Grape Leaf

When to Sample: At the "end of flowering" and "beginning of veraison" stages. If a single sampling is performed, choose the "beginning of veraison" stage or sample 20 days after the end of flowering (equivalent to the average of the two mentioned stages).

Where: From a homogeneous vineyard area (same rootstock, variety, soil). Sample from 16 rows (or sub-plots) with at least 3 vines per row or sub-plot. Identify the vines to ensure continuity and representativeness of successive annual samples.

How: Collect the entire leaf opposite the first cluster, identified from the base of the shoot, or the immediate leaf located above the cluster.

Quantity: 1 leaf per healthy and well-maintained vine (total of 48 leaves per plot).

Conditioning: Place the batch of leaves in a clean, sturdy plastic bag. Label each batch clearly with: Name, address, variety, rootstock, date of sampling, and plot reference.

Precautions: Send to the laboratory as soon as possible, ensuring the sample is not exposed to sunlight.