ALLELOPATHIC EFFECT OF INVASIVE SPECIES COMMON RAGWEED (Ambrosia artemisiifolia L.) ON WEEDS

Cilj rada bio je ispitati alelopatski utjecaj ambrozije (Ambrosia artemisiifolia L.) na klijavost i rast korovnih vrsta Teofrastov mračnjak (Abutilon theophrasti Med.), oštrodlakavi šćir (Amaranthus retroflexus L.) i bezmirisnu kamilicu (Tripleurospermum inodorum (L.) C.H. Schultz.). U laboratorijskim uvjetima ispitivan je utjecaj vodenih ekstrakata od suhe nadzemne mase ambrozije u koncentracijama od 1, 5 i 10% u petrijevim zdjelicama, te utjecaj biljnih ostataka ambrozije u dozama od 10, 20 i 30 g/kg tla u pokusu s posudama. U petrijevim zdjelicama, klijavost korova bila je inhibirana i do 100%. Jednako tako, negativan utjecaj viših koncentracija zabilježen je na duljinu klijanaca i svježu masu. Bezmirisna kamilica bila je najosjetljivija na primijenjene ekstrakte. Inkorporacija biljnih ostataka u tlo značajno je smanjila samo klijavost mračnjaka za 38,9%. Više doze djelovale su inhibitorno na duljinu klijanaca šćira i bezmirisne kamilice, te na svježu masu mračnjaka. Utjecaj ekstrakata u petrijevim zdjelicama bio je jači od utjecaja biljnih ostataka u posudama.The aim of this study was to determine the allelopathic effect of common ragweed (Ambrosia artemisiifolia L.) on germination and growth of weed species velvetleaf (Abutilon theophrasti Med.), redroot pigweed (Amaranthus retroflexus L.) and scentless chamomile (Tripleurospermum inodorum (L.) C.H. Schultz.). Under laboratory conditions, the effects of water extracts of dry aboveground biomass of ragweed in concentrations of 1, 5 and 10% were evaluated in Petri dishes, while the impact of ragweed plant residues at doses of 10, 20 and 30 g/kg soil were examined in the experiment with pots. In Petri dishes, weed germination was inhibited up to 100%. Likewise, the negative impact of higher concentrations was recorded on seedling length and fresh weight. Scentless chamomile was the most sensitive to applied extracts. Incorporation of plant residues into the soil significantly reduced only emergence of velvetleaf for 38.9%. Higher doses had inhibitory effect on seedling length of redroot pigweed and scentless chamomile, and the fresh weight of velvetleaf. The effect of extracts in Petri dishes was stronger than the impact of plant residues in pots