Table 3 Glucose, fructose, sucrose, and starch concentrations measured in leaves (a), stems (b) and roots (c) of 5C and Riesling x 5C (RR) 8 weeks after the beginning of treatments (n = 5–8). W = well-watered plants; D = drought-stressed; C = control, non-phylloxerated; P = root phylloxerated. * indicates statistically significant differences within the factors (Irrigation or Infestation). At root level, a significant interaction between factors (Irr x Inf) was observed in sucrose measured in 5C (within D level: C > P; within C level: W < D) and glucose (within W level: C > P; within C level: W > D) measured in RR

(a) Leaves

W

D

C

P

Irr x Inf

W

D

C

P

Irr x Inf

 Glucose, mg g^− 1

24.2 ± 2.7

15.1 ± 2.8*

17.7 ± 2.8

21.7 ± 2.7

n.s.

14.7 ± 1.1

9.2 ± 1.1*

12.3 ± 1.1

11.6 ± 1.1

n.s.

 Fructose, mg g^− 1

31.6 ± 3.8

18.7 ± 3.8*

21.5 ± 3.9

28.8 ± 3.7

n.s.

13.7 ± 1.1

8.6 ± 1.2*

11.3 ± 1.1

11.0 ± 1.2

n.s.

 Sucrose, mg g^− 1

101.5 ± 12.7

99.5 ± 11.9

89.7 ± 13.0

111.4 ± 11.5

n.s.

111.2 ± 9.6

110.4 ± 10.0

115.1 ± 10.0

106.4 ± 9.6

n.s.

 Starch, mg g^− 1

2.5 ± 0.4

3.4 ± 0.4

3.1 ± 0.4

2.7 ± 0.4

n.s.

9.1 ± 1.0

3.9 ± 1.1*

8.2 ± 1.0

4.8 ± 1.1*

n.s.

(b) Stems

W

D

C

P

Irr x Inf

W

D

C

P

Irr x Inf

 Glucose, mg g^− 1

7.6 ± 0.6

4.1 ± 0.6*

5.7 ± 0.6

6.1 ± 0.6

n.s.

3.3 ± 0.4

4.9 ± 0.4*

4.4 ± 0.4

3.8 ± 0.4

n.s.

 Fructose, mg g^− 1

4.7 ± 0.3

2.5 ± 0.3*

3.7 ± 0.3

3.5 ± 0.3

n.s.

1.7 ± 0.1

2.1 ± 0.1*

1.9 ± 0.1

1.9 ± 0.1

n.s.

 Sucrose, mg g^− 1

95.7 ± 4.6

93.4 ± 4.6

96.0 ± 4.8

93.1 ± 4.5

n.s.

80.4 ± 4.5

87.2 ± 4.5

84.0 ± 4.5

83.6 ± 4.5

n.s.

 Starch, mg g^− 1

11.5 ± 1.7

15.9 ± 1.8

15.1 ± 1.8

12.3 ± 1.7

n.s.

8.4 ± 1.4

19.1 ± 1.4*

13.8 ± 1.4

13.7 ± 1.4

n.s.

(c) Roots

W

D

C

P

Irr x Inf

W

D

C

P

Irr x Inf

 Glucose, mg g⁻¹

74.3 ± 8.3

60.1 ± 8.0

101.2 ± 8.0

33.1 ± 8.3*

n.s.

72.8 ± 7.4

38.0 ± 8.1*

84.1 ± 8.1

26.8 ± 7.4*

*

 Fructose, mg g^− 1

17.5 ± 2.0

19.5 ± 1.9

27.6 ± 1.9

9.4 ± 2.0*

n.s.

13.4 ± 1.8

13.7 ± 1.9

19.2 ± 1.9

7.9 ± 1.8*

n.s.

 Sucrose, mg g^− 1

77.7 ± 6.2

95.3 ± 6.0*

94.5 ± 6.0

78.5 ± 6.2

*

72.7 ± 5.0

93.7 ± 5.0*

98.7 ± 5.2

67.6 ± 4.8*

n.s.

 Starch, mg g⁻¹

18.7 ± 2.9

17.1 ± 3.0

15.3 ± 2.9

20.4 ± 3.0

n.s.

21.7 ± 2.7

13.2 ± 2.9*

18.3 ± 2.9

16.6 ± 2.7

n.s.