Science · Plants, Natives & Crops
Table Grape (Thompson Seedless)
Thompson Seedless is a grape cultivar with published growth-stage models developed in California. Vineyard management must also account for berry rots, insect feeding, and moisture stress.
Profile
- Cultivar
- Thompson Seedless.
- Support
- Grapevines require a suitable training and support system.
- Pruning
- Regular, appropriate pruning is important for productive vines.
- Development model
- The cited Thompson Seedless phenology model was studied in California's San Joaquin Valley.
- Model limitation
- UC advises testing a model locally before relying on it outside its tested conditions.
Water & soil context
- Moisture (VWC)
- Provide adequate root-zone moisture in well-drained soil; no cultivar-specific VWC target is documented.
- Salinity tolerance
- A salt-sensitivity class or threshold is not documented in the cited pages.
- Drought tolerance
- Grape drought stress can cause fruit drop; the cited pages do not establish a Thompson-specific drought class.
Illustrative monitoring-depth band
3–8 in
Editorial placement example, not a validated optimum or total rooting depth. Confirm the site's root distribution and soil horizons; multiple depths may be needed.
Manage watering to prevent fruit-production stress without treating a general grape recommendation as a cultivar-specific irrigation schedule.
Problems to watch
- Botrytis bunch rot
- Summer bunch rot
- Omnivorous leafroller
- Grape mealybug
- Thrips
- Sunburn
Stress signs
- Brown berries that split and leak
- Black, brown, or green spores on berries
- Chewed berries that rot or shrivel
- Cottony egg sacs and honeydew in clusters
- Scarring on berry skins
Where you'll find it
- Fresh table fruit
- Dried fruit
More plants, natives & crops
Published botanical and soil references are distinct from GroundWorx product guidance. Moisture thresholds and monitoring depths require site calibration; sources do not establish product performance or diagnose stress.