Potential control of Botrytis cinerea by yeasts in an integrated cultivation system of lilies

Abstract

The objective of this study was to compare a population of phylloplane yeasts in lilies cultivated in a conventional cultivation system to other lilies in an integrated system, as well as to evaluate the antagonism of Sporidiobolus pararoseus to Botrytis cinerea. The yeast community was estimated by the spore-fall method in the lower, middle and upper thirds of the plants, as well as in the abaxial and adaxial leaf surfaces. The yeast population was high on the leaf discs of the plants from the integrated system, and it was higher on the adaxial surface and on leaves from the middle third of the plants. To evaluate yeast antagonism, concentrations of 10⁵, 10⁶ and 10 ⁷ cells mL^-1 were sprayed on the leaf discs in three inoculation times: 24 hours before; simultaneously; and 24 hours after inoculation with B. cinerea at a concentration of 10⁴ spores mL^-1. The incidence and percentage of disc tissue area colonized and of B. cinerea sporulation were evaluated through a category scale, starting from the fourth day after the inoculation. All yeast concentrations reduced B. cinerea sporulation on the leaf discs in comparison to the control, and the yeast concentration of 10⁷ cells mL^-1 was the most effective.