How to treat a polycarbonate greenhouse in spring for mites? - briefly
Inspect the polycarbonate greenhouse for mite presence, then treat with a labeled horticultural oil spray, covering all surfaces and ventilation openings. Maintain cleanliness, employ sticky traps, and introduce predatory mites for ongoing prevention.
How to treat a polycarbonate greenhouse in spring for mites? - in detail
Effective management of mite infestations in a polycarbonate greenhouse during the spring requires a systematic approach that combines sanitation, environmental regulation, targeted treatments, and ongoing monitoring.
Initial inspection should focus on the undersides of leaves, frame joints, and polycarbonate panels where mites congregate. Use a hand lens or a low‑magnification microscope to confirm presence and estimate population density. Remove heavily infested foliage, and dispose of it away from the structure to reduce inoculum.
Sanitation involves cleaning all surfaces with a mild detergent solution followed by a thorough rinse. Pay particular attention to seams and drainage channels, as organic residue can provide a refuge for mites. After drying, apply a light coating of horticultural oil to the interior surfaces; the oil creates a physical barrier that limits mite movement without harming plant tissue.
Environmental control is critical. Maintain daytime temperatures between 15 °C and 22 °C and night temperatures no lower than 10 °C to discourage rapid mite reproduction. Increase ventilation to achieve relative humidity levels of 60 %–70 %; higher humidity interferes with mite egg viability. Install automated vent openers if necessary to ensure consistent airflow.
Targeted treatments can be divided into chemical and biological options. For chemical control, select a miticide registered for greenhouse use, such as abamectin or spirodiclofen, and follow label‑specified dosage and interval guidelines. Apply the product as a fine mist to ensure coverage of leaf undersides and structural crevices. Rotate active ingredients between applications to prevent resistance development.
Biological control agents include predatory mites (e.g., Phytoseiulus persimilis) and entomopathogenic fungi (e.g., «Beauveria bassiana»). Release predatory mites at a rate of 10–20 adults per square meter, distributing them evenly across the growing area. Maintain humidity above 60 % to support fungal efficacy, and avoid broad‑spectrum insecticides that could harm beneficial organisms.
Preventive measures should be integrated into routine greenhouse management. Implement a calendar for regular scouting, cleaning, and environmental checks. Use sticky traps placed near ventilation openings to detect early mite activity. Rotate crops or introduce non‑host plant periods to break the mite life cycle.
Finally, document all observations, treatments, and environmental parameters. Continuous record‑keeping enables rapid identification of trends and facilitates timely adjustments to the control program, ensuring long‑term protection of the greenhouse ecosystem.