Spring radiation frosts (night-time temperature drops to -2...-5°C in April–May) are statistically the most common cause of losses in fruit growing. A single severe frost can reduce the yield by 50–100%.
Protection methods:
1. Candles and heaters (cost: PLN 1,500–3,000/ha/season) — the cheapest investment, but an enormous amount of work and low effectiveness during severe frosts.
2. Overhead sprinkling (cost: PLN 15,000–25,000/ha investment) — effective down to -5°C, but requires large water resources and infrastructure.
3. SPAG EOLE anti-frost wind towers (indicative cost approx. PLN 140,000–240,000/unit, depending on the drive: PTO, electric or diesel; coverage up to 7.2 ha from one tower, depending on the frost type) — they mix warm air from the inversion layer with cold ground-level air. Automatic start-up.
4. SPAG anti-hail system (indicative cost approx. PLN 200,000–400,000/installation, minimum coverage 80 ha) — protection against hail and frost at the same time.