The muscadine grape (Vitis rotundifolia Michx.) is a native fruit crop of the Southeastern U.S., known for its resiliency, high nutritional value, and relatively low input cost in comparison to bunch grapes. Muscadine grape breeding efforts aim to answer production challenges by developing new germplasm with superior traits such as cultivars with large berry size, increased yield, and improved fruit quality attributes. This study aimed to evaluate the overall performance of the University of Arkansas breeding program advanced selections ‘AM-70’, ‘AM-195’, ‘AM-26’ and ‘AM-77’ and the University of Georgia bred selections ‘Ga. 10-1-222’, ‘Ga. 13-4-2’, ‘Ga. 6-1-269’ and ‘Ga. 10-1-294’ in Alabama conditions. Plants of ‘RubyCrisp’ were included for comparison. The experimental vines were planted at the Chilton Research and Extension Center (USDA hardiness zone 8A), Clanton, AL, in 2021. A RCB design with four single plant replications was utilized. Harvesting season spanned from Aug. 9 to Sept. 18, 2024. Fruit of ‘Ga. 10-1-222’, ‘Ga. 13-4-2’, ‘Ga. 6-1-269’, ‘Ga. 10-1-294’, ‘AM-70’, ‘AM-26’and ‘AM-77’ ripened early whereas ‘AM-195’ had a mid-season ripening and ‘RubyCrisp’ matured late in the season. Results suggest ‘Ga. 10-1-294’, was the highest yielding selection, with a total yield of 27.7 kg/vine, compared to the standard cultivar ‘RubyCrisp’, which yielded 24.3 kg/vine. However, no significant difference in total yield among the tested selections was found. The berries of ‘Ga. 6-1-269’ had the largest individual berry weight of 11.9 g, followed by cultivar ‘RubyCrisp’ (11.5 g). ‘AM-195’ berries were the firmest and it was found that the selections differ in flesh firmness. While ‘RubyCrisp’ produced the highest percent berries with wet stem scar (27.6%), ‘AM-26’ had the highest percent berries with dry stem scar (92.9%). ‘AM-70’ berries were the sweetest (17.10 Brix), followed by ‘AM-195’ (15.20 Brix). The TSS:TA ratio varied between 16.7 and 41.0 and was highest for ‘AM-70’. The important fruit productivity and fruit quality parameters evaluated in this study can inform breeders on selection of superior cultivars of muscadine grapes.
