Test en milieu reel de dix varietes de riz pluvial - Tolerances a la secheresse de dix varietes de riz : Etude en milieu reel dans la commune de glazoue au Benin

Dans le souci de mettre à la disposition du monde paysan de nouvelles variétés de riz pluvial à haut rendement, tolérantes à la sécheresse, des essais ont été conduits au cours de deux campagnes successives (2009-2010) en milieu réel à Kpakpazoumè dans la commune de Glazoué. L’objectif principal de cette étude était d’évaluer l’adaptabilité agro- cologique de dix variétés de riz pluvial supposées tolérantes à la sécheresse au centre du Bénin. Le dispositif expérimental utilisé est un bloc complètement aléatoire à trois répétitions et sans témoin. Au total, dix-neuf (19) caractères quantitatifs ont été évalués. L’analyse de variance utilisée pour une comparaison globale des moyennes a montré des différences significatives entre les lignées pour certains caractères comme le tallage à 60 jours après semis, le cycle semis-épiaison, le nombre de panicules au mètre carré, le nombre de grains par panicule, le taux de fertilité, le poids de 1000 grains. Les comparaisons deux à deux des moyennes ont été ensuite réalisées à l’aide de la méthode de Tukey. Les résultats obtenus ont montré que les variétés ARCCU 3Fa7-L16P5-B-B3 (R77), ARCCU 3Fa9L6P2-B-B-1(R80), WAB 368-B-2-H2-HB (R56),WAB 515-B- 10A1-4(R57) et IR 68702-072-1-4-B (R29) sont les plus productives avec respectivement des rendements en grains paddy de 841 g/m2 , 798 g/m2, 759 g/m2, 729 g/m2 et 710 g/m2. Ainsi, il a été recommandé une évaluation organoleptique de leurs grains dans des travaux ultérieurs. Après quoi, ces lignées pourraient être multipliées et vulgarisées.Mots clés : Kpakpazoumè, riziculture pluviale tolérance à la sécheresse, adaptabilité agro-écologique

La réduction de la croissance végétative à forte densité de semis comme stratégie d'adaptation variétale aux semis tardifs en culture cotonnière pluviale au Bénin

Reduced Vegetative Growth at High Planting Density as Varietal Adaptation Strategy for Late Sowing in Rainfed Cotton Cultivation in Benin. To study the effects of the factors sowing date and density on vegetative growth and yield of cotton in rainfed area, four trials were conducted at two sites in Benin in 2002 and 2003. A split-split plot design with three replications was performed to compare 10 different varieties, at three densities (42,000; 125,000; 167,000 plants.ha-1) and, two planting dates (June, July/August). Plant height, number of nodes per stem, branch length and field performance were evaluated. Planting date affected the morphology in limiting water conditions (shorter plants in late sowing). Delayed sowing reduced yields by 12% for early and compact variety Mar 88-214 against more than 30% for varieties with high vegetative development. At high densities, all genotypes were shorter with shorter branches. In delayed planting and high densities, Mar 88-214 and Guazuncho 2 produced at least 100 kg.ha-1 more than the vegetative varieties. Early and compact varieties sown at high densities are more suitable when the water conditions are limiting. Sowing density affects more clearly vegetative growth and yield of cotton than sowing date

Sélection des variétés de soja pour la résistance à la pustule bactérienne au Bénin

