It was stated that vanillin and p-coumaric acid used at concentrations 10<sup>-8</sup>-10<sup>-5</sup>M stimulated the growth of pine seedlings. Most effective were these substances used at concentration 10<sup>-7</sup>M. Both phenolic compounds stimulated the elongation, fresh and dry weight in very young seedlings (up to 3-4 weeks) and increased the fresh and dry weight only in older ones (7 weeks). The stimulation of growth processes in pine seedlings treated with vanillin and p-coumaric acid coincided with the increase of auxins in roots and with the decrease of free gibberellins in these plant organs. Neither vanillin nor p-coumaric acid influenced the level of ABA-like inhibitor both in the shoots and roots of pine seedlings.
Photosynthesis, respiration and growth of Scotch pine seedlings
