Table 4. Effect of N on the sugar-to-nitrogen concentration ratio (S/N) in different corn cultivars.
| Corn cultivars | Treatment | August 16th | September 6th | September 17th |
|---|---|---|---|---|
| Jingyu7 | LN | 2.96 ± 0.27aA | 1.57 ± 0.14 aA | 2.51 ± 0.24 aA |
| MN | 2.58 ± 0.15 bB | 1.47 ± 0.11 aA | 1.91 ± 0.22 bB | |
| HN | 2.02 ± 0.24 cC | 1.22 ± 0.12 bB | 2.00 ± 0.23 bB | |
| Nongda80 | LN | 2.72 ± 0.26 aA | 1.62 ± 0.21 aA | 2.23 ± 0.29 aA |
| MN | 2.33 ± 0.35 bB | 1.38 ± 0.74 aA | 1.97 ± 0.08 bB | |
| HN | 1.94 ± 0.15 cB | 1.16 ± 0.12 bB | 2.09 ± 0.18 aA | |
| Tangyu10 | LN | 2.56 ± 0.14 aA | 1.43 ± 0.15 aA | 2.74 ± 0.34 aA |
| MN | 2.35 ± 0.22 aB | 1.35 ± 0.14 aA | 2.12 ± 0.21 bB | |
| HN | 2.23 ± 0.10 bB | 1.31 ± 0.13 bB | 1.84 ± 0.12 cC |
Note: The statistical analyses are based on each cultivar. With respect to each cultivar, the values in the same column followed by different uppercase and lowercase letters are significantly different at the 0.01 and 0.05 probability levels, respectively. The corn cultivars were subjected to low (LN, 0 kg N ha−1), medium (MN, 75 kg N ha−1), and high (HN, 150 kg N ha−1) levels of N application over the cropping season (2002 and 2003). The data are average values across 2 years with ± one standard error.