Selection of Soybean Varieties for Resistance to Bacterial Pustule in Benin. Bacterial pustule caused by Xanthomonas axonopodis pv. glycines is a dreaded disease on soybeans inducing considerable yield losses worldwide. The aim of this study is to test 16 soybean varieties for resistance to bacterial pustule under natural infection and artificial inoculation. The study was conducted under greenhouse and field conditions at the experimental farm of the University of Parakou from July to October in 2013 and in 2014. The results show that the varieties JUPITER, ISRA25/72, TGX1985-77F, TGX1910-2F and TGX1985-11F are sensitive to moderately sensitive. The varieties TGX1448-2E, TGX1987-62F, TGX1990-15F, TGX1987-10F, TGX1835-10F, TGX1740-2F and TGX1440-1E are moderately resistant to resistant. The varieties TGX1988-5F, TGX1910-14F, TGX1989-21F and TGX1989-19F revealed moderately resistant in the greenhouse, but sensitive to moderately sensitive in the field. In 2013, yield losses from 2.7 to 28.1% were recorded with the varieties TGX1910-2F, ISRA25/72, JUPITER, TGX1910-2F, TGX1987-10F, TGX1835-10F and TGX1740-2F. Yield losses were calculated for each variety considering the yield difference between the natural infection and the artificial inoculation. The difference was than divided by the yield obtained in the natural infection. In 2014, varieties TGX1985-77F, TGX1740-2F, ISRA25/72, TGX1987-62F and TGX1910-14F showed losses ranging from 4.7 to 21.4%. The other varieties showed yield increases from 2.7 to 26% in 2013 and from 2.2 to 36.6% in 2014. With variety TGX1985-11F neither yield loss nor gain were observed over the two years. T For the 16 tested varieties, TGX1987-62F and TGX1990-15F are the most resistant; while TGX1989-19F, TGX1985-11F, TGX1440-1E, TGX1985-77F and TGX1910-14F are partial resistant. Those varieties have a high yield and could be recommended to the farmers. The two most resistant varieties could be integrated in a plant breeding program

Agromorphological Characterization Revealed Three Phenotypic Groups in a Region-Wide Germplasm of Fonio (Digitaria exilis (Kippist) Stapf) from West Africa

International audienceFonio is an ancient orphan cereal, cultivated by resource-poor farmers in arid and semi-arid regions of West Africa, who conserved and used the cereal for nutrition and income generation. However, the extent and patterns of phenotypic variation within the fonio germplasm remain scarcely evaluated to inform breeding decisions. In this study, we used alpha lattice design to assess the phenotypic variability of 180 fonio accessions using 20 agro morphological descriptors, including both qualitative and quantitative traits at Bengou research station in 2018 and 2019. Descriptive statistics, combined analysis and multivariate analyses, including principal components analysis (PCA), hierarchical clustering, and multiple factor analysis (MFA) were performed. As results, we found significant differences among fonio accessions and among agro ecological zones of provenance for most of the quantitative traits. Furthermore, highly significant positive correlations were found between grain yield and other yield-related attributes such as harvest index and thousand seeds weight, whereas significant negative correlations were found between grain yield and flowering and maturity times. Clusters analysis revealed three phenotypic groups. Group 1 was characterized by early maturing fonio accessions with higher grain yield. Groups 2 and 3 were characterized by late maturing accessions with intermediate to moderate grain yield. The accessions from Group 1 are candidate for yield improvement and development of fonio lines with enhanced lodging resistance. Accessions from Group 2 and 3 can be improved for yield through marker-assisted selection of best thousand seed weight. This study highlights how traits are correlated within the major phenotypic groups of fonio in West Africa, and we discussed how these groups could be further exploited for improving traits of economic importance. Furthermore, this study exhibited agro morphological descriptors that discriminate fonio accessions and provide useful information for parental selection with economically important agronomic traits

From shade to light : fonio, an african orphan crop, towards renewed challenges

The FAO recently estimated that demand for food will increase by 70% by 2050. The challenge will not only be on increasing the food supply but also on improving its nutritional value under an accelerating rate of environmental and social changes. One solution would be the wider use of underutilized crops to diversify alimentation and develop sustainable and low-input agriculture. Are orphan crops commodities for the future, and how can they be promoted. In this regard, fonio (Digitaria exilis Stapf) appears to be a promising crop. It is an indigenous staple cereal from Western Africa playing a crucial role in food security. Additionally, it is a model crop in important up-to-date concepts such as resilience, agroecology, population health, climatic changes, poverty reduction, and women's empowerment. Nevertheless, fonio has received limited attention from mainstream research compared to other dryland cereals, such as pearl millet and sorghum. Increasingly available genomic resources promise to promote advanced breeding strategies in fonio. This paper presents the past, present, and future of fonio research. We argue the need for interdisciplinarity and multistakeholder research approaches for increasing fonio production, conservation, and sustainable uses