Lettuce Greenhouse

Lettuce bolts and tipburns under heat and unstable transpiration, so cooling capacity and water temperature control define the summer production window. In warm climates the cooling strategy is the project, not an accessory to it.

• Day 18 – 22 °C, night 12 – 16 °C to prevent bolting
• Evaporative pad-and-fan or high-pressure fogging for cooling
• Root zone water held at 18 – 22 °C with chilling if required
• Air movement to prevent tipburn in dense plantings
• Semi-closed configurations where outside air is hot or dusty

In recirculating leafy systems the nutrient solution is the growing medium, so disinfection and oxygenation are continuous processes. Water volume turns over quickly, which means a pathogen or oxygen failure spreads across the entire crop within hours.

• Closed recirculation with continuous UV or ozone disinfection
• Dissolved oxygen maintained above 6 mg/l in the channels
• Feed EC 1.2 – 1.8 mS/cm, pH 5.5 – 6.0
• Automated dosing with inline EC and pH verification
• Water use of roughly 1 – 2 litres per head produced

Mobile gutter and conveyor systems reduce labour per head substantially and stabilise quality. The investment is justified when volume is high and local labour is expensive or difficult to secure.

For leafy crops, the packhouse and cold chain determine shelf life and customer acceptance. Aegis designs internal logistics and post-harvest flow as part of the project scope.

• Harvest to cooling time under 30 minutes
• Packing line capacity matched to daily output
• Traceability and food safety documentation
• Buffer storage for demand variation