ALLELOPATHIC EFFECT OF AROMATIC AND MEDICINAL PLANTS ON TRIPLEUROSPERMUM INODORUM (L.) C.H. SCHULTZ

The aim of the study was to evaluate the effect of six cultivated and wild aromatic and medicinal plants, basil (Ocimum basilicum L.), chamomile (Matricaria chamomilla L.), common mallow (Malva sylvestris L.), greater celandine (Chelidonium majus L.), lemon balm (Melissa officinalis L.) and lovage (Levisticum officinale Koch), on germination and growth of weed species scentless mayweed (Tripleurospermum inodorum (L.) C.H. Schultz). In total four experiments were conducted to assess the allelopathic potential of seed and plant aboveground biomass: I) seed cogermination in Petri dishes, II) seed cogermination in pots with soil, III) water extracts in Petri dishes and IV) plant residues in pots with soil. Weed seed germination was significantly reduced for 32.2% with lovage seeds in Petri dishes. In the pots with soil, seed allelopathic potential was less pronounced. The application of extracts from fresh plant biomass in concentrations of 5 and 10% reduced germination and growth of weed, with the extracts from chamomile and common mallow having the highest inhibitory effect. The extracts from dry plant biomass of basil, chamomile, common mallow, greater celandine and lovage in higher concentration completely (100%) inhibited germination and weed seedling growth. On average, the extracts from dry plant biomass had higher inhibitory effect. Reduction in weed seed emergence and growth was recorded when dry plant residues in rates of 10 and 20 g/kg were incorporated in the soil. Lovage and greater celandine residues exhibited the highest allelopathic effect.