Biocontrol of Citrus green mould and postharvest quality parameters

The potential for using Pichia guilliermondii BCC 5389 or Bacillus subtilis ABS-S14 by themselves or in combination for the control Penicillium digitatum in citrus, and their effects on postharvest quality of fruit was investigated. The percentage of disease with the combined antagonists was completely inhibited. Rapid colonization of P. guilliermondii was observed in the wounds during the first day to 6 days at 25 o C, whereas B. subtilis, increased marginally over 3 days. The populations then stabilized for the remaining incubation period. The percentage of spore germination of P. digitatum incubated with all treatments was inhibited by 100%. At concentrations of the combined antagonists of 1x10 8 CFU/mL, the incidence of green mould was reduced to 0% compared with the pathogen control itself (92.93%) after 5 days of incubation at 25 o C. The combination did not impair any of the quality parameters of fruit following incubation at 25 o C for 7 days.