Etude de l’effet de la date de semis et de l’age des plantules au repiquage sur le rendement de trois varietes de riz adoptees dans les perimetres irrigues villageois des regions de Tombouctou et de Gao

Les périmètres irrigués villageois (PIV) sont utilisés pour atténuer les effets néfastes des changements climatiques. Les variétés cultivées dans les PIV sont d’origine asiatique et souffrent des conditions agro climatiques des régions nord du Mali. Les expérimentations ont été conduites en milieu paysan dans les PIV de Tombouctou et de Gao afin de sélectionner des variétés ayant les caractéristiques désirables des producteurs. Sept paysans ont été sélectionnés par site pour la conduite des tests. Trois variétés de riz WARDA Sahel (WAS) et la variété Nionoka (témoin) ont été testées. Le dispositif expérimental utilisé était le factoriel en blocs dispersés avec comme facteur principal variétés et facteurs secondaires date de semis et l’âge des plantules au repiquage. La collecte des données a porté sur la variable rendement. Le logiciel GENSTAT version 4.0 a été utilisé pour l’analyse des données. Le test de Student-Newman-Keuls au seuil de 5% a été utilisé pour la séparation des moyennes à l’aide du logiciel SPSS version 17.0. Sur l’ensemble des sites, la variété SUTURA a enregistré le bon rendement. La période propice de semis des pépinières des trois variétés est la première quinzaine du mois de juillet. L’âge limite de repiquage des plantules est de 30 jours.Mots clés : Périmètre Irrigué Villageois (PIV), Variétés de riz, Rendement, Date de semis et Age des plantules au repiquag

Utilisation des facteurs climatiques pour la surveillance de la fréquence des occurrences de méningite/ paludisme à Bamako

Objectif : Notre travail consiste à : Déterminer les périodes de risque pour la méningite et le paludisme à Bamako; Etablir une corrélation entre : - d’une part les paramètres météorologiques (température de l’air, humidité relative de l’air, pluviométrie, insolation et vitesse du vent) et la fréquence des occurrences de paludisme ; - d’autre part les mêmes paramètres pour la méningite. Méthode : Nous avons fait une étude rétrospective de l’évolution du paludisme et de la méningite en fonction de la variation des paramètres météorologiques (température de l’air, humidité relative de l’air, pluviométrie, insolation et vitesse du vent) à Bamako. Résultats : Le paludisme, rare au 1er et 2èm trimestres, est très fréquent au 3è trimestre et au 4è trimestre. Quant à la méningite elle est fréquente au premier semestre et rare pendant le reste de l’année. La fréquence du paludisme est liée à la température moyenne de l’air, à la grande humidité de l’air, à la pluviométrie abondante, à la faible insolation et à la faible vitesse du vent. La fréquente de la méningite est liée à la haute température de l’air, à la faible humidité de l’air, à la faible pluviométrie, à la forte insolation et à la grande vitesse du vent. Conclusion : La fréquence du paludisme est liée à la grande humidité, et à la faible insolation. Quant à la méningite, sa fréquence est liée à la haute température, à la grande vitesse du vent et à la forte insolation

A simple soil organic-matter model for biomass data assimilation in community-level carbon contracts

Soil carbon (C) sequestration has been proposed as a transitional win-win strategy to help replenish organic-matter content in depleted agricultural soils and counter increases in atmospheric greenhouse gases. Data assimilation and remote sensing can reduce uncertainty in sequestered C mass estimates, but simple soil organic carbon (SOC) models are required to make operational predictions of tradeable amounts over large, heterogenous areas. Our study compared the performance of RothC26.3 and a reduced compartmental model on an 11-year fertilizer trial in subhumid West Africa. Root mean square error (RMSE) differences of 0.05 Mg C/ha between models on total SOC predictions suggest that for contractual purposes, SOC dynamics can be simulated by a two-pool structure with labile and stable components. Faster (seasonal) and slower (semicentennial and beyond) rates can be approximated by constants as instantaneous and infinite decay. In these systems, simulations indicate that cereal residue incorporation holds most potential for mitigation of transient C loss associated with recent land conversion to agriculture

First Detection of Leishmania major DNA in Sergentomyia (Spelaeomyia) darlingi from Cutaneous Leishmaniasis Foci in Mali

