ISHS Acta Horticulturae 618: XXVI International Horticultural Congress: Environmental Stress and Horticulture Crops
MIST, SOIL WATER POTENTIAL, AND CUTTING WATER POTENTIAL INFLUENCE ROOTING OF STEM CUTTINGS OF LOBLOLLY PINE |
| Authors: | A.V. LeBude, F.A. Blazich, B. Goldfarch, L.J. Frampton, F.C. Wise |
| Keywords: | vegetative propagation, shoot water potential, timber species. Pinus taeda |
| Abstract:
Two experiments were conducted to investigate the influence of mist, soil water potential (  soil), and cutting water potential ( cutting) on rooting hardwood (January) and softwood (June) stem cuttings of loblolly pine (Pinus taeda L.). Both experiments were arranged in a split-plot design.
Mist regime, a control and low mist (40% less mist than the control), was the main plot. soil treatments were the subplots.
Four soil treatments [-1.8 (wet), -2.6 (intermediate), and –3.6 (dry) kPa, and a control] were created using containers of various heights filled with coarse sand.
Tensiometers maintained the wet, intermediate, and dry treatments by controlling the frequency of subirrigation added to each treatment.
The medium for the control treatment consisted of 2 peat : 3 perlite (by volume), however, subirrigation was not added.
Mist regime was replicated twice.
Approximately 60 cuttings were set into each plot. cutting was measured destructively on one cutting per plot at 5 a.m. and 2 p.m. at 7-d intervals for 5 weeks after setting cuttings into the rooting media. soil was also measured at these times.
Rooting percentage was recorded after 10 weeks. soil, cutting, and rooting percentage data were analyzed statistically to determine the most significant relationship among variables.
Mean rooting percentages for January- and June-collected cuttings were 23% and 48%, respectively.
In January, cutting decreased with decreasing mist.
The effect of soil depended on mist regime.
In June, cutting decreased with decreasing mist and decreasing soil.
In January, rooting percentage of cuttings under the control mist increased as cutting decreased, whereas rooting percentage of cuttings under the low mist decreased as cutting decreased.
In June, rooting percentage of cuttings under the control mist was higher regardless of soil treatment.
Rooting percentage of cuttings in both mist regimes increased as cutting increased.
The greatest rooting percentage for both experiments occurred in an intermediate range of cutting (-0.40 to –0.75 MPa), indicating that stem cuttings of loblolly pine may need to experience some degree of moisture stress to develop adventitious roots.
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