Allelopathic effect of invasive species giant goldenrod (Solidago gigantea Ait.) on crops and weeds

Cilj istraživanja bio je utvrditi alelopatski potencijal invazivne vrste velike zlatnice (Solidagao gigantea Ait.) na klijanje i rast usjeva (mrkva, ječam, korijandar) i korovnih vrsta Teofrastov mračnjak (Abutilon theophrasti Med.) i oštrodlakavi šćir (Amaranthus retroflexus L.). Pokusi su provedeni s ciljem utvrđivanja učinka vodenih ekstrakata u petrijevim zdjelicama i posudama sa tlom. Istraživani su vodeni ekstrakti od suhe biomase velike zlatnice u koncentracijama od 1, 5 i 10 % (10,50 i 100 g/l). U petrijevim zdjelicama sve koncentracije ekstrakata pokazale su alelopatski utjecaj na klijavost i rast klijanaca usjeva te ih smanjile za 25% odnosno 60%. Klijavost i rast obje korovne vrste bili su značajno inhibirani primjenom ekstrakta. U pokusu s posudama s tlom alelopatski utjecaj bio je manje izražen. Zabilježeno je smanjenje nicanja te duljina izdanka i svježa masa klijanaca mrkve. Duljina korijena i svježa masa klijanaca ječma smanjeni su s većom koncentracijom ekstrakta. Nije zabilježen značajan utjecaj na nicanje i rast klijanaca A. theophrasti, dok je nicanje A. retroflexus inhibirano za 14,4%. Klijavost i rast testiranih vrsta smanjivali su se proporcionalno s povećanjem koncentracije biomase korova u ekstraktu. Uočene su pri tom razlike u osjetljivosti pojedinih vrsta, a A. retroflexus pokazao je najveću osjetljivostThe aim of the research was to determine allelopathic potential of invasive species giant goldenrod (Solidago gigantea Ait.) on germination and initial growth of crops (carrot, barley, coriander) and weed species velvetleaf (Abutilon theophrasti Med.) and redroot pigweed (Amaranthus retroflexus L.). Experiments were conducted to determine effect of water extracts in petri dish bioassay and in pots with soil. Water extracts from dry boveground biomass of goldenrod in concentrations of 1, 5 and 10% (10, 50 and 100 g/l) were investigated. In petri dishes, all extract concentrations showed allelopathic effect on germination and seedling growth of crops with reduction over 25 and 60%, respectively. Both weed species germination and growth were greatly suppressed with extract application. In pot experiment, allelopathic effect was less pronounced. Reduction in emergence percent, shoot length and fresh weight of carrot were observed. Barley root length and fresh weight were reduced with the highest extract concentration. No significant effect on seedling emergence and growth of A. theophrasti was recorded, while emergence of A. retroflexus was inhibited for 14.4%. Germination and growth of test species decreased proportionately as concentration of weed biomass in water extracts increased. Differences in sensitivity among species were recorded, with A. retroflexus being the most susceptible to extracts