. 2017 Sep 1;1(3):367–381. doi: 10.2527/tas2017.0045

Table 3.

Effect of hybrid maturity class and harvest date on whole corn plant characteristics (yr 2)

Item	Hybrid maturity class × Harvest¹						SEM	P-value²
Item	MEM:1	MEM:2	MEM:3	MLM:1	MLM:2	MLM:3	SEM	F-test	Int.	Maturity	Harvest
Plant DM, %³	39.28	48.54	60.81	35.50	47.15	57.54	–	–	–	–	–
Actual Population⁴	66975	66975	66975	67961	67961	67961	3076	1.00	1.00	0.09	NS
Grain Yield	11.84^cd	12.55^bc	12.92^ab	11.45^d	13.34^ab	13.75^a	0.25	<0.01	0.02	0.04	Q^MEM, L^MLM
Corn Stover Yield⁵^,⁶	9.69^b	9.89^b	9.77^b	10.72^a	10.08^ab	9.62^b	0.24	0.02	0.04	0.06	NS^MEM, L^MLM
Whole Plant Yield⁵^,⁶	21.53	22.44	22.69	22.17	23.41	23.37	0.51	0.07	0.92	0.03	L
Grain, %⁶	54.79^c	55.86^bc	57.03^b	51.49^d	56.96^b	58.91^a	0.50	<0.01	<0.01	0.76	L^MEM, Q^MLM
Residue NDF, %	61.27	64.32	63.11	65.40	68.10	67.96	0.60	<0.01	0.55	< 0.01	Q
Residue NDFD, %⁷	33.21^b	32.12^b	28.71^c	37.88^a	32.30^b	27.76^c	0.67	<0.01	<0.01	0.01	L^{MEM, MLM}
Residue TDN, %	49.36	46.95	46.15	48.29	45.47	43.04	0.51	<0.01	0.08	< 0.01	L
Whole Plant TDN, %	73.30^a	72.73^ab	72.84^ab	71.26^c	72.57^b	72.51^b	0.26	<0.01	<0.01	< 0.01	Q^MEM,MLM
TDN yield/ha⁸	15.78	16.48	16.53	15.87	17.01	16.95	0.40	0.12	0.72	0.23	L

^a–d

Means with different superscripts differ (P < 0.05).

MEM = moderately early maturity, MLM = moderately late maturity; harvest dates: 1 = August 23, 2012; 2 = September 6, 2012; 3 = September 24, 2012.

F-test = overall F-test, Int = Interaction between hybrid maturity class and harvest, Maturity = P-value for the hybrid maturity class effect, Harvest = orthogonal contrast P-value for the harvest effect; NS = not significant (P > 0.05), L = linear response (P < 0.05), Q = quadratic response (P < 0.05).

Average plant DM as a reference for each hybrid maturity class × Harvest combination (no data available for harvest 3).

⁴

Actual population in plants/ha.

⁵

Yield in t/ha.

⁶

Harvest Index, DM basis.

⁷

Residue in-situ NDF digestibility.

⁸

TDN yield/ha (t of TDN/ha) = whole plant TDN × whole plant yield.