Competition Between Fruiting and Vegetative Phases in the Red Raspberry

SummaryThe interaction between vegetative canes and fruiting canes of red raspberry was examined at sites in Scotland and N. America, using a range of cultivars. In the absence of vegetative canes, yields from fruiting canes were increased; and in the absence of fruiting canes, greater numbers of vegetative canes were produced. Separating the two phases in this way produced a biennial cropping system, in which the yield in the cropping year was considerably higher than in the conventional annual system. Cultivars varied both in the magnitude of their responses and in the nature of the changes in yield components influencing productivity. Among the cultivars tested the greatest response was obtained from Norfolk Giant, where cane numbers and yield per cane both contributed significantly to enhanced yield. The implications of these results for cultural methods and cultivar testing are discussed.