Introduction
Materials and methods
Experimental specimens
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level A: 1.3 M treatment concentration DMDHEU; and level B: 2.1 M treatment concentration DMDHEU. From earlier trials, it is known that with a treatment with 1.3 M concentration, a weight per cent gain (WPG) of the wood samples of approx. 15–20% is reached, with 2.1 M, a WPG of 25–30%.
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Scots pine (sapwood): Pinus sylvestris from Germany in trials 1–4. The average liquid uptake was 550 kg/m³. The wood was nearly free of heartwood; however, small bands of heartwood could appear.
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Beech: Fagus sylvatica from Germany in trials 1–4; average liquid uptake 660 kg/m³.
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Slash pine (pure sapwood): Pinus elliottii from Queensland, Australia in trials 1 and 3; average liquid uptake 485 kg/m³.
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Spotted gum: Corymbia maculata from Queensland, Australia in trial 1; average liquid uptake 250 kg/m³.
Modification level | Test specimens | |
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Scots pine | Beech | |
A | 2.79 ± 0.7 | 2.40 ± 0.24 |
B | 3.16 ± 1.03 | 3.42 ± 0.31 |
Termites
Field assay
Trial 1
Trial 2
Trial 3
Trial 4
Experimental design
Trial 1
Trial 2
Trial 3
Trial 4
Statistical analyses
Trial | Feeder specimens (unmodified) | Test specimens (modified with DMDHEU) | |||
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Scots pine | Beech | Slash pine | Spotted gum | ||
1 | 62.3 ± 2.9 | 2.2a ± 1.2 | 7.1a ± 2.8 | 1.0a ± 0.7 | 0.5a ± 0.3 |
2 | 68.0 ± 4.5 | 0.7b ± 0.4 | 2.9a ± 1.0 | N/A | N/A |
3 | 70.5 ± 6.4 | 10.3a ± 4.7 | 34.7a ± 16.3 | 4.0a ± 1.5 | N/A |
4 | 76.1 ± 2.8 | 11.6b ± 3.9 | 100.0a ± 0.0 | N/A | N/A |