Biological control by Pseudomonas fluorescens and Azotobacter chroococcum bacteria to Fusarium chlamydosporum caused yellowing and stiffness of the detached leaves of date palm growth summit

Abstract

        The objective of this study was to isolate and identify the pathogen cause yellowing and stiffness of the detached leaves of date palm  growth summit.Results of  isolation from roots  showed presence of the fungal Fusarium chlamydosporum  in palm trees of Babylon and Karbala provinces , this is the first record of the fungus F.chlamydosporum on palm trees in Iraq. The initial detection of pathogenic isolates of  F.chlamydosporum  using red radish seeds showed  that all isolates tested were  pathogenic and germination Percentage ranged between 12 – 27% , and the results show the effect of isolate of F.chlamydosporum (F.c3) in the severity of injury of palm seedlings  75 days old under the lathe house conditions,the isolate(F.c3) gave a significantly rise in the severity of the injury reached to 93.75% compared to comparison which was 0.0%,the treatment of addition bacteria Pseudomonas fluorescens and bacteria Azotobacter chroococcum from concentration 5 x 10⁷ , 6.5 x 10⁶ (colonial unit / Ml) respectively, achieved protection of palm seedlings from injury with the isolate (F.c3) under lathe house conditions, resulted in the treatment of bacteria P.fluorescens and A.chroococcum to a reduction in the severity of the injury reached to 6.25% and 18.75% respectively compared to the treatment (pathogenic fungal only) that  the severity of  injury  reach to 93.75%.