What should be done about spider mite on cucumbers in a greenhouse using folk remedies? - briefly
Apply neem oil or insecticidal soap to the cucumber leaves every 5–7 days, and supplement with a garlic‑pepper spray (1 L water, 2 Tbsp crushed garlic, 1 Tbsp hot pepper, 1 tsp liquid soap). Raise humidity to about 70 % and release predatory mites (e.g., Phytoseiulus persimilis) for biological control.
What should be done about spider mite on cucumbers in a greenhouse using folk remedies? - in detail
Spider mites thrive in warm, dry greenhouse conditions and can quickly defoliate cucumber vines. Effective control using traditional methods relies on a combination of cultural, mechanical, and botanical measures.
First, reduce the micro‑climate that favors the pest. Increase ambient humidity to 60 % or higher by misting the canopy several times a day or installing a low‑pressure fogger. Keep temperatures below 30 °C during the hottest period; ventilation fans and shade cloths help achieve this. Remove heavily infested leaves and dispose of them away from the growing area to break the life cycle.
Second, apply direct contact agents derived from common household or garden items. Prepare a spray by mixing:
- 1 L of water with 1 Tbsp of mild liquid soap (non‑synthetic, biodegradable).
- 1 L of water with 2 Tbsp of neem oil (cold‑pressed, unrefined).
- 1 L of water with 1 Tbsp of horticultural oil (e.g., canola or soybean oil) and a few drops of dish‑soap as an emulsifier.
Apply each solution to the undersides of leaves until runoff occurs. Repeat every 5–7 days for three cycles, then shift to a weekly schedule until mite populations drop below economic thresholds.
Third, introduce botanical extracts that act as repellents or growth inhibitors. A decoction of crushed garlic (10 g) and hot water (1 L) left to steep for 24 h, strained, and diluted 1:10 before spraying, reduces oviposition. Similarly, a tea made from dried rosemary (5 g) steeped in 1 L of boiling water for 30 minutes, cooled, and diluted 1:5 provides a deterrent effect.
Fourth, employ physical barriers and predators that are compatible with organic practices. Install fine mesh screens (mesh size ≤ 0.5 mm) on vents to prevent mite entry. Release predatory insects such as Phytoseiulus persimilis or Amblyseius swirskii at a rate of 5–10 predators per plant. Monitor predator establishment weekly and supplement releases if mite numbers rebound.
Finally, maintain sanitation and monitoring routines. Inspect plants daily, focusing on leaf undersides, and record mite counts using a hand lens (10×). Rotate crops annually, avoiding planting cucumbers in the same greenhouse sector for more than two consecutive seasons. Clean all tools, pots, and benches with a solution of 5 % hydrogen peroxide to eliminate residual eggs.
By integrating humidity management, soap‑ and oil‑based sprays, garlic‑rosemary extracts, physical exclusion, and biological control agents, growers can suppress spider mite outbreaks on cucumbers without resorting to synthetic chemicals. Regular scouting and prompt intervention are essential to sustain the effectiveness of these folk remedies.