La variablité morphologique de 67 accessions de fonio [Digitaria exilis (Kippist.) Stapf.] collectées au Niger a été évaluée au cours de deux années (2011 et 2012). Seize (16) caractères agro morphologiques (dont 14 caractères quantitatifs et 2 caractères qualitatifs) ont été évalués en station dans deux zones agroécologiques différentes (Tarna en zone sahélo-saharienne et Tara en zone soudanienne). La classification acsendante hierarchique (CAH) et l’analyse factorielle discriminante (AFD) ont mis en évidence quatre groupes (GI, GII, GIII et GIV). Les accessions du groupe GIV ont en moyenne un cycle de maturité compris entre 85 et 90 jours tandis que les autres groupes présentent un cycle de maturité superieur à 90 jours dans nos conditions expérimentales. Les résultats montrent que les variables les plus discriminantes qui permettent de décrire la variabilité entre les groupes identifiés sont la biomasse sèche (tige et feuille) par hectare, la longueur des entrenoeuds, le rendement en graine par hectare et dans une certaine mesure le cycle de la plante. L’observation des caractères qualitatifs a montré que cinq accessions (représentant 7& du total) ont des graines non decortiquées de couleur rouge et quatre accessions (6& du total), une tige de couleur rouge. Les caractères analysés peuvent ainsi constituer des critères de base pour différencier les accessions des autres régions de l’Afrique de l’Ouest et servir pour une étude de variabilité entre les restes des accessions de fonio collectées au Niger. Des possiblités d’amélioration peuvent également être envisagées une fois que le regime de réproduction de l’espèce est bien identifié.

This work evaluated a collection of hundred groundnut (Arachis hypogaea L.) varieties from different origin using twenty four (24) agro-morphological traits that can help to enhance selection efficiency in crop improvement. The experiment was carried out at the experimental station of INRAN-Tarna, in the region of Maradi (Niger) during the rainy season of 2010. Analysis of variance showed a large variability among varieties for the agro-morphological traits. Principal Component Analysis (PCA), Agglomerative Hierarchical Clustering (AHC) and Fisher Discriminant Analysis (FDA) revealed that this variability is structured into four distinct groups. Groups I and II consisted of early varieties that have a high emergence rate and high pods and seed weight. These groups included mainly local varieties and those introduced in Niger through seed dissemination. Groups III and IV are composed of late varieties with large pods while group III had mostly varieties with long leaflets. Understanding the genetic control of the most discriminating among the studied traits would bring significant contribution to the genetic improvement of this important crop.

In the south areas of Niamey, the capital of Niger, where there is a higher density of livestock because of the Niger River, cowpea is grown mainly for fodder. Unfortunately, there is a lack of dual-purpose cowpea varieties with high potential for fodder production. Therefore, an experiment was carried out in two sites (Ticko and Bogodjotou) located in the Southwest of Niamey during the rainy season of 2001 and 2002, in order to compare the production of nine cowpea varieties. The results indicated that in 2001, the fodder yield of all varieties were significantly (p<0.01) higher than those of 2002. But not significant difference was recorded between the two sites during the two years. In 2001, at Ticko, “Baban waké", Kanannado and IT93K-398-2 had higher fodder yields than the remaining varieties with 1032 kg/ha, 879 kg/ha and 866 kg/ha respectively. The lowest fodder yields were recorded for Locale variety which is grown by farmers, IT89KD-349 and TVu 1234- 9 with 715 kg/ha, 499 kg/ha and 677 kg/ha, respectively. In 2002, the highest fodder yields were also recorded for introduced varieties such as “Baban waké", IN92E-3, IT89KD-288, IT89KD-349, Kanannado, IT93K-398- 2 and TN256-87 compared to Locale variety. The results indicated the possibility to increase fodder production through the introduction of dual-purpose cowpeas and thus increasing farmers’ income. © 2011 International Formulae Group. All rights reserved.

The chemical composition of calyces and seeds of three ecotypes of Roselle from Niger was compared. The results indicate that calcium (Ca), potassium (K), sodium (Na), magnesium (Mg) and protein contents in calyces are significantly different (P<0.005) among ecotypes. The highest concentrations of K, Na, Mg and protein in calyces were recorded for ecotype E7 (35.66, 3.40, 6.01 and 101 mg/g d.w., respectively). Ecotype E9 had the highest Ca content in calyces (34.41 mg/g d.w.); while E3 and E7 had similar and lower contents. The protein content in calyces for E9 (52 mg/g d.w.) was approximately halved compared to those of E3 and E7. For all ecotypes, the concentrations of Ca, K, Mn, Na and Fe in the calyces were higher compared to those in the seeds. In contrast, P content was higher in seeds. The highest K, Na, Mg and P concentrations in seeds were registered for E7 and the lowest ones for E9. Ecotypes E3 and E9 recorded higher and similar Cu, Fe and Mn contents in calyces and in seeds compared to E7. The highest Zn concentrations in seeds were obtained for E3 and E7.

Although nitrogen application could improve growth and yield of roselle, fertilizer recommendations for Niger are lacking. The objective of this study was to evaluate the effects of two treatments of nitrogen (N1=50 kg N,ha-1 and N2=100 kg N.ha-1) on yields and yield components in three ecotypes of Roselle (A3, A7 and A9). An increase in nitrogen was associated with an increase in leaf yield in every ecotype. However, there was no significant difference in yields between N1 and N2. Compared with the control plants (N0), the increase was about 181& for A3, 70& for A7 and 95& for A9 at N2. This level of nitrogen significantly decreased seed yield by 30& for A3 and 48&, respectively for A7 and A9. Nitrogen treatment had no effect on calyx yield which was approximately identical for the three ecotype (420 kg ha-1). With the exception of the number of branches/plant, yield components were not affected by nitrogen application. Therefore, N1 could be considered as the optimum fertilization for leaf yield.