Source of Variations	d.f	Leaf Dry Weight
Block	4	10.29
Harvesting age (HA)	2	3752.88 **
Harvesting frequency (HF)	2	2731.08 **
Interaction (HA × HF)	4	200.75 **
Error	32	3.73
Total	44
Contrast
Linear (HA)	1	2482.52 **
Quadratic (HA)	1	18.94 *
Linear (HF)	1	1820.61 **
Quadratic (HF)	1	0.02
* and ** are significantly difference at p < 0.05 and p < 0.01 respectively.