Organic farming is becoming increasingly popular because it leads to healthier products. Due to limitations on the use of chemical protection, however, plants may be more susceptible to pathogen attacks. Therefore, the aim of the study was to determine the occurrence of fungal diseases in maize grown in organic versus integrated systems. The field experiment was conducted during the years 2017–2019 in Puławy, Poland. Three maize varieties, Ambrosini, Smolitop and Ricardinio, were cultivated in two fields with a different crop production system. The incidence of fungal diseases, such as northern corn leaf blight, eyespot, common corn rust, corn smut and Fusarium ear rot, was assessed. Fungal isolates were collected from leaves and cobs with disease symptoms and identified microscopically and molecularly. In both cultivation systems, northern corn leaf blight and eyespot were the most common, while corn rust and fusariosis were seen more often in organic cultivation. Alternaria alternata, Fusarium oxysporum, Fusarium poae, Fusarium graminearum and Fusarium sporotrichioides were the fungal species most frequently detected in the two systems. Additionally, Fusarium verticillioides was common in the organic system. Weather conditions, especially heavy rainfall and high air humidity, greatly influenced the incidence of such diseases.

Black root rot is a dangerous disease affecting many crops. It is caused by pathogens formerly known as Thielaviopsis basicola and then reclassified as two cryptic species, Berkeleyomyces basicola and B. rouxiae. The aim of this study was to perform species identification, morphological characterization, and pathogenicity tests for fungal isolates obtained from tobacco roots with black root rot symptoms in Poland. DNA sequences of the three regions (ITS, ACT, MCM7) were highly similar to the sequences of B. rouxiae deposited in the NCBI database. Phylogenetic analysis confirmed the assignment of the obtained isolates to this species. The cultures of four representative isolates (namely OT2, OT3, WPT7, WPT8) showed a similar structure and gray/brown color of the mycelium, although their growth rate varied from 3.8 to 5.1 mm/day depending on the isolate. The sizes of the endoconidia and chlamydospores showed a considerable variation, although they fit within ranges previously described for B. rouxiae. Pathogenicity tests performed on young tobacco plants grown in the inoculated peat substrate revealed differences among the four isolates. WPT7 demonstrated the lowest level of aggressiveness for tobacco. In contrast, the remaining three isolates caused severe disease symptoms and significantly reduced shoot and root dry weights of the susceptible cultivar Virginia Joyner. A parallel pathogenicity test performed on cultivar VRG 10TL confirmed the effectiveness of black root rot resistance derived from Nicotiana debneyi.

The common hop (Humulus lupulus L., Cannabaceae) is a perennial plant cultivated in the temperate climate zone and used in the brewing and pharmaceutical industry. In June 2021, symptoms of wilting...

Yellow lupin seeds are a rich source of protein, which is why they are grown for animal feed and human consumption. At the same time, there is growing interest in organic farming. However, this type of cultivation is more susceptible to diseases, including viral ones. Yellow lupin is most commonly affected by the bean yellow mosaic virus (BYMV) and cucumber mosaic virus (CMV). We have therefore determined the occurrence of these two pathogens in six new Polish yellow lupin cultivars (Goldeneye, Salut, Diament, Puma, Mister and Bursztyn) grown in accordance with organic farming rules. Field experiments were conducted over three years, from 2022 to 2024, in three locations in eastern Poland. The Goldeneye cultivar was the most susceptible to BYMV, with an average infection rate of 59.17% of plants. In contrast, the Puma cultivar was the least susceptible to BYMV infection, with an average infection rate of 23.34%. However, even within this cultivar, most plants were infected under conditions of strong pathogen pressure (up to 90% in one of the locations in 2024). CMV infections were less frequent, with no statistical differences being found between cultivars in terms of the number of infected plants.