Heat stress on plants and what to do

Here is the guide to manage heat stress in tomatoes, cucumbers, peppers and eggplants.

Signs of heat stress

Tomato: Leaf curling, flower drop, fruit cracking

Cucumber: yellowing, wilting, poor fruit set

Pepper: Deformed fruits, blossom end rot

Eggplant: Weak growth, poor fruit development

✅ How to Manage Heat Stress

1.⁠ ⁠Use Shade Nets

• During peak sun hours (12:00–17:00), use 30–50% shading nets to reduce sunlight intensity.

• In greenhouses, thermal or energy-saving screens are recommended.

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2.⁠ ⁠Water at the Right Time

• Irrigate early in the morning (6:00–9:00) or late evening (18:00–20:00).

• Use drip irrigation instead of overhead watering.

• Prefer deep and infrequent watering to encourage strong root systems.

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3.⁠ ⁠Apply Mulch

• Organic mulch (straw, dry grass) or plastic mulch (black PE film) helps conserve soil moisture and stabilize temperature.

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4.⁠ ⁠Use Foliar Nutrients

During heat stress, plants struggle to uptake nutrients from the soil. Support with:

• Seaweed extract (kelp-based),

• Amino acid foliar sprays,

• Potassium-rich foliar fertilizers.

These strengthen the plant and help overcome stress.

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5.⁠ ⁠Misting (Caution!)

• In greenhouses, ultra-fine misting can cool down the environment (only in very hot weather, above 40°C).

• For open field, misting should be very limited and only done in the early morning.

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6.⁠ ⁠Spacing Between Plants

• Ensure proper air circulation by using recommended plant spacing:

• Tomato: 40–60 cm

• Cucumber: 30–50 cm

• Pepper: 30–40 cm

• Eggplant: 40–50 cm

Avoid overcrowding.

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7.⁠ ⁠Use Heat-Tolerant Varieties

• Choose varieties bred for high-temperature resilience:

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🔄 General Tips

• Soil temperature above 30°C can harm root development. Mulching and drip irrigation help regulate it.

• Avoid excessive nitrogen fertilization – it causes excessive foliage and increases stress.

• Consider leaf analysis to detect deficiencies early.

If you have similar problems with your plants, send us a close-up photo and we will remind you what to do.