This study presents a comparative evaluation of 20 potato cultivars (super-elite class) from the early, mid-early, and mid-season maturity groups to identify high-yielding genotypes with varying harvest intervals in the southern agro-climatic zone of Karelia. Field experiments were conducted in 2023–2024 seasons, which were characterized by contrasting meteorological conditions (fluctuating thermal and moisture regimes in the first season and elevated average monthly temperatures in the second season). Potato was planted following annual grasses as a preceding crop. The soil was a sod-podzolic, light-to-medium loamy, ranging from slightly acidic to near-neutral, with moderate humus content and very high content of mobile phosphorus and potassium. Cvs. Latona, Elizaveta, and Lugovskoy were selected as control cultivars for their respective maturity groups, as per regional recommendations for the Northern zone. Tuberization dynamics of the tested cultivars was assessed by trial harvests carried out at 70th, 80th, and 90th days after planting occurred in early June. In northern latitudes, early potato production (mid-August, 70 days post-planting) was best provided by the cv. Meteor, which achieved an average yield of 21.4 t/ha and a marketability rate of 80.6%. The early-maturing cvs. Udacha, Red Scarlett, Kholmogorsky, Meteor, Felox, Sante, and Radonezhsky were found to be most effective for harvesting at the day 80th (late August), yielding up to 21.8 t/ha with marketability rate reaching 83.8%. To achieve the maximum productivity (24.4–27.6 t/ha; marketability rate of 72.8–83.1%) by the day 90 post-planting (first decade of September), cvs. Meteor, Felox, and Nevsky are recommended, along with the mid-season cv. Zhigulevsky (23.0 t/ha and marketability rate of 80.3%).
Kuznetsova et al. (Wed,) studied this question.