. 2020 Sep 2;11:1307. doi: 10.3389/fpls.2020.01307

Table 7.

Effects of year, cultivar, and levels of NPK on potassium accumulation (kg ha^–1) in different plant organs at different growth stages and on potassium harvest index of maize.

Treatments	At silking				At physiological maturity					Post-silking K accumulation^$	HI(K)^†
	Leaf	Stalk		Total	Leaf	Stalk		Grain	Total
	Leaf	Stem	Tassel	Total	Leaf	Stem	Other	Grain	Total
Year
Year 1	31.7a	119.5a	4.2a	155.3a	27.2a	48.6a	14.6b	40.0a	130.4a	−24.9a	0.32a
Year 2	31.8a	119.9a	4.1a	155.8a	28.2a	46.0a	15.4a	35.0b	124.6a	−31.2a	0.29b
Cultivar
P3522	35.2a	132.4a	2.3c	169.9a	27.6ab	52.4a	11.7b	39.8a	131.6a	−38.3b	0.31a
P3396	28.4c	119.3b	3.5b	151.2b	31.5a	42.8a	16.9a	37.1b	128.3a	−22.9a	0.30a
Rajkumar	31.8b	107.4c	6.5a	145.6b	24.0b	46.6a	16.4a	35.6b	122.6a	−23.0a	0.30a
Levels of NPK
N₁₀₀P₃₀K₃₀ (50% RDF)	27.5ef	93.7ef	4.3bc	125.5ef	25.6c	45.9cde	14.9cd	37.8b	124.3d	−1.29a	0.31a
N₁₅₀P₄₅K₄₅ (75% RDF)	31.5cd	126.0c	4.4bc	162.0c	31.2b	50.3bcd	16.3bc	43.2a	141.0c	−21.0ab	0.32a
N₂₀₀P₆₀K₆₀ (100% RDF)	37.2b	146.7b	4.8ab	188.7b	33.9b	55.0bc	17.3b	43.7a	149.9bc	−38.7bc	0.30a
N₂₅₀P₇₅K₇₅ (125% RDF)	40.7a	178.4a	5.3a	224.4a	38.8a	69.1a	20.3a	47.2a	175.4a	−49.0c	0.27a
N₃₀₀P₉₀K₉₀ (150% RDF)	39.8ab	153.4b	4.9ab	198.1b	34.8b	59.7b	19.3a	45.8a	159.5ab	−38.5bc	0.30a
P₆₀K₆₀ (100% RDF–N)	25.9f	85.8fg	3.4d	115.1fg	20.2d	34.0de	11.4f	25.3d	90.8e	−24.2ab	0.30a
N₂₀₀K₆₀ (100% RDF–P)	33.6c	114.9cd	3.8cd	152.3cd	25.4c	43.3cde	13.7de	38.1b	120.4d	−31.8bc	0.32a
N₂₀₀P₆₀ (100% RDF–K)	29.5de	102.7de	3.5d	135.7de	23.0c	38.5cde	12.5ef	33.7c	107.7d	−27.9bc	0.32a
Control (–NPK)	20.2g	75.6g	2.6e	98.5g	16.4e	29.7e	9.4g	22.9d	78.4e	−20.1ab	0.30a
Source of variation
Year	ns	ns	ns	ns	ns	ns	**	**	ns	ns	*
Cultivar	**	**	**	**	*	ns	**	**	ns	*	ns
Levels of NPK	**	**	**	**	**	**	**	**	**	*	ns
Year × cultivar	ns	ns	ns	ns	ns	ns	*	ns	ns	ns	ns
Year × levels of NPK	*	**	ns	**	ns	ns	ns	ns	ns	ns	ns
Cultivar × levels of NPK	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns
Year × cultivar × levels of NPK	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns

Year 1 and year 2 represent winter 2012–13 and 2013–14, respectively. Within year, cultivar, and levels of NPK, numbers followed by different letters indicate significant differences at p ≤ 0.05 (otherwise statistically at par). ns, non-significant (p > 0.05). *Significant at p ≤ 0.05. **Significant at p ≤ 0.01; Other = Tassel + cob + shank + husk; ^$– sign in post-silking K accumulation represents net loss of K from silking to physiological maturity stage; ^†HI(K), Harvest Index (Potassium).