Date post: | 18-Nov-2014 |
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Technology |
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The Bundaberg path to high early yields
(A challenge to traditional thinking)
Chris Searle
Suncoast Gold Macadamias
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)
0
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2 3 4 5 6 7 8 9 10 11 12 13
Yie
ld (
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Year
Traditional
Predicted
Fig1. Traditional yield curve and predicted yield curve from high input system
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ld (
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Fig 2. Traditional yield and predicted yield curves plus actual data from 7 businesses (210,000 trees 8x4 spacing )
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
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
1.4 m
One year old tree - 1.3 m high
3.2m
Four year old tree 3.2m high
4.4m
Six year old tree – 4.4m high
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
35cm
1.5m
18 month old tree Pruned three times since being planted
Original cut 2010
Old racemes 2011 flowering
2012 flowering
2013 flowering
2011 2012
Pruning promotes flowering at cut points. Often one year old wood will flower. Weight at end of branch drags it down opening canopy
Weight dragging down branch opening canopy
3.6m
3.5 year old tree Shaping starting to take place
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)
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
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