In seedless table grapes, the excessive natural fruit set leads to compact bunches, small berries withpoor colour, low uniformity of maturation and higher incidence of diseases, requiring flower and fruitthinning to attain a profitable production. Gibberellic acid spraying (GAc) and imposition of shading nets,cutting incident irradiance by 90, 98 or 100% at flowering, were tested in consecutive years aiming toexamine their influence on flower drop and consequent quality of ‘Sugraone’, ‘Thompson Seedless’ and‘Crimson Seedless’ grapes. Shade treatments reduced leaf gas exchange and leaf growth rates while nodifferences were found in GAc-treated vines. Effects on leaf gas exchange showed to be reversible aftershading net removal. Flower drop percentages increased in ‘Sugraone’ in response to 90% light reductionimposed at 50% bloom, and in ‘Thompson Seedless’ in response to GAc spraying and shade imposition,when compared to untreated vines.