In an attempt to develop biocontrol system for management of soft rot in Aloe vera, Pseudomonas fluorescens and Bacillus subtilis were evaluated for their antagonistic activity against Erwinia chrysanthemi in vitro. Soft rot diseases caused by the Erwinia chrysanthemi lead to significant yield losses of crops. Experiments were conducted on the effect of culture filtrates of combined application of (Pf32 + Pf 45 +Bs5) on the in vitro inhibition of pectinolytic enzymes of Erwinia chrysanthemi. The activity of pectate lyase activity, pectin methyl esterase, polygalacturonase, pectin trans eliminase activity produced by Erwinia chrysanthemi was higher, when compared to control. Maximum inhibition of above pectinolytic enzymes (PME, PG and PTE) was shown by Pseudomonas fluorescence treatment was followed Bacillus subtilis. Of all the treatments, Pseudomonas fluorescence treatment showed higher rate of inhibition of Pectinolytic enzymes of Erwinia chrysanthemi. This study indicates that combined application of (Pf32 + Pf 45 +Bs5) is the best biocontrol agent in the inhibition of Erwinia chrysanthemi causing soft rot of Aloe vera. The enzyme activity of inoculated aloe plants increased from the two day till the six DAI and slowly declined thereafter in all the 15 isolates.

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