Table 3.

B. papyrifera growth parameters estimated using equations under different water stress levels.

Measurement	Treatment	X0	a	GR50	DTlog	DTs
Plant height	T0	13.36 ± 0.59	102.54 ± 4.62a	7.29 ± 0.82	14.33 ± 1.32	6.20 ± 0.12
	T1	11.68 ± 0.69	83.94 ± 3.87b	6.45 ± 0.24	13.01 ± 0.13	5.18 ± 0.76
	T2	12.13 ± 0.02	87.14 ± 2.25ab	5.91 ± 0.65	15.16 ± 1.87	4.55 ± 0.94
	T3	13.37 ± 0.44	94.75 ± 2.96ab	5.97 ± 0.39	15.98 ± 1.02	5.38 ± 0.83
Significant difference		ns		ns	ns	ns
Leaf length	T0	4.56 ± 0.10	133.05 ± 3.82a	27.33 ± 1.02	4.87 ± 0.10	2.12 ± 0.08
	T1	4.67 ± 0.20	133.48 ± 9.79a	27.62 ± 2.50	4.85 ± 0.21	2.04 ± 0.23
	T2	3.78 ± 0.14	97.58 ± 2.10b	25.53 ± 0.25	3.82 ± 0.08	1.87 ± 0.09
	T3	3.86 ± 0.26	76.25 ± 6.47b	19.72 ± 2.12	4.17 ± 0.75	1.77 ± 0.12
Significant difference		ns		ns	ns	ns
Leaf width	T0	4.94 ± 0.23a	170.30 ± 8.64a	32.79 ± 0.74	5.20 ± 0.23	2.34 ± 0.17a
	T1	4.93 ± 0.10a	157.05 ± 2.04a	29.70 ± 0.65	5.30 ± 0.18	2.28 ± 0.02ab
	T2	3.95 ± 0.04b	112.15 ± 4.77b	26.03 ± 2.94	4.37 ± 0.28	1.77 ± 0.18b
	T3	4.36 ± 0.18ab	120.03 ± 1.51b	25.24 ± 1.36	4.78 ± 0.28	1.97 ± 0.04ab
Significant difference				ns	ns

Note: The means ± SE (n = 3) in the table indicate significant differences in B. papyrifera growth parameters estimated during different water stress phases at p ≤ 0.05, according to one-way ANOVA and Tukey-test. Different lowercase letters in the same column indicate significant differences in the measured factor among the four levels. a is the upper limit of the growth index of the whole growth process; X₀ is the time it takes to reach 50% of the maximum increase in the logarithmic growth period (days); GR₅₀ is the growth rate in the half of the logarithmic phase; DT_log is the duration of the logarithmic phase; and DT_s is the time from observation to logarithmic growth. ns is no significant differences. T0 is the control group, T1 is the mild drought, T2 is the moderate drought, T3 is the severe drought.