CARACTERISATION PERCEPTIVE DES VARIETES HYBRIDES CHINOISES DU MAÏS : LA SÉLECTIVITÉ SENSORIELLE EST-ELLE DÉTERMINANTE AU BÉNIN ?

Agricultural researches usually advocate high yielding competitive crop varieties in order to supply foodstuff to the increasing population. However, this is not to care for the social dimension of adoption in the technology transfer process. That is why the present paper acknowledges actors like producers, food processors, marketers and others, whose perception with respect to growing, harvesting and processing stages of maize, to be included in the perceptive evaluation of Chinese hybrid varieties at the research centers. Four new varieties of maize are promoted: T2 (Guidan 162), T3 (Jinguyuan 688), T4 (Jinyu No.8) and T5 (Xianyu 335). Actors compare new Chinese varieties of maize to their traditional ones. On the basis of a comparative appraisal index (CAI), ie. a new variety is likely to be adopted if the differences of score between its descriptors and those of the traditional variety are greater than zero. In terms of results, T2 and T4 are the most likely to be adopted in the South and the Center. In the North, on the contrary, T5 is substituted to T4. Because of a low performance on various descriptors, T3 is unlikely to be adopted. While in the south and the center of Benin, sensorial descriptors remain decisive in the adoption profile, agromorphological and harvest stage descriptors are more likely to affect adoption in the North. Based on the increasing economic importance of maize, actors’ perception in the North significantly matters in the process of adoption of new varieties

First report of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in the Republic of Benin

Tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious pest of tomato Solanum lycopersicum L. (Solanaceae) originating from South America. Due to previous outbreaks in neighbouring West African countries, surveillance was ongoing since 2014 in Benin. Tomato plants were regularly inspected and pheromone traps placed in tomato-producing localities in northern, southern and central Benin, including fields close to the border with Niger and Nigeria. In late 2017 and beginning of 2018 Gelechiidae moths were obtained from both the traps and the reared plant material. Morphological examination and molecular analysis of the gained specimens allowed to confirm the presence of the pest in the northern and central regions of Benin. We hence confirm the presence of T. absoluta in yet another West African country

Pratiques culturales et teneur en éléments anti nutritionnels (nitrates et pesticides) du Solanum macrocarpum au sud du Bénin

La pression foncière en région urbaine et périurbaine amène beaucoup deproducteurs maraîchers à avoir des pratiques culturales qui ne garantissentpas la qualité sanitaire des produits récoltés. Cette étude a analysé lespratiques de fertilisation et de traitements phytosanitaires sur les légumesfeuilles traditionnels les plus consommés afin d’identifier ceux à risque. Six(6) échantillons composites de feuilles de S. macrocarpum, répétés deux fois,issus de parcelles ayant reçu des doses de 20, 40 et (20+10+10) t/ha defientes de volaille et de graines de coton, sur un sol ferrallitique faiblementdessaturé au sud du Bénin, ont été analysés au cours des deux premièrescoupes pour la recherche de nitrates par colorimétrie. Dans la zone dedécrue, l’identification et le dosage des pesticides organochlorés parchromatographie en phase gazeuse couplée à un système de détection àcapture d’électrons ont été effectués sur dix (10) échantillons de feuilles et unéchantillon composite de sol (mélange de trois échantillons de sols) prélevésde façon aléatoire dans les champs maraîchers. Le diagnostic approfondi despratiques de fertilisation et de traitements phytosanitaires a montré que defortes doses d’engrais organiques et surtout d’engrais minéraux sontappliquées sur les légumes feuilles dans les zones prospectées. Les taux denitrate dans les feuilles et dans les sols sont faibles (<50mg/kg de matièrefraîche) mais ces taux ont augmenté de la 1ère à la 2ème coupe. Les teneursen pesticides organochlorés totaux sont comprises entre 0,320 et 2,225 μg/gde légumes secs. En dehors de l’endosulfan et du lindane retrouvés dans leséchantillons de légumes, à faibles teneur (respectivement 0,07 et 0,1 μg/g delégumes), les autres pesticides comme le DDT, l’endrine, l’heptachlore,l’aldrine, le dieldrine présentent des teneurs supérieures aux normes Codexappliquées pour le contrôle de la qualité des aliments. Les mêmes pesticidesse retrouvent dans les échantillons de sol.Mots clés: Pratiques culturales, fientes, pesticides organochloré

CARACTERISATION PERCEPTIVE DES VARIETES HYBRIDES CHINOISES DU MAÏS : LA SÉLECTIVITÉ SENSORIELLE EST-ELLE DÉTERMINANTE AU BÉNIN ?

