TABLE 2.

Effect of nitrogen fertilization level on grain filling parameters between two maize hybrids in 2015 and 2016.

Year	Genotype		N level	Wmax (mg kernel–1 d–1)	Tmax (d)	Gmax (mg kernel–1 d–1)	GFP (d)	Gmean (mg kernel–1 d–1)
2015	XY335		N0	132.2 ± 1.52d	26.3 ± 0.33c	8.8 ± 0.04d	44.9 ± 0.73d	0.29 ± 0.00d
			N150	128.8 ± 4.20d	25.5 ± 2.04c	8.4 ± 0.38d	46.2 ± 0.90c	0.28 ± 0.01d
			N300	149.9 ± 0.41b	25.9 ± 0.30c	10.2 ± 0.12a	44.2 ± 0.63d	0.34 ± 0.00a
	ZD958		N0	138.9 ± 3.27c	30.1 ± 0.61a	9.0 ± 0.26bc	46.5 ± 0.36c	0.30 ± 0.01c
			N150	147.0 ± 0.38b	29.3 ± 0.22ab	8.9 ± 0.06c	49.8 ± 0.44b	0.30 ± 0.01c
			N300	163.8 ± 0.71a	28.1 ± 0.39b	9.2 ± 0.02b	53.6 ± 0.37a	0.31 ± 0.01b
2016	XY335		N0	129.9 ± 2.16f	31.3 ± 0.16b	9.5 ± 0.09c	40.9 ± 0.96c	0.32 ± 0.01c
			N150	145.8 ± 1.24d	22.0 ± 0.39d	9.6 ± 0.37c	45.5 ± 2.10b	0.32 ± 0.01c
			N300	161.4 ± 1.68b	22.4 ± 0.50d	11.1 ± 0.24a	43.7 ± 1.15b	0.37 ± 0.01a
	ZD958		N0	139.7 ± 0.68e	32.7 ± 0.43a	9.5 ± 0.23c	44.1 ± 1.27b	0.32 ± 0.01c
			N150	151.9 ± 1.63c	24.6 ± 0.05c	10.2 ± 0.08b	44.7 ± 0.51b	0.34 ± 0.00b
			N300	174.7 ± 0.70a	25.1 ± 0.12c	10.4 ± 0.01b	50.4 ± 0.27a	0.35 ± 0.00b
ANOVA	Year (Y)			***	***	***	***	***
	Nitrogen (N)			***	***	***	***	***
	Genotype (G)			***	***	NS	***	NS
	N × G			*	NS	***	***	***
	Y × N × G			***	NS	NS	**	NS

W_max, kernel weight increment achieving maximum grain-filling rate; T_max, the days reaching the maximum grain-filling rate; G_max, maximum filling rate; GFP, active filling phase; G_mean, mean grain-filling rate. N0, N150, and N300 indicate 0, 150, and 300 kg ha^–1 N applied, respectively.

Different letters indicate significant differences between treatments at a 5% level.

*, **, and *** indicate different significance at 5, 1, and 0.1% level, respectively.

NS, no significance.