Evaluation du potentiel de biocontrôle de souches natives d’actinomycètes contre le flétrissement bactérien (Ralstonia solanacearum) de la pomme de terre.

In Madagascar, bacterial wilt caused by the soil-borne species complexe Ralstonia solanacearum is a major constraint to potato production. Native strains of actinomycetes were isolated from rhizospheric soil of potato to develop microbial biocontrol agents. Four out 84 isolated antagonistic actinomycetes showed highest antagonistic activity against strains of R solanacearum with clear halo zone diameter of 30mm. A field experiment carried out in the district of Ambatolampy in the Vakinankaratra region focused on applying solid (fertile soil) formulation of bioinoculants containing a single or multiple antagonistic and phosphate solubilizing actinomycetes strains revealed biocontrol potential against bacterial wilt (reducing bacterial wilt incidence up to 53%) and growth promoting potential of the variety Mevamena of potato (increasing total potato tubers up to 86%).

Key-words: antagonist, bacterial wilt, biofertilizer, biopesticide, potato, Ralstonia solanacearum, Vakinankaratra

21/03/2024