Summary of a working paper by
J.S. de Muckadell and P. Malim 1
This report, published under FAO/UNDP Project MAL/78/009, records preliminary results of rooting studies on nine dipterocarp species. The studies were undertaken to develop a feasible alternative to normal seedling production in face of difficulties due to variable seed crops and the recalcitrant nature of dipterocarp seeds. They were suspended after six months due to shortage of funds. The principal aspects discussed are rooting media, ortet, preparation and types of cuttings, differences among species, influence of ortet age and treatment, hormone treatment, time taken to root and development after transplanting.
Two high humidity rooting systems were used: an intermittent mist spray unit controlled by an electronic leaf and a polythene tent over a gravel filled reservoir. A slightly higher percentage of cuttings and better developed roots were produced by the former, although cuttings from it required a weaning period before potting up, while those from the latter did not. Only coarse sand was used in the first system in which free drainage is essential. In the second, three media types were used: coarse, medium and fine sand. Coarse sand tended to dry out; water logging of the fine sand was lethal; best results were obtained from medium sand.
The ortets were 8–12 months old seedlings. Nine cutting types were used, one being a double node cutting and the remainder single node with reduced leaves.
Rooting percentages varied widely between species, some (Dryabalanops lanceolata, Shorea leprosula and S. parvifolia) being fairly easy to root, some extremely difficult and others intermediate. There was some indication that a single node cutting taken two nodes below the tip was the easiest to root and that apical double node cuttings are not superior to single node cuttings. Small, weak cuttings gave poor results. On average a higher rooting percentage was obtained from the youngest cuttings, even within the narrow range of seedling ages available. There was an unexplained trend for ortets preconditioned with fertilizers to yield fewer successful cuttings than untreated seedlings. There was no marked response to hormone treatment of cuttings with 1500 ppm NAA, although for most species basal cuttings so treated gave higher percentages of rooting than those from near the apex. Studies of time taken for roots to form and of different transplanting times were inconclusive. Little work was possible on the culture of rooted stock after transplanting. However, it was clear that this phase would require close attention since rooting and newly rooted cuttings are extremely sensitive to environmental changes.
1 Forest Research Centre, Sepilok, P.O. Box 1407, Sandakan, Sabah, Malaysia.
Note abstracted at FAO Headquarters from Working Paper No. 20,FAO/UNDP MAL/78/009. (1984)
