Activité antifongique des extraits aqueux des graines d’Azadirachta indica A. Juss. sur le développement de Sclerotium rolfsii, agent pathogène des rhizomes de Zingiber officinale

With the aim of contributing to the fight against phytopathogens, an evaluation of the antifungal activity of the aqueous extracts of the seeds of Azadirachta indica on the development of Sclerotium rolfsii, a pathogenic fungus of the rhizomes of Zingiber officinale , was carried out through bioassays on mycelial growth and sclerotia formation. The biological tests were carried out in vitro by systemic application on S. rolfsii . The results obtained revealed a sensitivity of the fungus S. rolfsiidifferent concentrations of seed extracts and the commercial fungicide product Mancozeb. The concentration of 50 gl-1 of the extracts and of Mancozeb induced high inhibition rates which are respectively 76.37±7.35% and 80.14±3.4% on the mycelial growth of S. rolfsii . The numbers of sclerotia formed were reduced in the dishes at concentrations of 50 gl-1 (4.1±1.1 of sclerotia) and 20 gl-1 (7±1.8 of sclerotia) of the extracts. The 50 gl-1 concentration of the plant extract was more effective in inhibiting mycelial growth and sclerotia formation of S. rolfsii . The results of this study suggest that the aqueous extract from the seeds of A. indica can be used preventively in S. rolfsii control strategies