Our investigation of integrated biological control (IBC) started with an assay testing activity of the
predacious yeast Saccharomycopsis crataegensis UFMG-DC19.2 against Penicillium digitatum LCP 4354,
a very aggressive fungus that causes postharvest decay in oranges. Under unfavourable environmental
conditions, the yeast showed a high potential for control (39.9% disease severity reduction) of this fungus.
This result was decisive for the next step, in which S. crataegensis was tested in association with sodium
bicarbonate salt, a generally regarded as safe (GRAS) substance. The yeast was able to survive at different
concentrations of the salt (1%, 2% and 5%), and continued to grow for a week at the wound site, remaining
viable at high population for 14 days on the fruit surface. The yeast alone reduced the severity of decay by
41.7% and sodium bicarbonate alone reduced severity of decay by 19.8%, whereas the application of both
led to a delay in the development of symptoms from 2 to 10 days. Ingredients of the formulations were not
aggressive to fruits since no lesions were produced in control experiments.
