Seed Treatment and Germination Enhancers for Capsicum Species
This article summarizes germination-improvement treatments for pepper (Capsicum) seeds, including the use of gibberellic acid (GA₃) and other similar treatments. Recommendations are species-specific, with details on ppm ranges, soak times, and special notes for wild and cultivated species.
Overview
Gibberellic acid (GA₃) is a plant growth regulator that breaks seed dormancy and speeds up germination. In peppers, it is most useful for wild and slow-germinating species. Other treatments include potassium nitrate (KNO₃), hot water soaking, and mechanical scarification.
Species-Specific Recommendations
| Capsicum Species | GA₃ Treatment | KNO₃ Treatment | Other Treatment | Notes |
| C. annuum (common peppers) | Optional: 250 ppm GA₃ soak for 12 hrs | 0.2% KNO₃ soak 12–24 hrs | Maintain 27–30°C germination temp | Usually germinates well without treatments |
| C. chinense (Habaneros, etc.) | Recommended: 300 ppm GA₃ soak 24 hrs | 0.2% KNO₃ soak 24 hrs | Warm soak and maintain 28–30°C | Slower germination, GA₃ improves speed |
| C. baccatum (Aji types) | Recommended: 250 ppm GA₃ soak 18 hrs | 0.2% KNO₃ soak 24 hrs | Warm soak at 28°C | GA₃ useful for uniform germination |
| C. pubescens (Rocoto types) | Recommended: 400 ppm GA₃ soak 24 hrs | 0.2% KNO₃ soak 24 hrs | Scarify lightly or nick seed coat | Very slow and erratic germination without treatment |
| C. chacoense (wild type) | Strongly recommended: 500 ppm GA₃ soak 24 hrs | 0.2% KNO₃ soak 24 hrs | Mechanical scarification + warm soak | Hard seed coat, dormancy-breaking required |
| C. cardenasii (wild type) | Strongly recommended: 500 ppm GA₃ soak 24 hrs | 0.2% KNO₃ soak 24 hrs | Scarify + soak at 30°C | Known for very slow germination |
| C. eximium (wild type) | Strongly recommended: 500 ppm GA₃ soak 24 hrs | 0.2% KNO₃ soak 24 hrs | Hot water pre-treatment (50°C 10 min) | Breaks dormancy effectively |
Application Notes
- Prepare GA₃ solutions using distilled water. Mix to desired ppm and soak seeds fully submerged.
• For KNO₃, a 0.2% solution is common: dissolve 2 g KNO₃ per liter of water.
• Always rinse seeds after treatment before sowing in sterile seed-start mix.
• Maintain optimal germination temperatures (27–30°C for most cultivated species, slightly higher for wild).
Safety and Handling
- Wear gloves and eye protection when handling GA₃ or KNO₃.
• Dispose of leftover solutions responsibly.
• Do not exceed recommended soak times to avoid seed damage.