Table 6.

Paclobutrazol enhanced recovery of leaf PI, necrosis, and chlorophyll content of containerized evergreen oak (Quercus ilex 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 = 0.88 + 0.309T + 0.07T²	0.93	y = 4.06 − 0.14T − 0.021²	0.92	y = 46.7 + 3.60T + 0.20T²	0.90	y = 31.5 − 5.81T + 0.45T²	0.90
2 mL (0.06 fl oz) PBZ foliar spray	y = 0.16 + 1.99T − 0.13T²	0.94	y = 2.62 − 0.01T − 0.01T²	0.70	y = 88.1 + 5.97T − 0.52T²	0.88	y = 20.1 − 1.66T − 0.14T²	0.95
4 mL (0.12 fl oz) PBZ foliar spray	y = −0.20 + 3.04T − 0.30T²	0.90	y = 3.29 − 0.50T + 0.04T²	0.96	y = 55.2 + 6.44T + 0.64T²	0.89	y = 20.7 − 2.57T + 0.09T²	0.87
5 mL (0.15 fl oz) PBZ root drench	y = 1.33 + 0.807T + 0.02T²	0.97	y = 3.01 − 0.10T − 0.01T²	0.96	y = 61.3 + 7.53T − 0.01T²	0.71	y = 16.1 − 0.17T − 0.32T²	0.82
10 mL (0.3 fl oz) PBZ root drench	y = 1.57 + 1.79T − 0.14T²	0.95	y = 2.54 + 0.20T − 0.00T²	0.93	y = 82.0 + 0.52T + 0.83T²	0.88	y = 10.9 + 1.36T − 0.40T²	0.99

↵^zTwo milliliters PBZ foliar spray and 5 mL (0.15 fl oz) PBZ root drench-treated plants: PI and leaf chlorophyll content, values mean of eight trees, five leaves per tree. Pn and electrolyte leakage values mean of eight trees, two leaves per tree. Leaf necrosis values mean of eight trees. Four milliliters PBZ foliar spray and 10 mL (0.3 fl oz) PBZ root drench-treated plants: PI and leaf chlorophyll content, values mean of six trees, five leaves per tree. Pn and electrolyte leakage values mean of six trees, two leaves per tree. Leaf necrosis values mean of six trees. Controls: PI and leaf chlorophyll content, values mean of four trees, five leaves per tree. Pn and electrolyte leakage values mean of four trees, two leaves per tree. Leaf necrosis values mean of four 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; Pn = photosynthetic CO2 fixation.