The effects of soil temperature from soil mulching and harvest age on phenol, flavonoid and antioxidant contents of Java tea (Orthosiphon aristatus B.)

Chemical and Biological Technologies in Agriculture

Table 5 Pearson’s correlation of agronomic characters and soil temperature with secondary metabolites of Java tea

Agronomic characters	Correlation coefficient and P-value
Agronomic characters	Phenol	Flavonoids	Antioxidant
Plant height	0.198	− 0.067	0.015
	(0.353)	(0.780)	(0.940)
Number of leaves	0.070	− 0.122	− 0.230
	(0.768)	(0.665)	(0.303)
Fresh weight	0.792	− 0.524	0.353
	(< 0.01)	(0.026)	(0.083)
Dry weight	0.735	− 0.484	0.283
	(< 0.01)	(0.068)	(0.202)
Minimum soil temperature	− 0.453	0.523	− 0.185
	(0.045)	(0.015)	(0.366)
Mean soil temperature	− 0.460	0.394	− 0.125
	(0.031)	(0.063)	(0.517)
Maximum soil temperature	− 0.520	− 0.177	− 0.032
	(0.016)	(0.455)	(0.876)
GDD	0.674	− 0.237	0.374
	(< 0.01)	(0.276)	(0.042)

The confidence level is 95% (α = 0.05); the number in brackets is the P-value; the bold cell means significant correlation