Shoot Forcing and Rooting of Stem Cuttings of Morus (Mulberry) Species

Woody stem segments were forced to produce softwood shoots for propagation from 6 fruiting mulberry cultivars in the USDA-ARS collection at the National Clonal Germplasm Repository,  Davis, CA, including ‘Beautiful Day’, ‘Hunza White Seedless’, ‘Illinois Everbearing’, ‘Pakistan’, ‘Saharanpur Local’, and ‘Shangri-La’.  Stem segments 40 ±2 cm long and 2.5 – 9.5 cm caliper were harvested mid-September (run 1) and mid-October, 2013 and placed horizontally into flats of vermiculite in a greenhouse under drip irrigation in a randomized complete block design, blocking on stem diameter and gradients in the greenhouse. The number of 1 cm long buds and ≥3 cm long shoots were recorded on a weekly basis. When shoots ≥3 cm long, they were identified they were removed from the stem segments their bases were treated with 1000 ppm IBA in talc before planting in a 50/50 perlite-vermiculite mix and placed under intermittent mist. The cuttings were examined weekly to check for roots at least 1 cm long for data collection.  ‘Shangra-La’ produced the most leafy softwood shoots (5.3/stem segment), which rooted at 82% within 4 weeks.  Other cultivars produced few shoots and 50-100% rooting success was achieved for all other cultivars, except cuttings of ‘Saharanpur Local’ that did not root.