conditions with minimum and maximum temperatures of
19/30 °C night/day, under light conditions of 650 ± mol m-2
s-1 and 13 h photoperiods.
Plants were watered daily and
fertilized weekly with a solution of 170 mg L-1 of soluble
fertilizer (19N-19P-19K; Haifa Chemicals, Ltd.). After 18,
25 and 32 d the seedlings were sprayed with solutions of
salicylic acid (Merck®) prepared at three concentrations
(1.0, 0.01 and 0.0001 µM). Distilled water was applied as a
control. Tween 20® was added to the solution as a surfactant.
A completely random experimental design was used