Combination of Different Antagonistic Bacteria to Control of Potato Blackleg Disease Caused by Pectobacterium atrosepticum under Greenhouse and Field Conditions

Abstract

Three different antagonistic bacterial isolates, Pseudomonas fluoresces (Pf2), Bacillus subtilis(Bs3) and Rahnella acquatilis (Ra39) restricted the growth of Pectobacterium atrosepticum, the causal agent of black leg disease of potato, in vitro.   Under greenhouse and field conditions, potato plants pre-treated with the three antagonistic bacterial isolates, individually or in combination, showed reduced disease severity relative to non-treated control plants. All isolates produced siderophores in different degrees but did not produce indole acetic acid (IAA) or hydrogen cyanide (HCN).The obtained results indicated that combination of Pseudomonas fluoresces (Pf2), Bacillus subtilis (Bs3) and Rahnella acquatilis (Ra39) is beneficial in controlling black leg disease of potato caused by pectobacterium atrosepticum.