. 2022 Sep 9;13:992041. doi: 10.3389/fpls.2022.992041

TABLE 6.

Differences of C/N ratios in vegetative organs of maize at different stages.

Cultivar	Nitrogen rate	Root				Stem + sheath				Leaf
		Jointing stage	Silking Stage	Maturity stage	Mean	Jointing stage	Silking Stage	Maturity stage	Mean	Jointing stage	Silking Stage	Maturity stage	Mean
2019
	N 0	29.87 b	50.82 b	41.67 a	40.79 b	16.68 a	52.98 b	81.09 b	50.25 b	13.29 a	15.08 a	29.25 b	19.20 b
	N 120	18.63 d	42.65 c	29.93 c	30.40 c	8.47 c	49.61 c	66.38 d	41.48 d	9.94 b	12.50 bc	27.99 c	16.81
ZH 311	N 240	16.21 e	28.02 e	23.92 d	22.72 e	8.03 c	30.86 e	62.31 e	33.73 f	10.16 b	10.68 d	22.99 e	14.61 f
	N 360	15.96 e	28.17 e	21.95 d	22.03 e	8.20 c	34.34 d	57.54 f	33.36 f	10.20 b	10.92 d	23.24 e	14.78 f
	Mean	20.17 B	37.41 B	29.37 A	28.98 B	10.35 A	41.95 B	66.83 B	39.71 B	10.90 A	12.29 B	25.87 B	16.35 B
	N 0	35.40 a	61.05 a	37.34 b	44.60 a	14.58 b	65.14 a	90.73 a	56.82 a	13.72 a	15.22 a	37.72 a	22.22 a
	N 120	21.14 c	42.18 c	27.83 c	30.38 c	8.76 c	50.20 c	74.51 c	44.49 c	8.90 c	13.04 b	29.07 b	17.00 c
XY 508	N 240	20.52 cd	31.48 d	24.33 d	25.44 d	8.14 c	33.33 de	67.70 d	36.39 e	8.73 c	12.32 bc	26.08 d	15.71 d
	N 360	19.72 cd	30.79 de	23.08 d	24.53 d	7.27 d	33.71 d	65.39 d	35.46 e	8.06 c	11.93 c	25.79 d	15.26 e
	Mean	24.20 A	41.38 A	28.14 A	31.24 A	9.68 B	45.60 A	74.58 A	43.29 A	9.85 B	13.13 A	29.67 A	17.55 A
2020
	N 0	23.27 b	34.03 b	47.09 a	34.80 b	16.20 a	69.68 b	91.65 b	59.18 b	14.70 a	22.84 b	43.30 b	26.95 b
	N 120	15.97 c	33.98 b	32.39 b	27.44 c	10.86 c	53.83 c	84.40 c	49.70 d	11.88 v	14.96 d	37.88 c	21.58 d
ZH 311	N 240	14.67 d	27.05 ef	26.33 c	22.69 ef	9.79 ef	38.64 d	63.45 d	37.29 e	11.09 de	12.62 f	31.26 e	18.33 fg
	N 360	15.73 c	26.57 f	22.55 d	21.62 f	9.75 f	34.77 e	46.97 f	30.50 g	10.15 f	12.81 f	33.44 d	18.80 g
	Mean	17.41 B	30.41 B	32.09 B	26.64 B	11.65 A	49.23 B	71.62 B	44.17 B	11.96 A	15.81 B	36.47 B	21.41 B
	N 0	29.33 a	38.63 a	48.41 a	38.79 a	13.51 b	82.79 a	97.75 a	64.74 a	13.61 b	24.26 a	47.35 a	28.41 a
	N 120	15.84 c	28.98 d	34.34 b	26.39 c	11.15 c	55.46 c	92.56 b	53.06 c	11.34 d	15.78 c	43.54 b	23.55 c
XY 508	N 240	13.63 e	31.00 c	27.41 c	24.01 d	10.68 cd	38.46 d	60.82 d	36.65 e	10.60 ef	13.71 e	38.32 c	20.88 e
	N 360	15.79 c	28.53 de	24.99 cd	23.10 de	10.31 de	37.12 de	51.53 e	32.99 f	10.78 e	12.79 f	34.34 d	19.30 f
	Mean	18.64 A	31.78 A	33.79 A	28.07 A	11.41 A	53.50 A	75.66 A	46.86 A	11.58 B	16.64 A	40.89 A	23.04 A
F value	Years (Y)	247.65**	438.92**	87.42**	128.23**	178.45**	241.42**	20.99**	161.18**	115.33**	801.69**	2711.59**	3759.48**
	Cultivar (C)	99.22**	45.44**	0.28^ns	57.46**	15.78**	65.71**	84.83**	98.39**	29.91**	45.08**	383.86**	268.58**
	Nitrogen (N)	565.39**	427.27**	418.22**	1019.53**	701.75**	1026.62**	599.73**	1269.64**	205.82**	739.73**	524.01**	1470.09**
	Y × C	27.92**	10.64**	10.68**	2.82^ns	3.37^ns	0.40^ns	8.39**	1.98^ns	6.59*	0.00^ns	2.14^ns	6.08*
	Y × N	10.85**	123.71**	11.29**	25.12**	45.42**	47.11**	106.66**	73.00**	5.94**	177.66**	9.97**	59.27**
	C × N	16.28**	28.15**	2.41^ns	14.00**	34.17**	35.78**	5.98**	11.51**	1.10^ns	2.30^ns	22.45**	20.43**
	Y × C × N	5.48**	3.48*	1.71^ns	0.50^ns	4.04*	1.46^ns	1.66^ns	1.87^ns	11.51**	4.16*	27.31**	19.65**

Values followed by different lowercase letters are significantly different with p < 0.05; within cultivars, values with different uppercase letters are significantly different with p < 0.05 according to the least significant difference test. **p < 0.01; *p < 0.05; ^nsNot significant. The bold values are the mean value of one cultivar in different N treatments.