Name for gall-like, yellowish and two to four millimetre large growths in a bird's beak-like shape (nodose = nodular), which are induced by phylloxera infestation on the young, still unwoody roots. They are usually relatively harmless compared to the much more dangerous tuberosities (scabby tumours on old roots). Nodosities are also formed in large numbers on most American species such as Vitis cinerea var. helleri (Vitis berlandieri), Vitis riparia and Vitis rupestris, but phylloxera infestation does not induce tuberosities there. As long as only nodosities are formed, the vine usually survives the phylloxera infestation relatively unscathed.
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