Clipping and Gibberellin Treatments Promote Germination in Dormant Grape Seeds

‘Crimson Cabernet’ grape (Vitis vinifera) seeds showed physiological dormancy and germinated at ~60% after 60 days of chilling stratification. Fresh seeds harvested after physiological maturity and sown without drying failed to germinate after 30 days when sown on agar. In agar-sown fresh seeds cut at the distal seed end or intact seeds treated with gibberellic acid (GA), the seeds germinated at ~20% after 30 days. The highest germination percentages after 30 days were 63% to 83% in fresh, agar-sown seeds that were cut and treated with GA at 5000 mgL^–1 regardless of stratification time. Similar results were seen in seeds allowed to dry before sowing. Seeds cut and treated with GA at 5000 mgL^–1 germinated at 79% after 30 days. However, dry seeds sown on germination paper showed lower germination after cutting and GA treatment compared with agar-sown seeds. The highest germination percentages after 30 days in dry, cut seeds on germination paper treated with GA at 2000 and 5000 mgL^–1 were 33% and 55%, respectively, compared with agar-sown seeds, which germinated at 76% and 79%, with the same treatments. Results from this study provide a system that reduces the need for chilling stratification for grape seed germination by using partial seedcoat removal and GA treatment.