Allelopathic effects of Stellaria media (L.) Vill. on germination and early stages of growth of Raphanus sativus var. radicula

Influence of aqueous extracts of aboveground organs of common crop weeds Stellaria media on germination and seedlings growth of radish (Raphanus sativus L. var. radicula Pers.) was studied. Three different cultivars of radish (i.e. ‘Rowa’, ‘Krakowianka’, and ‘Półdługa’) were used to investigate if Stellaria media could produce allelopathins and if the impact of allelopathins differs between cultivars. The influence of allelopathins in various form of extracts was checked, i.e. decoction, infusion, and macerate, as the impact on germination rate, seedling growth (length and mass), and electrolyte leakage. Compared to the control group (distilled water used) the germination rate of radish seeds was lower, independently of the type of S. media extracts used. The growth of seedlings differed between cultivars and form of extract. It was noticed the inhibition of seedling growth for ‘Półdługa’ cultivar independently of extract form. The growth of two other cultivars was stimulated by the infusion, and slightly inhibited by the decoction and macerate. The extracts reduced the outflow of electrolytes through the cell membranes of radish seedlings of all but one the analysed radish cultivars. The exception was the macerate, which in the ‘Rowa’ cultivar caused the increase of the electrolyte leakage.