Etude de l’influence des modes de transformation sur les teneurs en lycopène de quatre variétés de tomates de la région du nord du Burkina Faso

Les traitements thermiques visent à stabiliser les aliments pour de longues périodes de stockage. Ils induisent des variations dans la composition de l’aliment. Le présent travail a pour but d’évaluer l’influence des modes de transformation (séchage, cuisson) sur les teneurs en lycopène de quatre variétés de tomates (Mongal F1, Tropimech, Royale et Rio Grande) de la région nord du Burkina Faso. Les résultats en milligrammes de lycopène par gramme de tomates sont ainsi exprimés : Purée : Tropimech (0,065), Mongal F1 (0,028), Royale (0,051) et Rio Grande (0,045. Après les traitements on a noté les évolutions suivantes : Séchage à l’ombre : Tropimech (- 0.009), Mongal F1 (+0.009) Royale (-0.010) et Rio Grande (-0.009). Séchage solaire : Tropimech (-0.021), Mongal F1 (-0.007) Royale (-0.011) et Rio Grande (-0.014). Cuisson : Tropimech (-0.038), Mongal F1 (-0.014), Royale (-0.025) et Rio Grande (-0.024). Séchage solaire puis cuisson : Tropimech (-0.044),  Mongal F1 (-0.017), Royale (-0.038) et Rio Grande (-0.0035). Séchage ombre puis cuisson: Tropimech (-0.045),  Mongal F1 (-0.018), Royale (-0.035) et Rio Grande (-0.033). D’une  manière générale, les teneurs en lycopène ont subi une baisse au cours de la transformation.Mots clés : Tomates, lycopène, mode de transformation

Integrated nutrient and water management for sustainable food production in the Sahel

The symposium (2014) focused on the challenges of crop production faced by farmers in the Sahel region. The presentation covers a three-year fertilizer micro dosing (MD) project that was combined with rainwater harvesting (RWH). The techniques are assessed in terms of effects on crop production and family income. It also explores the “warrantage” or inventory credit system where harvested crops are stored and used as collateral to access loans and credit. With improving crop varieties, MD and RWH can increase yields up to 200%. There is no evidence that the process caused land degradation or yield decline, suggesting long term sustainability

Sustainable intensification of crop– livestock systems through manure management in eastern and western Africa: Lessons learned and emerging research opportunities

In the mixed farming systems that characterise the semi-arid zones of eastern and western Africa, low rural incomes, the high cost of fertilisers, inappropriate public policies and infrastructural constraints prevent the widespread use of inorganic fertilisers. As population pressure increases and fallow cycles are shortened, such organic sources of plant nutrients as manure, crop residues and compost remain the principal sources of nutrients for soil fertility maintenance and crop production. In this paper, the effect of manure on soil productivity and ecosystem functions and services is discussed. This is followed by highlights of the management practices required to increase manure use efficiency. We end with a discussion of emerging new research opportunities in soil fertility management to enhance crop–livestock integration. Although the application of manure alone produces a significant response, it is not a complete alternative to mineral fertilisers. In most cases the use of manure is part of an internal flow of nutrients within the farm and does not add nutrients from outside the farm. Furthermore, the quantities available are inadequate to meet nutrient demand on large areas. Research highlights have shown that efficiency is enhanced by different management practices including the timing and methods of manure application, its sources and integrated nutrient management. Research opportunities include analysing and understanding the ecosystem functions and services of manure use, the establishment of fertiliser equivalency for different manure sources, the assessment of the best ratios of organic and inorganic plant nutrient combinations, the crop–livestock trade-offs required to solve conflicting demands for feed and soil conservation and the use of legumes to enhance soil fertility and for animal feed. The establishment of decision support system guides and assessment of the economic viability of manure-based technologies in farmer-focused research are presented as powerful management tools intended to maximise output while preserving the environment in the mixed farming systems of the semi-arid zones

Climate applications and agriculture: CGIAR efforts, capacities and partner opportunities

Climate variability creates risk in rainfed farming. Risk in turn discourages investment by farmers, governments and development agencies. For instance, in dry regions recurrent droughts debilitate and destabilize poor, agricultural-based societies, and contribute to land degradation by reducing vegetative cover and water supplies. Drought triggers the exploitation of diminishing resources in order to survive (Cooper 2004). Climate change caused by global warming is likely to increase the frequency of climatic extremes in the future and result in changes in cropping practices and patterns over time and spac

Community implementation of human landing and non-human landing collection methods for Wuchereria bancrofti vectors

In the drive towards elimination of lymphatic filariasis, enhanced surveillance of vector mosquitoes requires sound sampling methods which can be easily implemented and accepted by communities. Several tools have been validated as alternatives to human landing catches (HLC) for this purpose, but little is known about their effectiveness compared to HLC in terms of the vector density patterns. This study aimed at assessing the efficiency of four mosquitoes collecting tools (HLC, Center for Diseases Control (CDC) light trap, Double Net trap, Window Exit trap). These four sampling tools were evaluated in three different villages (Bapla, Ouessa and Koudjo) in Burkina Faso, when mosquito collection was managed by local people in each community. The results showed that HLC remained the most effective collection method in terms of vector abundance in all villages, followed by double net traps. Except in Bapla, the double net trap collected more Anopheles than CDC light traps. Across the study, the prevalence of Wuchereria bancrofti infection was estimated to be 0.6% and observed only in Anopheles gambiae sensu stricto. The Double Net trap is the least expensive of all three methods and was well accepted by the community. In conclusion, double net traps can be recommended for communities to use for lymphatic filariasis (LF) vector surveillance program for xeno-monitoring of post transmission assessment survey evaluation. Based on prevalence the mass drug administration (MDA) could be stopped in these villages without risk of resurgence of the disease, according to the current recommendations of World Health Organization (WHO). Set up surveillance and continue to use vector control tools

Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift rather than genetic selection of SOR is the underlying driver of population differentiation, which has significant implications for the emergence and potential spread of SOR within and between these parasite populations

Vector control and entomological capacity for onchocerciasis elimination

Mass drug administration (MDA) of ivermectin is currently the main strategy to achieve elimination of onchocerciasis transmission (EoT). Modelling suggests that EoT may not be reached in all endemic foci using annual MDA alone. Onchocerciasis and loiasis are co endemic in forest areas of Central Africa, where ivermectin treatment can lead to severe adverse events in individuals with heavy loiasis load, rendering MDA inappropriate. Vector control has been proposed as a complementary intervention strategy. Here, we discuss: (i) achievements and pitfalls of previous interventions; (ii) epidemiological impact, feasibility and combination with MDA to accelerate and/or protect EoT; (iii) role of modelling; (iv) opportunities for innovative methods of vector monitoring and control, and (v) strengthening entomological capacity in endemic countries