Stockplant Management for Optimized Rhizogenesis in Tectona grandis Stem Cuttings
ABSTRACT A 5-year stand of teak (Tectona grandis L. f.) was coppiced in 1999 and converted into a vegetative multiplication garden. Subsequently, three harvesting regimes
for the collection of single node stem cuttings were imposed: (1) once – in March (H1), (2) twice – in March and September (H2) and (3) three times in March, July and November (H3). Cuttings were treated basally with either:- T0 – control (6h in water), T1 – half the recommended dose of a mixture of IBA and thiamine (500ppm IBA +400ppm thiamine) or T2 – the full dose of the same mixture (1000ppm IBA +800ppm thiamine). Cuttings receiving IBA +thiamine rooted significantly
better than untreated cuttings, but even the best treatment only resulted in 38.3±3.8% rooting. This treatment produced
the greatest number of roots (5.2–12.1). The full dose treatment appears to have been supra-optimal. Rooting ability was also
affected by the frequency of stockplant pruning, with cuttings from stockplants pruned twice per year having the greatest
rooting percentage (27.8±3.8%) and the most roots (9.2±4.8). This bi-annual pruning (H2) resulted in the greatest number of rooted propagules (2.6 and 4.2 times more than H1 and H3, respectively). There was a significant interaction between Treatment×Pruning frequency. Bi-annual hedging of teak stockplants
is recommended for practical purposes, although further work is required to achieve commercially acceptable levels of rooting
from coppiced tree stumps.
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ABSTRACT: Stockplants of Triplochiton scleroxylon were grown in controlled-environment cabinets at the Institute of Terrestrial Ecology, Edinburgh, to test the effects of stockplant illumination on the rooting ability of leafy stem cuttings. The environmental variables were: (1) irradiance (PAR = 106 202 and 246 μmol m−2s−1) with a uniform light quality (red: far red ratio=1.75); (2) light quality (R:FR = 1.6 and 6.3) with a uniform irradiance (PAR=294 μmol m−2s−1); and (3) irradiance (PAR=250 and 650 μmol m−2s−1) and nutrients (with and without 0.2% solution of 1:1:1, N:P:K) at a uniform light quality (R:FR=6.3). In all experiments, measurements were made of shoot length and leaf size and in the third experiment, the net photosynthetic rates of each leaf were determined prior to taking cuttings. Leaf area and leaf and stem dry weights were measured, as were their starch and reflux-soluble carbohydrate contents.The results showed that decreasing R:FR and irradiance independently increased both shoot growth and rooting ability. Strong positive relationships between photosynthesis and rooting were found when stockplants were grown at low irradiance (250 μmol m−2s−1) with and without fertilizers. A similar relationship was found, at high irradiance (650 μmol m−2s−1) only when nutrients were added. A strong negative relationship between the same parameters occurred without fertilizers at high irradiance. In addition, a weak negative relationship was found between rates of photosynthesis and the starch content of cuttings. It is concluded that end-product inhibition prevented the rooting of cuttings from stockplants grown without fertilizers at high irradiance with an R:FR ratio of 6.3.Forest Ecology and Management. 01/1992;
- Trees-structure and Function - TREES-STRUCT FUNCT. 01/1996; 10(5).
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ABSTRACT: Single-node leafy and leafless cuttings harvested from one-year-old, 1.3 to 1.5 m tall Leucaena leucocephala seedlings were successfully rooted in a non-mist propagator which is suitable for use in the rural tropics. Cuttings with a leaf attached rooted more successfully than those without a leaf (71% and 39% respectively) and clones differed significantly (43% to 71%). There was also a clear pattern in rooting ability of cuttings collected sequentially down the main stem. Cuttings rooted most successfully when taken from node five to 13, counting from the apex; this was the region where internodes were longest (64 to 109 mm) of moderate diameter (2.9 to 5.5 mm) and all cuttings had a leaf attached.Agroforestry Systems 07/1998; 42(2):149-157. · 1.37 Impact Factor