Performance of some Antagonistic Bacteria in Minimizing Occurrence of Peanut Damping-off, Root- and Pod-Rot Diseases

Document Type : Original Article

Author

Plant Pathol. Res. Inst., Agric. Res. Centre, Giza., Egypt

Abstract

Seventeen bacterial isolates from soil, rhizosphere, geocarposphere, peanut roots and pegs beside three bioagents (Bacillus subtilis, Pseudomonas putida and P. fluorescens) were used to study their antagonistic effects on the casual pathogens of peanut damping-off, root- and pod-rots (Fusarium solani, F. moniliforme, Macrophomina phaseolina, Rhizoctonia solani, Sclerotium rolfsii). In vitro evaluation revealed that only nine isolates caused moderate to strong inhibition to the tested pathogens. P. fluorescens (Pf.5) show ever, gave the highest significant antagonistic effect against the five pathogens on PDA followed by B. subtilis (Bs.1), P. putida (PP) and Brevibacterium casei (S.5). In greenhouse and field experiments, the most effective isolates in reducing peanut damping-off, root- and pod-rot diseases were P. fluorescens (Pf.5) followed by B. subtilis (Bs1) and B. casei (S.5). Also the highest total peanut pod yield in the two seasons (2012 and 2013) was obtained by B. subtilis (Bs1) followed by P. fluorescens. The results confirmed the ability of some bioaegents to be near to the action of fungicide (Rizolex-T) in reducing peanut damping-off, root- and pod-rot diseases. In this respect, in greenhouse and field trials P. fluorescens (Pf 5.) effect was the nearest one to fungicide effect in minimizing of peanut damping-off, root- and pod- rots followed by B. casei (S.5) and B. subtilis (Bs1).

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