How to treat eggplant for spider mite in a greenhouse during flowering? - briefly
Apply a miticide (e.g., abamectin, neem oil, or spinosad) as a thorough foliar spray, covering leaf undersides and repeating every 7‑10 days while keeping humidity low and air flow high. Inspect plants daily and remove heavily infested leaves to limit spread during bloom.
How to treat eggplant for spider mite in a greenhouse during flowering? - in detail
Effective management of spider mite on flowering eggplant cultivated in a greenhouse requires an integrated approach that combines preventive cultural practices, biological agents, and, when necessary, targeted chemicals. The following protocol outlines each component in detail.
Monitor the crop daily with a 10 × magnifying lens. Record mite counts on the undersides of leaves; a threshold of 5–10 motile mites per leaf warrants intervention.
Maintain optimal greenhouse conditions to discourage mite reproduction: keep relative humidity above 60 % during the day, avoid prolonged periods of 20 % RH or lower, and regulate temperature between 22 °C and 27 °C. Reduce excess light intensity with shade cloths to limit plant stress.
Apply cultural controls promptly. Remove heavily infested leaves and destroy them away from the production area. Prune dense foliage to improve air circulation and expose leaf surfaces to natural predators. Ensure a clean sanitation regime: disinfect benches, tools, and walkways after each harvest cycle.
Introduce biological control agents as the first line of defense. Release predatory mites (Phytoseiulus persimilis, Neoseiulus californicus, or Amblyseius swirskii) at a rate of 10–20 predators per m², repeating releases every 5–7 days until mite populations fall below the action threshold. Supplement with entomopathogenic fungi such as Beauveria bassiana, applying a wettable powder at 2 g L⁻¹ every 10 days.
If biological measures prove insufficient, employ selective acaricides that pose minimal risk to pollinators and predatory mites. Preferred options include:
- Spiromesifen (2 % SC) applied at 100 mL ha⁻¹, repeat after 7 days.
- Abamectin (5 % EC) applied at 150 mL ha⁻¹, repeat after 10 days.
- Sulfur dusting at 2 kg ha⁻¹, repeat every 14 days.
Rotate chemicals with different modes of action to prevent resistance development; follow the label’s maximum application frequency and pre‑harvest interval.
After each treatment, re‑inspect the canopy to confirm mite decline. Maintain the biological program throughout the flowering stage to protect new growth. Record all interventions in a logbook to refine future pest‑management cycles.
By integrating vigilant scouting, environmental regulation, predatory mite releases, and judicious use of acaricides, growers can sustain healthy flowering eggplant and minimize yield loss caused by spider mites.