The Differentiation of Highbush Blueberry Flower Buds

Studies on flower differentiation processes have both a basic and applied interest. With an understanding of floral initiation and differentiation, cultural practices may be used to promote yield. The main objective of this work was to describe the differentiation process of flower organs in blueberry 'Croatan' in the conditions of southern Poland. The plant material was collected from a ten-year-old orchard. Bud samples were taken at monthly intervals beginning from August to April and every two weeks from April to the beginning of flowering. The collected material was fixed to prepare paraffin cross-sections. Results showed that the differentiation of flower buds takes place within two time periods: during autumn and spring. The differentiation is arrested during the winter months (December-February). Female gametophyte and pollen grains were completely formed in mid April. The differences in time in the course of flower differentiation could be also related to differences in time of fruit ripening.