Effects of High Auxin Concentrations, Cold Storage, and Cane Position on Improved Rooting of Vitis aestivalis Michx. Norton Cuttings

Abstract

More than 3,000 Norton hardwood cuttings were tested in an experiment conducted under commercial greenhouse propagation conditions. Treatment with 10,000 or 15,000 mg/L potassium salt of indolebutyric acid (KIBA) caused >70% of the cuttings to root, compared with 23% rooting of the nontreated control cuttings. In studies at a university greenhouse under intermittent mist, cuttings that were collected in January and stored in a cooler at 5°C for ≥55 days (>2300 hours of natural plus cooler chilling) formed more roots than cuttings receiving fewer hours of chilling. Cuttings in this experiment that were treated with 15,000 mg/L KIBA formed significantly more roots than cuttings not treated with auxin. Hardwood cuttings and softwood cuttings taken from more basal or middle cane segments rooted better than cuttings from nearer the apical region. Softwood cuttings formed more roots when treated with 2,500 mg/L KIBA compared to the nontreated control cuttings.