Table 3.
ANOVA results for the effects of the cultivar, CO2 application, tiller removal, and root restriction on the eight rice parameters
| Degrees of freedom | Sum of squares | Mean square | F value | Significance1) | ||
|---|---|---|---|---|---|---|
| Number of days to flowering (NDF) | Cultivar | 1 | 20,604.3 | 20,604.3 | 1,838.5 | *** |
| CO2 application | 1 | 1,451.8 | 1,451.8 | 129.5 | *** | |
| Root restriction | 2 | 334.2 | 167.1 | 14.9 | *** | |
| Tiller removal | 1 | 69.8 | 69.8 | 6.2 | * | |
| Residuals | 117 | 1,311.2 | 11.2 | |||
|
| ||||||
| Culm length (cm) | Cultivar | 1 | 462.2 | 462.2 | 24.2 | *** |
| CO2 application | 1 | 1,528.7 | 1,528.7 | 80.0 | *** | |
| Root restriction | 2 | 2,747.3 | 1,373.6 | 71.9 | *** | |
| Tiller removal | 1 | 217.1 | 217.1 | 11.4 | ** | |
| Residuals | 114 | 2,178.2 | 19.1 | |||
|
| ||||||
| Panicle number | Cultivar | 1 | 25.7 | 25.7 | 65.6 | *** |
| CO2 application | 1 | 5.2 | 5.2 | 13.3 | *** | |
| Root restriction | 2 | 321.0 | 160.5 | 410.0 | *** | |
| Tiller removal | 1 | 47.4 | 47.4 | 121.1 | *** | |
| Residuals | 114 | 44.6 | 0.4 | |||
|
| ||||||
| Number of fertile spikelets | Cultivar | 1 | 43,214 | 43,214 | 127 | *** |
| CO2 application | 1 | 14,214 | 14,214 | 42 | *** | |
| Root restriction | 2 | 376,497 | 188,248 | 553 | *** | |
| Tiller removal | 1 | 15,310 | 15,310 | 45 | *** | |
| Residuals | 114 | 38,784 | 340 | |||
|
| ||||||
| Ripe grains (%) | Cultivar | 1 | 2,486.4 | 2,486.4 | 25.9 | *** |
| CO2 application | 1 | 1,116.3 | 1,116.3 | 11.6 | *** | |
| Root restriction | 2 | 236.6 | 118.3 | 1.2 | ||
| Tiller removal | 1 | 13.8 | 13.8 | 0.1 | ||
| Residuals | 114 | 10,945.2 | 96.0 | |||
|
| ||||||
| Total weight of unhulled grains (g) | Cultivar | 1 | 45.7 | 45.7 | 220.6 | *** |
| CO2 application | 1 | 11.3 | 11.3 | 54.3 | *** | |
| Root restriction | 2 | 274.1 | 137.1 | 661.8 | *** | |
| Tiller removal | 1 | 8.5 | 8.5 | 41.2 | *** | |
| Residuals | 114 | 23.6 | 0.2 | |||
|
| ||||||
| Weight per thousand unhulled kernels (g) | Cultivar | 1 | 645.6 | 645.6 | 157.4 | *** |
| CO2 application | 1 | 40.5 | 40.5 | 9.9 | ** | |
| Root restriction | 2 | 9.5 | 4.8 | 1.2 | ||
| Tiller removal | 1 | 0.4 | 0.4 | 0.1 | ||
| Residuals | 114 | 467.7 | 4.1 | |||
|
| ||||||
| Dry weight of aerial parts (g) | Cultivar | 1 | 356.2 | 356.2 | 370.4 | *** |
| CO2 application | 1 | 57.1 | 57.1 | 59.3 | *** | |
| Root restriction | 2 | 1,833.9 | 917.0 | 953.4 | *** | |
| Tiller removal | 1 | 60.0 | 60.0 | 62.4 | *** | |
| Residuals | 114 | 109.6 | 1.0 | |||
1)
*** P < 0.001; ** P < 0.01; * P < 0.05.
Two cultivars, Nipponbare and Yamadawara were used.