EFFICACY OF ANTAGONISTIC FUNGAL AND BACTERIAL BIOAGENTS AGAINST FABA BEAN DAMPING-OFF DISEASE.

Faba bean damping-off caused by Rhizoctonia solani Kühn and Fusarium solani Mart are considered the most destructive diseases. All tested pathogenic fungal isolates of F. solani and R. solani that have been collected from various locations at nine governorates were clearly varied in their virulence onto faba bean plants (cv. Giza-429) under greenhouse conditions. F. solani El- Nubaria (Fs4) and R. solani El-Menia (R20) were the most virulent isolates. To evaluate the genetic diversity of the most aggressive isolates of R. solani and F. solani (9 isolates for each one), were investigated using random amplified polymorphic DNA (RAPD) technique. The most effective antagonistic bacterial and fungal isolates were identified by testing the ability of these isolates to utilize different carbon sources and amino acids using Biolog-System Technique. All tested bioagents (Trichodema hamatum-2, T. harzianum, Bacillus subtilis-1 and B. mylotquefaciens-1), culture filtrates, biocides (Bio-Arc and Bio-Zeid) and chemical fungicides (Rizolex-T, Vitavax-200 and Moncut) significantly reduced the percentages of damping-off and increased the percentage of survived plant compared with control. The most effective treatments for reducing these diseases were obtained by applying fungicides followed by both of active bioagents and biocides. Meanwhile, culture filtrates of bioagents were the least effective treatments. Rizolex-T and Moncut were the most effective fungicides against F. solani and R. solani. [ABSTRACT FROM AUTHOR]