Management of Postharvest Anthracnose Disease of Papaya (Carica papaya) Using Antagonistic Microorganisms

Abstract

The antagonistic potential of microbial agents isolated from different sources like compost, rhizosphere soil, healthy fruits surface were investigated against Colletotrichum gloeosporiodes under In vitro and In vivo. The results of In vitro evaluation of 22 isolates of antagonists against Colletotrichum gloeosporiodes by dual-culture test showed Trichoderma harzianum UHSF-15 (with 62.50% inhibition of radial growth), Bacillus amyloliquifaciens UHSB-BCA-15 isolated from banana rhizosphere soil (50.00% inhibition) and Bacillus amyloliquifaciensUHSB-BCA-16 isolated from kiwi fruit surface (47.85% inhibition) to be most effective. In vivo screening of five effective microbial agentsselected from In vitro studies revealed that, Bacillus amyloliquifaciens UHSB-BCA-15to be most effective with lowest per cent disease index of 13.89% followed by Bacillus amyloliquifaciensUHSB-BCA-16 with 16.67% and carbendazium at 0.1% with 20.83% at 9d after storage. The higher per cent disease index of 58.33% was recorded in untreated control fruits. In another experiment where C. gloeosporoidesspore suspension (1x106 CFU mL-1) was challenge inoculated on fruits, the fruits treated with biocontrol agent Bacillus amyloliquifaciens UHSB-BCA-15 at concentrations of 1x108 CFU mL-1 for 5 minutes was found to be effective in reducing postharvest infection to a greater level with 33.33% disease index followed by Bacillus amyloliquifaciens UHSB-BCA-16 with 50.00% disease index and carbendazium at 0.1% with 52.77% disease index compare to control (91.66% disease index) at 9d after storage.