Sizes of viburnum cultivars fruits in the Mari El Republic

The fruits sizes of Viburnum opulus cultivars in the Botanical Garden-Institute of VSUT are given. Cultivars 'Krasnaya Grozd’ and ‘Dachnaya' had large fruits, the other cultivars had an average fruit size. A close correlation was revealed between the sizes of fruits in different study years. The formation of fruits was influenced by both the varietal specificity factor and the factor of the year weather conditions. In the abnormally dry and hot conditions of 2021, viburnum fruits formed significantly smaller than in 2015.