Agricultural researches usually advocate high yielding competitive crop varieties in order to supply foodstuff to the increasing population. However, this is not to care for the social dimension of adoption in the technology transfer process. That is why the present paper acknowledges actors like producers, food processors, marketers and others, whose perception with respect to growing, harvesting and processing stages of maize, to be included in the perceptive evaluation of Chinese hybrid varieties at the research centers. Four new varieties of maize are promoted: T2 (Guidan 162), T3 (Jinguyuan 688), T4 (Jinyu No.8) and T5 (Xianyu 335). Actors compare new Chinese varieties of maize to their traditional ones. On the basis of a comparative appraisal index (CAI), ie. a new variety is likely to be adopted if the differences of score between its descriptors and those of the traditional variety are greater than zero. In terms of results, T2 and T4 are the most likely to be adopted in the South and the Center. In the North, on the contrary, T5 is substituted to T4. Because of a low performance on various descriptors, T3 is unlikely to be adopted. While in the south and the center of Benin, sensorial descriptors remain decisive in the adoption profile, agromorphological and harvest stage descriptors are more likely to affect adoption in the North. Based on the increasing economic importance of maize, actors’ perception in the North significantly matters in the process of adoption of new varieties

Les Pertes Economiques Dues A L’anthracnose De L’anacardier Au Bénin

Anthracnose caused by Colletotrichum gloeosporioides is a disease that causes losses of cashew production in Benin. This study aims to evaluate the economic losses in cashew nuts caused by the disease. The data were collected using a questionary on a sample of 84 farmers from 12 villages in Savè (Centre of Benin) and 126 farmers from 13 villages in N'Dali (North of Benin). These data included socio-demographic characteristics of the respondent, anthracnose expression, disease management methods, yield losses, cashew nut yield, and sale price per kg of cashew nuts. In Savè and N’Dali, 98.68% and 100% of farmers, respectively, reported the presence of anthracnose in their plantations. The yield losses were 316.95 kg/ha (72.19%) at Savè and 189.01 kg/ha (54.71%) at N’Dali. In the period of low demand, these losses amounted an average of 68061 FCFA/ha/farmer at Savè and 42316 FCFA/ha/farmer at N'Dali, while in the high demand periods, they were evaluated to 221576 FCFA/ha/farmer and 135339 FCFA/ha/farmer at Savè and at N'Dali, respectively

Effet De La Technologie, Du Cultivar Et De La Durée De Conservation Sur La Stabilité Et La Qualité Du Lait De Soja (Glycine maxima)

Three technologies named D (wet dehulled soybeans seeds), B (boiled soybean seeds before dehulling) and T (roasted soybean seeds before dehulling) for stabilized soymilk production were tested with TGX (large grain size) and Jupiter (small grain size) cultivars. Production yields, sensory, physicochemical and microbiological characteristics of produced milks were determined over a period of 3 months. . The bottled milk was sterilized at a temperature of 115°C under a pressure of 0.7 bar for one hour. The milks were stored at temperature storage place 27°C (for 3 months). The milk yield for technology D is 90.87 % for the jupiter and 92.01 % for the TGX. These yields are higher than the other technologies. Whatever the technology, the TGX cultivar gives a better yield 92.01 %. Sensory analysis revealed that the milk produced with technology D and jupiter cultivar is more appreciated by the 77 % panelist. This milk has a pH of 7.14 at the day of production and decreases to 6.83 after 3 months of storage. Protein, fat and Dry Soluble Matter (DSM) content decreased after storage by 4.30 to 4.13 %, 1.7 to 1.2 % and from 11.68 to 10.28 °Brix respectively. The viscosity was 1.24 cp at the beginning and 1.38 cp after storage. After 3 months of storage, the milk is stable and its microbiological quality complies with accepted standards in relation to spores, coliforms, yeasts and molds

Finding optimum climatic parameters for high tomato yield in Benin (West Africa) using frequent pattern growth algorithm.

