A polyketide antibiotic,2,4 DAPG was isolated from fluorescent pseudomonads. It was found to have more antifungal action to Pythium aphanidermatum at a concentration of 150µl. The DAPG produced by Pseudomonas chlororaphis isolate PA23 recorded the highest percent inhibition of P. aphanidermatum over control. This compound in spite of its antifungal action against P. aphanidermatum, it also significantly inhibited the mycelial growth of Rhizoctonia solani, Sclerotium rolfsii and Fusarium oxysporum f.sp cubense. Similarly, the sclerotial germination of R. solani, S. rolfsii and Macrophomina phaseolina were completely inhibited by DAPG. It also caused hyphal distortion in P. aphanidermatum, R. solani, S. rolfsii and inhibited the spore germination of Alternaria solani and Botryodiplodia theobromae. Similarly, it inhibited the egg hatching of the root knot nematode Meloidogyne incognita and caused juvenile mortality under in vitro. This compound was detected by TLC with an Rf value of 0.88. HPLC studies also revealed the presence of 2 peaks viz 2,4 DAPG and MAPG with a retention time of 11.14 and 22.07 min respectively.