Promising plum (Prunus domestica L.) cultivars developed by foreign and domestic breeders: a study in the south of Russia

Background. Active development of industrial horticulture in the southern regions of Russia requires targeted research into the ways to improve cultivated European plum. A study was conducted to evaluate a set of important traits in European plum cultivars developed domestically and introduced from foreign countries. Several genotypes were selected as promising for cultivation under the conditions of Krasnodar Territory. Materials and methods. The research materials included 17 introduced and local European plum cultivars with different ripening schedules. The study was carried out in the period from 2019 to 2024 in the environments of the western subzone of the foothill horticultural zone, Krasnodar Territory. Conventional programs and techniques were used for cultivar testing, and the Statistica 10.0 software package for statistical data processing. Results. Plum accessions were evaluated for a set of characteristics: early ripening and large fruit size; late ripening and large fruit size; high uniformity of fruits and yield; high quality of fresh fruits and processed products; high firmness of skin in fresh fruits. The effect of the cultivar and year factors on fruit size and yield was assessed using a two-factor analysis. Conclusion. Twelve European plum cultivars, developed in Russia, the USA, Ukraine, Romania and Serbia, were selected in Krasnodar Territory for one or several agronomic traits. Over six years of research, cvs. ‘Amers’, ‘Bolshoy Priz’, ‘Gerkules’, ‘Grossa di Felicio’, ‘Lider’, ‘Nenka’, and ‘Chachakskaya Rannyaya’ yielded fruits weighing more than 50 g. All of them can be included into breeding programs as sources of large fruit size. Depending on the ripening schedule, it was ascertained that the cultivar factor had the greatest effect on the large fruit size trait – from 64 to 78%, and the effect of the year factor varied from 20 to 34%. A statistically significant positive correlation was established between fruit weight and yield (r = 0.67).