surveillance. The actors are willing to build a more resilient and cooperative network in Guadeloupe with improved relevance, efficiency, and effectiveness of their work

A importância de uma marca coletiva na construção de territorios: O caso da associação acolhida na colônia/SC/Brasil

Objetiva-se avaliar o processo de construção da Acolhida na Colônia e a adoção, por ela, da estratégia “Sinais Distintivos” enquanto contribuição e consolidação do território das Encostas da Serra Geral, situado no Sudeste do estado de Santa Catarina, no Sul do Brasil, através do fortalecimento de alguns atributos territoriais (Identidade territorial, pertencimento e capital social). Foram realizados revisão bibliográfica, levantamento e análise de trabalhos acadêmicos e de documentos administrativos e coleta de dados de campo. Conclui-se que as estratégias utilizadas para implantar o agroturismo, as ações da Associação de Agroturismo e a efetividade de sua marca são elementos fundamentais para a construção do território, sobretudo pela sua contribuição para o fortalecimento do capital social, do sentimento de pertencimento e do reconhecimento da identidade territorial

Percepción de agricultores y personal técnico sobre adopción de prácticas agroecológicas en municipios de la provincia de Holguín, Cuba

El objetivo fue conocer la percepción de agricultores y personal técnico sobre la adopción de prácticas agroecológicas en los municipios de Báguanos, Banes y Gibara de la provincia de Holguín; como contribución para propiciar debates en los tomadores de decisiones respecto al mejoramiento de los incentivos. Se realizaron 74 entrevistas a agricultores y a técnicos en los municipios y la información obtenida fue procesada con análisis estadísticos descriptivos con el software XLSTAT 2014. Los resultados muestran diferentes conceptualizaciones de la Agroecología, el predominio de prácticas para la conservación del suelo y recomendaciones del incremento de incentivos para el fomento de alternativas agroecológicas

The 4 per 1000 goal and soil carbon storage under agroforestry and conservation agriculture systems in sub-Saharan Africa

The 4‰ initiative launched by the French government at COP21 in Paris in December 2015 aspires to increase global soil organic carbon (SOC) stocks at a rate of 0.4% per year. We conducted a systematic literature review on SOC storage under agroforestry and conservation agriculture systems in sub-Saharan Africa, where we reported 66 and 33 cases for both systems respectively. The results showed that SOC storage rates were significantly higher than 4‰ yr−1 in fallows and in multistrata agroforestry systems (P = 0.0001 and 0.0178, respectively), but not in alley cropping and parklands systems. For conservation agriculture, SOC storage rates were only significantly higher than 4‰ yr−1 (P = 0.0438) when all three principles were applied, i.e. no- or minimum tillage combined with crop residue retention and intercropping or rotation. The data showed very large variability in SOC storage rates as the result of various factors, including previous land-use history, experimental set up and approach used to determine SOC storage (diachronic versus synchronic approach), soil type, depth of soil sampling, type of crops and management, and duration of the experiment. SOC storage rates significantly decreased with time in the agroforestry systems (P = 0.0328). However, we were unable to find significant relationships with initial SOC stocks or tree density. Given the limited published data and the high variability in results, no significant relationships between SOC storage rates and site variables were found for conservation agriculture. We argue that there is a potential for SOC storage in agricultural soils of sub-Saharan Africa, as illustrated by SOC gaps observed on smallholder farms. Low SOC levels are, however, to a great extent the result of limited resources of most smallholder farmers. Practices such as agroforestry and conservation agriculture can restore SOC in these soils, but the 4‰ initiative has to be implemented on the grounds of the positive impact on crop productivity rather than on climate change mitigation. The efficiency in doing so will depend on the specific situations and will need economic support to smallholder farmers, including the promotion of good markets for sale of extra produce and for input supply, effective private support and policy, such as credit schemes and subsidies for inputs, and efficient extension services which incentivize farmers to invest in new technologies

An integrated diagnostic setup for the morphological and molecular identification of the Ceratitis FAR complex (C. anonae, C. fasciventris, C. rosa, C. quilicii, Diptera, Tephritidae)

The Ceratitis FAR complex (Diptera, Tephritidae) includes four economically important frugivorous flies (Ceratitis anonae, Ceratitis fasciventris, Ceratitis quilicii, Ceratitis rosa) whose immature stages and adult females cannot be properly resolved through morphological identification. In order to develop a simplified molecular tool for the identification of two of these species (C. rosa, C. quilicii), we selected a subset of six microsatellite markers out of a panel of 16 loci that were previously developed for the molecular differentiation of the taxa within the complex. These six markers were first tested in silico and then used for the actual genotyping of C. quilicii and C. rosa, resulting in the correct identification of all male reference specimens. Here, we propose an integrated morphological and molecular setup for the identification of the four species of the FAR complex. The decision map relies on preliminary DNA barcoding or morphological identification (when possible) to exclude species not belonging to the complex followed by (a) morphological identification of all adult male specimens and female C. anonae, (b) molecular identification via a panel of 16 microsatellite markers for immature stages, damaged vouchers and samples potentially including adult female C. fasciventris/C. quilicii/C. rosa and (c) molecular identification via a reduced panel of six microsatellite markers for samples including only C. quilicii and C. rosa. This simplified diagnostic setup was profitably implemented in the framework of the ERAfrica fruit fly project and will help correctly identify species within the FAR complex for their early detection and monitoring

Securing aquaculture-related resources through social interaction in the Pampanga river delta, Philippines: An ethnogeographic perspective on the strengths and pitfalls of social capital

Social relationships play a pivotal role in agricultural systems because they influence the economic behavior of stakeholders, but sociological studies aimed at understanding these links have until now not focused much on aquaculture. Here we examine how social capital among communities of the Pampanga River delta in the Philippines plays out in the conduct of aquatic livestock breeding, harvesting, and trading, and how it either facilitates or restrains the transformation of individual livelihoods. Relying on a mixed method of field surveys, participant observation, and questionnaires, we construct an ethnographic portrayal of how the main categories of stakeholder involved in aquaculture (from livestock producers to traders via landless gleaners) elaborate strategies to access or control aquaculture‐related resources. We show that the bonding and bridging efforts to construct social capital are strongly embedded in the cultural matrix, and that they are limited by environmental constraints (ecosystem carrying capacity, exposure to natural hazards) and shaped by historical legacies. The resulting pattern of social interactions is overall successful at buffering the negative impact of external forcing factors such as environmental hazards and global market crashes, but we also show how the different outcomes of social exchange are nonetheless unevenly distributed across the spectrum of stakeholders

Modeling dynamics and adaptation at operational and structural scales for the ex-ante economic evaluation of large dams in an African context

Dams can produce electricity and ensure water security, but at the same time they radically alter the hydrological regime of rivers with significant consequences for the economic and environmental welfare of the region in which they are located. Cost-benefit analysis (CBA) is currently the most frequently used framework for the economic evaluations of dams. Changes at different time scales influence the economic appraisal of dams. However, change and adaptation at both the operational and the structural level are often not included in the CBA evaluation. Not including change and adaptation limits the realistic estimation of cost and benefits, and the appreciation of resilient solutions that offer satisfactory responses for a large set of future scenarios. In this paper we consider the specific features of large dams in an African context, and identify methods for an economic evaluation that takes into account for change and adaptation at both the operational and the structural scales, as well as their interplay. These methods are then applied to the ex-ante evaluation of a system of existing dams on the Senegal River Valley. Results indicate the economic potential of the dams under changing conditions, for both adaptive and non-adaptive reservoir operation strategies