Propagation of dateplum (Diospyros lotus L.) rootstock by leafing stem cutting

The present experiments were tarried out to investigate a possibility of vegetative propagation by leafing two-year-old stem cutting of difficult-to-root dateplum rootstocks. Effects of six kinds of propagation beds, 5 levels of indolebutyric acid (IBA) concentration (0, 2,000, 4,000, 6,000, 8,000ppm), 3 levels of leafing bud number per scion (1, 2, 3), 3 kinds of defoliation treatments of the leafing buds (all, half, none) and 3 sampling portions of a shoot on the rooting rate of scions were examined. The scions were made at 5-8cm in length with 2 leaning buds, and their bases were dipped up to the depth of ca. 2cm for 10 seconds in the 50% alcoholic solution of IBA. The results obtained are summarized as follows; 1. In the experiment of the combination effect of kinds of propagation bed and IBA treatments, 45% rooting rate was obtained by 2,000ppm IBA in the bed with peatmoss and Kanuma soil mixture (3 : 2, V : V), and 40% rooting rates by 2,000ppm IBA in beds with Kanuma soil alone and with peatmoss and vermiculite mixture (3 : 2, V : V), while no rooting was observed in the bed with sand and cultivated soil, regardless of the IBA concentration used. 2. Of the IBA concentration level, the highest rooting rate (62.5%) and the largest number of roots per scion (7.8) were obtained by 8,000ppm, and both the rate and number decreased as the IBA concentration decreased. 3. Of the number of leaf buds per scion, rooting rates were 75% in the 1-bud, 50% in the 2-bud, 35% in the 3-bud and 15% in the disbudding plots, respectively. 4. The scion taken from the base of a shoot showed a higher rooting rate (95%) compared with that from the middle (60%) and top (10%) portions of a shoot. 5. Defoliation treatment of leaning scion affected greatly the rooting rate, i.e., 60% in the non-defoliated, 55% in the half-defoliated and 20% in the all-defoliated plots