4 Discussion
In concurrence with the findings of White et al. (1999) for raspberry, the present results show that the chilling requirement for bud dormancy release is underestimated when assayed as single node cuttings (Fig. 2). The underlying physiological mechanism is that, when severed, the buds are released from both apical dominance and the mutual correlative inhibition between adjacent buds. Because of this, buds of single node cuttings are able to burst with less chilling. It should be noted however, that in the present experiments in which single node cuttings were cut only from the middle part of the shoot where dormancy release is particularly late (Fig. 6), single node cuttings often had greater chilling requirements than entire shoots (cf. Fig. 3 and Fig. 5). When using multi-bud hard-wood cuttings as used and recommended by Jones et al. (2012), it should be kept in mind that cuttings from different parts of the shoot have divergent chilling requirements. On the other hand, the concurrent results with chilling and forcing of intact plants and severed entire shoots, demonstrate that the results obtained with the latter technique are quite representative for intact plants and is therefore recommended.