Table 2.
The chlorophyll fluorescence characteristics of peanut.
| Year | Treatment | Fv/Fm | ΦPSⅡ | qP | qN | ETR | |
|---|---|---|---|---|---|---|---|
| 2019 | P | 0.762 ± 0.016b | 0.369 ± 0.035b | 0.332 ± 0.004b | 0.840 ± 0.014a | 180.188 ± 2.946a | |
| The middle row | I | 0.782 ± 0.014ab | 0.448 ± 0.010a | 0.465 ± 0.004a | 0.757 ± 0.008b | 147.393 ± 6.231c | |
| RI | 0.777 ± 0.014ab | 0.462 ± 0.022a | 0.464 ± 0.006a | 0.765 ± 0.032b | 145.534 ± 4.614c | ||
| RI2 | 0.767 ± 0.014b | 0.466 ± 0.023a | 0.468 ± 0.009a | 0.771 ± 0.031b | 143.684 ± 6.427c | ||
| RI3 | 0.784 ± 0.005ab | 0.466 ± 0.013a | 0.467 ± 0.004a | 0.789 ± 0.019b | 146.515 ± 4.607c | ||
| The border row | I | 0.783 ± 0.024ab | 0.473 ± 0.032a | 0.472 ± 0.007a | 0.784 ± 0.03b | 158.086 ± 2.886b | |
| RI | 0.806 ± 0.007a | 0.474 ± 0.025a | 0.471 ± 0.008a | 0.791 ± 0.037b | 160.764 ± 5.467b | ||
| RI2 | 0.810 ± 0.009a | 0.479 ± 0.002a | 0.468 ± 0.009a | 0.742 ± 0.027b | 159.129 ± 10.925b | ||
| RI3 | 0.800 ± 0.016ab | 0.472 ± 0.016a | 0.469 ± 0.002a | 0.761 ± 0.026b | 159.505 ± 4.812b | ||
| 2020 | P | 0.766 ± 0.021b | 0.388 ± 0.020b | 0.418 ± 0.025c | 0.782 ± 0.007a | 169.632 ± 7.362a | |
| The middle row | I | 0.777 ± 0.004ab | 0.448 ± 0.010a | 0.463 ± 0.01b | 0.715 ± 0.015b | 124.299 ± 5.698d | |
| RI | 0.769 ± 0.008b | 0.462 ± 0.022a | 0.491 ± 0.004a | 0.66 ± 0.01c | 139.071 ± 4.99bc | ||
| RI2 | 0.763 ± 0.011b | 0.466 ± 0.023a | 0.492 ± 0.01a | 0.661 ± 0.01c | 137.034 ± 2.627bc | ||
| RI3 | 0.777 ± 0.017ab | 0.466 ± 0.013a | 0.497 ± 0.002a | 0.654 ± 0.015c | 134.623 ± 3.071cd | ||
| The border row | I | 0.779 ± 0.014ab | 0.473 ± 0.032a | 0.494 ± 0.008a | 0.68 ± 0.007c | 144.633 ± 3.345bc | |
| RI | 0.800 ± 0.013ab | 0.474 ± 0.025a | 0.502 ± 0.007a | 0.649 ± 0.014c | 148.724 ± 3.54b | ||
| RI2 | 0.806 ± 0.012a | 0.488 ± 0.018a | 0.498 ± 0.014a | 0.668 ± 0.027c | 149.681 ± 5.522b | ||
| RI3 | 0.806 ± 0.014a | 0.472 ± 0.016a | 0.503 ± 0.002a | 0.659 ± 0.017c | 149.016 ± 4.296b | ||
P, sole peanut; I, maize–peanut intercropping; RI, maize–peanut–intercropping, RI2, 20% N reduction for maize of RI; ICN3, 40% N reductions for maize of RI.
The parameters are: Fv/Fm (optimal/maximal photochemical efficiency of PSII in the dark), ΦPS II (actual photochemical efficiency of PS II in the light), qP (Photochemical quenching), qN (Non-photochemical quenching) and ETR (electron transport rate). Different lowercase letters represent signifificant (P<0.05).