Far-red light alters primocane morphology of red raspberry

Abstract

The objectives of the study were to determine whether raspberries responded to decreased red to far-red ratio and whether it was more effective at the beginning or end of the dark period. Increased proportions of far-red light increased the internode length when at the beginning of the dark period on the three raspberry cultivars 'Lauren','Reveille', and 'Titan'. Cultivars varied in that internode length also increased in ambient daylength compared to short days in 'Lauren' and 'Reveille', but not in 'Titan'. They also responded differently to photoperiod: 'Titan' and 'Lauren' grew under short days, whereas 'Reveille' ceased growth.