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Fusarium head blight (FHB) of cereals is the major head disease negatively affecting grain production worldwide. In 2016 and 2017, serious outbreaks of FHB occurred in wheat crops in Poland. In this study, we characterized the diversity of Fusaria responsible for these epidemics using TaqMan assays. From a panel of 463 field isolates collected from wheat, four Fusarium species were identified. The predominant species were F. graminearum s.s. (81%) and, to a lesser extent, F. avenaceum (15%). The emergence of the 15ADON genotype was found ranging from 83% to 87% of the total trichothecene genotypes isolated in 2016 and 2017, respectively. Our results indicate two dramatic shifts within fungal field populations in Poland. The first shift is associated with the displacement of F. culmorum by F. graminearum s.s. The second shift resulted from a loss of nivalenol genotypes. We suggest that an emerging prevalence of F. graminearum s.s. may be linked to boosted maize production, which has increased substantially over the last decade in Poland. To detect variation within Tri core clusters, we compared sequence data from randomly selected field isolates with a panel of strains from geographically diverse origins. We found that the newly emerged 15ADON genotypes do not exhibit a specific pattern of polymorphism enabling their clear differentiation from the other European strains.

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In a three-year field experiment the assessment of leaves and ears photosynthesis rate in spring wheat was made using a LI-COR 6400 portable photosynthesis system. The photosynthetic rate of spring wheat was affected by cultivars, nitrogen fertilization and weather conditions. We generally found a negative correlation between the yield of spring wheat and the rate of photosynthesis in flag leaves in phases 39–55 BBCH (the strength of this effect depended on the level of nitrogen fertilization). Strong negative correlation occurred for cv. Bryza in phases:  39–51 BBCH in treatment fertilized with lower dose of nitrogen and in phase 39–41 BBCH for dose 120 kg/ha. There was a significant negative correlation for cv. Tybald only in phase 39–41 BBCH for higher dose of nitrogen and 52–55 BBCH for lower dose. Our studies show that the photosynthetic activity of flag leaves decreased from the booting (39–41 BBCH) to heading stage (52–55 BBCH), and their function was taken over by ears. Contrary to flag leaf, in wheat ears the intensity of photosynthesis correlated positively with grain yield for most of the studied period (52–65 BBCH, with highly significant correlation at 56–57 BBCH and – only for high nitrogen treatments – at 59–61 BBCH; a negative correlation was generally observed at a later phase, i.e. at 65–69 BBCH). Contrary to flag leaf photosynthesis, the intensity of this process in wheat ears (at the heading and flowering stages) seems highly relevant for grain yield. High positive correlation was noted in 56–57 BBCH and 61–65 BBCH. However, the study was done in field conditions and for definitive conclusions observations over a longer period would be desirable.

This study aims to determine the effects of crops and their cultivation regimes on changes in the soil microbiome. Three plant species were selected for the study: Triticum aestivum, Brassica napus, and Pisum sativum ssp. arvense, that were cultivated in soils with a similar particle size fraction. Field experiments were performed on the area of the Iławski Lake District (north-eastern Poland) at the Production and Experimental Station ‘Bałcyny’ (53°35′49″ N, 19°51′20″ E). In soil samples counts, organotrophic bacteria and actinobacteria were quantified, and the colony development index (CD) and ecophysiological diversity index (EP) were computed. In addition, a 16S amplicon sequencing encoding gene was conducted based on the hypervariable region V3–V4. Further analyses included an evaluation of the basic physiochemical properties of the soil and the activities of dehydrogenases, catalase, urease, acid phosphatase, alkaline phosphatase, arylsulfatase, and β-glucosidase. Analyses carried out in the study demonstrated that the rhizosphere of Triticum aestivum had a more beneficial effect on bacteria development than those of Brassica napus and Pisum sativum ssp. arvense, as indicated by the values of the ecophysiological diversity index (EP) and OTU abundance calculated for individual taxa in the soils in which the studied crops were grown. More OTUs of the taxa Alphaproteobacteria, Gammaproteobacteria, Clostridia, Sphingomonadales, Rhodospirillales, Xanthomonadales, Streptomycetaceae, Pseudonocardiaceae, Acetobacteraceae, Solibacteraceae, Kaistobacter, Cohnella, Azospirillum, Cryptosporangium, Rhodoplanes, and Saccharopolyspora were determined in the bacteriome structure of the soil from Triticum aestivum cultivation than in the soils from the cultivation of Brassica napus and Pisum sativum ssp. arvense. Also, the activities of most of the analyzed enzymes, including urease, catalase, alkaline phosphatase, β-glucosidase, and arylsulfatase, were the higher in the soil sown with Triticum aestivum than in those with the other two plant species.