Table 5.

Paclobutrazol enhanced recovery of leaf PI, necrosis, and chlorophyll content of containerized English oak (Quercus robur L.) placed outdoors with time (9 weeks) based on quadratic regression analysis after the cessation of 3 weeks of drought.^{^z}

	PI		Leaf necrosis		Chlorophyll content		Electrolyte leakage (%)
Treatment	Regression: y = a + bT + cT²	_r2	Regression: y = a + bT + ct²	_r2	Regression: y = a + bT + cT²	_r2	Regression: y = a + bT + cT²	_r2
Control	y = −2.39 + 2.52T − 0.21T²	0.90	y = 4.06 + 0.05T − 0.04T²	0.89	y = 22.3 + 9.98T − 1.07T²	0.95	y = 28.2 − 1.56T − 0.21T²	0.92
2 mL (0.06 fl oz) PBZ foliar spray	y = −1.58 + 2.55 − 0.19T²	0.83	y = 1.97 − 0.20T + 0.01T²	0.91	y = 34.8 + 2.48T + 0.22T²	0.98	y = 13.0 −3.32T + 0.25T²	0.85
4 mL (0.12 fl oz) PBZ foliar spray	y = 1.36 + 0.70T + 0.02T²	0.87	y = 2.47 − 0.34T + 0.02T²	0.73	y = 28.4 + 11.47T − 0.38T²	0.93	y = 8.94 − 0.04T − 0.13T²	0.83
5 mL (0.15 fl oz) PBZ root drench	y = 0.62 + 1.30T − 0.06T²	0.47	y = 2.15 − 0.20T + 0.00T²	0.90	y = 51.2 − 4.48T + 1.83T²	0.77	y = 15.3 − 2.07T − 0.00T²	0.96
10 mL (0.3 fl oz) PBZ root drench	y = 0.17 + 2.66T − 0.28T²	0.77	y = 2.33 − 0.25T + 0.01T²	0.86	y = 34.8 + 8.32T − 0.21T²	0.81	y = 9.48 − 0.28T − 0.19T²	0.93

↵^zPBZ-treated plants: PI and leaf chlorophyll content, values mean of ten trees, five leaves per tree. Electrolyte leakage values mean of ten trees, two leaves per tree. Leaf necrosis values mean of ten trees. Controls: PI and leaf chlorophyll content, values mean of two trees, five leaves per tree. Pn and electrolyte leakage values mean of two trees, two leaves per tree. Leaf necrosis values mean of two trees.
Y = leaf PI, necrosis, chlorophyll content, and electrolyte leakage value; a = leaf PI, necrosis, chlorophyll content, and electrolyte leakage of control value (calculated intercept); b = rate of PI, necrosis, chlorophyll content and electrolyte leakage with time (T); c = rate of change of leaf PI, necrosis, chlorophyll content, and electrolyte leakage.
PBZ = paclobutrazol; PI = chlorophyll fluorescence.