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

Cilj rada bio je utvrditi alelopatski utjecaj ambrozije (Ambrosia artemisiifolia L.) na klijavost i rast ječma, pšenice, soje, salate, mrkve i bosiljka. 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. Vodeni ekstrakti smanjili su klijavost svih ispitivanih usjeva, i do 100%. Duljina klijanaca i svježa masa također su inhibirane, posebice s višim koncentracijama. Soja se pokazala kao najtolerantnija na djelovanje ekstrakata. Biljni ostatci značajno su smanjili klijavost samo salate i to za 6,4%. Najveći inhibitorni učinak na duljinu korijena zabilježen je kod mrkve, a duljinu izdanka kod bosiljka. Biljni ostatci pokazali su pozitivni i negativni utjecaj na svježu i suhu masu usjeva. Ječam i soja bili su pod najvećim, dok na pšenicu biljni ostatci nisu imali nikakav utjecaj. Utjecaj biljnih ostataka bio je manje izražen od ekstrakata u petrijevkama.The aim of this study was to determine the allelopathic effect of common ragweed (Ambrosia artemisiifolia L.) on germination and growth of barley, wheat, soybean, lettuce, carrot and basil. 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. The water extracts decreased germination of all tested crops, and up to 100%. The length and fresh weight of seedlings were also inhibited, in particular with higher concentrations. Soybean was the least susceptible to applied extracts. Ragweed plant residues significantly reduced germination only in lettuce by 6.4%. The highest inhibitory effect on root length was observed in carrot, and on shoot length in basil. Plant residues showed both positive and negative impact on the fresh and dry weight of crops. Barley and soybeans were least tolerant to plant residues, while no impact was observed in wheat. The effect of plant residues was less pronounced than extracts in Petri dishes