Evaluation of pre-harvest Bacillus licheniformis sprays to control mango fruit diseases

Abstract

Bacillus licheniformis was evaluated as a pre-harvest spray treatment either on its own or alternated with copper oxychloride to control mango fruit diseases. Prior to initiating the spray trials, in vitro and in vivo studies were done to determine the effect of stickers, spreaders, a biostimulant and a copper fungicide on the biocontrol agent's ability to effectively attach to and colonise the mango leaf surface. Bioboost, Nufilm-P, Biofilm and Agral 90 did not affect antagonist growth in vitro. However, copper oxychloride and Supafilm inhibited the in vitro growth of B. licheniformis, more pronouncedly after 8 h. The in vivo study showed that stickers and spreaders did not improve the ability of B. licheniformis to attach to and colonise the leaf surface. Pre-harvest B. licheniformis applications alone and alternated with copper sprays applied at 3-weekly intervals from flowering until harvest controlled moderate levels of anthracnose, bacterial black spot and soft rot.