Suitability of nine scab-resistant or partially scab-resistant apple cultivars: Bohemia, Rubinola, Topaz, Goldstar, Pinova, Redkroft, Free Redstar, Melfree and Gold Milenium for organic orchards was evaluated during the period 2002-2010. The trial consisted of two experimental plots. In the first plot, no plant protection chemicals were applied either to the trees or to the soil. In the second plot, with limited spraying programme, only those compounds that are allowed to be used in organic fruit production in Poland were applied in order to control pests and diseases: copper products, Carpovirusine Super SC and the garlic extract Liquid Bioczos. After planting, the ground in the tree rows was mulched with agricultural spun-web, linen residue felt or sawdust in a 1.2 meter wide strip. During the years of the experiment many trees were seriously infected with apple canker (Nectria sp.), which caused the loss of a certain number of them. Most susceptible were 'Rubinola', 'Topaz', 'Redkroft' and 'Pinova'. The smallest necrotic lesions were observed on the trees of 'Free Redstar', 'Melfree' and 'Gold Milenium'. The various materials for mulching did not significantly affect the size of the fruit yield. The highest yields were obtained from the 'Gold Milenium', 'Free Redstar', 'Topaz' and 'Pinova'. In 2010, following a very rainy season, we observed for the first time scab potted fruits of the cultivars: Rubino- la, Topaz, and Goldstar. The greatest problem was the control of aphids and apple mildew. Cutting back shoots with primary infestation was the most promising method. The 'Topaz', 'Rubinola', 'Bohemia' and 'Gold Milenium' appeared to be the most suitable for organic fruit production. In the year 2010, heavy thinning of fruitlets helped to obtain large fruits (diameter over 7.0 cm) of the cultivars: Bohemia, Topaz and Redkroft.
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