PHENOLOGY OF PEAR CULTIVARS IN THE SOUTHERN FOREST-STEPPE ZONE OF BASHKORTOSTAN

The paper presents research results on the main phenological development phases of pear cultivars in the changing climatic conditions of the southern foreststeppe zone of Bashkortostan. The study was carried out in the collection plantings of 2011, in the Kushnarenkovsky Breeding Centre (Bashkir Research Institute of Agriculture Ufa Federal Research Centre of RAS) in 2020–2025. The planting scheme was 5 × 3 m. The objects of research were 10 pear cultivars of various maturation periods of domestic breeding: Bashkirskaya letnyaya (control), Shatlyk, Bashkirskay ausennyaya, Bordovochka, Severyanka, Krasulya, Vidnaya, Svarog, Rumyanaya Kedrina, Pervushinskaya. During the research period, the winter hardiness of the cultivars turned out to be satisfactory, and no damage to the buds or bark of the trees was recorded. In the course of phenological observations, the average dates of onset were recorded; the sum of the active temperatures of significant phenological development phases of pear cultivars in the annual development cycle was determined. The average date of budbreak was recorded on April 18...20 with the sum of positive temperatures of 126... 154 о C, flowering – on May 4 ... 5, with the sum of temperatures of 243.8... 291.7 о C. The fruiting period of the studied pear cultivars begins in the early August and lasts until the mid-September at temperatures of 1639.7...2108.6 о C, depending on the ripening period. The period of active vegetation was 150–165 days; the required amount of active heat was 2581 о C. A significant positive correlation between flowering and the average daily, maximum air temperature and precipitation in May (r = 0.94, 0.91 and 0.82, respectively) was found in the Pervushinskaya cv. In the Bordovochka cv., the minimum air temperature during the flowering period had a significant effect on flowering (r = 0.85). Phenological observations of the studied cultivars have shown resistance to changes in the climatic conditions of the growing season within the southern forest-steppe zone of Bashkortostan.