Effects of juvenility on the rooting of trifoliate orange (Poncirus trifoliata [L.] Raf.) stem cuttings

The rooting ability of cuttings of current shoots from trifoliate orange (Poncirus trifoliata [L.] Raf.) trees at various ages was determined. All cuttings were collected in early June 2001. Rooting abilities varied among various ages of trifoliate orange trees. Forty-five days after cutting, the current shoots from one- and two-year-old trees had 100% rooting; those from 15- and 25-year-old trees had 0%. From three-year-old to five-year-old trees, the rooting percentage decreased as the age increased. The number of roots produced correlated positively with the rooting percentage. In another experiment, scions from current shoots from mature 'Aoshima' satsuma mandarin (Citrus unshiu Marc.) were grafted onto two-year-old trifoliate orange seedlings. All trifoliate orange portions of cuttings grafted with 'Aoshima' satsuma mandarin scions rooted.