TABLE 4.

Regression parameters for per-area marketable ear mass (Mt/ha) as a response of year of hybrid release (YOR) and factor scores for Low and High plant densities across all sweet corn hybrids at Urbana, IL in 2018–2020.

Plant density	Predictor variable	r *	Slope estimate	p-value	Variance explained (%)
Low	Year of hybrid release	0.44	0.03	<0.001	2.00
	Factor 1	–0.10	−0.17	0.19	–
	Factor 2	0.79	2.04	<0.001	50.0
	Factor 3	–0.30	−0.53	<0.001	4.00
			Adjusted R2		0.63
High	Year of hybrid release	0.36	0.08	<0.001	8.00
	Factor 1	–0.31	−1.66	<0.001	8.00
	Factor 2	0.41	2.38	<0.001	12.0
	Factor 3	–0.08	−0.44	0.35	1.00
			Adjusted R2		0.29

*Partial correlations between predictor variables and per-area marketable ear mass (Mt/ha). Proportion of variance explained by each of the regression models is shown in bold.