Table 4. The effects (F values and statistical significances) of plant age and its interactions with plant physiological stage on antioxidant indices and plant hormones analyzed in two-way ANOVA model.

	2018			2019
	Plant age	Physiological stage	Age × Stage	Plant age	Physiological stages	Age × Stages
Leaves
O•−2	6,215***	8,933***	7,051***	1,254***	13,405***	1,872***
MDA	172.1***	0.794ns	13.38***	566.8***	1.572ns	217.0***
SOD	7.853**	1,588***	69.732***	45.41***	1,279***	5.786*
POD	312.1**	3,040**	82.72**	418.3**	452.4**	586.7**
CAT	74.13***	742.0***	37.63***	4.231*	11.16**	11.62**
IAA	1,155***	1,138***	221.6***	541.2***	68.71***	744.8***
ABA	19.76***	269.2***	11.85**	34.38***	7.000**	0.659ns
ZT	659.2***	68.463***	5.831*	7.782**	85.54***	14.59***
GA	69.04***	53.75***	1.144ns	17.95***	166.3***	34.56***
Roots
O•-2	2,010***	6,232***	909.5***	4,413***	2,418***	3,772***
MDA	1.329**	6.254***	1.243**	94.26***	417.6***	55.58***
SOD	12.23***	196.5***	7.004**	32.08***	5.183*	142.4***
POD	1,428***	3,383***	178.4***	203.7***	81.87***	1.371*
CAT	35.15***	1,251***	18.60***	1.77ns	0.524ns	0.212ns
IAA	77.91***	91.97***	87.92***	1,064***	737.2***	1,799***
ABA	3,396***	15,089***	4506***	249.0***	668.8***	309.8***
ZT	12.06***	0.158ns	2.883ns	175.0***	16.52**	63.04ns
GA	12.23***	9.564**	14.85***	1.542ns	3.664ns	22.08***

Notes:

^*P < 0.05.

^**P ≤ 0.01.

^***P ≤ 0.001.

^nsnot significant.