Table 1.

Effect of exogenous kinetin on the net CO₂ assimilation rate (A), stomatal conductance (g_s), intrinsic water-use efficiency (A/g_s), instantaneous water-use efficiency (A/E), transpiration rate (TrmmoL), intracellular CO₂ concentration (C_i), internal to ambient CO₂ concentration ratio (C_i/C_a) and mesophyll efficiency in the leaves of coffee seedlings under optimum and cold stress conditions, 25/20 °C and 12/12 °C, respectively.

Parameter	Optimum Conditions		Cold Stress Conditions
	Control	Kinetin	Cold	Cold + Kinetin
A (µmoL CO2 m−2 s−1)	2.84 ± 1.61 Aa	1.83 ± 0.11 Aa	1.55 ± 0.55 Aa	2.54 ± 0.17 Aa
gs (mmoL m−2 s−1)	31.9 ± 16.1 Aa	17.6 ± 3.2 Aa	8.12 ± 4.7 Ba	18.0 ± 1.8 Aa
A/gs (µmoL mmol−1)	0.10 ± 0.04 Ba	0.11 ± 0.02 Aa	0.21 ± 0.05 Aa	0.14 ± 0.02 Ab
A/E (µmoL mmol−1)	4.13 ± 1.86 Ba	3.99 ± 0.88 Aa	10.4 ± 2.62 Aa	7.03 ± 0.79 Ab
Trmmol (mmoL H2O m−2 s−1)	0.75 ± 0.38 Aa	0.47 ± 0.08 Aa	0.17 ± 0.10 Bb	0.36 ± 0.04 Aa
ci (µL L−1)	333 ± 125 Aa	215 ± 37.8 Aa	81.2 ± 54.9 Ba	161.9 ± 29.7 Aa
ci/ca	0.83 ± 0.31 Aa	0.54 ± 0.09 Aa	0.05 ± 0.003 Bb	0.41 ± 0.07 Aa
ci/gs	7.91 ± 1.03 Ab	12.23 ± 0.15 Aa	7.54 ± 3.00 Aa	8.95 ± 1.04 Ba

Within a row, different capital letters, (A, B) denote the statistically significant differences between the parameter means within temperature treatments, whereas different small letters, (a, b) denote the statistically significant differences for the parameter means within kinetin treatments (p < 0.05, Newman–Keuls test). Data are expressed as means ± S.D (n = 3).