# Pierce's disease

- URL: https://backyardgrapes.com/diseases/pierces-disease/
- Scientific name: Xylella fastidiosa
- Category: Bacterial
- Affects: Leaves
- Severity: high
- Favored by: Warm regions with sharpshooter insects; worse near rivers and citrus.
- Easily confused with: Esca (trunk disease), Grapevine leafroll

**Summary:** A bacterium spread by sharpshooter insects that clogs the vine's plumbing and kills it over 1–3 years.

**What to look for:**
- Leaf edges scorch — drying from the margin inward, often with a yellow/red band.
- Green "islands" remain along the veins as the rest of the leaf browns.
- Leaf blades drop but the leaf stalk (petiole) stays attached to the cane.
- Uneven, patchy cane maturity; fruit shrivels; vine declines and dies.

**Treatment — Cultural / prevention:**
- No cure — focus on prevention and removing dead vines promptly.
- Remove nearby weedy or riparian host plants that harbour the bacterium.
- Plant tolerant/resistant varieties in high-pressure regions.

**Treatment — Organic / low-toxicity:**
- Manage sharpshooter insect vectors and habitat around the vineyard.

**Treatment — Conventional (chemical):**
- Insecticides targeting the sharpshooter vectors, where locally recommended.

Pierce's disease is caused by the bacterium *Xylella fastidiosa*, which lives in the
vine's water-conducting tissue (xylem) and is injected by sap-feeding "sharpshooter"
leafhoppers. As the bacteria multiply they block water flow, so the vine slowly
starves and dries out.

There is no cure — a confirmed vine will decline over one to three seasons. Because
it is spread by an insect and by nearby host plants, management is about the vector
and about choosing tolerant varieties in warm regions where the disease is present.
A tell-tale sign is the "matchstick": the leaf blade falls but its stalk stays on the
cane.

**Image credits:**
- Symptoms of Pierce's disease in grapevines caused by Xylella fastidiosa: marginal leaf scorch — [Photo: A.C. Goheen, Compendium of Grape Diseases (APS Press, 1988), American Phytopathological Society (APSnet Education Center)](https://www.apsnet.org/edcenter/apsnetfeatures/Pages/Pierces.aspx)
- Symptoms of Pierce's disease on a grapevine leaf — [Photo: Jack Kelly Clark / UC ANR, UC Davis](https://www.ucdavis.edu/food/news/new-insight-why-pierces-disease-so-deadly-grapevines)
- Pierce's disease in a vineyard vine: scorched leaf margins and shrivelling grape clusters — [Gardenia.net](https://www.gardenia.net/disease/pierce-disease-in-grapevines-symptoms-control)

**Sources:**
- [Pierce's Disease of Grape: Identification and Management (Bulletin 1514)](https://fieldreport.caes.uga.edu/publications/B1514/pierces-disease-of-grape-identification-and-management/) — University of Georgia Cooperative Extension
- [Pierce's Disease - Grape Pest Management Guidelines](https://ipm.ucanr.edu/agriculture/grape/pierces-disease/) — UC IPM
- [Pierce's Disease - Background and Management](https://extension.umd.edu/resource/pierces-disease-background-and-management) — University of Maryland Extension
- [Pierce's Disease of Grapevines: A Review of Control Strategies and an Outline of an Epidemiological Model](https://www.frontiersin.org/articles/10.3389/fmicb.2018.02141/full) — Frontiers in Microbiology (2018)