Table 1.

Experimental design matrix to screen for variables that determine the yield of essential oil from fresh leaves of Oyama sieboldii and ANOVA results^a.

Run	BBD experimentsb				ANOVA
	X1	X2	X3	Y	Source	Sum of squares		Degree of freedom		Mean square		F-value	P-value
1	385	0.64	30	13.44	Modelb	133.60		9		14.84		172.66	<0.0001c
2	700	0.64	30	19.09	X1	55.46		1		55.46		645.09	<0.0001c
3	385	1.07	30	13.39	X2	0.06		1		0.06		0.65	0.4482
4	700	1.07	30	18.96	X3	26.23		1		26.23		305.13	<0.0001c
5	385	0.86	20	12.94	X1 X2	0.00		1		0.00		0.01	0.9132
6	700	0.86	20	16.81	X1 X3	1.12		1		1.12		13.02	0.0086c
7	385	0.86	40	15.83	X2 X3	0.66		1		0.66		7.70	0.0275c
8	700	0.86	40	21.81	X12	20.60		1		20.60		239.59	<0.0001c
9	540	0.64	20	15.14	X22	16.64		1		16.64		193.55	<0.0001c
10	540	1.07	20	15.71	X32	7.80		1		7.80		90.72	<0.0001c
11	540	0.64	40	19.25	Residual	0.60		7		0.09
12	540	1.07	40	18.19	Lack of fit	0.46		3		0.15		4.25	0.0980
13	540	0.86	30	20.31	Pure error	0.14		4		0.04
14	540	0.86	30	20.55	Corrected total	134.20		16
15	540	0.86	30	20.14	Credibility analysis of the regression equations
16	540	0.86	30	20.59	Index mark	Standard deviation	Mean	Coefficient of variation %	Press	R2	Adjust R2	Predicted R2	Adequacy precision
17	540	0.86	30	20.51	Y	0.29	17.80	1.65	7.55	0.9955	0.9897	0.9437	39.52

^aThe results were obtained with Design Expert 7.0 software.

^bX₁ is the microwave irradiation power (W), X₂ is the amount of magnesium chloride (mmol/gDW), X₃ is the microwave irradiation time (min), and Y is total yield of essential oil (mL/kgDW).

^cSignificant at P < 0.05.