Reduced tillage is considered as one of the main tools to save biological diversity; however, it increases pressure of diseases, including wheat leaf blotches. The aim of present study was to clarify the impact of reduced soil tillage on the development of winter wheat leaf blotches in different schemes of crop rotation. The impact of different growing technologies on the severity of winter wheat disease was evaluated in a two-factorial experiment: A – soil tillage system, and B – different combinations of wheat pre-pre-crop and pre-crop (wheat, oilseed rape, barley and faba beans). Diseases were assessed every 10 days approximately and total impact of diseases was evaluated by calculating AUDPC (Area under Diseases Progress Curve). Tan spot, caused by Pyrenophora tritici-repentis was dominated disease over the long period, regardless of meteorological conditions. Development of Septoria leaf blotch was not influenced by neither crop rotation nor soil tillage. The level of tan spot was essentially higher after wheat, regardless of the pre-pre-crop. Reduced soil tillage promoted severity of tan spot. Ploughing mitigated effect of previous crops and differences in tan spot level were insignificant. Despite many positive effects of conservation tillage, increasing of fungicide treatment could be necessary, in conditions, when the tan spot is most devastating and widespread wheat disease.

The common control method of leaf blotches is the application of fungicides; however, the results of trials are inconsistent. The aim of the present study was to evaluate the impact of the fungicide treatment intensity on the severity of leaf blotches and to assess the correlation between the development of diseases and winter wheat (Triticum aestivum) yield in 2018–2021. The development of diseases was evaluated regularly. In this study, the severity of leaf blotches at the medium milk ripening (GS 75–77) was used. Tan spot dominated in 2018, 2019, and 2021, but Septoria tritici blotch dominated in 2020. Fungicides significantly decreased the severity of tan spot and Septoria tritici blotch, but the efficacy of used fungicide treatment schemes differed during trial years – it was more pronounced under higher pressures of leaf blotches. In the year with a high severity of Septoria tritici blotch, the best efficacy was obtained when fungicide was used two times (at GS 32–33 and GS 55–59), but for tan spot – when the dose of fungicide was done in two or three applications. Usage of fungicides increased wheat yield only under high pressure of diseases. A strong significant correlation between the severity of Septoria tritici blotch at GS 75–77 and grain yields was established only in 2020, when the severity of the disease was higher.

The apple scab induced by Venturia inaequalis is an economically significant disease of apples worldwide and is predominantly controlled by multiple fungicide applications. Therefore, resistant apple cultivation is important for long-standing disease control. The knowledge about cultivar resistance is mainly founded on their evaluation in orchard conditions and testing in a greenhouse that is laborious and requires a large space. This study evaluated apple cultivar resistance and the virulence of V. inaequalis strains by inoculating detached leaves and immature fruits. Nine V. inaequalis strains originating from different apple-growing regions and host genotypes were tested on eight apple genotypes. Microscopic and macroscopic symptom development and host tissue reactions were monitored during the experiments. The tested V. inaequalis strains and cultivars showed different levels of virulence and resistance, respectively. Cultivar ‘Lobo’ was scored as partially susceptible, with almost all strains tested. The incompatible interaction with or without host tissue reactions was observed only on the cultivar ‘Priscilla’ with all the strains and field populations tested. The results of this study using detached leaves and immature fruits were concordant with the data obtained in the cultivar evaluation trials in the orchards..