Table 2 Mean value and standard deviation per species and per treatment of the parameters measured for growth at weeks 14–15, growth at harvest, plant description at harvest. Column P indicates the results of either Student’s t test or the Mann–Whitney test for comparison of two treatments. For the bark area ratio and bark thickness ratio, Student’s t test was used for comparison with the theoretical mean of 1. *P < 0.05; **P < 0.01; ***P < 0.001; NS: not significant

Growth at weeks 14–15

 Diameter rel. incr. (-)

0.63 ± 0.20

0.80 ± 0.16

*

0.61 ± 0.30

0.95 ± 0.46

*

0.34 ± 0.10

0.60 ± 0.17

***

 Ovalisation index (-)

0.98 ± 0.04

1.11 ± 0.07

***

1.01 ± 0.04

1.18 ± 0.07

***

1.01 ± 0.03

1.03 ± 0.05

NS

 Height rel. incr. (-)

0.39 ± 0.27

0.07 ± 0.05

***

0.43 ± 0.13

0.27 ± 0.21

*

0.27 ± 0.11

0.20 ± 0.11

NS

 Rel. slenderness (-)

 − 0.14 ± 0.12

 − 0.40 ± 0.06

***

 − 0.09 ± 0.16

 − 0.32 ± 0.13

***

 − 0.05 ± 0.08

 − 0.25 ± 0.05

***

 New leaves (-)

4 ± 2

3 ± 1

*

6 ± 1

5 ± 2

NS

5 ± 2

6 ± 3

NS

Growth at harvest

 Final diameter (mm)

14.0 ± 2.9

16.0 ± 3.2

NS

8.1 ± 0.9

9.8 ± 1.3

***

5.2 ± 1.2

6.5 ± 1.6

**

 Final ovalisation index (-)

0.99 ± 0.04

1.11 ± 0.06

***

0.99 ± 0.06

0.93 ± 0.26

**

1.00 ± 0.03

1.01 ± 0.04

NS

 Final height (mm)

1044 ± 173

838 ± 167

***

565 ± 151

496 ± 155

NS

277 ± 94

285 ± 82

NS

Plan biomass, stem length and leaves at harvest

 M_103°C roots (g)

13.5 ± 5.3

14.8 ± 5.9

NS

7.9 ± 2.0

8.8 ± 2.9

NS

2.0 ± 1.1

3.0 ± 1.7

*

 M_103°C stem (g)

15.6 ± 6.5

16.1 ± 7.1

NS

4.8 ± 1.5

5.7 ± 2.1

NS

1.8 ± 1.1

2.9 ± 1.6

**

 M_68°C leaves before (g)

7.1 ± 2.9

7.3 ± 3.3

NS

1.0 ± 1.4

0.7 ± 1.1

NS

2.7 ± 1.7

3.1 ± 2.0

NS

 M_68°C leaves after (g)

3.5 ± 1.6

2.3 ± 1.1

*

4.9 ± 2.0

5.8 ± 2.2

NS

1.6 ± 0.8

2.0 ± 1.3

NS

 M_68°C leaves total (g)

10.6 ± 3.5

9.6 ± 3.5

NS

5.9 ± 2.8

6.5 ± 2.9

NS

4.2 ± 2.4

5.1 ± 3.0

NS

 M total (g)

39.6 ± 14.4

40.5 ± 16.0

NS

18.6 ± 5.1

21.0 ± 6.1

NS

8.0 ± 4.5

11.0 ± 6.1

NS

 Leaf mass ratio (-)

0.27 ± 0.04

0.24 ± 0.04

*

0.30 ± 0.11

0.31 ± 0.08

NS

0.52 ± 0.08

0.45 ± 0.10

**

 Stem mass ratio (-)

0.39 ± 0.05

0.39 ± 0.004

NS

0.26 ± 0.06

0.27 ± 0.06

NS

0.22 ± 0.06

0.27 ± 0.06

***

 Shoot mass ratio (-)

0.66 ± 0.04

0.64 ± 0.02

**

0.57 ± 0.08

0.58 ± 0.10

NS

0.74 ± 0.05

0.72 ± 0.06

NS

 Root mass ratio (-)

0.34 ± 0.04

0.36 ± 0.02

**

0.43 ± 0.08

0.42 ± 0.10

NS

0.26 ± 0.05

0.28 ± 0.06

NS

 Stem specific length (mm.g⁻¹)

78 ± 34

60 ± 22

NS

121 ± 24

91 ± 22

***

202 ± 98

139 ± 96

***

 Leaf area ratio (m².kg⁻¹)

5.3 ± 1.0

4.5 ± 0.8

*

4.9 ± 2.0

5.3 ± 1.8

NS

8.4 ± 1.6

7.4 ± 1.9

*

 Specific leaf area (m².kg⁻¹)

19.9 ± 2.0

19.4 ± 1.9

NS

15.7 ± 2.9

16.8 ± 2.3

NS

17.5 ± 2.3

17.2 ± 1.9

NS

 Total leaf area (cm²)

2020 ± 619

1733 ± 598

NS

945 ± 9487

1142 ± 562

NS

684 ± 387

836 ± 501

NS

 Number of leaves (-)

14 ± 4

13 ± 3

NS

10 ± 6

12 ± 4

NS

15 ± 6

17 ± 7

NS

Wood and bark at harvest

 Wood specific gravity (g.cm⁻³)

0.23 ± 0.03

0.18 ± 0.02

***

0.34 ± 0.02

0.38 ± 0.03

***

0.51 ± 0.04

0.53 ± 0.003

NS

 Bark specific gravity (g.cm⁻³)

0.25 ± 0.01

0.26 ± 0.01

NS

0.23 ± 0.02

0.21 ± 0.02

**

0.28 ± 0.03

0.26 ± 0.03

**

 Wood area including pith (mm²)

77 ± 35

95 ± 41

NS

33 ± 9

46 ± 12

***

9 ± 4

18 ± 9

***

 Bark area (mm²)

55 ± 19

56 ± 21

NS

18 ± 5

25 ± 9

**

11 ± 4

15 ± 6

NS

 Bark area ratio (-)

0.43 ± 0.05

0.38 ± 0.04

**

0.36 ± 0.05

0.35 ± 0.06

NS

0.57 ± 0.05

0.46 ± 0.07

***

 Bark thickness ratio (-)

0.95 ± 0.18^NS

2.16 ± 0.654^***

***

1.19 ± 0.32^**

1.55 ± 0.54^***

**

1.03 ± 0.14^NS

1.05 ± 0.25^NS

NS