Evaluation de l’effet repulsif d’extraits de neem (Azadirachta indica A. Juss., 1830) sur le charançon de la patate douce (Cylas puncticollis Boheman, 1833) en condition de laboratoire a Korhogo, nord de la Cote d’Ivoire

Une stratégie de gestion intégrée des insectes nuisibles à la culture de la patate douce a été élaborée pour réduire les pertes dues à ceux-ci. Ainsi, les propriétés répulsives des extraits de feuilles et d’amandes de neem ont été évaluées sur Cylas puncticollis, un charançon de la patate douce. Pour ce faire, quatre concentrations d’extraits ont été préparées à raison de quatre répétitions par concentration. Le test a consisté à la détermination du pourcentage de charançons présents dans la zone traitée. Chacune des concentrations d’extraits a été appliquée sur la moitié d’un papier buvard placé dans une boite de Pétri de 9 cm de diamètre et sur lequel 10 charançons ont été posés. Les effets répulsifs des extraits ont été comparés à ceux d’un insecticide chimique et l’eau distillée. Le test avec 20 cL/L d’extraits de feuilles a causé 85 % de répulsion contre 45 % pour les amandes à 25 g/L. Les extraits ont significativement causé plus de répulsion que l’eau distillée et l’insecticide chimique. Les tests ont révélé un potentiel plus répulsif des extraits de feuilles comparé à celui des amandes. Les extraits de neem pourraient constituer une alternative crédible à la lutte chimique pour la protection de la patate douce contre ce charançon. English title: Evaluation of the repellent effect of neem extracts (Azadirachta indica A. Juss., 1830) on the sweet potato weevil (Cylas puncticollis Boheman, 1833) under laboratory conditions in Korhogo, northern Côte d’Ivoire Abstract An integrated pest management strategy for sweet potatoes has been developed to reduce pest losses. Thus, the repellent properties of neem leaf and kernel extracts were evaluated on Cylas puncticollis, a sweet potato weevil. For this purpose, four concentrations of extracts were prepared with four replicates per concentration. The test consisted of determining the percentage of weevils in the treated area. Each of the extract concentrations was applied to half of a blotting paper placed in 9 cm diameter Petri dishes on which 10 weevils were placed. The repellent effects of the extracts were compared to those of a chemical insecticide and distilled water. Test with 20 cL/L leaf extract caused 85% repellence compared to 45% for almonds at 25 g/L. Compared to the chemical insecticide and distilled water, the extracts caused significantly more repellence. The tests revealed a higher repellent potential of the leaf extracts compared to those of almonds. Neem extracts could be a credible alternative to chemical control for the protection of sweet potato against this weevil. Keywords: Neem extracts, Repellent effect, Sweet potato, Cylas puncticolli

Contamination aux metaux lourds de la matrice eau-sediment et muscle du tilapia Oreochromis niloticus de trois fermes piscicoles en Cote d’Ivoire

La présente étude a pour objectif de déterminer le niveau de contamination du mercure, du cadmium, de l’arsenic et du plomb dans l’eau, les sédiments et le muscle du tilapia Oreochromis niloticus dans trois fermes piscicoles en Côte d’Ivoire. L’eau, les sédiments et les spécimens de poisson ont été prélevés par mois de février à juillet 2017 en cage dans la lagune Aghien (ST1), en étang continental (ST2) à Agboville et en cage dans le barrage de Taabo (ST3). Les paramètres physico-chimiques mesurés ont montré qu’à l’exception de la conductivité, des matières en suspension et des solides totaux dissous, aucune variation saisonnière n’a été observée. En revanche, les valeurs moyennes des paramètres physico-chimiques calculées sont significativement différentes entre les fermes. Les valeurs de chaque métal mesurées dans la matrice eau-sédiment-muscle varient significativement entre les deux saisons dans toutes les fermes. Cependant, aucune différence entre les fermes échantillonnées n’a été observée. Les concentrations des métaux lourds mesurées dans le muscle sont inférieures aux valeurs seuils établies par l’OMS à l’exception de l’As. Cette contamination élevée en arsenic pourrait porter atteinte à l’intégrité biologique et à la santé humaine.Mots clés : Métaux lourds, Accumulation, Oreochromis niloticus, Ferme piscicole ivoirienn

