Table 1.
Effects of different treatments on the fitting parameters of light response curves of maize leaves
| Stage | Treatment | α | Pnmax (µmol CO2 m–2 s–1) | Isat (µmol m–2 s–1) | Ic (µmol m–2 s–1) | Rd (µmol m–2 s–1) | |
|---|---|---|---|---|---|---|---|
| V6 | SL | 0.053a | 36.14b | 1500c | 48.01a | 2.45a | |
| SH | 0.051a | 44.94a | 1877a | 56.20a | 2.82a | ||
| FL | 0.049a | 27.10c | 1223d | 19.69b | 0.96b | ||
| FH | 0.053a | 42.22a | 1683b | 49.86a | 2.62a | ||
| V10 | SL | 0.056a | 34.98c | 1674bc | 33.05a | 1.80a | |
| SH | 0.056a | 40.00a | 1796a | 35.39a | 1.96a | ||
| FL | 0.056a | 33.26d | 1584c | 24.32b | 1.34b | ||
| FH | 0.056a | 37.19b | 1698ab | 34.23a | 1.86a | ||
| R1 | SL | 0.049a | 30.61b | 1610bc | 31.18b | 1.48b | |
| SH | 0.042a | 38.32a | 1924a | 50.08a | 2.09a | ||
| FL | 0.046a | 19.10c | 1565c | 17.87c | 0.82c | ||
| FH | 0.048a | 31.37b | 1748b | 34.48b | 1.64b | ||
| R3 | SL | 0.070a | 19.73b | 1621b | 21.51b | 1.42b | |
| SH | 0.060ab | 26.89a | 1825a | 34.87a | 2.01a | ||
| FL | 0.043b | 9.44c | 1192c | 26.76b | 1.03c | ||
| FH | 0.050ab | 20.34b | 1648ab | 28.97ab | 1.37bc | ||
| R6 | SL | 0.064a | 18.85b | 1549b | 19.84b | 1.21bc | |
| SH | 0.059a | 25.53a | 1949a | 35.27a | 1.97a | ||
| FL | 0.060a | 13.23c | 1219c | 17.63b | 0.94c | ||
| FH | 0.049a | 20.83b | 1684ab | 30.24a | 1.43b | ||
| ANOVA (F values) | |||||||
| V6 | SWS | 0.05 | 35.38*** | 28.40*** | 11.40** | 14.07** | |
| W | 0.37 | 146.26*** | 89.60*** | 13.96** | 19.99** | ||
| SWS*W | 1.71 | 10.22* | 0.88 | 4.58 | 8.13* | ||
| V10 | SWS | 0.01 | 23.67** | 9.46* | 4.86 | 10.45* | |
| W | 0.00 | 92.26*** | 14.82** | 7.46* | 14.87** | ||
| SWS*W | 0.06 | 1.36 | 0.02 | 2.85 | 4.10 | ||
| R1 | SWS | 0.33 | 109.69*** | 6.26* | 49.80*** | 17.50** | |
| W | 0.57 | 128.52*** | 31.54*** | 75.12*** | 28.97*** | ||
| SWS*W | 1.80 | 6.69* | 2.19 | 0.31 | 0.68 | ||
| R3 | SWS | 6.22* | 128.43*** | 23.83** | 0.02 | 20.08** | |
| W | 0.06 | 147.65*** | 28.27*** | 10.70* | 15.95** | ||
| SWS*W | 1.28 | 6.38* | 4.14 | 5.50* | 1.20 | ||
| R6 | SWS | 1.18 | 36.55*** | 1330** | 2.55 | 20.11** | |
| W | 1.42 | 70.00*** | 28.17*** | 38.34*** | 47.69*** | ||
| SWS*W | 0.23 | 0.29 | 0.16 | 0.39 | 2.21 | ||
Note: Duncan’s multiple-range test was used to test differences among treatments at the P < 0.05 level. Different lowercase letters in the same column indicate significant differences among treatments at the same stage. SL: stable soil water with 55% FC, SH: stable soil water with 75% FC, FL: fluctuating soil water with 55% FC, FH: fluctuating soil water with 75% FC, SWS: soil water stability, W: soil water content, SWS*W: the interaction between soil water stability and soil water content, α: the initial slope of the light response curve, Pnmax: maximum net photosynthetic rate, Isat: saturated light intensity, Ic: light compensation point, Rd: dark respiration rate, V6: six-leaf stage, V10: ten-leaf stage, R1: silking stage, R3: milk stage, and R6: physiological maturity stage. *, **, and *** indicate significance levels at P < 0.05, P < 0.01, and P < 0.001, respectively