Cucumber (Cucumis sativus)

📚 Family/Class: Cucurbitaceae (박과) 🌱 Genus/Sub-category: Cucumis (오이속) 🧬 Species/Type: Cucumis sativus 🌍 Origin: India & Southern Asia

Cucumber is one of the fastest-growing greenhouse crops. Because of its extremely high leaf area index (LAI) and soft tissue, it is highly sensitive to humidity and transpiration stress. Precision steering is required to manage its massive water requirements while keeping vegetative and generative loads balanced, preventing diseases like powdery mildew and downy mildew.

Global Climate Strategy

🌍 South Korea (RDA Smart Farm)

Typically grown in plastic multi-span greenhouses. Requires strong night heating (15-18°C) to prevent downy mildew during winter. Focus is on air circulation to reduce boundary layer humidity around the dense canopy. ^[1]

⚙️ Tech Level: Medium (Forced-air heaters, air circulation fans, drip irrigation)

🌍 The Netherlands (WUR)

High-tech cultivation on rockwool gutters with high plant densities. High-wire training systems are standard. Focus is on managing VPD precisely (0.7 - 1.1 kPa) to ensure constant transpiration without causing root-zone waterlogging.

⚙️ Tech Level: Very High (Rockwool slab gutters, high-wire training, high-pressure fogging)

Crop Steering Parameters

Cucumber steering must be highly reactive due to the rapid growth cycle. The goal is to maintain strong vegetative vigor (thick stems) while steering generatively to support fruit elongation.

Parameter	🌱 Vegetative Target (Leaf Growth)	🍅 Generative Target (Fruit Growth)
Temperature DIF	Low day-to-night temperature difference (e.g., Day 22°C / Night 20°C).	Large day-to-night temperature difference (e.g., Day 24°C / Night 16°C) to trigger flowering.
VPD (kPa)	0.5 - 0.7 kPa (Prevents water stress, encourages leaf cell expansion).	0.9 - 1.2 kPa (Drives transpiration, though must be monitored to avoid wilting).
Irrigation & Space Strategy	Frequent, small irrigation shots to keep root-zone moisture high. Lower EC (1.6 - 1.8 mS/cm).	Longer dry-backs between shots. Higher EC (2.2 - 2.5 mS/cm) to steer the crop generatively.

Fertigation Strategy

Cucumbers require a massive amount of water and a balanced nutrient supply. High potassium levels are required to support fruit expansion and maintain fruit quality.

Phase 1: Vegetative Vigor

Balanced Nitrogen and Phosphorus to support rapid root and shoot expansion. Target EC: 1.8 - 2.0 mS/cm.

Phase 2: Generative / Brix Steering

Increase Potassium (K) relative to Nitrogen (N) for fruit cell elongation. Target EC: 2.2 - 2.6 mS/cm.

Ready to steer your crop?

AgriAtlas provides the theory, but every greenhouse is unique. Use our precise engineering calculators to hit these target VPD and Temperature DIF values based on your specific facility's U-Value and heating capacity.

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