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Germination et utilisation de Caesalpinia benthamiana (Baillon) P.S.Herendeen & J.L.Zarucchi (Leguminosae-Caesalpiniaceae) dans l’aménagement anti-érosif des retenues d’hydraulique pastorale au Bénin

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: Caesalpinia benthamiana est un arbuste sarmenteux fortement épineux. Ses aptitudes agronomiques et à la lutte antiérosive des retenues d’hydraulique pastorale ont été testées dans le cadre du Projet de Développement de l’Elevage (PDE) au Bénin. Il en est de même des conditions optimales de germination. Elles ont été déterminées dans le but d´une domestication de l’espèce. Les résultats montrent que le séjour des graines de l’espèce dans l’eau bouillante pendant une durée de 2 à 10 mn, a eu un effet hautement significatif (P<0,001, R² = 0,91) sur la germination des graines. Les taux de germination les plus élevés (44%) ont été relevés sur des graines ayant séjourné pendant 4 à 6 minutes dans l’eau à 100 °C pendant 15 jours et les plus faibles valeurs (1%) chez les témoins. Les vitesses germinatives les plus élevées ont été obtenues après 6 minutes d’immersion. La faculté germinative baisse à partir de 8 minutes, et se traduit par une mortalité élevée des graines. Le taux de reprise des plantules repiquées sur les berges suivant une densité de 1 m X 1 m après un an de suivi a atteint 69,87%. Ce résultat indique que l’espèce peut bien pousser sur les digues et pourrait dans une certaine mesure contribuer à protéger ces ouvrages contre l’érosion et le comblement par piétinement animal en zone guinéenne et soudano-guinéenne. Mots clés: Caesalpinia benthamiana, pré traitement, germination, retenue, hydraulique pastorale.
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... La persistance du stock en graines des Fabaceae dans le sol permet également à la régénération de s'exprimer dans la période favorable. Cependant, l'utilisation du feu comme principal outil d'aménagement des unités de végétation dans le domaine soudanien (Scott, 2000 ; Traoré et al., 2008Dayamba et al., 2008 ; Niang-Diop et al., 2010 ; Holou et al., 2011). Pour certaines légumineuses tropicales, les températures comprises entre 80 et 100 °C font augmenter d'une manière significative la germination des graines. ...
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