Hormone Treatments Affect Stem Cutting Propagation Strategies of Four Interspecific Hybrid Southern Grape Cultivars

Improving stem cutting propagation of grapevine species (Vitis sp.) is important for supporting growing interest in southern grapevine production, particularly for lesser-known cultivars. More efficient and reliable propagation techniques can help nurseries increase the availability of grapevine plants for local growers and support development of the southern U.S. wine industry. Hardwood and semi-hardwood cuttings of four winegrape cultivars, ‘Mamont Noir’, ‘MidSouth’, ‘Miss Blanc’, and ‘Norton’, were subjected to 10 hormone treatments consisting of indole-3-butyric acid (IBA) alone or in combination with ascorbic acid (ASC). Treatments were applied as a three-second basal quick dip. Sixty days after treatment, total shoot and root number, average shoot and root length, rooting percentage, and cutting and root quality were evaluated. Based on the results, semi-hardwood or hardwood ‘Mamont Noir’ cuttings can be propagated using 50 ppm ASC or 50 ppm ASC + 500 ppm IBA. For nurseries where hardwood cuttings better fit the production schedule, ‘Miss Blanc’ cuttings rooted well regardless of hormone treatment. Additional research is needed to optimize hormone treatments for ‘MidSouth’ and ‘Norton’.