Young Vine Decline
Phaeomoniella chlamydospora, Phaeoacremonium spp. (P
2 host plants
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Grapevines show stunted growth, shortened internodes, interveinal leaf chlorosis, and vascular discoloration in first 5-10 years after planting. Multiple fungi colonize xylem tissue during nursery grafting or from soilborne pathogens. Use virus-tested nursery material grafted under sanitary conditions. Plant in well-drained soil and avoid water stress. Systemics during nursery grafting help reduce incidence.
Cultural management is your first line: remove infected material, clean up debris, and improve the growing environment to make conditions less favorable for the pathogen. Avoid wounding plants during maintenance, as many pathogens enter through fresh cuts. Chemical options are available for severe cases, but they work best as preventive treatments applied before symptoms appear.
Quick Reference
Management
Nursery contamination; poor nursery sanitation; grafting in wet conditions; weak nursery vines more susceptible; poor soil drainage; water stress; excessive nitrogen; pruning during wet conditions
Cultural Controls
- Use resistant or tolerant rootstocks. Remove infected trees from nurseries and young orchards. Collect hardwood cuttings or scion stock in the winter or early spring. Use the best orchard management practices, including the best possible insect and disease control, irrigation, drainage, fertilization, and pruning. Control pear psylla. See the PNW I