How can cucumbers be cured of spider mites in a greenhouse? - briefly
Apply a contact miticide such as neem oil or abamectin to foliage, repeating the spray every 5‑7 days until mite numbers decline. Introduce predatory mites like «Phytoseiulus persimilis» and maintain greenhouse humidity above 60 % to reinforce control.
How can cucumbers be cured of spider mites in a greenhouse? - in detail
Spider mites (Tetranychidae) rapidly colonize cucumber foliage in greenhouse production, causing stippling, yellowing, and reduced yield. Effective control requires an integrated approach that combines cultural, biological, and chemical measures.
Sanitation and environmental management reduce population buildup. Remove plant debris and weeds that harbor mites. Maintain relative humidity above 60 % to deter mite reproduction; low humidity accelerates their life cycle. Regulate temperature between 22 °C and 26 °C, avoiding prolonged periods above 30 °C, which favor mite development. Ensure adequate air circulation with fans to prevent microclimates where mites thrive.
Biological agents provide sustainable suppression. Release predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus at a rate of 10–20 predators per square meter. Apply them in the early morning or late afternoon to minimize UV damage. Monitor predator establishment weekly and supplement releases if mite counts exceed the economic threshold (approximately 5 mites per leaf).
Botanical oils and soaps act as contact miticides. Spray neem oil (1 % v/v) or horticultural oil (2–3 % v/v) until leaf surfaces are uniformly wet. Apply insecticidal soap (2–3 % solution) at 5‑day intervals, covering the undersides of leaves where mites congregate. Rotate products to prevent resistance.
Chemical acaricides are reserved for severe infestations. Use products registered for greenhouse cucumbers, such as spirotetramat or abamectin, following label rates and pre‑harvest intervals. Implement a rotation schedule that alternates modes of action (e.g., organophosphate, pyrethroid, and oxadiazine) to mitigate resistance development. Observe the mandatory waiting period before harvesting to ensure residue compliance.
Monitoring is essential for timely interventions. Inspect foliage with a 10× hand lens twice weekly, counting mites per leaf segment. Record data in a log to track population trends and evaluate treatment efficacy. Adjust control tactics based on observed thresholds.
Combining these practices—environmental regulation, predator releases, oil or soap applications, judicious chemical use, and systematic scouting—provides comprehensive management of spider mites on cucumber crops within greenhouse settings.