Science Fair Project: Light Effects on Basil Growth

Designing a science fair experiment on basil (Ocimum basilicum) and light sources is a great choice—basil responds dramatically to light quality, duration, and intensity.

Key Variables to Test

• Light Source: Natural sunlight vs. LED grow lights (full-spectrum, red/blue) vs. fluorescent (cool white + warm white tubes).
• Photoperiod: 12h, 16h, 18h, 24h light cycles.
• Intensity: Measure PPFD (µmol/m²/s) at canopy level.
• Spectral Quality: Compare blue-heavy (vegetative) vs. red-heavy (flowering) spectra.

Basil's Light Requirements

• Optimal: 16–18 hours of high-intensity light (300–600 µmol/m²/s).
• Temperature: 70–85°F (21–29°C) day, 60–70°F (16–21°C) night.
• Airflow & Humidity: Good circulation prevents damping off; 50–70% RH.

Experimental Design Tips

1. Use uniform seeds, same soil mix, container size.
2. Control watering and fertilization (dilute fish/seaweed weekly).
3. Measure: germination rate, height, leaf count, leaf area, fresh/dry weight, chlorophyll content (SPAD meter), essential oil yield (if equipment available).
4. Replicate: minimum 5 plants per treatment.
5. Document daily with photos and data logs.

Resources

Search "basil light spectrum study" or "LED basil growth" for peer-reviewed papers. NASA and university horticulture sites have relevant research. Good luck—your project can yield real insights for indoor herb growers!