Antagonism Activity of Phosphate Solubilizing Bacteria Against Ganoderma philippii and Fusarium oxysporum of Acacia Plants

Ganoderma philippii and Fusarium oxysporum 0148c are the primary pathogenic fungus that causes root rot and damping-off in young Acacia plants. The best treatment to date is the use of biological control agents. Phosphate solubilizing bacteria (PSB) isolated from acid soil is a bacterial isolate classified as plant growth-promoting bacteria (PGPB). PGPB has an indirect function as a biocontrol agent for fungal pathogens. This study aimed to determine the potential of PSB isolate EF.NAP 8 in inhibiting G. philippii and F. oxysporum 0148c from acacia plants. The method used is a dual culture antagonism test and observation of abnormal hyphae after the antagonism process. The results showed that the isolate EF.NAP 8 inhibited G. philippii by 34.44% and F. oxysporum 0148c by 33.33%. The abnormality of hyphae after antagonistic activity results in hyphal malformations such as hyphae lysis and hyphae coiling. The antagonistic activity of PSB EF.NAP 8 isolate is one of part of the ability of a bacterium classified as PGPB in the form of biocontrol activity against pathogenic fungi. This provides information regarding the opportunity to utilize EF.NAP 8 as a candidate agent for controlling fungal pathogens on acacia plants.