Fusarium species are common plant pathogens that cause serious crop losses worldwide. Fusarium spp. colonize not only the main host plants, crops, but also alternative hosts. The effectiveness of fungicide use in disease management ranges from very successful to possibly promoting the growth of the pathogen. Triazole fungicides are widely used to control these pathogens due to their broad-spectrum activity and systemic nature. This paper reviews the sensitivity of 40 Fusarium strains isolated from weeds, non-gramineous plants, and spring wheat to metconazole, prothioconazole, and tebuconazole. The effect of fungicides was determined by the percentage inhibition of F. graminearum, F. culmorum, F. sporotrichioides, and F. avenaceum fungal mycelial growth. The 50% effective concentration (EC50) values of all isolates on metconazole were lower than 2.9 mg L⁻¹, prothioconazole EC50 ranged from 0.12 to 23.6 mg L⁻¹, and tebuconazole ranged from 0.09 to 15.6 mg L⁻¹. At 0.00025–0.025 mg L⁻¹, the fungicides were ineffective, except for the growth of the F. avenaceum species. It was observed that isolates from weeds were more sensitive to low concentrations of fungicide than isolates from crop plants. In general, information is scarce regarding the comparison of fungicide resistance in Fusarium isolates from weed and crop plants, making this study an additional contribution to the existing knowledge base.

Fusarium Head Blight (FHB) is one of the most common worldwide wheat and other small grain diseases. The infection is caused by Fusarium graminearum and other related species, which significantly reduce grain yield and contaminate grains with mycotoxins which are harmful for humans and animals. Fusarium pathogen survives the winter well in plant debris left on the field. Weeds around and within crops are alternative hosts of Fusarium fungi when an economically important host plant is not present. This article focuses on the determination of DNA content of Fusarium species (F. graminearum and F. avenaceum) in artificially inoculated wheat plants with isolates from weeds, as well as its influence on the severity of FHB and spring wheat 1000-grain weight under field conditions. Fungal DNA content in grains was evaluated by quantitative real-time PCR. The results showed that the DNA concentration of F. graminearum was significantly higher in the grain than F. avenaceum. The severity of FHB when wheat heads were inoculated with F. graminearum was significantly higher than with F. avenaceum. All F. graminearum strains statistically significantly reduced the weight of spring wheat grains, while F. avenaceum did not affect the weight of 1000 grain. This investigation has shown that weeds in crop rotations are a potential source of FHB infection. However, the severity of the disease is more affected by the Fusarium species than the host plant. This experiment is, to our knowledge, the first report on the estimation of Fusarium DNA content in artificially inoculated wheat plants with isolates from weeds, as well as its comparison with pathogenicity to wheat and its effect on 1000-grain weight.

Despite significant efforts in recent decades to combat Fusarium head blight (FHB), this disease remains one of the most important and widely studied diseases of wheat and other cereal plants. To date, studies have focused on small grain cereals as hostplants for these pathogens, but it was recently discovered that asymptomatic non-gramineous plants and weeds can serve as alternative sources of fungi associated with FHB. The aim of this study was to evaluate the pathogenicity of Fusarium avenaceum, F. culmorum, F. graminearum and F. sporotrichioides isolated from non-gramineous plants and weed species to spring wheat under greenhouse conditions. A total of 91 Fusarium isolates, including 45 from weeds and 46 from non-gramineous plants were floret inoculated at mid anthesis. The FHB incidence and severity (%) of inoculated heads and the area under the disease progress curve (AUDPC) were calculated. To determine yield losses, the weight of 1000 grains (TGW) was evaluated. Results of the research showed that FHB severity (%) values in Fusarium spp.-inoculated heads from non-gramineous plants varied from 9.3% to 69.6% and AUDPC values ranged from 161.5% to 1044.6%. TGW was most significantly reduced by the F. culmorum isolates BN26r and BN39fl from Brassica napus and isolates BV15.1l and BV142.1pe from Beta vulgaris (37%, 30%, 28.8% and 31.8% respectively, compared to the water control). In Fusarium-inoculated heads from weeds, FHB severity values ranged from 6.2% to 81.0% and AUDPC values varied from 134.2% to 1206.6%. TGW was most significantly decreased by CBP1401r isolate from Capsella bursa-pastoris (52%). The study results suggest that the pathogenicity of Fusarium species isolated from different hosts to wheat more strongly depends on the Fusarium species and strain than the hostplant. Under greenhouse conditions, F. culmorum strain groups obtained from weeds, non-gramineous plants and Triticum were more pathogenic to wheat than the water control and other Fusarium species.