Definition - What does Nodosity mean?
Nodosity commonly occurs on the roots of grapevines. The nodes have the appearance of bumps or knot-like protrusions. They are the result of the accumulation and clustering of some genes which are involved in the metabolization of starches.
While nodosity in a vine can be benign, excessive formations are unhealthy and may be a sign of disease or the presence of a pest.
WineFrog explains Nodosity
The occurrence of nodosity in the root structure of a grapevine can be detrimental to the overall health of the vine.
It first may be the symptom of underdeveloped suberized endodermis.
The nodes are forms which are pouch-like leaf galls or superficial root galls. These types of galls are a sign that phylloxera has infected the vine. These insects attach themselves to the root and feed on its cortex and cause the build-up of amino acids and starch, creating deformations (nodosity). If not treated, it will eventually lead to necrosis and the destruction of the root system, and eventually, the death of the vine.