37 research outputs found
Analyses of labour productivity among small-holder cassava farmers for food security and empowerment in central Madagascar
Open Access JournalLabour productivity affects food security, but quantifying this relationship has been scarce with respect to empirical literature. The Central Madagascar dataset explores the influence of labour productivity and related variables on the food security status of cassava farmers. Drawing on both theory and empirical
evidence, this paper argues that fundamental effects of links between labour productivity and food security are most times often overlooked currently in policy analyses. The study used a probit regression analytical procedure to explain the effect of labour productivity on food security of 180 Malagasy smallholder
cassava farmers selected through a multi-stage random sampling technique. Results showed that 25% of the cassava farmers were food in-secure. Labour productivity had a direct relationship with food security status of farmers at 1% level of probability as well as membership of cooperatives and farm size. Aged farmers were more food insecure at 10% level of probability than their younger counterparts. Households with high dependency ratio and family labour tend to be food insecure at 1% and 10% level of probability respectively among the farmers sampled. The results therefore call for land re-distribution and re-form policies aimed at encouraging younger farmers who seem to be more labour productive by allocating
more land to these group (as cooperatives) to increase cassava cultivation thereby giving a boost to food security
Effect of transaction costs on market participation among smallholder cassava farmers in Central Madagascar
High transaction costs deter entry of small farmers into the market. With the data from 240 smallholder cassava farmers in Central Madagascar, this study identified strategies to promote successful smallholder commercialization. The coefficients for membership of cooperatives, native of community and farming experience, have a direct relationship with decision to participate in the market and which is significant at 1% level and road condition to the nearest town is good at 10% level. The coefficients for age, distance to the nearest town and distance from the farm to the market have an indirect relationship with decision to participate in the market and significant at 5, 10 and 1% levels, respectively. The results also show that the coefficients for personal means of transportation and marketing experience have a direct relationship with decision to sell cassava off-farm and at 10 and 1% level of significance, respectively, while distance to the nearest town and distance from the farm to the market had an indirect relationship with decision to sell off-farm at 5% level of significance each and cost of transportation at 1% level. The study raises policy issues which might reduce these transaction costs by providing more market outlets, better rural infrastructure and also bulking centres
Malagasy traditional treatments of infectious plant diseases exert anti-virulence activities against Pseudomonas aeruginosa and Ralstonia solanacearum
peer reviewedTraditional Malagasy farmers have developed a range of biological methods to restrict plant diseases without reliance on external or
synthetic inputs. Five common Malagasy traditional practices demonstrated to be efficient against potato crop bacterial disease in
experimental fields have been investigated for their antibacterial (i.e. bacteriostatic and bactericidal effects) and anti-virulence (i.e. antiquorum
sensing and anti-biofilm) activities against two phytopathogens, Pseudomonas aeruginosa and Ralstonia solanacearum. Results
show that polar (methanolic) extracts of recipes exert anti-virulence activities rather than bacteriostatic and/or bactericidal activities.
Indeed, three recipes (R5, R7 and R9) reduce the expression of QS-dependent virulence factors whereas only recipe (R5) exhibit antibiofilm
activities without affecting bacterial growth. R4 and R6 were not active, suggesting other bacterial targets and/or other
bioactivity properties. Innovative approaches, inspired from ancestral practices, should be considered in the struggle against infectious
diseases to limit the overuse of antibiotics for controlling infectious plant diseases and to reduce the overspread of multidrug resistant
bacteria
An active fraction from Dalbergia trichocarpa Baker disrupts the formation and maintenance of biofilms in Pseudomonas aeruginosa PAO1
peer reviewedThe bark of Dalbergiatrichocapra Baker is traditionally used in Madagascar as an anti-infective remedy. Beyond the recently known anti-quorum sensing (QS) properties of the D. trichocarpabark n-hexane extract, QSindependent anti-infective activities have been also detected. Indeed, chromatographic fractionation allowed the elution of fraction F1 that affects neither bacterial growth nor the expression of QS-related genes (lasB and rhlA) but significantly reduces the formation of biofilm (55.8 ± 2.3%, as compared to control conditions). Moreover,F1 is able to disrupt the structure of one-day old preformed biofilms, which consequently increases the effectiveness of an antibiotic, levofloxacin, on biofilm-encapsulated bacteria (dead bacteria in presence of levofloxacin-F1 were two-fold higher compared to levofloxacin alone). This F1-triggered disruption of biofilm formation is presumably due to an induced reduction in flagellar-dependent motilities (swimming and swarming) as well as in exopolysaccharides production. The inhibitory effect on biofilm appears reversible as the biofilm formation resumes when F1 is discarded from the culture medium. This interesting non-bactericidal mechanism of action may justify the traditional uses of D. trichocarpa in Malagasy medicine. Further work aims at identifying the compound(s) responsible for this biofilm disruption
Comportement à la fatigue de profilés laminés avec semelles de renfort rivetées. Rapport d'essais
Comparative study of p-extensions based on conventional assumed displacement and hybrid-Trefftz FE models
Support trees in vanilla agroforests of Madagascar: diversity, composition and origin
Abstract Trees in agroforestry systems provide multiple ecological and economic functions. Smallholder vanilla agroforests include shade trees common across agroforestry systems, and small-statured support trees carrying the vanilla vine. Support trees have received little scientific attention so far. The objectives of our study were to assess the diversity, composition and geographic origin of support trees in vanilla agroforestry systems of north-eastern Madagascar. The region is a global biodiversity hotspot, has been undergoing a rapid land-use change and produces a large share of the globally traded vanilla spice. The studied vanilla agroforests differed in land-use history: established either directly inside forest (forest-derived) or on land previously used for slash-and-burn agriculture (fallow-derived). Among the support trees, we found 122 species of which 25% were endemic to Madagascar. The species richness per plot was four times higher in forest-derived than in fallow-derived vanilla agroforests. The species distribution was particularly uneven in fallow-derived vanilla agroforests with one species ( Jatropha curcas ) comprising 52% of all individuals. In forest-derived vanilla agroforests, 44% of all trees were native or endemic to Madagascar, whereas in fallow-derived vanilla agroforests only 11% were native or endemic. We conclude that there is a considerable diversity among support trees in Malagasy vanilla agroforestry . The support tree diversity is strongly affected by land-use history. Fallow-derived vanilla agroforests currently have a comparatively low species richness, yet they can play an important role in land rehabilitation, and more emphasis on growing native and endemic tree species would contribute to aligning production with conservation goals
