Evaluation of Ribes nigrum L. Prospective Hybrids in Estonia

The evaluation of promising hybrids of blackcurrant (Ribes nigrum L.) was carried out in 2017–2019 at Polli Horticultural Research Centre of the Estonian University of Life Sciences, in South Estonia. The objective of the Estonian blackcurrant breeding programme is to produce cultivars that are winter hardy, resistant to gooseberry mildew (Sphaerotheca mors-uvae (Schw.) Berk.) and gall mite (Cecidophyopsis ribis Westw.), well suited to machine harvesting, and with good yield and quality of fruits. The evaluation plot was established in the autumn of 2015. Twenty blackcurrant promising hybrids from the Estonian blackcurrant breeding programme and cultivars ‘Pamyat Vavilova’ and ‘Titania’, as the standard, were evaluated for beginning of flowering and fruit ripening (expressed in growing degree days, GDD), winter hardiness, resistance to diseases and pests (expressed in scores 1–9), number of fruits per cluster, drop of flowers and young fruits (%), yield (kg per bush), weight of fruit and content of the soluble solids (°Brix). Fruits were analysed for titratable acids, anthocyanins and polyphenols. The evaluation revealed the best blackcurrant genotypes to be: 1-11-3 (‘Asker’ × ‘Intercontinental’), 6-11-3, 6-11-5 (‘Karri’ × ‘Pamyat Vavilova’) and 7-11-5 (‘Karri’ × SRI 9154-3). All these genotypes are winter hardy and visually resistant to gall mite and gooseberry mildew, and produced good yields and large fruits.