How should strawberries be treated for mites after harvesting? - briefly
Immediately cool the berries, rinse them with a solution of an approved post‑harvest miticide or botanical oil, dry thoroughly, and store at 0‑2 °C in low humidity to suppress mite activity. Use only registered treatments and inspect storage containers regularly to prevent re‑infestation.
How should strawberries be treated for mites after harvesting? - in detail
After picking, strawberries must be inspected for any signs of mite activity. Remove any fruit that shows webbing, discoloration, or visible mites, as these items can spread infestation to the remaining batch.
A rapid cooling step reduces mite metabolism. Place the berries in a forced‑air cooler set to 0 °C–2 °C and maintain this temperature for at least three hours. Cooling also preserves fruit quality and slows microbial growth.
Chemical control is applied only after cooling and inspection. Use a registered acaricide approved for post‑harvest use, such as a phosphine‑based fumigant or a food‑grade pyrethrin formulation. Follow the label for concentration (e.g., 0.5 g m⁻³ for phosphine) and exposure time (typically 12–24 h). Ensure proper ventilation before the product reaches the market.
Biological options include releasing predatory mites (e.g., Neoseiulus californicus) into storage containers. Introduce 10–20 predators per kilogram of fruit and maintain humidity at 85 %–90 % and temperature around 15 °C to support their activity. Predatory mites consume spider mites and their eggs, reducing population without chemical residues.
Store the treated strawberries in sealed, low‑oxygen containers to limit mite reproduction. Maintain relative humidity at 90 %–95 % and temperature at 0 °C–2 °C. Monitor the storage environment daily with sticky traps placed inside the containers; replace traps every five days and record any captures.
When the storage period ends, sort the fruit again. Discard any berries that develop signs of infestation during storage. Clean and sanitize all handling equipment with a 1 % hydrogen peroxide solution, then rinse with potable water. Allow equipment to dry completely before the next load.
Record all actions—inspection results, cooling duration, chemical dosage, biological releases, storage conditions, and trap counts—in a logbook. This documentation supports traceability and helps refine future post‑harvest mite management protocols.