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Field experiments on control of apple scab (Venturia inaequalis) were conducted in the three commercial orchards in the Skierniewice region and in the Dąbrowice experimental orchard of the Research Institute of Horticulture near Skierniewice. The data obtained from the experimental orchard allowed by using Burkard apparatus and forecasting models (A-scab and MetApple Venturia inaequalis) to determine term and size of V. inaequalis ascospore discharges, analysis of the relationship between weather data and sporulation of scab fungus, and the occurrence of apple scab risk infection. The aim of the study was to assess the effectiveness of tested apple protection programs containing Sercadis ® application against apple scab in 2011, 2012 and 2015. A-scab and MetApple Venturia inaequalis forecasting models were very useful for timely start and running control programs of apple scab due to correct forecasts of V. inaequalis ascospore discharges and classification of critical periods of apple scab. The most favorable conditions for apple scab development occurred at the orchards in olsza and Prusy. The MetApple Venturia inaequalis model showed respectively 21 and 18 days with conditions favoring primary apple scab infections which resulted in severe scab infections of Jonagored and Lobo apple tree cultivars. The obtained results indicated that even under very favorable weather conditions for apple scab infection, the efficacy of studied programs with the use of Sercadis ® solo at a dose of 0.25 l/ha was high. The control was very high and amounted to 98% and 89% in protection of leaves, and 98% and 98% in protection of fruits of Jonagored and Lobo cultivars, respectively.