The use of allelochemicals to delay germination of Astragalus cycluphyllus seeds.

The effect of different concentrations of allelochemicals including Ephedrin, Vanillin, abscisic acid (ABA), Eucalyptus camadulensis [E. camaldulensis] and Juglans ragia [J. regia] leaf and Onobrychis sativa [O. viciifolia] seed extracts were tested on percentage germination, start of germination and seedlings growth of Astragalus cycluphyllus. All considered compounds delayed start of germination with respect to the control, but among these allelochemicals different concentrations of ABA and 33.3 mM of Vanillin delayed germination for a longer period than other allelopathic compounds. Ephedrin, Vanillin and E. camadulensis leaf extract reduced percentage of germination. In addition, in Ephedrine, J. regia compounds seedlings had abnormal growth and twisted form. Therefore, only ABA had no negative effect on percentage of germination and seedling growth.