Paper · 2008 · Australian Journal of Grape and Wine Research

Understanding variability in winegrape production systems

R.G.V. BRAMLEY; R.P. HAMILTON

7
claims
15
verbatim quotes
280
citations
3
research areas
—
Not open access

Abstract

Spatial variability in winegrape yield was studied over several vintages in blocks planted to Cabernet Sauvignon, Merlot and Ruby Cabernet in the Coonawarra, Clare Valley and Sunraysia regions of Australia using new yield monitoring technology, a differentially corrected global positioning system (GPS), a geographical information system and some simple methods of spatial analysis. In any given year, yield was highly variable and typically of the order of 10 fold (i.e. 2 to 20 t/ha). However, through the use of k-means clustering and a method based on assessment of the probability of achieving yield targets relative to the mean annual block yield, temporal stability in the patterns of yield variation was demonstrated, even though there were substantial year to year differences in mean annual yield in these blocks. The methods used to demonstrate temporal stability in the patterns of yield variation also promote identification of zones of characteristic performance within variable vineyard blocks. Of significance in this work was the finding that, whilst k-means clustering is the more statistically robust of the two methods used, the ability to incorporate expert knowledge into the yield target method enhances the ability of the manager to accommodate the effects of abnormal events (e.g. an unusually cold flowering period) in the zone identification process. Targeted harvesting of different zones, followed by comparison between commercial lots of wine, provided indication that wine characteristics vary from zone to zone. However, the ranking of wine scores for the various zones changed between seasons. Our results have important implications for the adoption of Precision Viticulture. In particular, they support the introduction of a system of zonal vineyard management. Thus, rather than being managed uniformly, individual blocks can be split into zones in which the management of both inputs to, and outputs from the production system can be applied differentially.

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Claims 7

Observationobservedoriginal resultmeasured

Claim · model-written summary

Winegrape yield was highly variable within a year, typically about tenfold (2 to 20 t/ha).

Taxon
winegrapeVitis viniferae0
Outcome
yielde1
Value
2 to 20 t/hae1
Qualifier
highly variablee1

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e1

“yield was highly variable and typically of the order of 10 fold (i.e. 2 to 20 t/ha)”

✓ located verbatim in the source · abstract, characters 403–486 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Patterns of winegrape yield variation were temporally stable across seasons.

Taxon
winegrapeVitis viniferae0
Outcome
patterns of yield variatione2
Qualifier
temporal stabilitye2

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e2

“temporal stability in the patterns of yield variation was demonstrated”

✓ located verbatim in the source · abstract, characters 655–725 · show in text ↑
Method / resourceobservedoriginal resultpositivemeasured

Claim · model-written summary

K-means clustering was more statistically robust than the yield target method for zoning.

Taxon
winegrapeVitis viniferae0
Outcome
statistically robuste3
Comparator
yield target methode4

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e3

“k-means clustering is the more statistically robust of the two methods used”

✓ located verbatim in the source · abstract, characters 1069–1144 · show in text ↑
e4

“the ability to incorporate expert knowledge into the yield target method enhances the ability of the manager to accommodate the effects of abnormal events”

✓ located verbatim in the source · abstract, characters 1146–1300 · show in text ↑
Observationobservedoriginal resultpositivemeasured

Claim · model-written summary

Incorporating expert knowledge into the yield target method helped managers accommodate abnormal events.

Taxon
winegrapeVitis viniferae0
Outcome
accommodate the effects of abnormal eventse4
Qualifier
incorporate expert knowledge into the yield target methode4

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e4

“the ability to incorporate expert knowledge into the yield target method enhances the ability of the manager to accommodate the effects of abnormal events”

✓ located verbatim in the source · abstract, characters 1146–1300 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

Wine characteristics varied from zone to zone within winegrape blocks.

Taxon
winegrapeVitis viniferae0
Outcome
wine characteristicse5
Qualifier
vary from zone to zonee5

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e5

“wine characteristics vary from zone to zone”

✓ located verbatim in the source · abstract, characters 1500–1543 · show in text ↑
Observationobservedoriginal resultmeasured

Claim · model-written summary

The ranking of wine scores for vineyard zones changed between seasons.

Taxon
winegrapeVitis viniferae0
Outcome
ranking of wine scores for the various zonese6
Qualifier
changed between seasonse6

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e6

“the ranking of wine scores for the various zones changed between seasons”

✓ located verbatim in the source · abstract, characters 1554–1626 · show in text ↑
Recommendationauthor interpretationoriginal resultbasis n/a

Claim · model-written summary

Zonal vineyard management is recommended for winegrape blocks rather than uniform management.

Taxon
winegrapeVitis viniferae0
Outcome
zonal vineyard managemente7

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Vitis vinifera
Vitis vinifera · TaxonDarijanus · CC BY-SA 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Spatial variability in winegrape yield was studied over several vintages”

✓ located verbatim in the source · abstract, characters 0–72 · show in text ↑
e7

“they support the introduction of a system of zonal vineyard management”

✓ located verbatim in the source · abstract, characters 1726–1796 · show in text ↑