On the control of bud release in macadamia (Macadamia integrifolia)

Abstract

Macadamia (Macadamia integrifolia) is a recurrent flushing tree, with buds alternating between growth and quiescence. Here we report on factors governing bud release. We used staggered tip-pruning (equivalent to branch decapitation) to generate a range of trees with different flush maturities, but uniform maturity within any given canopy. We then tip-pruned the trees again to remove the most recent flush, and monitored the time taken for visible axillary bud emergence. New flushes appeared 9–16 days after tip-pruning. The slowest bud emergence was associated with flushes of intermediate maturity, approximately 7 weeks old. Overall, the variation in bud emergence was most closely related to the growth rate of the most recent flush at the time of pruning, and not related to the levels of stored carbohydrates.