%0 Journal Article
%T Inhibition de Phytophthora palmivora, agent de pourriture brune des cabosses de cacaoyer en C te d¡¯Ivoire, par Trichoderma sp.
%A J Mpika
%A IB Kebe
%A IS Druzhinna
%A M Komon-Zelazowska
%A BCP Kubicek
%A S Ake
%J Sciences & Nature
%D 2009
%I 
%X La pourriture brune des cabosses du cacaoyer caus¨¦e par Phytophthora palmivora entra ne en C te d¡¯Ivoire 30 % de pertes sur les productions. Actuellement, pour combattre cette maladie, la lutte int¨¦gr¨¦e est envisag¨¦e. Elle inclue les pratiques culturales, la s¨¦lection des vari¨¦t¨¦s r¨¦sistances et l¡¯utilisation des antagonistes contre Phytophthora sp. notamment les esp¨¨ces du genre Trichoderma. Cette derni¨¨re approche n¨¦cessite l¡¯isolement, l¡¯¨¦tablissement d¡¯une collection des Trichoderma issus de la cacaoy¨¨re et l¡¯¨¦valuation du potentiel antagoniste de celle-ci pour le choix des antagonistes efficaces ¨¤ Phytophthora palmivora. A cet effet, des confrontations directes in vitro aussi bien que in vivo sur feuilles et sur cabosses ont ¨¦t¨¦ r¨¦alis¨¦es. Quarante trois isolats de Trichoderma montrent une activit¨¦ antagoniste vis ¨¤ vis de Phytophthora palmivora sur milieu de culture, avec des taux d¡¯inhibition de l¡¯ordre de 34 ¨¤ 79 % mais, aussi r¨¦duisent significativement la sensibilit¨¦ foliaire de 6 clones de cacaoyer et de cabosses. Ces tests in vitro et in vivo ont permis de retenir les isolats T.spirale T4, T.virens T7, T.asperellum T54 et T.harzianum T40 ¨¤ forte action inhibitrice vis ¨¤ vis de Phytophthora palmivora, offrant une forte aptitude ¨¤ r¨¦duire la sensibilit¨¦ et surtout ¨¤ renforcer la r¨¦sistance intrins¨¨que du clone sensible NA32 au parasite. Ces tests d¡¯antagonistes ont permis la s¨¦lection des Trichoderma sp. candidats aux essais au champ. La r¨¦alisation des essais au champ ¨¦valuera l¡¯efficacit¨¦ en milieu r¨¦el des antagonistes naturels sur le d¨¦veloppement de la maladie. Cocoa black pod disease in C te d¡¯ivoire, due to Phytophthora palmivora , can cause crop losses up to 30%. At present, for controlling cocoa black pod rot, an integrated pest management strategie was envisaged, and include cultural pratices, selection for resistant cocoa varieties and biological control microorganisms. The latter approach need isolation, establishment of collection microorganisms found in the cocoa ecology of C te d¡¯Ivoire and evaluations for their ability to control P. palmivora for screening biocontrol candidates. In vitro direct confrontation also although leaf disc and the cocoa pod biocontrol screening biotest have been carried out. Fortythree of isolates Trichoderma expressed in vitro inhibition against P. palmivora on high-nutrient media, with in the order of 34 ¨¤ 79 % of inhibition rate but, also were significantly reduced the level of susceptibility of six clones and cocoa pods to P. Palmivora. The isolates T.spirale T4, T.virens T7, T.asperellum T54 et T.harzianum T40 were found to be very effective against P. palmivora by these in vitro and in vivo tests, exhibiting high potential to reduce the susceptibility and especially to reinforce intrinsic resistant susceptible clone (NA32) towards P. palmivora. These screening tests pemitted the selection of Trichoderma isolates candidates for field trials. This field trials will assess for efficacy biocon
%U http://www.ajol.info/index.php/scinat/article/view/48579