Allelopathic potential of weed species Johnson grass (Sorghum halepense (L.) Pers.) on radicchio

U istraživanju je proučavan alelopatski učinak divljeg sirka (Sorghum halepense (L.) Pers.) na klijavost i razvoj radiča. Ukupno su provedena tri pokusa: utjecaj vodenih ekstrakata divljeg sirka u Petrijevim zdjelicama, utjecaj vodenih ekstrakata divljeg sirka u posudama s tlom i utjecaj biljnih ostataka divljeg sirka u posudama s tlom. U pokusima provedenim u Petrijevim zdjelicama i u posudama s tlom ispitivane su vodeni ekstrakti koncentracije od 1%, 5% i 10%. U pokusu s biljnim ostacima ispitivani su dvije doze od 10 g i 20 g po kg tla. Dobiveni rezultati pokazali su da divlji sirak ima značajan alelopatski učinak na rast i razvoj radiča. Pokusi provedeni u Petrijevim zdjelicama imali su najveći učinak, gdje je kod većih koncentracija ekstrakta zabilježen veći negativni utjecaj na klijanje sjemena, duljinu korijena, duljinu izdanaka te svježu masu. U posudama s tlom ekstrakti nisu pokazali značajan alelopatski učinak u odnosu na kontrolni tretman. Biljni ostaci divljeg sirka u obje ispitane doze od 10 g i 20 g po kg tla pokazali su značajan inhibitorni učinak na nicanje sjemena te na suhu masu klijanacaThe aim of the study was to evaluate the allelopathic effect of johnsongrass (Sorghum halepense (L.) Pers.) on the growth and development of radicchio. Three experiments were conducted in total: the influence of water extracts of johnsongrass in Petri dishes, the influence of water extracts of johnsongrass in pots with soil and the impact of plant residues of johnsongrass in pots with soil. Water extracts in concentrations of 1%, 5% and 10% were examined in experiments carried out in Petri dishes and pots with soil. In a trial with plant residues, the residues were examined in the amount of 10 g and 20 g per kg of soil. The results showed that johnsongrass had significant allelopathic effect on the growth and development of the radicchio. The results also showed that the tests performed in Petri dishes had the greatest effect, while the larger concentration of the extract had a greater negative impact on germination, root length, shoot length and fresh weight. In pots with soil there was no significant allelopathic effect noticed compared to the control treatment. Johnsongrass plant residues sampled in both doses of 10 g and 20 g per kg of soil showed a significant inhibitory effect on the germination of seeds and the dry weigh