The Potential of Rhamnolipid as Biofungicide against Rigidoporus microporus Isolated from Rubber Tree (Hevea brasiliensis)

Rigidoporus microporus is the main causal of white root disease (WRD) in rubber trees (Hevea brasiliensis). The present study investigates use rhamnolipid, a biosurfactant produced by Pseudomonas aeruginosa USM-AR2 against R. microporus. In vitro dose-responses towards rhamnolipid were determined on different isolates using poisoned food technique (PFT). Inhibition mycelial growth was found to be dose-dependent, with highest inhibition 76.74% at 200 ppm (pH 6.29) SEG isolate. On contrary, lowest concentration applied 10 5.97) had effectively inhibited RL 19 34.36%. AM isolate assumed most aggressive pathogen due recorded all concentrations tested. At same time, least compared other isolates. (ppm), which reduced 50% (EC50), 17.82 for isolate, 12.52 26, and 11.80 This result indicated that inhibit might vary based aggressiveness virulence levels It pH changes after incorporating into PDA not factor affecting obvious an inhibitory effect fungal vitro. first report has been shown control potentially.