Symptoms

•  Symptoms on foliage

During crop season, infected plants are stunted and have an erected port. The leaves, sometimes curled, show chlorotic areas with some mottling and a purplish color, especially at the level of the apical area (photo 1). The stems may have "zig zag" patterns, and with short and thickened nodes and aerial tubers. Heavily infected plants have foliage that looks burnt

• Symptoms on tubers

Tubers of infected plants are often small, many and deformed. Germination is affected with fail and thin sprouts. The point of attachment of the stolon is marked and pinkish. The symptoms observed on cut tubers are a browning of the vascular ring associated with necrotic spots and streaks in the tuber flesh (photo 2). The symptoms are more pronounced after frying and gave their name to the disease (Zebra chip, photo 3).

More info on the web site (https://www.anses.fr/fr/content/le-projet-caliso)