Flowering of 'Oblacinska' sour cherry clones in Serbia

Flowering is one of the most important factors in plant fertility. Fruit set in fruits is directly influenced by the beginning, sequence, flow, duration and abundance of flowering. The objective of this study was to evaluate the variability of flowering in 41 'Oblacinska' sour cherry (Prunus cerasus L.) clones, and to recommend early-flowering genotypes for growing in warmer locations where late spring frosts are rare, and some late-flowering clones for sites more susceptible for spring frost. Results from the three years period (2004-06), showed that 'Oblacinska' sour cherry clones flowered in a fixed sequence each year. Average for clone VII/2N, which flowered the earliest, was April 8 and petal fall took place by April 21, whereas clone III/1 bloomed last on April 14 and petal fall took place on April 25. Statistical analysis showed that almost all sub-phases of flowering were under the significant influence of both ecological and genetic factors. Besides, ecologic factors had the highest impact to the variability of beginning of flowering (79.8%), full bloom (76.8%), petal fall (80.2%) and duration of flowering (85.56%). Clones III/1, III/13, V/6 and V/2 were considered as late flowering, whereas clones VII/2N, VI/27, VI/28 and IX/P were early flowering, taking place five days earlier then previous group.