This research was carried out to determine the effects of a brassinosteroid compound (22S-, 23S-homobrassinolide) on yield and quality attributes of a field-grown table grape cultivar 'Alphonse Lavallee'. The vines were sprayed at anthesis (first week of May) with the compound over two growing seasons. The solutions were prepared at the concentrations of control, 10(-3) and 10(-4) mg.L-1. Clusters were harvested when those of the control vines reached 16 degrees Brix. Yield and quality parameters were analyzed. There were no clear effects of the compound on yield and quality, except for the cluster length. The low concentration resulted in longer clusters. High concentration increased the tensile strength of the pedicel to some degree. Seasonal differences were observed in most of the parameters studied.