Grape Vine Petiole

When to Sample: At the beginning of veraison.

Where: From healthy vines, sample in a homogeneous area (same rootstock, variety, soil).

How: Collect one petiole per vine from the leaf opposite the second cluster on the shoot located in the middle of the cane or spur (winter pruning wood).

Quantity: 50 whole petioles per sample.

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