Table 8.

Regression coefficients and their standardized values of three conventional components for crop yield changes during 2003–2017 national summer maize trials^†.

Regression	Item	Ear number per area gap	Ear kernel number gap	1000-kernel weight gap	R2
Coefficient	Min	0.114	1.01	1.62	0.67
Coefficient	Max	0.156	1.32	1.90	0.74
Coefficient	Mean	0.147	1.19	1.76	0.69
Standard coeff.	Mean	0.598	1.17	1.10

^†The analysis was separately applied to individual maturity spans from 1 d to 15 d for each of even and odd maturity groups of longer days. The same below.