Damping-off and root-rot diseases have significant impact on bean production and geographically wide spread and when being severe can completely destroy the legume crop. In this study, certain commercial products i.e., Bio-Cure B, Bio-Cure F, Bio-Healthy, Rhizo-N, Symbion-N, Symbion-NG and Symbion-NR, were evaluated for their efficacy to control damping-off disease and their effect on the yield of bean, under naturally infested field conditions during growing
seasons of 2012-2015. Three pathogenic fungi i.e., Rhizoctonia solani, Fusarium solani and Pythium ultimum, were isolated from diseased bean seedlings showing damping-off symptoms collected from Qaha region, Qaluibiya Governorate. Disease incidence was decreased with application of commercial bio-products as seed or soil drench treatments. Application of the tested bio-products as soil drench treatment was more effective against damping-off disease and
increasing nodule production and the yield than their application as seed treatment. Rhizo-N was the most effective to control the disease, but Bio-Health was the lowest effective and Bio-Cure B, Bio-Cure F, Symbion-N, Symbion-NG and Symbion-NR recorded moderate effects. Meantime, nodule production and yield of bean were increased with application of the tested bio-products compared to the check treatment. Nitrogen fixation bacterial products i.e., Symbion-N,
Symbion-NG and Symbion-NR, were the most effective to increase the yield and nodule formation compared to the tested bio-control products i.e., Bio-Cure B, Bio-Cure F, Bio-Health and Rhizo-N, which gave moderate effects. Application of Bio-Cure F or Rhizo-N or Symbion-NR for three times as soil drench treatment were more effective to control the disease and to increase the yield and nodule formation than when applied one time, during 2015 growing season.