Abstract
Even though the corollas abscise at the base of the flower at anthesis, the corollas of some grape cultivars remain on their ovaries for a while. The retention of corollas can lead to the russeting of berries, especially in ‘Sun Verde’, whose long ovary, narrow corolla, short filaments, and incomplete corolla dehiscence make it hard to remove the corollas. We investigated the effectiveness of 3 types of radial brush fixed to the top of a dipping cup to dislodge the corolla during the 1st gibberellin treatment. Three days after gibberellin treatment, the rate of corolla fall in brushed grapes was 2 to 3 times that in the control (unbrushed) grapes. The removal of all corollas by hand led to the lowest occurrence of severe russeting at maturity, followed by brushing, and non-removal in ‘Sun Verde’ grape. Brushing significantly decreased the incidence of severe russeting relative to the control.
