Definition - What does Petiole mean?
A petiole is the stalk which connects a leaf to the stem.
In vineyards, this anatomy is used to determine the health and nutritional status of the overall vine. A sample of the petiole adjacent to the grape bunches allow viticulturists to know if a vineyard needs fertilizer or if the plant is properly absorbing essential nutrients.
WineFrog explains Petiole
The petiole anatomy of a grape vine is where the stalk of a leaf is attached to a stem. It is the transitional part, sometimes appearing as a bump between the leaf blade and the stem. Its function is to support the weight of the leaf.
It also provides a function to vineyard estate managers in determining the health needs of grape vines. Samples are taken from the petiole when the vineyard is in full bloom and early in varaison, when grapes mature and change color.
A sample can provide information of the health of the vine and what might be lacking in the soil.