Allelopathy, a biological phenomenon, is a valuable tool for weed management and minimization of synthetic pesticide use in sustainable agricultural production. The aim of the study was to evaluate the allelopathic potential of nine sunflower genotypes. Water extracts from dry sunflower leaves collected in two growth stages (butonisation and flowering) were tested in two concentrations (1 and 2.5%) on germination and growth of lettuce under laboratory conditions. The allelopathic effect of extracts was influenced by genotype, growth stage and extract concentration. The majority of extracts exhibited negative allelopathic potential with seed germination being the least affected, and root length reduced up to 85% compared to the control. A higher concentration of water extracts resulted in a greater reduction of lettuce growth parameters. On average, extracts collected in the flowering stage inhibited lettuce shoot length to a greater degree. Several genotypes showed a greater negative impact, especially on shoot length and seedlings’ fresh weight. Further investigations of selected sunflower genotypes with the highest allelopathic potential on weed species and studies on phytochemical analysis are needed.

Salvia pratensis L. is a valuable medicinal plant rich in bioactive compounds, yet its allelopathic potential remains underexplored. This study evaluated allelopathic effects and total phenolic (TPC) and flavonoid (TFC) contents of water extracts from the dry aboveground biomass of S. pratensis. To assess their selectivity and potential application in sustainable weed management, extracts at five different concentrations were tested on the germination and early growth of lettuce, radish, tomato, and carrot. The results demonstrated that the phytotoxic effects of S. pratensis extracts were both concentration- and species-dependent. Higher extract concentrations significantly inhibited germination and seedling growth, while lower concentrations of extracts stimulated shoot elongation by up to 30% compared to the control. Phytochemical analysis revealed that S. pratensis extracts contain notable TPC and TFC contents, with their concentrations increasing consistently with the extract concentration. Correlation analysis showed that higher TPC and TFC contents were strongly negatively correlated with germination and seedling growth parameters. Radish exhibited the highest sensitivity to the extracts, while lettuce was the most tolerant. Further research under field conditions is needed to assess the efficacy, selectivity, and practical potential of S. pratensis extracts in sustainable crop production systems.

Fuzarijska palež klasova (FHB) pšenice ekonomski je značajna bolest koja može imati nepovoljne posljedice na prinos i kvalitetu pšenice. Do danas ne postoji mjera zaštite koja osigurava potpunu zaštitu usjeva pšenice, ali kombinacija više mjera može dati dobre rezultate. Učinkovitost svake pojedine mjere pod utjecajem je okolišnih uvjeta koji prevladavaju tijekom vegetacijske sezone, a učinkovitost će ovisiti i o osjetljivosti pojedine sorte na FHB. Sve veći broj istraživanja potvrđuje kako je integrirana zaštita bilja (IZB) ključ za što uspješniju borbu protiv FHB-a. Kako bi primijenjene mjere zaštite bile što uspješnije, od iznimne je važnosti dobro poznavati uzročnika bolesti, njegov životni ciklus i ekologiju. Budući da je F. graminearum dominantni uzročnik FHB-a na području Republike Hrvatske, osobiti naglasak je stavljen na sve dostupne mjere zaštite u njegovu suzbijanju.

The phytopathogenic fungi Sclerotinia sclerotiorum and Botrytis cinerea pose a significant problem in global agriculture, as they cause substantial yield losses and economic damage. Their threat arises from a broad host range, the ability to survive in soil for long periods, and the emergence of new strains with increased resistance to fungicides. They are most commonly controlled through the application of chemical fungicides; however, their use is associated with negative environmental impacts, the development of resistance, and potential risks to human health. This study aimed to evaluate the antifungal activity of aqueous extracts from leaves and flowers of Canadian goldenrod ( Solidago canadensis L.) against the growth of these fungi. In vitro tests were conducted at concentrations of 75 and 150 mg/mL, and the effectiveness of the extracts was compared with that of commercial fungicides. The highest growth inhibition was observed with the flower extract at the higher concentration (150 mg/mL). In S. sclerotiorum , the leaf extract (150 mg/mL) significantly reduced sclerotia formation (91 %). In B. cinerea , no sclerotia were formed during the observation period; however, the flower extract (150 mg/mL) was the most effective in inhibiting mycelial growth. The results confirm the antifungal potential of S. canadensis extracts in inhibiting mycelial growth and sclerotia formation in S. sclerotiorum . However, their effectiveness is still considerably weaker compared to commercial fungicides, suggesting that, for now, they can primarily be considered a supplementary measure or a basis for further development of more effective bioformulations.

Allelopathic plants and their chemical compounds offer promising possibilities for sustainable weed management. This study aimed to assess the phytotoxic potential of birthwort ( Aristolochia clematitis L.) on the germination and early growth of crops (wheat, barley, basil) and the weed species redroot pigweed ( Amaranthus retroflexus L.). Extracts from fresh and dry aboveground biomass of A . clematitis , in different concentrations, were evaluated using a Petri dish bioassay and a pot experiment with soil. The results indicated that allelopathic effects of A. clematitis extracts depended on extract concentration, biomass type, test species, and application method. Germination and growth of the test species generally decreased as the concentration of weed biomass in the water extracts increased. In the Petri dish bioassay, extracts from fresh biomass had both positive and negative effects, while higher concentrations of dry biomass extract suppressed germination and seedling growth by up to 90 %. In the pot experiment, the allelopathic impact was less pronounced, and inhibition was observed only with the application of extracts from dry biomass. Variability in species sensitivity was also noted, with barley and A. retroflexus being the most affected. A. clematitis shows great potential as a subject for further research.