Gray Leaf Spot
Stemphylium spp. · fungus
- Issue type
- disease
- Seedborne
- No
- Resistance code
- St
- Affects
- Tomato
Symptoms
Small dark spots that turn gray-brown, crack, and shot-hole, on foliage only, fruit stays clean while the canopy thins. Mostly a warm-region disease.
Management
The Sm resistance gene (code St) is bred into most southern-adapted hybrids, which is why the disease now shows mainly in heirloom plantings across the South.
Varieties with documented resistance
| Variety | Level | Code | Days | Breeding |
|---|---|---|---|---|
| Big Beef | resistant | St | 70-73 | F1 hybrid |
| Florida 91 | resistant | St | 70-74 | F1 hybrid |
| Solar Fire | resistant | St | 70-75 | F1 hybrid |
| Manalucie | resistant | St | 80-85 | open-pollinated |
| Floradade | resistant | St | 75-80 | open-pollinated |
| Marion | resistant | St | 75-80 | open-pollinated |
| Tropic | resistant | St | 80-85 | open-pollinated |
| Rebelski | resistant | St | 75-80 | F1 hybrid |
| Red Deuce | resistant | St | 70-75 | F1 hybrid |
| Skyway 687 | resistant | St | 72-78 | F1 hybrid |
| Florida 47 | resistant | St | 72-78 | F1 hybrid |
| Heatmaster | resistant | St | 70-75 | F1 hybrid |
| Phoenix | resistant | St | 72-78 | F1 hybrid |
| Bigdena | resistant | St | 75-80 | F1 hybrid |
Sources & References
Evidence: 1 source, all independent references.
- Tomato Production and Cultivar Guides · University of Florida IFAS Extension, University or Government