The document presents a method for achieving high early yields in macadamia orchards through maximizing light interception, growth, and productivity. The key aspects of the method are applying high nitrogen fertilizer to double the canopy volume each year, repeat mechanical pruning to create new flowering sites, and maintaining low skirts and graft unions. This approach aims to reach a sustainable yield of 4.5 tons per hectare by year nine, making macadamia farming profitable sooner. Actual yield data from several farms supports that this intensive approach can achieve much higher early yields than traditional methods.

1. The Bundaberg path to high
early yields
(A challenge to traditional thinking)
Chris Searle
Suncoast Gold Macadamias

2. Objective
• Reach a sustainable yield 4.5 t NIS /ha
(36% SKR = 1.6t of kernel) by year nine
Why ?
• High early yields are the key to making
macadamia profitable in the short to
medium term (Precocity)

3. 6
5
4
Yield (NIS) t/ha
3 Traditional
Predicted
2
1
0
2 3 4 5 6 7 8 9 10 11 12 13
Year
Fig1. Traditional yield curve and predicted yield
curve from high input system

4. 6
5
4
Yield (NIS) t/ha
3
Traditional
Predicted
2
1
0
2 3 4 5 6 7 8 9 10 11 12 13
Year
Fig 2. Traditional yield and predicted yield curves plus actual
data from 7 businesses (210,000 trees 8x4 spacing )

5. Method
Maximise light interception
• Double canopy volume every year
• High fertliser (N) inputs
Maximise potential productivity
• Divert energy into crop not growth
• Repeat mechanical pruning (every time tree
grows 50cm cut off 20cm) - internal complexity
• Low graft and low skirts

6. Maximise light interception by maximising
growth
High Nitrogen program (poor soils)
• Year 1 100g N /tree /year (32kg/ha)
• Year 2 200g N /tree /year (63 kg/ha)
• Year 3 300g N /tree /year (94 kg/ha)
• Year 4 400g N /tree /year (125kg/ha)
• Minimum - apply monthly, 12 months of year
• Ensure all micronutrient deficiencies are
corrected – no impediments to growth

7. One year old
tree - 1.3 m
high
1.4 m

8. Four year
old tree
3.2m 3.2m high

9. Six year old
tree –
4.4m high
4.4m

10. Maximise potential productivity
• Low graft union (minimise wind damage)
• Repeat mechanical pruning (every time tree
grows 50cm cut off 20cm)
• Create multiple sites for flower development
at cut points (internal complexity)
• Maximise productivity by maintaining low
skirts (don’t cut off 2 year old wood)
Divert energy into yield not growth

11. 18 month old
tree
Pruned three
times since
1.5m
being planted
35cm

12. 2011 Original cut
2012
2010
2013
flowering
2012
flowering Old racemes
2011 flowering
Weight dragging down branch opening canopy
Pruning promotes flowering at cut points. Often one year old
wood will flower. Weight at end of branch drags it down
opening canopy

13. 3.5 year old
tree
Shaping
3.6m
starting to
take place

14. Not all varieties the same
• Minimum pruning (A203, A4, 344)
• Moderate pruning (842, 816)
• Heavy pruning ( A268, 741)
Pruning also
• reduces wind damage
• reduces leaning trees (mechanisation)

15. Change in the profitability equation
Cost
8 x mechanical prunings @10c a tree/time = 80c
1,000 g N /tree = $2.50
Total = $3.30 = 1 kg NIS
High early yields
• Reduce debt – earlier breakeven
• Macadamia a viable investment (IRR 6%)
• Allows you to set up for mature orchard phase

16. Challenge - maintain yield 4.5 t NIS
(1.6 t/ha kernel) in mature orchards
Maximise light distribution (key)
• mechanical hedging and limb removal?
• maintain production of fruiting wood
Maintain tree and soil health over long term
• Soil health - continue organic matter program
• Minimise soil loss
Future - need varieties that have 20% higher yield -
breed the ‘wildness’ out of macadamia