Tomato is one of the most appreciated vegetables in the world. Predicting its yield and optimizing its culture is important for global food security. This paper addresses the challenge of finding optimum climatic values for a high tomato yield. The Frequent Pattern Growth (FPG) algorithm was considered to establish the associations between six climate variables: minimum and maximum temperatures, maximum humidity, sunshine (Sun), rainfall, and evapotranspiration (ET), collected over 26 years in the three agro-ecological Zones of Benin. Monthly climate data were aggregated with yield data over the same period. After aggregation, the data were transformed into 'low', 'medium', and 'high' attributes using the threshold values defined. Then, the rules were generated using the minimum support set to 0.2 and the confidence to 0.8. Only the rules with the consequence 'high yield' were screened. The best yield patterns were observed in the Guinean Zone, followed by the Sudanian. The results indicated that high tomato yield was associated with low ET in all areas considered. Minimum and maximum temperatures, maximum humidity, and Sun were medium in every Zone. Moreover, rainfall was high in the Sudanian Zone, unlike the other regions where it remained medium. These results are useful in assessing climate variability's impact on tomato production. Thus, they can help farmers make informed decisions on cultivation practices to optimize production in a changing environment. In addition, the findings of this study can be considered in other regions and adapted to other crops

Distribution, pathological and biochemical characterization of Ralstonia solanacearum in Benin

In 2006 and 2007, 75 strains of Ralstonia solanacearum were collected from wilting tomato, pepper and eggplant in Benin. The distribution and the incidence of tomato bacterial wilt in the field were assessed by counting wilted tomato plants on 3 plots of 50 m2 per field. The isolated bacterial strains, including the reference strain, were identified using ELISA, pathogenicity test and carbohydrate oxidation. Bacterial wilt is widely distributed in Benin and was found in five of the eight agro-ecological zones (AEZ) of Benin, which correspond to eight of the 12 districts of Benin. The disease was more severe in ferralitic soil (AEZ V), in valleys and lowlands (AEZ IV) and in highlands (AEZ I). The incidence of tomato bacterial wilt was up to 71%. No R. solanacearum strains were isolated from AEZ II, AEZ VII and AEZ VIII. Strains identified as R. solanacearum were more widely distributed in the south than the center and the north of Benin. Based on biochemical characteristics, Beninese R. solanacearum strains were grouped into biovar I/race1 and biovar III/race 1

Inventaire des maladies de l’anacardier (Anacardium occidentale L.) dans la préfecture de Tchamba au Togo

L’anacardier (Anacardium occidentale L.) est d’une grande importance socio-économique. Malheureusement, il est attaqué par bioagresseurs dont les maladies fongiques et bactériennes. La présente a pour but d’inventorier les maladies majeures de cette culture, d’évaluer leur prévalence, incidence et sévérité, et d’identifier les pathogènes associés dans 5 des 10 cantons de la préfecture de Tchamba au Togo. Trois vergers par canton ont été évalués par rapport aux symptômes de maladies. Les résultats ont révélé 7 maladies : dessèchement des bourgeons (DB), anthracnose, jaunissement foliaire, rouille noire, gommose, chancre bactérien et rouille rouge. Le DB a donné les taux d’incidence et de sévérité respectifs de 15,99% et 19,19%, supérieur à ceux des autres maladies (p = 0,03). La prévalence des maladies a varié de 20% à 100%. Les pathogènes associés identifiés sont Colletotrichum gloeosporioides pour l’anthracnose, Cochliobolus sp. pour le jaunissement foliaire, Cephaleuros virescens pour la rouille rouge, Lasiodiplodia theobromae pour la gommose et Xanthomonas sp. pour le chancre bactérien. Il ressort de ces résultats que l’anacardier est la cible de pathologiesaussi bien fongiques que bactériens et que de stratégies de lutte adaptées doivent être déployées.   English title: Cashew (Anacardium occidentale L.) diseases’ inventory in the prefecture of Tchamba in Togo Cashew (Anacardium occidentale L.) is an important tropical crop worldwide. However, it is attacked by several bioagressors among which fungal and bacterial diseases. The present study aimed to survey the major diseases of cashew tree, assess their prevalence, incidence and severity, and to identify the associated pathogens in five from the ten districts of the prefecture of Tchamba in Togo. Three cashew plantations per district were visited and fungal and bacterial disease symptoms evaluated. The results revealed seven diseases occurring in the surveyed area: Dieback of buds, anthracnose, leaf yellowing, black rust, gum disease, bacterial canker and red rust. Dieback of buds recorded significantly higher disease incidence of 15.99% and severity of 19.19% than the other diseases (p = 0.03). The prevalence of the diseases varied from 20% to 100%. The associated pathogens of the diseases were Colletotrichum gloeosporioides for anthracnose, Cochliobolus sp. for leaf yellowing, Cephaleuros virescens for red rust, Lasiodiplodia theobromae for gum disease and Xanthomonas sp. for bacterial canker. These results revealed the importance of fungal and bacterial diseases occurring in the studied area, thus appropriate control measures must be developed