Table 5. Correlation analysis of buckling resistance, lodging index and plant type characteristics and root morphology.

Parameters	N1		N2		N3
	Lodging index	Breaking resistance	Lodging index	Breaking resistance	Lodging index	Breaking resistance
Plant height	0.174	0.348	0.088	0.47	0.143	0.459
Center of gravity height	0.349	0.162	0.094	0.291	0.072	0.646*
Fresh weight of single stem	0.198	0.472	0.195	0.253	0.401	0.609*
First node length	0.769**	−0.571	0.695*	−0.552	0.505	−0.509
First node stem diameter	−0.677*	0.697*	−0.507	0.519	−0.166	0.503
Second node length	0.624*	−0.829**	0.607*	−0.753**	0.228	−0.810**
Second node stem diameter	−0.607*	0.817**	−0.621*	0.771**	−0.268	0.820**
Third node length	0.334	−0.369	0.187	−0.294	−0.064	−0.408
Third node stem diameter	−0.259	0.602*	−0.242	0.503	0.013	0.765**
Root length	−0.496	0.442	−0.385	0.439	−0.062	0.415
Projected area	0.048	0.18	−0.234	0.438	−0.285	0.669*
Surface area	0.048	0.18	−0.234	0.438	−0.285	0.669*
Mean diameter	0.694*	−0.383	0.275	−0.106	0.141	−0.139
Root volume	0.402	−0.073	−0.029	0.253	−0.309	0.562
Root tip number	−0.572	0.417	−0.338	0.334	0.098	0.157

Note:

* and ** indicate significant correlations at the 0.05 and 0.01 levels. N1, first node; N2, second node; N3, third node.