Which symptom is associated with Flavescence Dorée?

Which symptom is associated with Flavescence Dorée?

• A. Leaves discoloration with pustules and cracks
• B. Leaves turning purple in autumn
• C. Grapes ripen earlier
• D. Vine becomes more vigorous

Answer: (A)

Flavescence Dorée is a grapevine yellows disease caused by a phytoplasma that disrupts the plant’s normal leaf function. The primary symptom you’re looking for is foliar discoloration—leaves become yellowing or reddening, often in a patchy or mosaic-like pattern as the infection progresses. Some affected leaves also develop surface irregularities, such as pustule‑like features or cracks, reflecting tissue damage from the phytoplasma. This combination of leaf color change and surface alterations is what ties FD to foliar symptoms. The other signs listed don’t fit FD as well: changing leaves to purple in autumn isn’t a typical FD hallmark, grapes ripening earlier contradicts the disease’s tendency to slow or halt ripening, and increased vine vigor is the opposite of what FD usually does, since infection generally weakens the vine.

Flavescence Dorée is a grapevine yellows disease caused by a phytoplasma that disrupts the plant’s normal leaf function. The primary symptom you’re looking for is foliar discoloration—leaves become yellowing or reddening, often in a patchy or mosaic-like pattern as the infection progresses. Some affected leaves also develop surface irregularities, such as pustule‑like features or cracks, reflecting tissue damage from the phytoplasma. This combination of leaf color change and surface alterations is what ties FD to foliar symptoms.

The other signs listed don’t fit FD as well: changing leaves to purple in autumn isn’t a typical FD hallmark, grapes ripening earlier contradicts the disease’s tendency to slow or halt ripening, and increased vine vigor is the opposite of what FD usually does, since infection generally weakens the vine.