Yield and Stability of New Medium-Maturing Potato Varieties (Solanum tuberosum L.) in the Forest-Steppe and Polissia Soil and Climatic Zones of Ukraine

Purpose. To carry out a comprehensive study and evaluation of new medium-maturing potato (S. tuberosum) varieties for yield, starch content and stability under the conditions of the Ukrainian Forest Steppe and Polissia. Methods. The qualification examination of potato varieties for their suitability for distribution in Ukraine (VSD) was conducted in 2021 and 2023 at eight research sites of the Ukrainian Institute for Plant Variety Examination located within the soil and climatic zones of the Forest-Steppe and Polissia. The area of the accounting plot was 25 m2, the location of the plots was randomised, replicated four times. Results. The economic and valuable characteristics of Ukrainian medium-maturing potato varieties – ‘Fanatka’, ‘Svitana’, ‘Marfusha’ and ‘Melaniia’, as well as foreign varieties – ‘TRIPLE7’, ‘Tiger’, ‘CAMELIA’ and ‘CARDYMA’ were analysed. The average yield of ‘Fanatka’, ‘Svitana’, ‘TRIPLE7’, ‘Tiger’, ‘CAMELIA’ and ‘CARDYMA’ in the Forest-Steppe was 3–12% higher than in Polissia. The maximum values of this indicator in both soil and climatic zones were shown by the varieties ‘Svitana’ (Forest-Steppe – 28.2 t/ha; Polissia – 26.0 t/ha) and ‘CAMELIA’ (Forest-Steppe – 29.3 t/ha; Polissia – 27.7 t/ha). In 2021, the highest average potato yield was obtained in the Forest-Steppe zone (23.3 t/ha); in 2023, in Polissia (21.1 t/ha). ‘Fanatka’ and ‘TRIPLE7’ varieties were more stable than ‘Svitana’, ‘Melaniia’, ‘CAMELIA’, ‘CARDYMA’, ‘Marfusha’ and ‘Tiger’, whose yields were highly dependent on the growing conditions. In terms of quality indicators, the best foreign varieties were ‘TRIPLE7’, ‘Tiger’ and ‘CARDYMA’. Their starch content was 15.6–17.8% in the Forest-Steppe and 17.1–18.1% in Polissia; dry matter – 23.9–25.8% in the Forest-Steppe and 25.4–25.8% in Polissia. Conclusions. According to the results of the VSD qualification test, the varieties ‘Fanatka’, ‘Svitana’, ‘Melaniia’, ‘TRIPLE7’, ‘CAMELIA’ and ‘CARDYMA’ are recommended for cultivation in the Forest-Steppe and Polissia zones; ‘Marfusha’ and ‘Tiger’ are recommended for Polissia only. According to qualitative indicators, the variety ‘TRIPLE7’ stood out with starch content of 17.8% in Forest-Steppe and 18.1% in Polissia; dry matter – 25.8% in both soil and climatic zones.