Leishmania major complex is the main causative agent of zoonotic cutaneous leishmaniasis (ZCL) in the Old World. Phlebotomus papatasi and Phlebotomus duboscqi are recognized vectors of L. major complex in Northern and Southern Sahara, respectively. In Mali, ZCL due to L. major is an emerging public health problem, with several cases reported from different parts of the country. The main objective of the present study was to identify the vectors of Leishmania major in the Bandiagara area, in Mali. Methodology/Principal Findings: An entomological survey was carried out in the ZCL foci of Bandiagara area. Sandflies were collected using CDC miniature light traps and sticky papers. In the field, live female Phlebotomine sandflies were identified and examined for the presence of promastigotes. The remaining sandflies were identified morphologically and tested for Leishmania by PCR in the ITS2 gene. The source of blood meal of the engorged females was determined using the cyt-b sequence. Out of the 3,259 collected sandflies, 1,324 were identified morphologically, and consisted of 20 species, of which four belonged to the genus Phlebotomus and 16 to the genus Sergentomyia. Leishmania major DNA was detected by PCR in 7 of the 446 females (1.6%), specifically 2 out of 115 Phlebotomus duboscqi specimens, and 5 from 198 Sergentomyia darlingi specimens. Human DNA was detected in one blood-fed female S. darlingi positive for L. major DNA. Conclusion: Our data suggest the possible involvement of P. duboscqi and potentially S. darlingi in the transmission of ZCL in Mali

Implementing Preventive Chemotherapy through an Integrated National Neglected Tropical Disease Control Program in Mali

Neglected tropical diseases (NTDs) are a group of chronic infections that affect the poorest group of the populations in the world. There are currently five major NTDs targeted through mass drug treatment in the affected communities. The drug delivery can be integrated to deliver different drug packages as these NTDs often overlap in distribution. Mali is endemic with all five major NTDs. The integrated national NTD control program was implemented through the primary health care system using the community health center workers and the community drug distributors aiming at long-term sustainability. After a pilot start in three regions in 2007 without prior examples to follow on integrated mass drug administration, treatment for the five targeted NTDs was gradually scaled up and reached all endemic districts by 2009, and annual drug coverage in the targeted population has since been maintained at a high level for each of the five NTDs. Around 10 million people received one or more drug treatments each year since 2009. The country is on the way to meet the national objectives of elimination or control of these diseases. The successes and lessons learned in Mali are valuable assets to other countries looking to start similar programs

Disaggregation of SMOS soil moisture over the Canadian prairies

In this study, we used the Disaggregation based on Physical And Theoretical scale Change (DISPATCH) algorithm under very wet soil conditions in Western Canada for the disaggregation of coarse resolution 40-km soil moisture derived from the Soil Moisture Ocean Salinity (SMOS) satellite. The algorithm relies on the Soil Evaporative Efficiency (SEE), which was estimated using the 1-km resolution data from the MODerate resolution Imaging Spectoradiometer (MODIS). The study aimed to: (i) evaluate DISPATCH under wet soil conditions, (ii) test the linearity/non-linearity of the relationship between soil moisture and SEE, and (iii) propose a more robust procedure to calibrate the SEE model under very wet soil conditions. The disaggregated soil moisture values were compared to 0-5 cm in situ measurements and the soil moisture derived from the L-MEB (L-band Microwave Emission of the Biosphere) model from airborne brightness temperature at 1.4 GHz collected during the Canadian Experiment for Soil Moisture in 2010 (CanEx-SM10) field campaign. The results show a correlation between 0.7 and 0.8 and bias values similar to 0 m(3)/m(3). The DISPATCH algorithm shows better disaggregation results under very wet soil conditions when a non-linear relationship is considered between SEE and soil moisture instead of a linear model. This is mainly due to the small variability of surface temperature inside the area covered by the SMOS pixel under very wet soil conditions, and the difficulty in accurately estimating the maximum soil temperature (Ts-max), which is a driving factor for SEE. A sensitivity analysis was conducted and it shows that the linear model performs well only if Ts-max can be determined more accurately. The possibility to determine Ts-max using high resolution MODIS data over a larger area than the SMOS pixel is examined and discussed in the paper