Table 4. Radiation use efficiency and its related parameters of winter rapeseed under different densities and row spacing arrangements during 2012–2014.
| Year | Density | Row Spacing | Incident radiation (MJ m−2) | Intercepted radiation (MJ m−2) | Intercepted percent (%) | Total aboveground biomass (g m−2) | Radiation use efficiency (g MJ−1) |
|---|---|---|---|---|---|---|---|
| 2012–2013 | D15 | R15 | 1312.5 | 1030.0cd | 78.5f | 1064.1f | 1.03f |
| R25 | 1218.4 | 964.7g | 79.2f | 1029.4h | 1.07d | ||
| R35 | 1292.1 | 996.2f | 80.6e | 1048.4g | 1.05e | ||
| D30 | R15 | 1266.9 | 1027.0cd | 81.1e | 1175.6b | 1.15b | |
| R25 | 1238.3 | 1009.1e | 84.1d | 1123.7d | 1.11c | ||
| R35 | 1226.7 | 1019.7de | 86.5b | 1079.1e | 1.06de | ||
| D45 | R15 | 1208.9 | 1032.5c | 85.4c | 1238.7a | 1.20a | |
| R25 | 1312.6 | 1138.0a | 87.2b | 1149.8c | 1.01g | ||
| R35 | 1243.3 | 1108.3b | 89.1a | 1062.7f | 0.96h | ||
| Mean | 1257.7 | 1036.2 | 83.5 | 1107.9 | 1.07 | ||
| 2013–2014 | D15 | R15 | 1337.7 | 951.6h | 82.7g | 1062.1h | 1.12c |
| R25 | 1389.5 | 1126.6b | 83.9f | 1186.1d | 1.05f | ||
| R35 | 1353.7 | 1125.6b | 83.2g | 1110.4g | 0.99h | ||
| D30 | R15 | 1280.9 | 986.3g | 84.2f | 1115.0f | 1.13b | |
| R25 | 1302.8 | 1105.5c | 89.7d | 1208.2b | 1.09d | ||
| R35 | 1259.5 | 1089.7d | 90.4c | 1168.3e | 1.07e | ||
| D45 | R15 | 1266.5 | 1014.6f | 87.1e | 1257.3a | 1.24a | |
| R25 | 1358.3 | 1032.6e | 91.0b | 1107.9g | 1.07e | ||
| R35 | 1284.4 | 1160.3a | 92.7a | 1199.4c | 1.03g | ||
| Mean | 1314.8 | 1065.9 | 87.2 | 1157.2 | 1.09 |
Values followed by different letters within the same column are significantly different according to the least significant difference (LSD) test (P < 0.05); Each data represents the mean of three replications.
D15, D30 and D45 mean densities of 15, 30 and 45 × 104 plants ha−1; R15, R25 and R35 mean inter-row spacing of 15, 25 and 35 cm.