Ringspot

Tomato ringspot virus causes highly variable leaf symptoms on raspberry and blackberry: you might see mottled or mosaic patterns, chlorotic spotting, ring spots, or severe leaf curling. Infected plants often appear stunted with delayed emergence of new canes, or may show no obvious symptoms at all but simply lack vigor and produce less fruit. The virus also causes crumbly berries that shatter during harvest. In the northern Willamette Valley and Clark County, where this virus is established, virus-infected raspberries of common cultivars like Meeker or Puyallup decline steadily, while some cultivars show severe dwarfing that resembles root rot.

The virus spreads slowly (about 6-8 feet per year along a row) through dagger nematodes (Xiphinema americanum) living in soil; many common weeds like dandelion and chickweed are native hosts. Since the nematode cannot be eradicated once established, prevention is essential. Test new planting sites for dagger nematodes at least a year before planting. Use only certified, virus-free stock, rogue out diseased plants immediately and at least five plants beyond visible symptoms, and carefully clean all equipment moving between fields to avoid spreading contaminated soil. If infection occurs, fallowing for 18 months prior to replanting can eliminate nematodes and flush the virus from them.