Abstract
Thinning trials with vinasse in comparison to lime sulphur were carried out for 4 years at different sites in South Tyrol. Beside the thinning effect, the influence on fruit quality, phytotoxic damage on the leaves and the return bloom of treated trees were evaluated. Depending on the dosage the vinasse treatments showed a good thinning effect, but russetting and leave damages were significantly higher in comparison to lime sulphur. Return bloom of vinasse treated trees was lower than of those treated with lime sulphur. In conclusion, vinasse treatments can not substitute lime sulphur for flower thinning in organic apple orchards.