Stacking tolerance to drought and resistance to a parasitic weed in tropical hybrid maize for enhancing resilience to stress combinations

Open Access JournalMaize is a food security crop cultivated in the African savannas that are vulnerable to the occurrence of drought stress and Striga hermonthica infestation. The co-occurrence of these stresses can severely damage crop growth and productivity of maize. Until recently, maize breeding in International Institute of Tropical Agriculture (IITA) has focused on the development of either drought tolerant or S. hermonthica resistant germplasm using independent screening protocols. The present study was therefore conducted to examine the extent to which maize hybrids simultaneously expressing resistance to S. hermonthica and tolerance to drought (DTSTR) could be developed through sequential selection of parental lines using the two screening protocols. Regional trials involving 77 DTSTR and 22 commercial benchmark hybrids (STR and non-DTSTR) were then conducted under Striga-infested and non-infested conditions, managed drought stress and fully irrigated conditions as well as in multiple rainfed environments for 5 years. The observed yield reductions of 61% under managed drought stress and 23% under Striga-infestation created desirable stress levels leading to the detection of significant differences in grain yield among hybrids at individual stress and non-stress conditions. On average, the DTSTR hybrids out-yielded the STR and non-DTSTR commercial hybrids by 13–19% under managed drought stress and fully irrigated conditions and by −4 to 70% under Striga-infested and non-infested conditions. Among the DTSTR hybrids included in the regional trials, 33 were high yielders with better adaptability across environments under all stressful and non-stressful testing conditions. Twenty-four of the 33 DTSTR hybrids also yielded well across diverse rainfed environments. The genetic correlations of grain yield under managed drought stress with yield under Striga-infestation and multiple rainfed environments were 0.51 and 0.57, respectively. Also, a genetic correlation between yields under Striga-infestation with that recorded in multiple rainfed environments was 0.58. These results suggest that the sequential selection scheme offers an opportunity to accumulate desirable stress-related traits in parents contributing to superior agronomic performance in hybrids across stressful and diverse rainfed field environments that are commonly encountered in the tropical savannas of Africa

Developpement des systemes de production innovants d’association mais/legumineuses dans la zone subhumide du Mali

Parmi les 3 piliers de l’intégration agriculture-élevage (traction animale, fumure organique, cultures fourragères) diffusés en Afrique de l’Ouest, seules les cultures fourragères ont été peu adoptées. Pourtant, les associations maïs/légumineuses ont l’avantage d’améliorer la production et l’alimentation animale. Elles représentent une alternative dans la gestion des risques et des incertitudes pour les agro-éleveurs, confrontés aux changements globaux (climatiques, pression foncière, dégradation des ressources naturelles). L’objectif de cette étude est de déterminer la contribution des associations maïs/légumineuses dans l’amélioration de la production de maïs grain et le bilan fourrager des exploitations agricoles. Le dispositif en blocs dispersés chez 10 producteurs, a consisté en 3 traitements, T1 (maïs seul), T2 (maïs/ niébé) et T3 (maïs/mucuna) durant 2 campagnes agricoles. En 2013 - 2014, les rendements de maïs grain ont été de 2433 kg/ha et en biomasse 2597 kgMS/ha. Par contre, en 2014 - 2015 les rendements ont été de 1932 kg/ha de maïs grain et de 5134 kgMS/ha de biomasse. Les besoins en matière sèche pour 90 jours de supplémentation ont été de 4,62 UBT en 2013 - 2014 et de 9,13 UBT en 2014 - 2015. Ces résultats montrent la contribution des associations maïs/légumineuses dans l’amélioration du rendement de maïs grain et de fourrages dans la zone subhumide au Mali.Mots clés : légumineuses, maïs, fourrage, Mal

