Apple fruit rot can be caused by several fungi. In Northern Europe, the most common storage rot, Bull’s eye rot, is caused by Neofabraea spp., bitter rot by Colletotrichum spp., brown rot by Monilinia fructigena, grey mould is caused by Botrytis cinerea and Fusarium rot by several Fusarium species. Blue mold decay caused by Penicillium expansum is an important disease in several European countries. Incidence of different causal agents may vary depending on cultivar, climate during growing season and agricultural practices. The main objective of the study was to obtain baseline information about apple rot-causing fungi, their incidence during fruit storage and to evaluate the fungicide sensitivity of most of isolated fungal species. The study was performed during the storage period of apples after the growth season of 2013. Rotten apples were sorted in the storage and part of them was brought to the laboratory in order to obtain fungal isolates. Fungi were identified according to the morphological characteristics and sequencing of the ITS1-5.8S-ITS2 region. During storage in February and March the total percentage of rotten apples in various cultivars varied from 3.6 to 58.9%. All post-harvest diseases described in Northern Europe were detected. In part of the storehouses apple rot caused by Cadophora luteo-olivacea was observed. Alternaria spp. and Cladosporium spp. were detected on few apples as secondary infection agents. Using the most often isolated fungal species, sensitivity tests were performed against five commonly used fungicides. In general, the sensitivity of tested fungi to the fungicides was high with exception of several Neofabraea and Alternaria isolates.

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.