Assessing canopy quality

The Richard Smart Vineyard Scorecard can be used from veraison to harvest to assess the quality of canopies.

In order to obtain data for this scorecard, a point quadrat technique can be used:

  • A sharpened metal rod is stabbed 50 times into the canopy at right angles in the fruit zone in random areas.
  • Contacts with leaves (L), clusters (C) and canopy gaps (G) are noted.

    % canopy gaps = Number of Gs / 50 x 100
    Optimum 40% canopy gaps

    Mean leaf layer number = Total number of Ls / 50
    Optimum 1 – 1.5 leaves

    Fruit exposure = Number of external Cs / Total number of Cs x 100
    Optimum 60% fruit exposure

Other methods of assessing canopy quality include:

  • Sun-fleck assessment: measuring the amount of sunlight falling on a thin ruler inserted into the fruit zone
  • Measuring leaf areas: pick 20 random leaves, cut disc from them, weigh the leaves and the discs and calculate the leaf area using:

    Weight leaves / Weight discs = Area leaves / Area discs

    This can be used to measure the ratio of leaf area/crop weight (cm2/g):

    Low = <5, Moderate = 8 – 12, High = >20