Enhancing the bioefficacy of Bacillus amyloliquefaciens DGA14 with inorganic salts for the control of banana crown rot

The efficacy of Bacillus amyloliquefaciens DGA14, sodium carbonate (SC), sodium bicarbonate (SBC) and sodium hypochlorite (SH), applied alone or in various combinations, was evaluated in vitro and in vivo. DGA14 had variable responses in 1% (w/v) salts such as normal cell growth in SBC, reduction of cell cultivability by 1000-fold in SC and total inhibition by SH. DGA14 as stand-alone treatment controlled pathogens in vitro by 70% while SC, SBC or SH by 20-45%. DGA14 + SC restricted the mycelium growth of pathogens by 88%, DGA14 + SBC by 83% and DGA14 + SH by 52%. The efficacy of DGA14 against pathogens in vitro was enhanced by 21% and 15% with the amelioration of SC and SBC, respectively. Post-harvest application showed that fruit dipped for 30 min in DGA14 + SBC reduced crown rot by 93%, DGA14 + SC by 70% and DGA14 + SH by 9%. Our result indicates that the combination of B. amyloliquefaciens DGA14 with SBC managed crown rot disease comparable with synthetic fungicides without negative effects on fruit quality 14 days after treatment. (C) 2013 Elsevier Ltd. All rights reserved.