Growth, Cold Hardiness, and Carbohydrate Content of Vidal blanc Grapevines Propagated by Hardwoodvs.Softwood Cuttings

Abstract

Vidal blanc (<i>Vitis</i> x sp.) hardwood and softwood cuttings propagated in 1983 (H-83 and S-83) and 1984 (H-84 and S-84) were evaluated for root and shoot growth in the nursery, carbohydrate content, cold hardiness, and vine survival and growth after planting in the field. Roots and shoots of H-84 cuttings were significantly larger than those of S-84 cuttings. S-84 cuttings had a greater starch and total carbohydrate content in the roots than any of the other cuttings when dug in October. Roots of S-83 and H-83 cuttings dug in December had similar starch and water soluble carbohydrate (WSC) levels. Shoots of S-83 cuttings had a lower starch content than H-83 cuttings, but WSC content was similar. In freezing tests, S-84 cuttings had less phloem injury at -25°C and greater primary bud hardiness than H-84 cuttings when collected from the nursery in mid-winter. S-83 and H-83 cuttings grew vigorously when planted in the field in the spring and were not significantly different in shoot length at the end of the first growing season.