Daily Light Integral (DLI) & Photonic Efficacy Engineering in Vertical Plant Factories

1. DLI Computation & Photonic Efficacy

Daily Light Integral (DLI) represents the total cumulative moles of photosynthetic photons delivered per square meter per day (\( ext{mol m}^{-2} ext{ d}^{-1}\)). It is calculated from PPFD (\(\mu ext{mol m}^{-2} ext{ s}^{-1}\)) and photoperiod (hours):

DLI = PPFD × Photoperiod (hours) × 3600 ÷ 1,000,000 [mol m⁻² d⁻¹]

2. Target DLI Benchmarks for Commercial Crops

• Lettuce & Leafy Greens: 14 - 17 mol/m²/day (Target PPFD: 200 - 250 µmol/m²/s at 18h photoperiod).
• Sweet Basil & Herbs: 16 - 20 mol/m²/day.
• Fruiting Tomatoes & Strawberries: 22 - 30 mol/m²/day.