2018 Volume 17 Issue 1 Pages 41-47
The seed propagation type of strawberry cultivar ‘Yotsuboshi’ was investigated for the summer-to-autumn cultivation period in northern Japan. Plants sown on 27 January initiated the first inflorescence in mid-May, and the cumulative number of inflorescences was increased as a result of monthly two-week long-day (24 h) treatment, which was applied once between May and August. Plants sown on 27 February were still juvenile in May and were therefore not notably affected by the long-day treatment. Treatment in June or July led to the induction of flower buds, but since the resulting yield was insufficient, seeding in January was determined to be more effective. Then, two-week long-day (24 h) treatment in June and/or July was applied to plants sown on 13 January in 200-cell or 406-cell trays. There was little difference between the two with respect to cell size in growth at planting, the cumulative numbers of inflorescences, or monthly yield. Long-day treatment in June increased the yield and number of fruits in September, while the July treatment had the same effect after October. Two applications of the treatment in June and July increased the yield after October and the number of fruits after September. These results suggest that ‘Yotsuboshi’ sown in January with long-day treatment in early summer could be promising for summer-to-autumn production in northern Japan.
