Table 2. Effect of nitrogen levels and ratios on culm breaking strength and culm lodging resistance index.
| N level (kg ha -1) | N ratio | 2012–2013 | 2013–2014 | ||||
|---|---|---|---|---|---|---|---|
| Lodging score | Culm breaking strength(Newtons) | Culm lodging resistance index | Lodging score | Culm breaking strength(Newtons) | Culm lodging resistance index | ||
| 180 | 7:1:2:0 | 0 | 13.57abc α | 25.81ab | 18.06 | 13.84ab | 26.00ab |
| 5:1:2:2 | 1.67 | 16.36a | 32.02a | 7.5 | 15.52a | 29.43a | |
| 3:1:3:3 | 0 | 16.74a | 33.01a | 3.33 | 15.49a | 29.83a | |
| 225 | 7:1:2:0 | 32.22 | 12.10bc | 23.24b | 44.31 | 12.77ab | 24.06ab |
| 5:1:2:2 | 3.89 | 15.32abc | 29.72ab | 16.25 | 14.39ab | 27.12ab | |
| 3:1:3:3 | 0 | 15.78ab | 30.84ab | 5.56 | 15.21a | 28.91ab | |
| 270 | 7:1:2:0 | 71.11 | 11.81c | 22.43b | 57.78 | 11.19b | 20.83b |
| 5:1:2:2 | 0 | 12.99abc | 25.28ab | 44.31 | 12.60ab | 23.48ab | |
| 3:1:3:3 | 0 | 13.15abc | 25.63ab | 41.25 | 13.16ab | 24.40ab | |
| F | |||||||
| Nitrogen levels(NL) | 9.85** | 8.46** | 7.34** | 8.84** | |||
| Nitrogen ratio(NR) | 10.16** | 10.40** | 0.99 | 4.99* | |||
| NL×NR | 0.69 | 0.56 | 1.96 | 0.07 | |||
α Values in a column followed by the same letter are not significantly different at P < 0.05 as determined by the LSD test. The test was conducted separately between the two years.
* F-test significant at 5% level.
** F-test significant at 1% level.