Pierce's disease

Symptoms

Scorched leaf margins with a sharp boundary against green tissue, premature leaf drop while petioles stay attached, irregular cane maturation (matchstick pattern), raisining of berries on the vine.

Plants affected

• grape vine

Easily confused with

• Flavescence dorée

  How to tell them apart: On grapevine both cause leaf reddening/yellowing with dieback and BOTH are notifiable - distinguishing guides which official protocol, but either way contact the plant-health authority. Flavescence doree phytoplasma (Candidatus Phytoplasma vitis): downward leaf rolling, triangular sectorial red (red cultivars) or yellow (white cultivars) discoloration, non-lignified rubbery canes and flower/bunch abortion, leafhopper-vectored. Pierce's disease (Xylella fastidiosa subsp. fastidiosa): marginal leaf scorch with concentric green-to-brown zones, irregular green islands on canes that mature unevenly, sharpshooter-vectored.

• Esca disease complex

  How to tell them apart: Xylella fastidiosa (Pierce's disease): scorch starts at the leaf margin and spreads inward as a dull-green to yellow band, then dries to brown, often leaving a narrow concentric 'green island' or chlorotic halo between dead and healthy tissue. Petioles can stay attached after the blade falls ('matchsticks'), canes ripen patchily ('green islands' on the bark), and decline is whole-vine, progressive over 1-3 seasons, worst in hot regions and near vector activity. There is NO internal wood streaking pattern in the leaf itself; symptoms are uniform across the canopy of an affected vine. Phaeomoniella chlamydospora (esca complex): leaves show the classic 'tiger-stripe' pattern — interveinal yellow (white cultivars) or red (red cultivars) bands running parallel to the veins, with green tissue retained right along the veins, drying to necrotic stripes; a cut trunk reveals dark brown/black streaking and a central soft white rot, and sudden summer 'apoplexy' (whole-shoot collapse) can occur. Esca is tied to old wood/pruning wounds and trunk vascular browning, not to leaf-margin scorch.

Common questions

How do I recognise Pierce's disease on grape vine?

Scorched leaf margins with a sharp boundary against green tissue, premature leaf drop while petioles stay attached, irregular cane maturation (matchstick pattern), raisining of berries on the vine.

Do I have to report Pierce's disease?

Yes. Pierce's disease is a regulated quarantine organism in the EU. A suspected finding must be reported to your national plant protection organisation — they will confirm it and tell you what to do next.

How is Pierce's disease treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.