In Vitro Effects of Antagonistic Microorganisms on Fusarium oxysporum [Schlecht. Emend. Synd & Hans] Infecting Arachis hypogaea L.

Abstract

In  an  attempt  to develop  biocontrol  system  for  management  of Fusarium wilt in groundnut, Trichoderma viride, Trichoderma harzianum, and Pseudomonas fluorescens were evaluated for their antagonistic  activity against  Fusarium  oxysporum in vitro .The conidia of Fusarium oxysporum  were found  to  be inhibited by all the  three  antagonistic microorganisms. Among  them,  highest percent  inhibition of  conidial  germination was brought out  by Trichoderma viride [89.4%] followed by Trichoderma harzianum [85.7%] and Pseudomonas fluorescens [83.15%]and inhibition of radial mycelial growth were 86.6%, 84.0%,  60.0% respectively.This inhibition is due to the volatile and non volatile metabolites and cell wall degrading enzymes produced by Trichoderma spp . Antagonistic  activity of Pseudomonas  spp.against Fusarium oxysporum is mainly due to the antibiotics, Fe-chelating siderophores and hydrogen cyanide.