SWV determination of glyphosate in Burkina Faso soils using carbon fiber microelectrode

This paper presents an evaluation using carbon fiber microelectrode (CFME) for the determination of glyphosate in soils from Burkina Faso treated with Glyphonet SL 360 by square wave voltammetry (SWV).The maximum intensity of the electrochemical response signal of  glyphosate has been optimized and conditions using a 0.2 M of phosphate buffer solution at pH 5.2 as supporting electrolyte and the SWV parameters frequency of 60 Hz, a scan increment of 10 mV and a pulse height of 60 mV. The limit of detection for glyphosate in the Glyphonet SL 360 formulation was 25 ìg L-1 while the quantification limit was 83 ìgL-1with a linear dynamic range up to 50 ìg L-1. In these conditions, a sequence of experiments led to recoveries in the range 88.5 to 102.3% for soil samples spiked with 50, 100 and 200 ìgL-1 of glyphosate with a standard deviation of 11.5, 4.2 and 2.3% respectively indicating the precision of the method. The optimized method was successfully applied to determine the residues of glyphosate in soils collected in the fields in two different dates from the application period.Keywords: Glyphosate, Glyphonet SL 360, carbon fiber microelectrode, square wave voltammetry, sensitivit

Comportement des dromadaires adultes sur paturages sahelien et subhumide en station au Mali: 1. Description des principales activites

No Abstrac

Serological Evaluation of Onchocerciasis and Lymphatic Filariasis Elimination in the Bakoye and Falémé foci, Mali

In Mali, ivermectin-based onchocerciasis elimination from the Bakoye and Falémé foci, reported in 2009–2012, was a beacon leading to policy shifting from morbidity control to elimination of transmission (EOT). These foci are also endemic for lymphatic filariasis (LF). In 2007–2016 mass ivermectin plus albendazole administration was implemented. We report Ov16 (onchocerciasis) and Wb123 (LF) seroprevalence after 24–25 years of treatment to evaluate if onchocerciasis EOT and LF elimination as a public health problem (EPHP) have been achieved

Yam Daabo interventions’ effects on postpartum family planning use in Burkina Faso at 24 months after childbirth

Introduction After testing the interventions for improving the prevalence of contraceptive use, very few studies have measured the long-term effects thereafter the end of the implementation. This study aimed to measure Yam Daabo interventions’ effects on contraceptive use in Burkina Faso at twelve months after completion of the intervention. Methods Yam Daabo was a two-group, multi-intervention, single-blind, cluster randomized controlled trial. Interventions comprised refresher training for the provider, a counseling tool, supportive supervision, availability of contraceptive services 7 days a week, client appointment cards, and invitation letters for partners. We used generalized linear mixed-effects models (log Poisson) to compare the modern contraceptive prevalence at 12 months post-intervention in the two groups. We collected data between September and November 2018. We conducted an intention-to-treat analysis and adjusted the prevalence ratios on cluster effects and unbalanced baseline characteristics. Results Twelve months after the completion of the Yam Daabo trial, we interviewed 87.4% (485 out of 555 women with available data at 12 months, that is, 247/276 in the intervention group (89.5%) and 238/279 in the control group (85.3%). No difference was observed in the use of hormonal contraceptive methods between the intervention and control groups (adjusted prevalence ratio = 1.21; 95% confidence interval [CI] = [0.91–1.61], p = 0.191). By contrast, women in the intervention group were more likely to use long-acting reversible contraceptives (LARC) than those in the control group (adjusted prevalence ratio = 1.35; 95% CI = [1.08–1.69], p = 0.008). Conclusion Twelve months after completion of the intervention, we found no significant difference in hormonal contraceptive use between women in the intervention and their control group counterparts. However, women in the intervention group were significantly more likely to use long-acting reversible contraceptives than those in the control group. Trial registration The trial registration number at the Pan African Clinical Trials Registry is PACTR201609001784334. The date of the first registration is 27/09/2016