Frost Tolerance of Flower Buds, Self-Pollination and Fruit Quality Traits in Local Sour Cherries of Latvia

The aim of the study was to characterise the variability of flower bud frost tolerance, self-pollination and fruit quality in Latvian local sour cherries; and to select the most promising aces-sions. Data on fruit set after self-pollination, frost tolerance of flower buds, fruit and stone weight, stem retention force and soluble solid content were collected for 29 accessions of local cherries in 2016–2019. Sour cherry cv. ‘Latvijas Zemais’ clones no. 64, D7, and 4 were the most promising for fruit processing; clones no. 62, 65, Matkules, and Lietuvas were promising as pollinators due to tolerance to spring frosts and high level of fruit set after self-pollination, and cv. ‘Latvijas Zemais’ clones Eglīša, Piïkas 3, Matkules, and Dumbrava had relatively high fruit weight and soluble solid content for fresh consumption. ‘Latvijas Zemais’ clone no. 62 was superior with stable fruit set after self-pollination (21.54%), cold resistant flower buds (89.5%) and high proportion of fruit flesh (93.8 %), clone no. 52 had high soluble solid content (18.88 Brix) and clone Eglīša had large fruit (5.56 g). The highest contribution to variability was provided by fruit weight, stone weight, and soluble solid content, which explained 79.90% of total variability.