Teak (Tectona grandis) is a priority species for plantation development in Papua New Guinea (PNG), although expansion of the planted area is constrained by a lack of high quality seed sources. To address this problem, clonal methods were used for capturing selected plus trees within existing plantations (9 candidates) and an existing clonal seed orchard (20 candidates). Truncheon cuttings were collected from the lower branches of each of the 29 candidate trees. Truncheons were cool-stored for 5 days during transportation before being planted in a potting medium that was a mixture of coarse sand and forest soil (at ratio 1:1 by volume) and placed under intermittent mist. Adventitious root development in the truncheons occurred over a period of 5 to 6 months, and successfully rooted truncheons were planted in a hedge garden and used as a further source for cuttings. Subsequent cutting experiments using softwood single-node cuttings evaluated the effects of (i) rooting media (coarse sand vs a mixture of coarse sand and coconut husk) in the non-mist propagators, and in the mist system, coarse sand, fine sand, jiffypot (coco pellets) and a mixture of perlite and coconut husk, (ii) cutting length (6, 8, 10 and 12 cm), and (iii) rooting ability of clones. After 12 weeks a significantly greater rooting percentage was recorded in a mixture of coarse sand and coconut husk (78%±3.95 se) compared to coarse sand alone (52.3%±2.85 se) in the non-mist propagators. Rooting percentage variation did not differ significantly across the rooting media in the mist propagation system. However, a greater rooting percentage was attained in jiffypots (85%±0.05 se) compared to in coarse (64.6%±0.07 se) and fine sand (65.3%±0.06 se). For the cutting length experiment, s significantly greater rooting percentage (94%±0.04 se) was recorded with the cutting length of 10 cm compared with 6 cm (50%±0.09 se) and 8 cm (53.1%±0.09 se) cutting lengths. At week 12 after insertion of cuttings in jiffypots, no significant variations in rooting percentages were found among the clones. Low rooting percentages were recorded across all clones. Nevertheless, cutting survival of these clones was significantly higher without producing roots at week 12 after insertion in jiffypots in the mist house. Clones obtained from leafy stem cuttings were successfully acclimatized and would be used in teak clonal seed orchard (CSO) establishment to become a source of high quality germplasm for planting in PNG.
IUFRO Research Group 3.08 Small-scale Forestry Conference, Sunshine Coast, Australia 11-15 October 2015
Small-scale and Community Forestry and the Changing Nature of Forest Landscapes, Proceedings from the IUFRO Research Group 3.08 Small-scale Forestry Conference / Meadows, John, Harrison, Steve R, Herbohn, John (eds): pp.141-149