Pg. 41-43 Clonal Propagation of Litchis by Cuttings

Branches of 12-year-old HLH Mauritius trees were girdled and 200 mm terminal and subterminal cuttings were taken from girdled and non-girdled branches 30 days later. Cuttings were treated respectively with 0, 5 000 and 10 000 mg/kg IBA (3-lndole butyric acid) and rooted in peat and sand (1: 1) in a mistbed at 29 ± 2°C. Best rooting was obtained with girdled cuttings. In another trial, rooting percentages of four litchi cultivars were determined when cuttings were cut in December. Cuttings of HLH Mauritius, Fay Zee Siu, Third Month Red and a Mauritius selection were cut and treated as described. Rooting percentages were determined after 90 days. Cuttings were transplanted into 8 t bags and survival percentages determined 30 days later. Rooting percentages varied between O and 83,3%. IBA treatments enhanced rooting. Survival percentages were between 30 and 100%. In another trial single node cuttings of 20 mm were cut and treated with IBA. Cuttings that received 10 000 mg/kg IBA have rooted best (52,5%).

Summary:

• The study evaluated clonal propagation of litchis (Litchi chinensis) by cuttings as an alternative to airlayering, which requires large amounts of plant material.
• Branches of 12-year-old HLH Mauritius trees were girdled and cuttings taken 30 days later, treated with 0, 5,000, and 10,000 mg/kg indole-3-butyric acid (IBA), and rooted in peat and sand under mist conditions.
• Girdled cuttings rooted better than non-girdled, with sub-terminal girdled cuttings showing the highest rooting percentages.
• Four litchi cultivars (HLH Mauritius, Fay Zee Siu, Third Month Red, Mauritius Burgershall) were tested for rooting in December; rooting percentages varied widely from 0 to 83.3%.
• IBA treatment strongly enhanced rooting; the cultivar Third Month Red rooted poorly compared to others.
• Survival rates after transplanting ranged from 30% to 100%, with proper IBA treatment and hardening off improving success.
• Single node cuttings of 20mm length treated with 10,000 mg/kg IBA rooted better but had fragile roots making transplanting difficult.
• Best rooting occurred in December with IBA treatment at 5,000 to 10,000 mg/kg.
• The article concludes girdling a month before taking cuttings improved rooting, IBA application promoted rooting, some cultivars root better than others, and gradual hardening off after rooting is essential for survival.
• Single node cuttings can root with moderate success but require careful handling and suitable rooting media to avoid root damage during transplanting.
• The study highlighted that time until cuttings can be transplanted to an orchard remains to be determined.
• The research was supported by the South African Litchi Growers Association and referenced various previous studies on litchi propagation.