Optimized Design and Experiment on Novel Combination Vacuum and Spoon Belt Metering Device for Potato Planters

Table 5

Variance analysis of regression equation.

Source	Missing seed index Y1				Multiple seed index Y2				Qualified seed index Y3
	Sum of squares	Degree of freedom	F value	Significant level P	Sum of squares	Degree of freedom	F value	Significant level	Sum of squares	Degree of freedom	F value	Significant level
Model	29.06	9	16.50	0.0006	59.58	9	14.04	0.0011	86.46	9	25.97	0.0001
x1	14.05	1	71.79	<0.0001	7.41	1	15.72	0.0054	41.86	1	113.16	<0.0001
x2	1.90	1	9.72	0.0169	10.58	1	22.44	0.0021	3.51	1	9.49	0.0178
x3	3.51	1	17.95	0.0039	14.85	1	31.50	0.0008	3.92	1	10.60	0.0140
x1x2	0.040	1	0.20	0.6648	12.25	1	25.98	0.0014	13.69	1	37.01	0.0005
x1x3	1.44	1	7.36	0.0301	0.72	1	1.53	0.2557	4.20	1	11.36	0.0119
x2x3	1.10	1	5.64	0.0493	0.040	1	0.085	0.7793	1.56	1	4.22	0.0789
	0.54	1	2.75	0.1412	8.58	1	18.20	0.0037	4.82	1	13.03	0.0086
	0.73	1	3.75	0.0940	4.23	1	8.97	0.0201	8.49	1	22.95	0.0020
	5.74	1	29.34	0.0010	0.58	1	1.24	0.3024	2.66	1	7.19	0.0314
Residual	1.37	7			3.30	7			2.59	7
Lack of fit	1.12	3	5.91	0.0594	1.89	3	1.79	0.2880	0.26	3	0.15	0.9263
Pure error	0.25	4			1.41	4			2.33	4
Total	30.42	16			62.88	16			89.05	16

Note. (highly significant, ); (significant, ).