Hydroponic lettuce and leafy greens cultivated under vertical farming LED arrays or greenhouse NFT gutters are highly susceptible to inner-leaf tipburn caused by localized calcium deficiency under rapid biomass expansion. Controlled air velocity (0.3–0.5 m/s) over the growing point ensures steady transpiration flux.
Maintaining a DIF of +4 to +6°C (Day Temperature minus Night Temperature) regulates internode length and crop balance. When vegetative vigor is excessive, reducing DIF steers the plant toward reproductive flowering; increasing DIF restores leaf expansion and canopy Light Extinction (Beer-Lambert k-factor).
Target root-zone drain fraction: Recirculating Closed-Loop to avoid substrate EC accumulation and root hypoxia.
Primary Pathological Risks: Inner Leaf Tipburn, Pythium Root Rot, Bolting under High Temperature, Shore Flies, Sciarids.
Biological Predator Sizing & Release Strategy: Hypoaspis miles (Stratiolaelaps scimitus), Steinernema feltiae entomopathogenic nematodes.
Use Inwoovation Lab's free, browser-based calculators to model exact thermodynamics for your Lettuce & Greens crop:
Maintain horizontal air movement (0.3 to 0.5 m/s) directly into the heart of the lettuce head, keep DLI at 16 mol/m²/day with an 18h photoperiod (PPFD ~250 µmol/m²/s), and maintain night VPD >0.6 kPa.