Allelopathic effect of Sonchus arvensis L. on germination and early growth of spring wheat

In laboratory bioassay the allelopathic influence of ground perennial sow thistle Sonchus arvensis over-ground and rootstock biomass water extracts on spring wheat Triticum aestivum L. variety SW Estrad C2 grain germination and early growth was investigated. Grinded 50 g of air-dried plant part (over-ground or rootstock) was stirred into 500 ml of distilled water and left for 24 hours at a room temperature. Filtered water extract was taken as a stock solution. Stock solution was applied in 2-, 5-and 10-fold dilution, distilled water application served as control treatment. The spring wheat grain germination was checked after 5 and 11 days of sprouting using 5, 10 and 15 grains per Petri dish as different concentration of recipient plant. Spring wheat grain germination was more inhibited by Sonchus arvensis over-ground part than by rootstock water extracts. Spring wheat grain germination in Sonchus arvensis root water extract of stock solution was higher by 20-45% and by 5-30% than in Sonchus arvensis over-ground part water extract of stock solution, sprouting grains 5 and 11 days, respectively. During longer germination period of 11 days, negative effect of Sonchus arvensis over-ground part and root stock solution on spring wheat grain germination was moderated. Sonchus arvensis over-ground part and rootstock water extracts inhibited more spring wheat radicle growth than its seedling growth. Low concentration water extracts of Sonchus arvensis over-ground part showed tendency to increase spring wheat grain germination. The highest allelopathic inhibitory effect of Sonchus arvensis over-ground part and rootstock water extracts on spring wheat grain germination and early growth of seedlings and radicles was established in stock solution. Increase of recipient plant spring wheat grain number per Petri dish had no essential influence on its germination initiation, seedling and radicle growth in Sonchus arvensis over-ground part and rootstock water extracts.