Preliminary Assessment of Bud Fertility Dynamics and Pruning Implications in Twenty-Two Indigenous Turkish Grapevine Cultivars

Bud fertility is a major determinant of grapevine productivity and an important criterion for selecting appropriate pruning strategies, yet information on indigenous Turkish Vitis vinifera cultivars remain limited. This study evaluated the bud fertility characteristics of 22 indigenous grapevine cultivars grafted onto 1103 Paulsen rootstock to identify cultivar-specific pruning requirements. Bud fertility, shoot emergence, and cluster formation were assessed using single-node cuttings collected during winter dormancy and forced under controlled conditions. Marked differences in shoot emergence and cluster production were observed among cultivars and bud positions. In most cultivars, the highest fertility occurred in the middle portion of the cane, whereas Oglak Karası and Rumi Uzum exhibited increasing fertility toward distal buds, indicating a preference for long cane pruning. Based on fertility distribution patterns, the majority of cultivars were classified as suitable for short pruning, while several cultivars showed better adaptation to medium pruning. These results demonstrate substantial variation in bud fertility among indigenous Turkish grapevine cultivars and highlight the importance of cultivar-specific pruning strategies for improving yield potential. The findings provide baseline information for 22 indigenous Turkish cultivars and contribute to the development of more efficient pruning recommendations under local viticultural conditions.