Influence of drought on allelopathic properties of Pinus sylvestris L.

Abstract

Objective – to investigate the influence of drought on allelopathic activity of Pinus sylvestris L. plants in conditions of M.M. Gryshko National Botanical Garden of the NAS of Ukraine.
 Material and methods. The choice of study objects was due to their habitat: plants of P. sylvestris grew in compliance with the necessary agricultural technology including regular irrigation at site 1 (control) and in the conditions of drought at site 2 that models natural ecosystems (experiment). The allelopathic activity of leaves and soil was determined. In the model experiments, Lepidium sativum L. ‘Azhur’, Triticum aestivum L. ‘Poliska 90’, Amaranthus caudatum L. ‘Rothschwanz’ were applied as the test plants.
 Results of the current study revealed that the allelopathic potential of needles and rhizosphere soil of P. sylvestris depends not only from the species but also from drought conditions. The inhibitory effect was stronger against root elongation than shoot elongation of seedlings.
 Conclusion. This study provides a laboratory-based evidence of the allelopathic effect of P. sylvestris exudates under drought stress on model plants. Studies showed that plants grown under conditions of lower soil moisture exhibit stronger inhibitory effect or slightly stimulate the growth of test objects in comparison with plants that had better water supply. This testifies to the relationship between soil moisture and seasonal allelopathic activity of the plants.