TABLE GRAPES
SCIENTIFIC NAME: Vitis spp.
FAMILY: Vitaceae
At the August Indoor meeting of the RFC of A Darwin Branch, Walter Kuppelweiser (DPI and F) gave us an excellent presentation on the ins and outs of growing grapes in the Top End and has kindly made his notes available as follows.
1. Reason for Grape Growing
- Quarantine restrictions on the importation of fresh grapes.
- No long term storage grapes after 20th September.
- First grapes from temperate growing areas after 20th November
2. Climatic Conditions
- Weather conditions are critical at harvest time in September - November.
- Early rains and high relative air humidity are often very damaging.
- Temperature: Katherine has lower minimum temperatures.
3. Grape Varieties
- In sandy soils grafting onto nematode-tolerant rootstocks is necessary.
- In Darwin, from 21 varieties only 3 reasonably good varieties were selected. In Katherine more varieties seem to perform.
- Varieties in Darwin: Maroo seedless, Alphonse Lavallee, Royal Ascot.
- Most varieties in Darwin just don't fruit.
4. Pests and Diseases
- Bird and fruit piercing moth net protection is essential.
- During the wet season frequent fungicide sprays are needed on some varieties (1- 2 per week).
- Pests are mealy bugs, broad mites, caterpillars.
5. Fertilisers
- 1-4 m2 area per vine, depending on age of vine (if fertigation, the area is equal to the irrigated area).
- Rough guide: 30g N, 20g P, 30g K, 14g Ca, 7g Mg, 1g Fe, 2g Zn and 1g B per 1 m 2 each year.
- These quantities must be increased if high yields are produced.
- Monthly applications for young vines, then the applications should be suited to the crop cycle.
6. Irrigation
- Irrigate daily; 10 litres per 1 m2 (When lots of foliage: give more; when little foliage: give less.)
7. Pruning
- Defoliate with 500 ppm Ethephon spray.
- Defoliate by hand if only a few vines.
- Spur prune for NO yield at the end of December.
- Cane prune for yield in June.
- From pruning it takes about 125 days for the grapes to mature.
8. Training System for the Vines
- A type of overhead trellis system is necessary in the tropics, permanent cordons are needed. Spacings are 4m x 2m or 3m x 2m.
9. Bunch Trimming
- Stunted grape bunches are often characteristic.
- Bunch thinning and trimming is necessary.
10. Grape Harvesting
- Because of the irregular bud burst, 2 or 3 pickings must occur.
- 4-5 weeks before harvest, spray a suitable insecticide to control ants and mealy bugs.
11. Yield
- Grape yield achieved at CPRS
Variety kg/m2, 1989 kg/m2, 1990 Maroo seedless 1.9 1.0 Alphonse Lavallee 1.2 0.7 Royal Ascot 2.4 0.8
12. Packing and Storage
- Good fruit is usually packing in 5kg cartons or boxes.
- Grapes are cool-stored at 1°C, at 90% relative humidity.
13. Market
- Only small quantities of grapes will be needed at the prices which are currently charged in October-November.
- A 5ha vineyard approximately can produce 40,000 kg of grapes in 6 weeks.
- That means that 950 kg of grapes need to be sold daily.
14. Marketing
- Make sure that the grapes are not sold to somebody who keeps them on the shelf until they are unsightly - reduce price if necessary.
DATE: January 1992
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