Phenology, flowering and yield performance of 13 diverse strawberry cultivars grown under Nordic field conditions

As part of an overall assessment of the commercial suitability of strawberry cultivars for the Nordic environment, we studied 13 diverse cultivars in an experimental field in South East Norway. Early-maturing cultivars were characterized by early initiation of floral primordia and early flowering and fruit maturation. High temperatures in July and early August delayed floral initiation in the early cultivars, resulting in more synchronous initiation of early and late cultivars. The recent Norwegian cultivar Nobel', which has an everbearing parent, differed from the other cultivars by early initiation also at elevated summer temperature. Inadequate yield and berry size were identified as important causes for outdating of older cultivars, such as Senga Sengana' and Glima'. Overall, the high-yielding and large-fruited Sonata' was judged as the best fresh consumption cultivar in Norway, and market trends indicate that it will continue to expand its market share at the expense of Korona', mainly because of inadequate fruit firmness and shelf life of the latter. Adequate yields and berry quality justify the use of the late maturing Florence' for prolongation of the fresh market season. The results are discussed together with practical experiences and market preferences in an attempt to provide overall cultivar recommendations for Norway.