Controlling of rot root pathogens on cucumber using some plant extracts and bio-control agentTrichoderma harzianum
Different fungal pathogensthat cause rot root disease have a significant impact on cucumbers, which has a tremendous economic limitation onthe yield of this important vegetable crop. The current study aimsto examine the effect of cold aqueous extract of three plants (Acacia farnesiana,Myrtus communisand Nerium oleander) on theradial growth and the biomass of some pathogenic fungi (Rhizoctoniasolaniand Macrophominaphaseolina)with the presence of Trichoderma harzianumas a bio-control agent. Fungal pathogens were isolated from root parts of infected cucumber plants that were collected from different regions of Najaf province, while the bio-control fungus was obtainedfrom the Bio-control Laboratory, Faculty of Agriculture -University of Kufa.Results of the currentstudy showed that 20%of the cold aqueous extract of M.communispowder was superior to the rest of the studied extracts in inhibiting the radial growth of studiedfungi, as the radial growth of R. solanireached 3.49cm, M. phaseolina3.02cm, and T. harzianum3.67cm. Thely apparent effect of the same extra extract on the growth of the fresh and dry biomass of the aforementioned fungi.The outcomes demonstrated that the 20%concentration of cold aqueous extract of M. communisalso increased the percentage of seed germination andthe fresh weight of cucumber plants.The cold aqueous extract of M. communisleaves and T. harzianumas a biological can be used ,to inhibit the growth of both pathogens of rot root disease, thus protecting cucumber seedlings and producinghealthy plants