The traditional method of planting bananas in the Ord River Irrigation Aria (ORIA) is with corm material 'bits' planted at 1440 plants per hectare from March or May, with plant spacing of 2.4m (1440 plants per hectare) and 3m between rows. Two suckers are then selected to develop on each parent plant to give 2880 plants per hectare.
There are numerous variations on this. Details of five systems used are:
1. Traditional system
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Uses bits cut from corms.
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March to May planting of bits at 1440 plant per hectare, doubling to 2880 plants per hectare after selecting two suckers from each parent corm prior to harvesting parent bunch.
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Three ratoon and one parent crop expected over three to four years.
2. Traditional and drop parent bunch
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As per 'traditional' but with parent bunches cut down in December/January to cycle the ratoon crop into June-September for the higher price window and minimise storm damage.
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May also have lifestyle benefits, that is, avoiding harvesting in hot wet months.
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Three ratoon crops only over three to four years.
3. Full plant stand at establishment
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Bits planted at 2880 per hectare from March to August.
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Three ratoon and one parent crop expected over three to four years.
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Slower cycling of parent crop – later harvest.
4. Annual tissue culture
- Late August planting, with explants imported from Queensland and maintained in a nursery.
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Planted at 2880 plants per hectare.
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Parent crop only, harvest about July.
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Replant August with new explants.
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Higher costs of production, more intensive management but returns higher than other methods. May result in fruit quality and maturity problems in cooler months and years.
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Not proven in commercial context.
5. Tissue culture and ratoons
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Late August planting, with explants imported from Queensland and maintained in a nursery.
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Planted at 2880 per hectare or 1440 and then doubling at sucker selection as traditional method, reducing the cost due to the number of plants purchased.
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Three ratoon and one parent crop expected over three to four years.
Risk management strategies
Storm damage from September through to March is a recurring threat to bananas and estimated farm damage varies from 0 to 30% loss annually. The worst case scenario for growers in the ORIA would be to lose up to 100% of the crop every three years.
A number of strategies have been developed to mitigate against the risk and its impact, including:
- planting at different dates – a range so that the entire crop is at different stages
- dropping parent bunches in December and January
- manipulating sucker selection and plant density.
These strategies and possible outcomes are summarised in Table 1.
| Planting system | Plant date | Yield estimated t/ha | Expected loss to storms | High price window (June-Sept) | Estimated returns/ha |
|---|---|---|---|---|---|
| Traditional | March to May | 40-60 | 30% | No | Lowest |
| Drop parent bunch | March to May | 40 | 20% | Yes | Intermediate |
| Annual tissue culture | August | >60 | 0% | Yes | Highest |
| Tissue culture and ratoons | August | >60 | 10-30% | Yes for parent bunch | Highest |
| Full density at planting | March to August | 40-60 | 10-30% | Possible for parent bunch | Intermedate to high |