Evaluation of Flowering and Runnering Characteristics of Everbearing Strawberry, and Selection of Its Suitable Cultivar in Warm-region Cultivation from Winter to Spring in Japan

Elucidation of the suitable cultivation time, cultivars, and cultivation methods is needed to grow everbearing strawberry cultivars from winter to spring in warm regions of Japan. We compared the flowering and runnering characteristics of 17 everbear ing cultivars under natural and 24-h day-length conditions in cold and warm regions from summer to spring. In the warm region, flowering was suppressed mainly from October to December and the number of inflorescences was fewer than that in the cold region because of the high temperature. The flowering was suppressed even in the strong everbearing cultivars, such as ‘Summer Amigo’ and ‘Miyoshi,’ during the high-temperature period. Furthermore, flowering was also suppressed under the 24-h daylength condition. This suggests that production is difficult during the period from summer to autumn in the warm region. In contrast, during the period from winter to spring, most of the test cultivars, including weak everbearing cultivars, such as ‘Natsuakari,’ continuously flowered and the flowering rate reached almost 100% in both the cold and warm regions. Flowering was also promoted under 24-h day-length conditions. This suggests that various everbearing cultivars are suitable for cultivation during the period from winter to spring in the warm region. Moreover, the number of runners in the cold and warm regions was correlated. Finally, ‘Summer Drop’ might be suitable for warm regions of Japan because flowering and runnering in this cultivar were marked under 24-h day-length conditions during the period from winter to spring in the warm region.