Table 3 Water use efficiency (WUE) of winter wheat (kg ha⁻¹ mm⁻¹) under ambient (aCO₂) and elevated carbon dioxide (eCO₂) at a high rainfall site near Pullman, at a low rainfall site near Lind and at an irrigated site near Moses Lake, WA.

APSIM

12.29 ± 0.31

13.94 ± 0.27

15.52 ± 0.31

16.95 ± 0.36

18.18 ± 0.37

19.07 ± 0.39

19.56 ± 0.40

CropSyst

12.01 ± 0.30

13.94 ± 0.27

15.52 ± 0.31

16.95 ± 0.35

18.18 ± 0.38

19.07 ± 0.40

19.56 ± 0.41

DSSAT

12.00 ± 0.32

13.06 ± 0.35

14.09 ± 0.39

15.00 ± 0.37

15.80 ± 0.38

16.51 ± 0.39

17.06 ± 0.41

EPIC

11.87 ± 0.29

13.06 ± 0.33

13.97 ± 0.37

14.69 ± 0.33

15.25 ± 0.36

15.68 ± 0.39

16.03 ± 0.42

STICS

13.71 ± 0.33

16.10 ± 0.40

17.92 ± 0.38

19.33 ± 0.35

20.47 ± 0.39

21.32 ± 0.39

21.92 ± 0.43

APSIM

9.67 ± 0.35

11.39 ± 0.43

12.86 ± 0.43

14.48 ± 0.43

15.68 ± 0.45

16.38 ± 0.46

17.06 ± 0.47

CropSyst

11.74 ± 0.37

13.71 ± 0.42

15.53 ± 0.45

17.30 ± 0.48

18.94 ± 0.49

20.23 ± 0.51

20.90 ± 0.52

DSSAT

10.92 ± 0.33

12.35 ± 0.39

13.80 ± 0.41

15.19 ± 0.42

16.45 ± 0.43

17.64 ± 0.45

18.69 ± 0.47

EPIC

13.05 ± 0.36

15.49 ± 0.44

17.89 ± 0.47

20.40 ± 0.50

22.61 ± 0.52

24.58 ± 0.55

25.46 ± 0.59

STICS

9.79 ± 0.32

11.95 ± 0.43

14.38 ± 0.43

16.60 ± 0.45

17.43 ± 0.46

17.83 ± 0.43

18.10 ± 0.47

APSIM

13.09 ± 0.35

14.35 ± 0.40

15.18 ± 0.41

15.35 ± 0.42

15.52 ± 0.43

15.69 ± 0.44

15.72 ± 0.45

CropSyst

17.60 ± 0.37

19.04 ± 0.41

19.85 ± 0.43

20.36 ± 0.44

20.69 ± 0.45

20.94 ± 0.47

21.11 ± 0.48

DSSAT

13.87 ± 0.35

15.21 ± 0.39

16.48 ± 0.41

17.57 ± 0.43

18.51 ± 0.44

19.32 ± 0.45

19.95 ± 0.43

EPIC

13.33 ± 0.36

14.77 ± 0.41

15.37 ± 0.43

15.85 ± 0.44

16.46 ± 0.45

17.16 ± 0.46

16.87 ± 0.48

STICS

12.26 ± 0.37

13.32 ± 0.42

14.22 ± 0.43

15.03 ± 0.45

15.78 ± 0.47

16.28 ± 0.42

16.56 ± 0.45