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The experiment was established in the spring of 1999 on grey brown podsolic soil formed from boulder clay. Apple trees of cv. Golden Delicious were planted on rootstock at 3.5×1.2 m (2381 trees⋅ha-1). The first factor in the experiment consisted of the levels of potassium in the arable soil layer: 120, 160 and 200 mg K⋅kg-1 of soil d.m., on the basis of annual chemical analyses and determined by universal method. The second factor comprised three forms of potassium fertilizers: potassium chloride (KCl-60%), potassium sulphate (K 2 SO 4) and potassium nitrate (KNO 3). Each year the analyses of macro-and microelements in the soil and leaves were made. The increase in available potassium levels from 120 to 200 mg K⋅kg-1 of soil d.m did not have influence on the content of available forms of iron, manganese, zinc, copper and boron in the herbicide fallow strips in the tree rows or in the arable (0-20 cm) and subarable (20-40 cm)soil layers. Application of potassium sulphate fertilizer caused a significant increase in the content of zinc in herbicide strips in both soil layers compared with potassium chloride and potassium nitrate. Different potassium fertilizer forms did not cause any significant changes in amounts of available forms of iron, manganese, copper and boron. The increase in available potassium levels from 120 to 200 mg K⋅kg-1 of soil d.m significantly reduced the content of manganese in leaves of trees. However, no significant influence on the content of iron, zinc, copper and boron in leaves of apple trees was found.

Viticulture in a cool climate is more challenging than in traditional wine regions. Due to the weather conditions, the berries may not achieve their full maturation composition. Therefore, suitable grape cultivars should be selected for cultivation in cool climate regions. The aim of this research was to compare selected grape cultivars grown under the same climatic conditions in terms of their antioxidant activity, chemical composition, and macronutrient contents. Their dry matter content, total soluble solids, pH, total acidity, and vitamin C were also analyzed. This research confirmed the existence of differences between the cultivars regarding their antioxidant activity, total soluble solids and polyphenols, and content of vitamin C and macronutrients.

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