How to fight kidney mites on blackcurrant? - briefly
Apply horticultural oil or a sulfur‑based spray early in the season, then prune and discard any infested canes and fruit. Rotate to resistant cultivars and keep the area clean to prevent reinfestation.
How to fight kidney mites on blackcurrant? - in detail
Kidney mite infestations on blackcurrant vines require an integrated approach that combines monitoring, cultural practices, biological agents, and targeted chemicals.
First, identify the pest. Adult kidney mites are microscopic, oval, and reddish‑brown. Damage appears as stippled leaves, yellowing, and reduced fruit set. Inspect foliage weekly, especially during warm, dry periods when populations peak.
Second, reduce habitat suitability. Remove weeds and fallen leaves that shelter mites. Prune dense canopies to improve air circulation and sunlight penetration, which discourages mite development. Apply a mulch of coarse organic material to promote beneficial predatory arthropods.
Third, employ biological control. Introduce predatory mites such as Neoseiulus californicus or Phytoseiulus persimilis at a rate of 200 000 individuals per hectare. Release them early in the season, repeat every 2–3 weeks, and monitor predator‑prey ratios to ensure effectiveness.
Fourth, use selective acaricides only when thresholds are exceeded (e.g., >10 mites per leaf sweep). Recommended products include:
- Abamectin 0.5 % soluble concentrate – apply at 0.2 L ha⁻¹, repeat after 7 days if needed.
- Sulfur dust – apply at 1 kg ha⁻¹, avoid use during high temperatures to prevent phytotoxicity.
- Neem oil 5 % – apply at 2 L ha⁻¹, incorporate into a spray program for added repellency.
Observe pre‑harvest intervals and resistance management guidelines; rotate chemicals with different modes of action.
Fifth, maintain a record‑keeping system. Log dates of inspections, treatments, and predator releases. Analyze trends to adjust the program annually.
By consistently applying these steps—accurate scouting, habitat modification, predator augmentation, judicious acaricide use, and thorough documentation—blackcurrant growers can suppress kidney mite populations and protect yield quality.