The Basics of Canopy Measurement

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The Basics of Canopy Measurement
James M. Meyers Justine E. Vanden Heuvel,
Cornell University

• WAWGG February 4, 2009

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Agenda

• Canopy Architecture and Sunlight
• Measuring Canopy Architecture
• Point Quadrat Analysis (PQA)
• Enhanced Point Quadrat Analysis (EPQA)
• Measuring Sunlight Distribution
• Cluster Exposure Mapping
• Leaf Exposure Mapping

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Why We Measure Canopies

• Canopy measurements provide insight into vine
  performance and fruit quality.

• Energy Production (photosynthesis)
• Exposed Leaf Area
• Fruit Quality
• Cluster Exposure
• Functional Crop Load (yield vs. exposed leaf
  area)

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Agenda

• Canopy Architecture and Sunlight
• Measuring Canopy Architecture
• Point Quadrat Analysis (PQA)
• Enhanced Point Quadrat Analysis (EPQA)
• Measuring Sunlight Distribution
• Cluster Exposure Mapping
• Leaf Exposure Mapping

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Point Quadrat Analysis (PQA)

• What is PQA?
• PQA is a simple field method for measuring key
  parameters of canopy architecture
• Why perform PQA?
• PQA metrics quantify canopy differences
• PQA metrics provide insight into vine performance

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Point Quadrat Measurement Zone

• Measurements are taken at consistent height
  (usually middle of the fruiting zone), but can be
  somewhat dynamic due to variations in vineyard
  floor and trellising.

(Photo J. Meyers)
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Sampling Frequency

• Canopy is sampled, at the designated height, at
  consistent intervals along the row.

(Photo J. Meyers)
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Sampling Vector

• At each sampling location, data is collected from
  one outer edge of the other outer edge.

(Photo J. Meyers)
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Point Quadrat Data Collection

• A tape measure or meter stick is used to ensure
  consistently spaced measurements.

(Photo from Sunlight into Wine, credited to B.W.)
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Point Quadrat Data Collection

• A rod is passed through the canopy. As the rod
  contacts biomass, the contacts are identified and
  recorded.

(Photo from Sunlight into Wine, credited to B.W.)
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Sample Dataset
L
c
L
S
S

• In this example, ignoring shoots, the first
  insertion produces the following dataset L L C.

(Photo from Sunlight into Wine, credited to R.S.)
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PQA Standard Analysis Metrics
Sample Dataset
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PQA Standard Analysis Metrics
Sample Dataset
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PIC Simplified Analysis Results

• PIC is often used to establish treatment efficacy.

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Enhanced Point Quadrat Analysis (EPQA)

• What is EPQA?
• Data collection method is the same as standard
  PQA
• EPQA uses computer software to calculate canopy
  parameters with more precision than standard PQA
  metrics
• Why perform EPQA?
• EPQA is more descriptive than standard PQA
• EPQA adds metrics for canopy symmetry and
  trellising consistency
• EPQA provides the foundation for canopy exposure
  mapping

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Agenda

• Canopy Architecture and Sunlight
• Measuring Canopy Architecture
• Point Quadrat Analysis (PQA)
• Enhanced Point Quadrat Analysis (EPQA)
• Measuring Sunlight Distribution
• Cluster Exposure Mapping
• Leaf Exposure Mapping

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Calibrated Exposure Mapping
(Photo from Decagon website)
(Photo from Sunlight into Wine, credited to B.W.)
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Calibrating a Canopy

• Sunlight calibration curve is unique to each
  canopy
• Curve can be fitted with only two known PPF
  points
• 100 PPF always at layer 0
• Measure PPF at a second known canopy layer
  (OLN/2)
• Fit curve to the two points
• Sample the fitted curve at layer 1 to determine
  calibration value (Ep1)

100 90 80 70 60 50 40 30 20 10
Photon Flux
(x1, yEp1)
0 1 2 3 4 5 6
Canopy Layer
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Cluster Exposure Map

• The precise exposure of each cluster in the PQA
  dataset is calculated.

0-9.9
10-19.9
20-29.9
30-39.9
40-49.9
50-59.9
60-69.9
70-79.9
80-89.9
90-100
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Leaf Exposure Map

• The precise exposure of each leaf in the PQA
  dataset is calculated.

0-9.9
10-19.9
20-29.9
30-39.9
40-49.9
50-59.9
60-69.9
70-79.9
80-89.9
90-100
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Treatment Effect Cluster Exposure Map

• Umbrella trained hybrid canopy in Finger Lakes
  subjected to
• Shoot Thinning (ST)
• Hedging (H)
• Combination (ST-H)

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Treatment Effect Leaf Pulling

• Cluster exposure map comparing control and
  leaf-pulled VSP canopies on Long Island.

(Data from J. Scheiner)
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Natural Variability in Cluster Exposure

• EPQA and CEM data 18 panels within a block of
  Scott-Henry trained Finger Lakes Riesling.
• Substantial natural variation was observed.

Ambient PPF
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Map Your Own Canopies

• An Excel spreadsheet is available for growers and
  researchers who wish to map exposure in their own
  canopies.
• Contact
• Jim Meyers
• Jmm533_at_cornell.edu

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The Basics of Canopy Measurement
James M. Meyers Justine E. Vanden Heuvel,
Cornell University

• WAWGG February 4, 2009