Iva xanthiifolia Nutt., popularly known as “ierboaie”, is a neophyte invasive species notorious for being an allergenic weed, identified in the west of Romania, in two locations near Oradea, in Bihor County, near the border with Hungary. This species belongs to the allergenic weeds, being considered by some even more dangerous than Ambrosia artemisiifolia L., the two representing in summer the primary source of allergies, or diseases like hay fever, due to the pollen released in the atmosphere.The research is about the results of the allelophatic effect upon the germination and growth of plants, immediately after springing, viewed as the interaction between the species of Iva xanthiifolia and five other crop plants: wheat (Triticum aestivum L.), rye (Secale cereale L.), barley (Hordeum vulgare L.), rape (Brassica napus L.) and lucerne (Medicago sativa).
The experiments that were performed consisted in applying treatments with aqueous extracts obtained from different vegetative organs (roots, leaves, stems and seeds) harvested from Iva xanthiifolia plants. In all cases, the results indicate a rather large inhibitor effect, no matter if the aqueous extracts were obtained from green plants or dehydrated ones.