Table 1. Effects of experimental treatments on the net photosynthetic rate of maize leaves (Pn, µmol CO2 m−2 s−1) in 2015–2016.
Abbreviations for different treatments are defined in Fig. 3. Values followed by different letters within a column are significantly different at the 5% probability level (least significant difference; n = 3).
| Years | Planting densities | Irrigation modes | Before irrigation at 11-leaf stage | After irrigation at 11-leaf stage | Before irrigation at silking stage | After irrigation at silking stage | Filling stage |
|---|---|---|---|---|---|---|---|
| 2015 | L | NI | 22.5a | 24.9abc | 25.7ab | 26.6bcd | 19.8c |
| IV | 23.2a | 28.0a | 27.2a | 28.2abc | 22.3ab | ||
| IS | 23.2a | 24.8abc | 26.0ab | 31.4a | 23.8a | ||
| IVS | 22.8a | 28.1a | 27.6a | 31.9a | 24.0a | ||
| M | NI | 22.5a | 23.5bc | 24.7abc | 25.2cd | 18.1cd | |
| IV | 22.7a | 27.4a | 26.2ab | 27.1bcd | 20.2bc | ||
| IS | 23.0a | 23.8bc | 24.7abc | 30.0ab | 22.6ab | ||
| IVS | 22.5a | 27.8a | 26.4ab | 30.0ab | 22.9a | ||
| H | NI | 21.9a | 22.4c | 21.5c | 21.1e | 14.4e | |
| IV | 21.9a | 25.8ab | 23.0bc | 23.6de | 16.5de | ||
| IS | 22.7a | 22.5c | 21.3c | 25.7cd | 18.6cd | ||
| IVS | 21.8a | 26.1ab | 23.2bc | 26.1bcd | 18.6cd | ||
| Average | L | 22.9A | 26.4A | 26.6A | 29.5A | 22.5A | |
| M | 22.7A | 25.6AB | 25.5A | 28.0A | 20.9B | ||
| H | 22.1A | 24.2B | 22.2B | 24.1B | 17.0C | ||
| NI | 22.3A | 23.6B | 24.0A | 24.3B | 17.4C | ||
| IV | 22.6A | 27.0A | 25.5A | 26.3B | 19.7B | ||
| IS | 23.0A | 23.7B | 24.0A | 29.0A | 21.7A | ||
| IVS | 22.4A | 27.3A | 25.7A | 29.3A | 21.9A | ||
| ANOVA | PD | ns | * | ** | ** | ** | |
| IM | ns | ** | ns | ** | ** | ||
| PD × IM | ns | ns | ns | ns | ns | ||
| 2016 | L | NI | 21.4abc | 22.7cde | 23.3cd | 23.5def | 15.2de |
| IV | 22.7a | 26.6a | 26.9ab | 27.2bcd | 17.8bc | ||
| IS | 23.1a | 24.8abc | 25.2abc | 29.6ab | 19.5ab | ||
| IVS | 23.3a | 26.7a | 27.1a | 31.3a | 19.9a | ||
| M | NI | 19.3bcd | 20.6de | 21.0def | 21.3fg | 13.7ef | |
| IV | 21.1abc | 25.0abc | 25.6abc | 25.8de | 16.6cd | ||
| IS | 21.8ab | 23.6abcd | 23.9bcd | 28.6abc | 17.3c | ||
| IVS | 22.5a | 26.0ab | 25.8abc | 29.8ab | 17.8bc | ||
| H | NI | 16.4e | 17.7f | 18.2f | 18.7 g | 9.2 g | |
| IV | 18.4de | 22.6cde | 21.8de | 22.3ef | 12.3f | ||
| IS | 18.8cde | 20.2ef | 20.1ef | 25.8de | 13.3ef | ||
| IVS | 19.4bcd | 23.0bcde | 22.0de | 26.5cd | 14.6de | ||
| Average | L | 22.6A | 25.2A | 25.6A | 27.9A | 18.1A | |
| M | 21.2B | 23.8A | 24.1B | 26.4A | 16.3B | ||
| H | 18.2C | 20.9B | 20.5C | 23.3B | 12.4C | ||
| NI | 19.0B | 20.3C | 20.8C | 21.2C | 12.7C | ||
| IV | 20.7A | 24.7A | 24.8A | 25.1B | 15.6B | ||
| IS | 21.2A | 22.9B | 23.0B | 28.0A | 16.7AB | ||
| IVS | 21.7A | 25.2A | 25.0A | 29.2A | 17.4A | ||
| ANOVA | PD | ** | ** | ** | ** | ** | |
| IM | ** | ** | ** | ** | ** | ||
| PD × IM | ns | ns | ns | ns | ns |
Notes.
ANOVA, analysis of variance
**
significance at 1% probability level
*
significance at 5% probability level
- ns
- not significant
- IM
- irrigation mode
- PD
- planting density
Lowercase and uppercase letters in columns indicate significant differences among planting density and irrigation mode treatments, respectively.