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.

Seven disease control products produced at a grapevine farm in Mała Wieś (Masovian County, Poland) were tested and compared with standard chemical control and no control. The following substances were used as disease control agents: lavender, lemon, and orange oils; Saccharomyces cerevisiae HDT18 yeast fermentation liquid; mint; and Habanero Orange hot pepper decoction. Results were compared with treatments using standard fungicides, a control without control, and two commercial products containing tansy extract and chili and garlic extract. The tested products were generally less effective in protecting against fungal diseases than the standard chemical control. However, they improved total yield, yield used for vinification, total acidity, sugar content, and pH of harvested grapes compared to untreated grapes. Our own preparations (HDT-18, lemon oil, mint decoction, and hot pepper) reduced total yields and simultaneously reduced the number of grapes infected with diseases, which is particularly important in mechanical harvesting without sorting. Must parameters (sugar, pH, TA) enabled wine production from each of the experimental combinations tested. These approaches may be useful in organic farming programs in cold climates. Although they may reduce total yields, they also reduce the number of grapes unsuitable for vinification.