Effects of temperature and photoperiod on growth and flowering in red currant cultivars (Ribes sativum Syme)

A. Sønsteby, M. Sadojevic, O.M. Heide
We studied the environmental control of shoot growth and floral initiation in annual shoot plants of four red currant cultivars under phytotron conditions. Under natural day length conditions at Ås, Norway (69°40’N), the cultivars ‘Junifer’, ‘Red Dutch’, and ‘Rosetta’ ceased growing and initiated irregular flower formation at 24 and 18°C in late August, indicating a critical photoperiod of approximately 15 h. At 12°C and under outdoor conditions, the processes were delayed by 3-6 weeks depending on the cultivar, indicating a critical photoperiod of approximately 14 h under Nordic field conditions. In 10-h short day (SD), the cultivars ‘Junifer’, ‘Red Dutch’ and ‘Rovada’ ceased growing within 2-3 weeks at 18 and 24°C and within 2-4 weeks at 12°C, followed by irregular floral initiation. However, in 20-h long day (LD), flower initiation was generally scarce, and with contrasting temperature responses among the cultivars, flower initiation was advanced by low temperature in ‘Red Dutch’ and by high temperature in ‘Rovada’ and ‘Junifer’. Flowering performance in the following spring confirmed these results, which demonstrate that red currants are quantitative SD plants with diverse temperature and photoperiod interactions.
Sønsteby, A., Sadojevic, M. and Heide, O.M. (2024). Effects of temperature and photoperiod on growth and flowering in red currant cultivars (Ribes sativum Syme). Acta Hortic. 1388, 183-190
DOI: 10.17660/ActaHortic.2024.1388.28
https://doi.org/10.17660/ActaHortic.2024.1388.28
growth cessation, floral initiation, Ribes, short-day plants, subartic
English

Acta Horticulturae