%0 Journal Article
%T Evaluation de l\'activit¨¦ insecticide de deux plantes Hyptis suaveolens (Linn) et Khaya senegalensis (A. Juss) sur les insectes ravageurs du ni¨¦b¨¦ (Vigna unguiculata L. Walp.)/Use of two insecticidial plants for sustainable cowpea (Vigna unguiculata L. Walp.) protection
%A DK Kossou
%A P Atachi
%A TE Zannou
%A S Bougourou
%J Sciences & Nature
%D 2007
%I 
%X Une strat¨¦gie de protection de la culture de ni¨¦b¨¦ par les biopesticides a ¨¦t¨¦ test¨¦e avec les extraits aqueux d\'Hyptis suaveolens (Linn.) et de Khaya senegalensis (A. Juss), issus de mat¨¦riels v¨¦g¨¦taux conserv¨¦s pendant un an, trois mois ou un jour ¨¤ 5¡ãC. Les ravageurs cibl¨¦s sont Aphis craccivora Koch, Megalurothrips sjostedti Trybom et les bruches. Au champ, Callosobruchus maculatus Fabricius et son parasito de Uscana lariophaga Steffan sont vis¨¦s. Les biopesticides sont compos¨¦es de 37,5 kg de mati¨¨re v¨¦g¨¦tale pil¨¦e, le tous dilu¨¦ dans 375 litres d\'eau appliqu¨¦e ¨¤ l\'hectare. Les resultats ont montr¨¦ que la forme fra che des feuilles de H. suaveolens s\'est r¨¦v¨¦l¨¦e plus efficace sur les pucerons et les thrips. L\'¨¦corce de 3 mois de K. senegalensis a aussi ¨¦t¨¦ plus efficace sur les pucerons. Par contre, l\'¨¦corce fra che ou celle conserv¨¦e pendant 3 mois pr¨¦sentent les m¨ºmes effets sur les thrips. Les extraits aqueux des deux plantes ¨¤ l\'exception de l\'¨¦corce fra che, ont r¨¦duit (P=0,05) la ponte chez C. maculatus, et favoris¨¦ le parasitisme des oeufs par U. lariophaga. De plus, la vigueur des graines r¨¦colt¨¦es n\'a pas ¨¦t¨¦ affect¨¦e (P=0,05). Ces deux plantes peuvent ¨ºtre exploit¨¦es pour une production et une protection durables du ni¨¦b¨¦. Cowpea production and protection that preserve human heath and environment, needs to be assessed on alternative uses of pest control methods that do not only rely on synthetic insecticides. Plant materials, Hyptis suaveolens (Linn.) leaves and Khaya senegalensis (A. Juss) bark stored for one year, three months or one day, were processed in aqueous forms and tested against Aphis craccivora (Koch.), Megalurothrips sjostedti (Trybom.) and Callosobruchus maculatus Fabricius in field. Their effects on egg-laying activity of C. maculatus and its parasito d Uscana lariophaga Steffan were evaluated. Results showed that fresh leaves of H. suaveolens were the most effective on aphids and thrips. Three months storage bark powder extract of K. senegalensis also was effective on aphids. Whereas fresh bark extract or that from 3-month stored material showed similar control level on thrips. All stored plant materials involved in the aqueous extracts of both plants, regardless of storage periods and except the fresh bark form of K. senegalensis, reduced significantly (P=5 %) egg laying activity of C. maculatus on pods, and favoured parasitism of U. lariophaga. Plant aqueous extracts did not significantly affect seed vigour. Overall results reveal that sustainable cowpea production and protection could be developed based on these plants.
%U http://www.ajol.info/index.php/scinat/article/view/42126