Table 6. Variance of hardness of laminated bamboo at different culm position and lamination direction

Source of diversity	Sum of squares	Db	Median square	F count	Sig.
Culm position (B)	521,234.724	2	260,617.362	12.695**	0.001
Lamination direction (L)	616,101.431	1	616,101.431	30.010**	0.001
Interaction (B × L)	36,027.539	2	18,013.770	0.877ns	0.441
Error	246,357.491	12	20,529.791
Total	1,419,721.185	17

Significantly different at 1% test level;
not significantly different.