What should be done with kidney mites on currants? - briefly
Treat the infestation with a registered miticide (e.g., spirodiclofen or a horticultural oil) applied during the dormant period, and prune out heavily damaged canes to lower mite populations. Follow up with regular scouting and sanitation to prevent recurrence.
What should be done with kidney mites on currants? - in detail
Kidney mites (Eriophyes vitis) attack currant bushes, causing leaf deformation, reduced photosynthesis, and lower fruit yield. Effective control requires a combination of monitoring, cultural practices, biological agents, and targeted pesticide applications.
First, inspect foliage weekly from early spring through late summer. Look for tiny, pale‑green or reddish patches on leaves, especially the lower surface. When infestations exceed 5 % of leaf area, intervene.
Cultural measures:
- Prune out heavily infested shoots and dispose of them away from the orchard.
- Maintain a clean orchard floor; remove fallen leaves and fruit to eliminate overwintering sites.
- Space plants at least 1 m apart to improve air circulation and reduce humidity, which discourages mite development.
- Apply a 2‑week mulch of organic material (straw, leaf litter) after harvest to encourage natural predators.
Biological options:
- Release predatory phytoseiid mites (e.g., Phytoseiulus persimilis) in early summer when mite populations begin to rise.
- Encourage native predators such as ladybird larvae and lacewing adults by planting nectar‑rich companion species (e.g., dill, fennel).
Chemical interventions:
- Use horticultural oil or sulfur spray at the first sign of infestation; cover the entire canopy to ensure contact with hidden mites.
- If oil or sulfur proves insufficient, apply a miticide containing abamectin or spirotetramat, following label rates and observing the pre‑harvest interval.
- Rotate chemicals with different modes of action to prevent resistance.
Resistant cultivars:
- Select currant varieties reported to show lower susceptibility to kidney mites, such as ‘Titania’ and ‘Ben Nevis’.
Integrating these steps—regular scouting, sanitation, biological augmentation, and judicious pesticide use—provides a comprehensive strategy for managing kidney mite outbreaks on currant bushes and preserving both plant health and fruit quality.