Are all floral buds created equal?

June 2011 | Stuart Tustin, Ben van Hooijdonk and collaborators | Plant & Food Research / PIPS

This PIPS resource examines whether spur, terminal and axillary floral buds produce the same fruit size and quality in Royal Gala and Cripps Pink. The work compares bud types across Australian growing regions and links fruit performance with leaf area and photosynthetic potential.

For Royal Gala, axillary buds consistently produced smaller fruit. Terminal buds produced larger fruit than spurs in Tasmania and Queensland, while the South Australian result showed no significant size difference between terminals and spurs. For Cripps Pink, terminals produced the largest fruit, followed by spurs, with axillary buds producing the smallest fruit across the studied regions.

The notes then connect bud quality with Artificial Bud Extinction (ABE), where excess floral buds are removed before spring budbreak and preferred bud types are retained close to target crop load. The approach is intended to allocate early-season carbohydrate to the fruit that will make up the commercial crop.

New Zealand Scifresh work cited in the notes showed more consistent return bloom and, in one off-year example, 67 t/ha at 188 g mean fruit weight under ABE versus 56 t/ha at 175 g in unmodified trees. Australian results also showed that lowering floral-bud density increased the proportion of buds setting fruit.