Alternaria Stem Canker
- Issue type
- disease
- Seedborne
- No
- Resistance code
- ASC
- Affects
- Tomato
Symptoms
Dark cankers girdle stems at soil line or wound sites with brown streaking in the pith; dark zonate lesions can mark fruit. Historically a California field problem.
Management
The Asc resistance gene (code ASC) shut this disease down in commercial production, a clean case of single-gene resistance solving a regional problem; it persists mainly where susceptible heirlooms are grown.
Varieties with documented resistance
| Variety | Level | Code | Basis | Days | Breeding |
|---|---|---|---|---|---|
| Big Beef | resistant | ASC | Breeder declared | 70-73 | F1 hybrid |
| Bella Rosa | resistant | ASC | Independently observed | 72-76 | F1 hybrid |
| Florida 91 | resistant | ASC | Independently observed | 70-74 | F1 hybrid |
| Patio | resistant | ASC | Breeder declared | 65-70 | F1 hybrid |
| Red Deuce | resistant | ASC | Breeder declared | 70-75 | F1 hybrid |
| Florida 47 | resistant | ASC | Independently observed | 72-78 | F1 hybrid |
| Phoenix | resistant | ASC | Independently observed | 72-78 | F1 hybrid |
This is the page where the difference matters most, because it is where a variety gets chosen for its resistance. Breeder declared means the claim comes from whoever breeds or sells the seed, which for most resistance genes is the only evidence that exists. Independently observed means an institution with no stake in the sale grew the plant and reported what happened.
Sources & References
Evidence: 1 source, an independent reference.
- Tomato Production and Cultivar Guides · University of Florida IFAS Extension, University or Government