Allelopathic effects of some plant species on growth and development of crops and weeds

Cilj rada bio je utvrditi alelopatski utjecaj korovnih vrsta na rast i razvoj usjeva, te mogućnost primjene aromatičnih i ljekovitih biljaka u suzbijanju korova. Ispitan je utjecaj biljne mase i sjemena korovnih vrsta: poljski osjak (Cirsium arvense), poljski mak (Papaver rhoeas), bezmirisna kamilica (Tripleurospermum inodorum), oštrodlakavi šćir (Amaranthus retroflexus), crna pomoćnica (Solanum nigrum) i divlji sirak (Sorghum halepense) na pšenicu, ječam, mrkvu, soju i uljnu bundevu. Djelovanje ljupčaca (Levisticum officinale), bosiljka (Ocimum basilicum), prave kamilice (Matricaria chamomilla), matičnjaka (Melissa officinalis), crnog sljeza (Malva sylvestris) i velikog rosopasa (Chelidonium majus) utvrđeno je na rast i razvoj korovnih vrsta Teofrastov mračnjak (Abutilon theophrasti), oštrodlakavi šćir, strjeličasta grbica (Lepidium draba), crna pomoćnica, divlji sirak i bezmirisna kamilica. Alelopatski utjecaj ovisio je o korovnoj vrsti, usjevu, koncentraciji odnosno dozi, biljnom dijelu te stanju biljne mase. U prosjeku su ekstrakti od svih vrsta, osim divljeg sirka, smanjili klijavost za više od 20,0%, a rast klijanaca do 41,2% u Petrijevim zdjelicama. Vodeni ekstrakti primijenjeni u posude s tlom smanjili su nicanje i rast usjeva i do 65%. Inkorporacija biljnih ostataka korova u posude s tlom smanjila je nicanje usjeva i do 65,3%. Zajedničko klijanje sjemena usjeva i korova kao i korijenovi eksudati nisu pokazali značajan utjecaj na klijavost usjeva. Alelopatski utjecaj aromatičnoga i ljekovitog bilja također je ovisio o biljnoj vrsti i korovu, koncentraciji i dozi te stanju biljne mase. Pri zajedničkom klijanju sjemena zabilježen je negativan utjecaj na klijanje i do 90,0%. Zajedničko klijanje sjemena u posudama s tlom slabije je djelovalo na korove. Vodeni ekstrakti od svježe i suhe mase smanjili su klijavost i rast korova i do 100%. Biljni ostatci smanjili su nicanje korovnih vrsta i do 60,0% te negativno utjecali na rast klijanaca.The aim of the study was to determine the allelopathic effect of weeds on crop growth and development, and the possibility of applying aromatic and medicinal plants in weed control. The effects of biomass and seeds of weed species creeping thistle (Cirsium arvense), field poppy (Papaver rhoeas), scentless mayweed (Tripleurospermum inodorum), redroot pigweed (Amaranthus retroflexus), black nightshade (Solanum nigrum) and johnsongrass (Sorghum halepense) on wheat, barley, carrot, soybean and oil pumpkin was examined. The effect of lovage (Levisticum officinale), basil (Ocimum basilicum), chamomile (Matricaria chamomilla), lemon balm (Melissa officinalis), common mallow (Malva sylvestris) and greater celandine (Chelidonium majus) was evaluated on growth and development of weeds species velvetleaf (Abutilon theophrasti), redroot pigweed, hoary cress (Lepidium draba), black nightshade, johnsongrass and scentless mayweed. The allelopathic effect depended on the weed and crop species, concentration or rate, plant part and plant biomass. On average, the extracts from all weed species, except johnsongrass, reduced the germination over 20.0% and growth up to 41.2% in Petri dishes. The water extracts applied in the pots reduced the crop emergence up to 65%. In the pots, the incorporation of weed residues reduced the emergence up to 65.3%. The seed cogermination and weed root exudates showed no significant effect on crop germination. The allelopathic effects of aromatic and medicinal plants depended on the plant and weed species, concentration and rate and plant biomass. The cogermination reduced the weed germination up to 90.0%. In the pots, the seed cogermination showed a lower effect on weeds. The water extracts from the fresh and dry biomass reduced the germination and growth of weeds up to 100%. The plant residues reduced the weed emergence up to 60.0% and showed a negative effect on the seedling growth