Fig. 6. Relationships between effects on biomass (BM) and effects on LAI of limited (A) water and (B) N supply for ambient (A) and elevated (1·5 × ambient, AE) [CO₂] of wheat ‘Yecora Rojo’ grown at Maricopa, Arizona in 1992–93 and 1993–94 (H₂O limitation) and 1995–96 and 1996–97 (N‐limitation). Ratios were calculated from measurements of biomass and LAI at different occasions throughout each growing season in water‐stressed (H₂O–) and well‐watered (H₂O+) and N‐limited (N–) and non‐limited (N+) treatments, respectively. References about data sources with information about experimental performances can be obtained from Jamieson et al. (2000) and Ewert et al. (2002).