Effect of water stress on allelopathic potential of petunia (Petunia hybrida L.)

The aim of the paper was to evaluate the influence of water stress i.e., different net irrigation water on the allelopathic potential of petunia (Petunia hybrida L.). Water extracts were prepared from aboveground biomass of petunias grown at different net irrigation water (51.5 mm, 91.5 mm and 132.5 mm) in three concentrations (1%, 2.5% and 5%). The experiment was performed under controlled laboratory conditions in Petri dishes and the allelopathic potential of petunia water extracts was assessed by measuring seed germination, root and shoot length, and fresh weight of radish seedlings. The results of the experiment showed a statistically significant allelopathic effect of petunia water extracts on all the measured parameters. The allelopathic potential largely depended on the extract concentration. Petunia extracts of higher concentrations showed a greater negative effect and reduced germination, shoot and root length, and fresh weight of seedlings up to 79.9%, 93.4%, 83.1% and 69.5%, respectively. Positive effect was determined on shoot length and fresh weight of radish seedlings with 1% concentration extracts. As a rule, water stress i.e., net irrigation water did not have a significant effect on the allelopathic potential of petunia. The exception was recorded with the highest extract concentration on the shoot length of seedlings where extracts from petunias grown at 51.5 mm had greater inhibitory effect compared to extracts from petunias grown at 91.5 and 132.5 mm.